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| ‘THE FEEDING OF ANIMALS _

The Rural Texrt=Book Series
Eprrep spy L. H. BAILEY

Carleton, THE SMALL GRAINS.

B. M. Duggar, Puant Puysiotocy, with
special reference to Plant Production.

J. F. Duggar, SOUTHERN FIELD Crops.

Gay, THE BreEps oF Live-StTock.

Gay, THe PRINCIPLES AND PRACTICE OF
Jupeine Live-SrTock.

Goff, THe PRINCIPLES OF PLANT CULTURE,
Revised.

Harper, ANIMAL HUSBANDRY FOR SCHOOLS.

Harris and Stewart, THE PRINCIPLES OF
AGRONOMY.

Hitchcock, A TExtT-Boox or GRASSES.

Jeffery, TExtT-Book or LAND DRAINAGE.

Jordan, THE FEEDING or ANIMALS. Revised.

Livingston, FIELD Crop PRODUCTION.

Lyon, Fippin and Buckman, So1ts—THEIR
PROPERTIES AND MANAGEMENT.

Mann, BEGINNINGS IN AGRICULTURE.

Montgomery, THE Corn Crops.

Piper, Forace PLANTS AND THEIR CULTURE.

Warren, ELEMENTS OF AGRICULTURE.

Warren, Farm MANAGEMENT.

Wheeler, MANURES AND FERTILIZERS.

White, PRINCIPLES OF FLORICULTURE.

Widtsoe, PRINCIPLES OF IRRIGATION PRACTICE.

‘Sdofloy polq-]JaW “[ GLVIg

THE

_ FEEDING OF ANIMALS

BY
WHITMAN HOWARD JORDAN

DIRECTOR OF THE NEW YORK AGRICULTURAL
EXPERIMENT STATION, GENEVA

REVISED EDITION

dew Bork
THE MACMILLAN COMPANY
1917

Ati rights veserved

Copryrricut, 1901 anp 1917
Br THE MACMILLAN COMPANY

Set up and electrotyped June, 1901
Reprinted September, 1903; February, 1905; October, 1906
February, 1908; January and July, 1909; October, 1910
February, 1912; January, 1914

New and Revised Edition, January, 1917

Mount Pleasant Press
J. Horace McFarland Cumpany
Harrisburg, Pa.

TABLE OF CONTENTS

PART I. THE PRINCIPLES OF FEEDING

CHAPTER I

IntTRopDUcTION: Man’s RELATION TO ANIMAL LIFE .
The conditions and problems involved in feeding animals.

CHAPTER II

Tue RELATIONS OF PLANT AND ANIMAL LIFE

Origin of animal foods, 1; The plant stores energy, 2;

Plant substance a source of animal substance, 3; The
plant a source of animal heat, 4; Food a source of motive
power, 5.

CHAPTER III

THe CHEemiIcaAL ELEMENTS INVOLVED In ANIMAL NUTRI-
TION Soa ome he ; ; OR et eee
Chemical elements involved in animal growth, 6.
The Elements and Their Sources: Carbon, 7; Carbon in
the air, 8; Oxygen, 9; Uses of oxygen, 10; Hydrogen,
11; Nitrogen, 12; Supply of nitrogen, 13; Uses of
nitrogen, 14; Argon, 15; Sulfur, 16; Phosphorus, 17;
Chlorine, 18; Iodine, 19; Potassium, 20; Sodium, 21;
Calcium, 22; Iron, 23. Proportions of the Elements in
Plants and Animals: Elements in plants, 24; Elements
in plant ash, 25; Elements in animals, 26; Ash elements
in animals, 27; Classes of matter, 28; Combustion does
not destroy matter, 29; Relation: of combustible to
incombustible substance, 30; Organic and inorganic

classes, 31.

(v) -

PAGES

3-8

SEE

12-25

vi CONTENTS

CHAPTER IV

THE Be econ oF ANIMAL NUTRITION . 26-46

The classes of compounds, 32; Distribution of ele-
ments, 33. Water: Measurement of water-content, 34;
H-ygroscopic water, 35; Physiological water, 36; Water
in living plants, 37; Sap or plant juice, 38; Proportion
of water in plants, 39; Effect of stage of growth on
water-content, 40; Influence of soil moisture, 41; Supply
of water to plants, 42; Water in feeding-stuffs, 43; Con-.
ditions affecting water-content of feeds, 44; Relation of
water to preservation of cattle foods, 45; Water in the
animal, 46; Variations of water-content of animal
bodies, 47. Ash: Mineral compounds in the ash of plants
and animals, 48; Rearrangement of ash elements during
ignition, 49; The ash compounds of plants, 50; Varia-
tions of plant ash, 51; Variations of ash due to species,
52; The distribution of mineral compounds in the differ-
ent parts of the plant, 53; Influence of manufacturing
processes on the ash constitutents, 54; The mineral
compounds of animal bodies, 55; The distribution of
inorganic compounds in the animal body, 56; Ash ele-
ments in the soft tissues, 57; Ash elements in the blood,
58.

PAGES

CHAPTER V

Tue Compounps oF ANIMAL Nutrition, CoNTINUED—
Tus NrrroGEN CoMPpounns © ¢.) (Rie | ea ae I-67

The importance of protein, 59. Protein: How protein
is determined, 60; So-called proteins greatly unlike, 61;
Classification of proteins, 62; The true proteins, 63;
Ultimate composition of proteins, 64; Familiar exam-
ples of proteins, 65. Simple Proteins: The albumins,
66; The globuiins, 67; Plant globulins, 68; Animal glob-
ulins, 69; Glutenins, 70; Alcohol-soluble proteins, 71;
Albuminoids, 72; Histones, protamines, 73. Conjugated
Proteins: Nucleo-proteins,, 74; Glyco-proteins, 75;
Phospho-proteins, 76; Hzmoglobin, 77; Lecitho-pro-
teins, 78. Derived Proteins: 1. Primary Protein Deriva-
tives: Proteins and metaproteins, 79; Coagulated pro-

CONTENTS

teins, 80. 2. Secondary Protein Derivatives: Proteoses,
peptones, 81; Important properties of the proteins, 82;
The unlike constitution of the various proteins, 83;
Cleavage products of the proteins, 84. Nitrogen Com-
pounds That Are Non-Proteins: Amino-acids and
amides, 85; Extractives, 86.

CHAPTER VI

THE Compounps or ANIMAL Nutrition, ConcLUDED—
CARBOHYDRATES, AcIps, Fats, AND OILS

Elementary composition of the non-nitrogenous
compounds, 87; Classification of non-nitrogenous com-
pounds, 88; The carbohydrates, 89; Classification of
carbohydrates according to structure, 90; The mono-
saccharides or simple sugars, 91; Dextrose, 92; Levulose,
93; Galactose, 94; The pentoses, 95; Di-saccharides,
96; Saccharose, 97; Maltose, 98; Lactose, 99; The sugars
as a class, 100; Other more complex poly-saccharides,
101; The starches, 102; Glycogen, 103; The pentosans,
104; Galactans, mannans, levulans, dextrans, 105; The
pectin bodies, 106; Dextrin, 107; Cellulose, 108; The
acids, 109; Fats and oils, 110; Fats or oils in grains and
seeds, 111; Nature and kinds of fats, 112; Physical
properties of the fats and oils, 113; Milk-fat, 114;
Fatty acids, 115; Ether-extracts, 116; Lecithins, 117;
Enzyms, anti-bodies, hormones, vitamines (accessories),
118.

CHAPTER VII

Tue DIGESTION oF Foop

Digestion vs. assimilation, 119; General changes in
food through digestion, 120. Ferments: Definition of fer-
ments, 121; Organized ferments, 122; Structure and
distribution of organized ferments, 123; Conditions of
growth of organized ferments, 124; Results of fermenta-
tion, 125; Manner of action of ferments, 126; Bacteria in
the digestive tract, 127; Unorganized ferments, 128;
Enzyms and their action, 129. The Alimentary Canal:

PAGES

68-86

. 87-122

Vili CONTENTS

Parts of the alimentary canal, 130. The Mouth: Masti- 498
cation, 131; The teeth, 132; The saliva, 133; Origin of
saliva, 134; Properties and office of saliva, 135; Quan-
tity of saliva excreted, 136. The Stomach: The rumi-
nant stomach, 137; Esophageal groove, 138; The rumen,
139; The reticulum, 140; Rumination, 141; The omasum,
142; The abomasum, 143; The gastric juice, 144; Arti-
ficial digestion, 145; Changes in stomach digestion, 146;
Hydrochloric acid essential in stomach digestion, 147;
The stomachs of the horse and pig, 148. The Intestines:
Form and length of intestines, 149; Food in the small
intestine, 150; The bile, 151; Functions of bile, 152;
The pancreatic juice, 153; The enzyms of the pan-
creatic juice, 154; Steapsin, 155; Amylopsin, 156;
Intestinal juices, 157; Intestinal bacteria, 158; Effects
of intestinal fermentations, 159; Stimuli to digestion,
160; Secretins, 161; The psychic factor, 162; Digestion of
food as a whole, 163; Stomach digestion, 164; Digestion
in intestines, 165; Digestive fluids act together, 166;
Action of intestinal juices, 167; Summary of changes
in digestion, 168. Absorption of Food: Function of
lacteals and blood vessels in absorption, 169; Manner of
food absorption, 170; Changes in the walls of the intes-
tinal tract, 171; Place of maximum absorption of food,
172. The Feces: Constituents of feces, 173; The feces
not wholly undigested food, 174. The Relation of the Dif-
ferent Food Compounds to the Digestive Processes: Digesti-
bility of the proteins, 175; Digestibility of the carbo-
hydrates, 176; Starches unlike in rate of digestibility,
177; Digestibility of cellulose and gums, 178; Digesti-
bility of the fats, 179. Factors Which May Influence
Digestion: Meaning of ‘‘digestibility,” 180.

CHAPTER VIII

CoNDITIONS INFLUENCING DIGESTION . : é . 123-137

Palatableness, 181; Influence of quantity of ration,
182; Effect of drying fodders, 183; Influence of the con-
ditions and methods of preserving fodders, 184; Influ-

CONTENTS ix

ence of the stage of growth of the plant, 185; Influence PAGES
of methods of preparation of food, 186; Wetting food,
187; Cooking foods, 188; Influence of grinding foods,
189; Effect of common salt, 190; Influence of frequency
of feeding and watering animals, 191; Influence of
season and storage, 192; Influence of the combination
of food nutrients, 193; Influence of work, 194; Influence
of species, breed, age, and individuality, 195; Lower
digestibility with horses for coarse foods, 196; Deter-
mination of digestibility, 197; The inaccuracies of
digestion coefficients, 198.

CHAPTER IX

Tue DIsTRIBUTION AND USE oF THE DiGESTED Foop . 138-150

The blood, 199; The blood corpuscles, 200; The blood
plasma, 201; The heart, 202; Circulation of blood, 203;
The lungs, 204; Object of respiration, 205; The use of
food, 206; Nutrients are oxidized, 207; Oxidases, 208;
Proteins not wholly oxided, 209; Rate of oxidation of
nutrients, 210. Elimination of Wastes: Elimination of
urea, 211; Elimination of carbon dioxid, 212; Elimina-
tion of water, 213. The Liver: Regulation of carbo-
hydrate use, 214.

CHAPTER X

THE FUNCTIONS OF THE NUTRIENTS. : . 151-196

General uses of food, 215; Uses of energy, 216; Func-
tions of water, 217. Functions of the Mineral Elements:
Relation of mineral elements to vital processes, 218;
Relation of mineral elements to animal structure, 219;
Distribution of mineral elements in animal body, 220;
Relation of mineral elements to elimination of waste
products, 221; Relation of mineral elements to a proper
equilibrium between the acids and bases of the animal
body, 222; Relation of mineral elements to osmosis,
223; Relation of mineral elements to muscular control,
224; Relation of mineral elements to tissue development,
225; General considerations, 226; Supply of mineral ele-

x CONTENTS

ments, 227; Relative efficiency of different phosphorus
compounds, 228. Functions of Protein: Proteins as
tissue-formers, 229; Protein as a source of fats, 230;
Protein as a source of energy, 231. Functions of Car-
-bohydrates: Carbohydrates the chief source of energy,
232; Proportion of ration used as fuel, 233; Fats from
carbohydrates, 234. Functions of the Fats and Oils:
Fats and carbohydrates similar in function, 235. Food
as a Source of Energy: Work performed by the animal
organism, 236; Work requires the expenditure of energy,
237; The animal organism does not originate energy,
238; The nature of energy, 239; Transformations of
energy though the use of machinery, 240; The horse a
machine, 241; Measurement of energy, 242; Determina-
tion of energy units in feeding-stuffs, 243; Metabolizable
energy, 244; Loss of food energy in feces, 245; Loss of
food energy in urine, 246; Loss of food energy in gases,
247; Recent determinations of metabolizable energy,
248; Distribution of losses of food energy, 249; Influence
of size of ration on losses of methane, 250; Influence
of size of ration on losses in the undigested residue, 251;
Influence of individuality on energy losses, 252;
Estimates of metabolizable energy on the basis of
digestible organic matter, 253; Comparison of metaboliz-
able energy in coarse fodders and grains, 254; Net
energy, 255; Work of mastication, 256; Difference in
total energy use with different rations, 257; The work of
digestion, 258; Total energy expended in feed consump-
tion, 259; Calculation of net energy value, 260; Net
energy of various feeds, 261; Computing net energy
values of feeding-stuffs, 262; Estimation of produce
tion values proposed by Armsby, 263. Energy Rela-
tions.—Heat Regulation: Relation of protein to
muscular activity, 264; Energy chiefly from carbohy-
drates and fats, 265; Heat regulation, 266; Animal heat a
secondary or waste product, 267; The critical tempera-
ture, 268. The Nutritive Inter-Relation of the Food Com-
pounds and the Need of Combining These in the Ration:
Protein physiologically necessary, 269; Carbohydrates

~

CONTENTS ; XI

physiologically economical, 270; Protein-sparers, 271; P?4¢=8
Nutritive value of the gums, 272; Relative importance

of the nitrogen compounds of feeding-stuffs, 273; Rela-

tive ‘nutritive efficiency of the true proteins, 274; A

single amino acid a limiting factor, 275; Nutritive value

of the gelatinoids, 276; Synthesis in the animal of phos-
phorus-bearing proteins, 277; The function of certain
unidentified bodies, 278; Relation of production

values to profit from feeding animals, 279.

CHAPTER XI
AWS DeeOTEMEON. ee 200

: CHAPTER XII

Sources oF KNOWLEDGE . . : . 201-215

Conclusions from feeding practice, 289; Practical
feeding experiments, 290; Inconclusiveness of ordinary
feeding experiments, 291; Chemical and physiological
studies, 292; More accurate methods of investigation
than practical feeding tests, 293; Studies of food
sources of animal fats, 294; The respiration apparatus,
295; Determination of energy values, 296; Calculation
of the energy value of a ration, 297; Energy value of
digested nutrients, 298; Measurement of food com-
bustion, 299; Respiration calorimeter, 300; Study of
the efficiency of individual proteins, 301.

PART II. THE PRACTICE OF FEEDING

CHAPTER XIII

CaTTLE Foops—NatTurAL Propucts . ‘ : 2 . 219-241

Classification of cattle foods, 302. Forage Foods:
Classes of forage crops, 303; Green vs. dried fodders;
conditions of drying, 304; Effect of drying fodders,

xii CONTENTS

305; Losses through curing fodders, 306; The harvest- ?A¢=S
ing of forage crops, 307; Maximum yield of forage crops
at maturity, 308; Value of crops not proportional to
yield, 309; Age decreases digestibility, 310; Maize unlike ~
other grasses, 311; Alfalfa, 312. Silage: Nature of the
changes in the silo, 313; losses in silo, 314; Corn an
important silo crop, 315; Extent of loss in the silo, 316;
Necessary loss in silo, 317; Financial importance of
silo losses, 318; Ensiling vs. field-curing, 319; Crops for
silage, 320; Construction of silo, 321; Filling the silo,
322; Mature corn desirable for silage, 323; Cutting and
shredding ensilage material, 324; Rate of filling silo,
325. The Straws: 326. Roots and Tubers: 327% Grains
and Seeds: 328. Storage of grain, 329.

CHAPTER XIV

CatTTLE Foops—CoMMERCIAL FEEDING-STUFFS . , . 242-271

Classes of commercial by-product feeding-stuffs, 330;
Wheat offals, 331; Structure of the wheat grain, 332;
The milling of wheat, 333; Composition of milling prod-
ucts of wheat, 334; Milling processes compared, 335;
Screenings, 336; Residues from breakfast foods, 337;
The oat grain, oat hulls, 338; Oat clippings, 339; Barley
feed, 340; Hominy feed, 341; Brewers’ grains; malt-
sprouts, 342; Residues from starch and glucose manu-
facture, 343; Structure of the maize kernel, 344; Manu- |
facture of starch, 345; Residues from the manufacture of
beet-sugar, 346; The oil meals in general, 347; Methods
of extracting oils, 348; Cottonseed meal, 349; Cotton-
seed hulls, 350; Extraction of oil from the cottonseed
kernels, 351; Composition of cottonseed oil by-prod-
ucts, 352; Linseed oil (oil meal), 353; Extraction of
linseed oil, 354; Old process vs. new process linseed
meal, 355. Chemical Distinctions in Cattle Foods:
Coarse foods vs. grains and grain products, 356; Classi-
fication of feeds according to the proportion of nutrients,
357; Misleading terms for feeding-stuffs, 358; Classi-
fication of feeding-stuffs, 359. Foods of Animal Origin:

CONTENTS xiii

360. Milk, 361; Milk of several breeds, 362; Dairy 4°"
~ by-products, 363; Slaughter-house and other animal
refuses, 364.

CHAPTER XV

THe PrRopUCTION OF CATTLE Foops . ? . 272-280

Adaptability of crops to environment, 365; ee vs.
old species of plants, 366; Adaptability of crops to kind
of animal production, 367; Productive capacity of
crops, 368; Crops of high productivity, 369; Home sup-
ply of protein, 370; Legumes and fertility, 371. Sozling-
crops: Soiling-crops a necessity, 372; Conditions favora-
ble to soiling, 373; The economy of soiling-crops,
374; Selection of soiling-crops, 375; Soiling-crop area
and rotations, 376.

CHAPTER: XVI

THE VALUATION OF FEEDING-STUFFS . ; . 281-291

Basis of assigning values to feeding-stuffs, 377; Coutt
mercial values of feeding-stuffs, 378. Valuation of feeds
by method of least squares, 379; Physiological values,
380; Energy values as a basis of valuation, 381; Con-
ditions involved in the selection of feeding-stuffs, 382;
Digestibility as a basis for selecting feeding-stuffs,
383; Values based on digestibility, 384; Digestibility
of various feeds, 385; Valuations based on protein con-
tent, 386; Feed values based on feeding experiments,
387; The verdict of the cow, 388.

_ CHAPTER XVII

THE SeLecrion AND COMPOUNDING OF RaTions _.-__ . 292=306

Palatableness as a factor in feeding animals, 389;
Adaptation of. rations; 390; Physiological require- |
ments, 391; Feeding standards, 392; Nutritive ratio,
393; Calculating a ration, 394; Calculation of digestible
nutrients, 395; Digestible nutrients in a given ration,
396; Correcting an insufficient ration, 397;-Relation

XIV CONTENTS

of ration to size of animal, 398; The protein supply, 7°49"
399; Earlier protein standards revised, 400; Presence of
growth-promoting bodies, 401; Influence of ration on
quality of product, 402; Home supply of feeding-stuffs

to be considered, 403; Seleiion of a ration largely a
business matter, 404.

CHAPTER XVIII

MAINTENANCE RATIONS . . . ; ; . 307-318

Definition of maintenance ration, 405; Chivideter of
maintenance ration, 406; Uses of production ration, 407;
Maintenance ration easily provided, 408. Maintenance
Ration for Bovines: Various investigations concerning
maintenance needs, 409; Fasting katabolism as a
measure of maintenance needs, 410; Distribution of
maintenance energy, 411; Use of nutrients in fasting
metabolism, 412; Computation of maintenance needs,
413; Maintenance rations for bovines, 414. Maintenance
Food for Horses: Studies of the maintenance needs of the
horse, 415; Maintenance rations for horses, 416; Main-
tenance food for sheep, 417.

CHAPTER XIX

“Mix PRODUCTION. : “ : 319-345

Composition of cow’s milk, 418; Milk secretion,
419; Food sources of milk proteins, 420; Food sources of
milk-fats, 421; The rate of formation of milk solids,
422; Uses of nutrients in milk production, 423; Pro-
tein requirements for milk production, 424; Relative
importance of protein overstated, 425. Feeding
Standards for Dairy Cows: Thaer’s hay values, 426;
Grouven’s milk-feeding standards, 427; Wolff’s feeding
standard, 428; Kiihn’s feeding standard, 429; The
Wolff-Lehmann feeding standards, 430; American feed-
ing standards, 431; Woll’s standard, 432; Standards
for milk production based on elaborate American feed-
ing experiments, 433; Requirements of certain feeding
standards for dairy cows, 434; Calculation of rations

- CONTENTS ; XV

for dairy cows, 4385; Suggested practical rations for P4A¢=8
dairy cows, 436; The sources of commercial protein for
milk production; the home supply, 487; Commercial
proteins, 438; No single protein food essential, 439.
The Relation of Food to the Composition and Quality
of Milk: Effect of food on the proportion of milk solids,

_ 440; Effect of food on the constitution of milk solids, 441;
Influence of food on the milk-fats, 442; Effect of food on
the flavors of milk and its products, 443.

CHAPTER XX

FEEDING GROWING ANIMALS . 3 : , ; ? . 346-361
The requirements for growth, 444; Food freely appro-
priated by growing animal, 445; Influence of kind of
food on kind of growth, 446; Estimated energy require-
ments for one pound of gain in weight by growing
cattle and sheep, 447; Milk for young animals, 448. The
Feeding of Calves: Skimmed milk as a substitute for
whole milk in feeding calves, 449; Calf rations without
milk products, 450. The Feeding of Lambs: Feeding
ewes with lamb, 451; Grain foods accessible to lambs,
452; Standards for growing sheep, 453. Feeding Colts:
Food as related to quality of the horse, 454; Feeding
the colt through the dam, 455; Rations for the colt
before weaning, 456; Oats as horse feed, 457; Rations
for growing colts, 458. .

~

CHAPTER XXI

FEEDING ANIMALS FOR THE PRODUCTION OF MEAT . 362-386

Beef Production: Nature of the growth with beef
production, 459; Rate of increase of fattening animals,
460; The food needs of the fattening steer, 461; Scientific
experiments with fattening animals, 462; Practical
feeding experiments in fattening animals, 463; German
fattening for bovine’s rations excessive, 464; The selec-
tion of a fattening-ration, 465; Suggested rations for
fattening steers, 466. Mutton Production: Place of
sheep on the farm, 467; The nature and extent of the

XV CONTENTS

growth in fattening sheep, 468; Food needs of fatten- PAS=8
ing sheep, 469; Quantity of nutrients for fattening

sheep, 470; The selection of a ration for sheep, 471.

Pork Production: Changes in pork production, 472;
Character of the growth in pork production, 473; Food
requirements for pork production, 474; Pigs unwisely

fed, 475; Point of view in feeding pigs, 476; Influence of

ration on the development of swine, 477; Dairy wastes

as food for pigs, 478; Protein foods other than milk
products for swine, 479; Forage crops for swine, 480.

CHAPTER XXII

FEEDING WoRKING ANIMALS ‘ . 887-398

The horse a machine, 481; The work performed by a
horse, 482; Influence of conditions on the food expendi-
ture for a unit of work, 483; The food requirements of a .
working horse, 484; Estimate of work ration for the
horse based on energy relations, 485; Source of the ration
for working horses, 486; Nutritive ratio for working
horses, 487; Oats for working horses, 488; Suggested
rations for working horses, 489.

CHAPTER XXIII

Tue Frerepine or Pouttry. By William P. Wheeler. . 399-417

Food needs of birds intensive, 490; Kinds of foods for
poultry, 491; Incidental effects of the food with laying
hens, 492; Digestive apparatus of birds, 493; Constitu-
ents of the body of the hen, 494; Composition of eggs,
495; Necessity for considering the water-supply, 496;
Efficiency of protein from animal sources for fowl, 497;
Ash constituents important for egg production, 498;
Common salt a necessity for fowls, 499; Supply of grit
for fowls, 500; Feeding standards for fowls, 501; Main-
tenance rations for fowls, 502; Rations for laying hens,
503; Rations for young birds, 504; Adaptability of vari-
ous foods for fowls, 505; Knowledge of the nutrition of
fowls limited, 506.

CONTENTS

CHAPTER XXIV

Ture RELATION OF Foop TO PRODUCTION

Food unit defined, 507; The unit of production, 508;
Factors involved in food economics, 509; Relation of
food to production with various species, 519.

CHAPTER XXV

GENERAL MANAGEMENT

Factors in general management of animals, 511; The
selection of cows, 512; The general-purpose cow, 513;
The selection of animals for meat production, 514;
Relation of age to meat production, 515; Manipulation
of the ration, 516; Quantity of the ration, 517; Environ-
ment and treatment of animals, 518; Cruelty to ani-
mals, 519.

APPENDIX

1. Average composition of American feeding-stuffs

2. Average coefficients of digestion .

3. Computation of energy-production values ;

4, Food standards for milk production as developed by
Haecker, Savage, and Eckles

5. Feeding standards

6. Fertilizing Constituents of pase Feeding-Suntra,

XV1i

PAGES

. 418-424

. 425-434

. 435-463

435
441
448

455
457
460

'~ PART I

IE PRINCIPLES OF FEEDIN

’

THE FEEDING OF ANIMALS

CHAPTER I

INTRODUCTION: MAN’S RELATION TO
ANIMAL LIFE

THERE was a time somewhere in the dim past when
the beast of the field knew no master. The only obe-
dience which he rendered to a superior power was an
unconscious submission to Nature’s stern forces. He
wandered forth at will to find in the untilled pastures
such food as the wild herbage afforded, and, unre-
strained, he sought a place of rest in the tangled thicket.
He knew no refuge from the winter’s cold and storm
but some sheltered nook or forest recess to which his
brute intelligence guided him, and he was his own defense
against the dangers which beset him.

Man had not come to be a controlling factor in the
development of the various forms of animal life. If the
brute knew him at all, it was as the huntsman, as an
enemy, but not as a superior to whom must be paid a
tribute of service or of food and clothing. The wild
ox and horse possessed those characteristics which best
fitted them to cope with the untoward conditions of
their environment; but there had not yet appeared those
specialized capacities of growth, draft, speed, or pro-
duction which now render these animals so very valuable
for the service and sustenance of the human family.

The qualities developed were those demanded by the

(3)

4 THE FEEDING OF ANIMALS

necessities of existence without reference to utility as
measured by the needs of a higher form of life. The fiber
of the body must possess endurance, and it mattered
little whether or not the muscle could furnish a juicy
steak. The brute mother must defend her young and
supply it with milk, and this being accomplished, her
maternal functions ceased. She was neither so endowed
that she could opén the fountains of her life to feed gen-
erously a not too grateful master, nor so submissive
that she would. The wild horse must be fleet and endur-
ing that he might escape the enemy, but not that he
might bear heavy burdens or win a contest in the pre-
scribed form of the race-track.

In the lapse of centuries there have been many changes
in the relation of man to the animal creation. Bird
and beast in various forms have come to minister to
man’s wants, and in their present domesticated condi-
tion are, in their turn, utterly dependent upon him for
the food and shelter which are necessary to their physical
welfare, or even existence. It is not too much to assert
that the domestic animal, in the artificial environment
imposed upon it, is entirely at man’s mercy, even in
the development of those attributes and characteris-
tics which otherwise would be determined by the demands
of an unaided warfare with nature. The juicy sirloin of
the shorthorn, the almost abnormal milk glands of the
champion butter cow, the delicate fiber of merino wool,
and the marvelous speed of the modern race-horse are
evidences of man’s skill in recasting natural types into
forms of greater usefulness to him. From the animal
of nature, under the direction of a higher intelligence,
has proceeded the animal of civilization, an organism
obedient to the environment which has been created for it.

INTRODUCTION ; 5

This interdependence of man and the lower orders
of life has a vast economic significance. A large part
of human activity is devoted to the production and
transportation of food for animals and to the traffic in
the products of the dairy, slaughter-house, and sheep-
fold, and to their utilization in various ways. The pros-
perity of every farm is maintained to a greater or less
extent by feeding domestic animals, and our railroads,
our markets, in fact, nearly all our important business
enterprises, are more or less dependent upon the extent
and prosperity of animal husbandry.

THE CONDITIONS AND PROBLEMS INVOLVED IN
FEEDING ANIMALS

The first and simplest form of animal husbandry is
that which was practised by the nomad. His flocks
and herds subsisted wholly by grazing and were moved
from place to place according to the supply of forage
afforded by different localities. No shelter was pro-
vided for the animals and no food was stored for their
use. The only intelligence or special knowledge that
was brought to bear upon the business of the herdsman
was a familiarity with the traditions and superstitions
touching the care of cattle and the acquaintance which
a roving life would give with the pastures furnishing
the most abundant and sweetest wild grasses during the
various seasons of the year. There was not then even
a dim promise of the modern traffic in meats or of the
fine art of dairying as we now know it. As man began to
give up this wandering life, erect permanent dwellings,
and confine his ownership of land to definite limits, he
acquired the art of tillage, not only that he might have

6 THE FEEDING OF ANIMALS

food for his family but also for his cattle. He then began
to store fodder in stacks, and later in barns, to meet the
demands of the inclement portions of the year.

For centuries, however, grazing was the chief depen-
dence for securing the production of meat and milk because
the foods supplied during the cold season were not in
such abundance or so nutritious as to sustain continu-
ous growth or milk secretion. Even within the remem-
brance of men now living, live-stock was not expected
to produce an increase during the winter months but was
simply maintained from autumn until spring in order
that profits might be realized from summer pasturage.
Formerly the demands of the market were much simpler
than they are now. Butter and cheese were produced
almost wholly from summer dairying, and no such variety
of fresh meats was offered to consumers during the entire
year as is now the case. But great changes have occurred
during the last fifty years, more especially during the past
twenty-five. First of all, we have a modern type of animal,
greatly unlike that of previous times. The ideal dairy
cow of today is a high-pressure milk-machine extremely
sensitive to her environment and demanding a degree of
care in management and feeding, if she is to do her safe
maximum work, which was not necessary with coarser
and less delicate organisms. Every successful dairyman
must now provide proper winter quarters for his herd
and throughout the entire year must supply rations
that will support continuous, generous production. He
must do this, too, by the use of a greater variety of
foods than was formerly available. Not only has the
number of useful forage crops greatly increased, but the
average farmer no longer produces all the food which his
animals consume. He now buys numerous kinds of com-

INTRODUCTION | \ v,

mercial feeding-stuffs. These purchased materials are

not wholly the cereal grains whose value through long

experience has come to be measured by certain prac-
tical standards, but they consist in part of compara-
tively new by-products from the manufacture of oils,
starch, and human food preparations—feeding-stuffs
which differ greatly in their nutritive properties. Besides
all these changes, animal husbandry is now called upon

as never before to feed the prosperous part of humanity

with high-class products having special qualities of
texture and flavor that depend to some extent upon
feeding. Certainly the conditions and problems to be
met in this branch of human industry have grown more
and more complex.

We must add to this the fact that, as is true with
every department of man’s activity, science has laid
her hands upon the business of the farmer and has forced
him into a new range of thought and practice. This
influx of knowledge has greatly influenced the require-
ments for meeting a sharpened competition and has
rendered it imperative for the practitioner to bring to
bear upon a great variety of agricultural problems a
clear understanding of fundamental facts and principles.

The feeding of animals involves many difficult ques-
tions. These begin with the production of forage and
grain crops where it is necessary to discover what ones
will yield the largest food-values to a unit of expendi- —
ture. Economy demands that the several feeding-stuffs
which are at command shall be so combined that there
shall be no waste of material or energy. With several
considerations in view, a decision must be reached as to
the most profitable commercial foods to purchase when
the number is large and the range of prices is wide. The

8 THE FEEDING OF ANIMALS

influence of the various foods upon the quality of the
product, especially dairy products, has in recent years
become an important matter. These and related problems
confront the stockman and dairyman, and they demand
for their wise solution more than what is ordinarily
designated as practical experience. The investigator
who shall successfully inquire into these matters must
possess scientific qualifications of a high order; and the
practical man, who, in a business way, conforms his
methods to the highest standard which scientific research
has already made possible must be familiar with the
knowledge fundamental to the feeder’s art.

CHAPTER II
THE RELATIONS OF PLANT AND ANIMAL LIFE

ANIMAL nutrition has an intimate relation to plant
growth. The farmer producing meat and milk should
understand the relation which animal life sustains to
plant life in order that he may so direct plant production
as to best serve his purposes in feeding whatever class of
animals he utilizes. The efficiency of the various plant
products in sustaining animal life is to him a matter of
great importance.

1. Origin of animal foods.—The compounds which
together constitute animal foods have their origin in plant
life. For this reason, a study of the fundamental facts
of animal nutrition begins with the plant. It is in the
plant that the simple compounds derived from the soil
and air are utilized for the production of the more highly
complex compounds which are used for the growth of
the animal body and for the maintenance of its
activities.

As soon as the young rootlets from a germinating seed
come in contact with the soil and the first leaves reach the
air, assimilative growth begins and continues, as for
instance, in the wheat plant until the stalk of grain has
reached its full height and has attained the ultimate
object of its existence in the production of seed. Certain
agricultural plants have the capacity of producing not
less than 10,000 pounds an acre in a single year of plant
substance which may serve as food for animals.

(9)

10 THE FEEDING OF ANIMALS

2. The plant stores energy.—Plant life both synthesizes
simpler compounds into complex organic substance and
stores energy. We get evidence of this fact when wood
is utilized as fuel for the production of heat, heat being
one form of energy. Scientific investigation has traced
the source of this heat to the chemical energy of the sun’s
rays, which becomes stored in the plant. Combustion
of the plant tissue liberates this energy in another form.
Not only does this energy become available as heat, but
it is also available for a variety of uses in the animal
body. (See Pars. 206, 207.)

3. Plant substance a source of animal substance.—
The animal body, outside of the water which it con-
tains, has its immediate origin in the food which the
animal consumes. The mass of bone and flesh which
make up the body of the immense bullock is derived from
the plant substance which, in other combinations, was
collected from the soil and air. The animal eats his
daily ration and makes his daily gain of tissue. If food
is withdrawn, his body wastes and dies. If his food varies
in amount, his growth is somewhat proportional to the
quantity eaten. It is self-evident that the bones, blood,
and flesh of an animal are derived from what he eats.

4, The plant a source of animal heat.—The plant not
only supplies building-material for the animal body, but
is the source of the heat with which the animal organ-
ism is kept warm. No matter how cold the surrounding
atmosphere, we find that when in health the temperature
of the ox remains at about 101° F., with but small varia-
tion. Just as we warm a room through the combustion
of vegetable matter, such as wood, so the temperature
of the animal is kept at the necessary heat by the com-
bustion of his food. The combustion, in the latter case,

PLANT AND ANIMAL LIFE ; 11

is not so rapid as in the former, but the changes are the
same though more slowly carried on.

5. Food a source of motive power.—Food not only
furnishes the constructive material for the ox’s body and
maintains animal heat, but it also supplies the animal
machine with motive power. The energy which the
plant acquires during its time of growth, through the
vital processes of the animal, is transformed in part
into motion. An animal is a living mechanism, a combina-
tion of muscles and levers which are moved not by means
of a spontaneous internal generation of energy, but
through a supply of energy from without, the energy
stored by the plant. (See Pars. 236-241.)

CHAPTER III

THE CHEMICAL ELEMENTS INVOLVED IN
ANIMAL NUTRITION

Ir 1s fundamentally necessary, to an intelligent under-
standing of the principles and economy of cattle-feeding,
to know the kinds and sources of the materials out of
which vegetable and animal tissues are constructed. We
are primarily concerned with chemical elements.

6. Chemical elements involved in animal growth.—
Approximately eighty substances are now believed to be
chemical elements, i. e., substances that have not been
resolved into two or more simpler ones, and of which, so
far as is now known, all forms of matter are composed.
About one-fifth of these fundamental substances are
involved in plant growth, those that occupy a prominent
place in animal nutrition being even less in number.
These fifteen elements are the following, some of which
are of minor importance: carbon, oxygen, hydrogen,
nitrogen, sulfur, phosphorus, chlorine, iodine, silicon,
fluorine, potassium, sodium, calcium, magnesium, iron,
and manganese.

At ordinary temperatures, four of these, oxygen,
hydrogen, nitrogen, and chlorine are gases and the remain-
ing ones are solids. Carbon, oxygen, hydrogen, and
nitrogen are constant and important ingredients of the
atmosphere and they exist in the soil in gases as well as
in the various combinations. The other eleven, though
sometimes present in the air in minute quantities, are

(12)

THE CHEMICAL ELEMENTS 13

found to no appreciable extent outside of plants and
animals except as fixed compounds in water and in the
crust of the earth. These fifteen elementary substances
are nearly all absolutely essential to the existence of
animal life as now constituted. From the standpoint of
necessity, they are, therefore, nearly all of equal value;
but, if we take into consideration the relative ease and
abundance of the supply, certain ones are greatly more
important than the others.

THE ELEMENTS AND THEIR SOURCES

7. Carbon.—This is a familiar substance in common
life. Coal and charcoal consist chiefly of carbon, while
graphite, much used in lead-pencils and diamonds, is
pure carbon. Carbon makes up a large proportion of
vegetable and animal tissue. This is made evident when
vegetable and animal tissues become black through heat-
ing to a temperature which causes them to decompose,
leaving the carbon as a residue while the elements with
which it was associated are driven out. The dark humus
bodies of the soil have undergone somewhat the same
change.

8. Carbon in the air.—An immense quantity of carbon
exists in the air, combined with oxygen as carbon dioxid.
The average proportion of this compound in the atmos-
phere by weight is approximately .06 per cent. As the
weight of a column of air over 1 inch square of the earth’s
surface is fifteen pounds, it follows that over every acre
of land there is an average of 28.2 tons of carbon dioxid,
or 7.7 tons of carbon. As we know that plants draw their
supply of carbon from the atmosphere and as vegetable
tissue is the primary source of this element to the animal,

/ .
14 THE FEEDING OF ANIMALS

we safely reach the conclusion that the carbon in the
tissues of animal life was once floating in space.

Boussingault determined the average yearly amount of
carbon withdrawn from the air by the crops grown on a —
particular field during a period of five years to be 4,615
pounds. A large crop of maize or alfalfa would acquire
even more than this. Such large drafts upon the atmos-
pheric supply of carbon raise the question whether this
supply remains constant. Investigation has shown that
it does. The processes of decay through oxidation of
vegetable and animal substance on the earth’s surface,
the combustion of wood and coal as fuel and of food com-
pounds by animal life are all returning carbon to the air
as carbon dioxid and it would appear that a balance is
being maintained. The round traveled in the circula-
tion of carbon is from the air to the plant, from the plant
to the animal, and from the animal back to the air—a
cycle of movement that has always existed and which will
, continue so long as life exists.

9. Oxygen.—This element, next to carbon, is the most
abundant component of the vegetable and animal tissues.
It is second to none in the importance of its relations to the
vital processes of nearly all forms of life. We are not
familiar with this substance by sight because it is a trans-
parent, colorless gas. The air is over one-fifth oxygen by
volume. More than 21,000,000 pounds of this element are
contained in the air above a single acre of land, a quan-
tity which remains remarkably constant and is practically
uniform over the entire surface of the globe. Like carbon,
it is being continuously withdrawn from the air for pur-
poses of combustion and is, like carbon, as continuously
returned. Water contains nearly 89 per cent of oxygen,
and it is estimated that the crust of the earth is one-half

THE CHEMICAL ELEMENTS 15

oxygen. That which enters directly into the uses of animal
life is derived chiefly from the atmosphere and water.

10. Uses of oxygen.—All life, whether vegetable or
animal, is dependent on the use of oxygen, during which
use this element passes into fixed combinations and back
again into the free form. The free oxygen of the air is
used by an animal in breathing and this it returns to the
air in part combined with carbon as carbon dioxid. On
the other hand, the plant appropriates the carbon dioxid
and, through synthetical processes, the carbon is built
into the plant tissues and the oxygen, which is set free, is
returned to the atmosphere and may be used to sustain
the demands of animal life. Oxygen is a factor in all
processes of decay and in many other chemical changes.
Fire is due to its union with the elements of the fuel. It
is the agent which maintains combustion in the furnaces
of our industries. The energy derived from the sun’s
rays, which is stored in vegetable tissue, when the oxygen
is torn from its union with carbon is set free when through
combustion the oxygen is returned to its former combina-
tion. This circulation of oxygen is effected through the
opportunities offered by the vital processes of the plant
and animal. (See Par. 207.)

11. Hydrogen.—In a free state, this element is the
lightest known gas and is found abundantly in nature
only in combination with other elements. A minute
proportion exists in the air which is derived from volcanic
action and possibly from decay under certain conditions.
When hydrogen and oxygen are combined in the forma-
tion of water, intense heat is produced. Hydrogen con-
stitutes about one-ninth of water by weight and it is
found also in a large number of soil compounds. It is an
essential constituent of vegetable and animal tissues, but

/

16 THE FEEDING OF ANIMALS

exists in these in a much smaller proportion than carbon
or oxygen. Its source to the plant is largely water and it
is furnished to the animal in water and other compounds.

12. Nitrogen and its compounds have been the
subject of much scientific investigation in their re-
lations to agricultural practice. Like oxygen, nitrogen
is an invisible, tasteless, and odorless gas, which,
according to previous determinations, forms about 77
per cent of atmospheric air by weight. The existence in
the air of newly discovered elements, such as argon, has
modified previous determinations. The only place in
nature where nitrogen or its compounds exist in large
quantities, outside of the air and in the tissues of living
organisms, is the sodium nitrate beds which are found
in Chile and other localities. Soil spaces contain nitrogen
and it is taken into solution in small proportions in all
natural waters. It is found in mineral and organic com-
pounds in the soil, but in quantities very insignificant as
compared with such elements as oxygen and silicon. Few
agricultural soils contain over 144 per cent of combined
nitrogen. Minute quantities of its compounds, such as
ammonium carbonate and ammonium nitrate, exist in
the atmosphere, which are being constantly carried to the -
soil in rain-water and as constantly replaced by ammonia
from decomposing animal and vegetable matter and by
the products of oxidation of nitrogen through combustion
and electrical action. Although the compounds of nitro-
gen exist in a comparatively small proportion, they play
a very prominent part in agriculture, both commercially -
and physiologically. The nitrogen balance of the farm is
important both to the crop-producer and the cattle-feeder.

13. Supply of nitrogen.—The available supply of
nitrogen compounds is often dangerously near the demand,

THE CHEMICAL ELEMENTS 17

and sometimes below it. The large quantity found in the
air is inert for animal uses, and is ignored by a large
majority of plants. Much of that in the soil is also un-
available. Its immediately useful compounds on the farm
are constantly subject to loss through fermentations which
the farmer can not wholly prevent and through soil losses
which are to some extent beyond control. The sale of
crops removes from the farm much nitrogen. The sources
of supply to balance this outgo are the nitric acid and
ammonia of the rainfall, the free nitrogen captured by a
class of plants known as legumes, that which is secured
through purchase of fertilizers and the residues of animal
foods. These facts relate primarily to plant production,
but they also sustain an essential relation to the main-
tenance of animal life.

14. Uses of nitrogen.—Physiologically, the nitrogen
compounds of foods stand in the front rank. These com-
pounds are necessary building-material for the funda-
mental tissues of the animal, and are intimately related to
prominent chemical changes which are involved in growth
and in the maintenance of life.

Nitrogen compounds have come to have an important
place in commerce. It is the most costly ingredient of
fertilizers and the value of commercial cattle foods is in
part dependent upon their content of these compounds.
For all these reasons, the partial control which the farmer
might now assume over the income and outgo of nitrogen
compounds has become an important feature of farm
economics. (See Par. 59.)

15. Argon.—Argon exists in the atmosphere to the
extent of about nine-tenths of 1 per cent. So far as known,
argon does not function in vegetable and animal life.

16. Sulfur.—This common and familiar substance is

B

18 THE FEEDING OF ANIMALS

found in all soils and natural waters and in all the higher
forms of animal and vegetable life. We know it as “brim-
stone” when fused in sticks and as “flowers of sulfur”
when in a finely divided form. Its most common com-
mercial compounds are sulfuric acid and the sulfates of
potassium, sodium, calcium, and magnesium. Sulfur is an
element essential to the building up of some of the most
important tissues of the animal body and is supplied in
food in the form of the sulfates and in protein com-
binations. (See Par. 64.) .

17. Phosphorus.—This element occupies a very impor-
tant place in animal nutrition. It does not exist in nature
in an uncombined form and that found in laboratories is
produced only by chemical means, but its compounds are
widely distributed, those in the soil being chiefly the
phosphates of calcium, magnesium, and iron. Large
deposits of calcium phosphate are known, from which is
obtained the crude phosphatic rock that serves as a basis
for the manufacture of commercial fertilizers. All feeding-
stuffs in their natural forms contain phosphorus com-
pounds. such as phosphates, certain fats, and organic
nitrogen compounds. Phosphorus is a constituent of the
fiesh of animals, and, combined with lime, constitutes a
large part of bone. (See Par. 55.)

18. Chlorine.—The chief source of chlorine to animal
life is common salt. In some form or combination it is
essential to the nutrition of the animal. In a free state,
at ordinary temperatures, it is a greenish colored, dis-
agreeable gas. When combined with hydrogen, it forms
hydrochloric acid—a compound that occupies a promi-
nent place in the digestion of food. Any ordinary mixed
ration contains this element in a quantity sufficient for
the animal’s needs. (See Par. 144.)

=

THE CHEMICAL ELEMENTS 19

19. Iodine.—Iodine is distributed in nature only in
minute quantities. It is apparently absent in some plants,
but is found in minute quantities in others. Nevertheless
it appears to exercise important functions in animal life.

20. Potassium.—Familiar compounds of this element
are the potassium carbonate leached from wood-ashes,
saleratus, and the caustic potash of the market. This
element is found in the flesh of all animals, mostly as the
phosphate, and is abundantly supplied for the purposes
of nutrition in the ordinary combinations of natural
feeding-stufis.

21. Sodium.—This is the basal element of common
salt, a compound which is furnished to domestic animals
in a liberal supply. This is the only sodium compound
which it is necessary to consider. Sodium plays an impor-
tant part in the digestion of food as it is the basis of cer-
tain bile salts and is concerned in other ways in the
digestive processes. (See Par. 151.)

22. Calcium.—The most commonly known compound
of this element is lime, which is calcium united with
oxygen. Large masses of lime-rock, or calcium carbonate,
exist in many parts of the earth’s surface. All soils con-
tain lime compounds. Its universal presence in plant
tissues and in the milk of all animals in most instances
assures a sufficient supply to meet the demands of animal
life. The growing animal makes a generous use of lime
because, in union with the phosphoric acid, it is the chief
building-material of the bony framework. A deficiency
of food lime causes an abnormal development of the bony |
structure. Lime is especially important for poultry, for
egg-shells are mostly a lime compound. (See Par. 55.)

23. Iron.—The common properties of iron are familiar
to everyone. Iron rust and iron ore are oxides of this

20 THE FEEDING OF ANIMALS

element. Iron is taken up by plants and animals in small
quantities only, but is absolutely essential to their growth
and welfare because of its important relation to certain
metabolic processes. (See Par. 200.)

PROPORTIONS OF THE ELEMENTS IN PLANTS AND
ANIMALS

In order to reach an intelligent understanding of the
relation of supply and demand which exists between the
vegetable and animal kingdoms and the raw materials
of the inorganic world, it is necessary to know the propor-
tions in which the elements are found in living organisms.

24. Elements in plants.—It has been estimated by a
German scientist, Knop, that if all the species of the
vegetable kingdom, exclusive of the fungi, were fused into
one mass, the ultimate composition of the dry matter of
this mixture would be the following:

Per cent
at DOD. <6 nf fe og PI sta os 45
rarer 99 8.5 ee eee ee 42
Hydrogen oo. 0S. eS 6.5
Nitragen 00.0. oe Se 1.5
Minetal compounds (ash) ..0a ses. 5

The composition of various single species or parts of
a plant, such as the fruit or straw, shows considerable
variation from these average figures:

TABLE I

Carbon | Oxygen |Hydrogen| Nitrogen Ash

ee | | | | _ ______.

Per cent | Per cent | Per cent | Per cent | Per cent
Cloverhayy..... 47.4 37.8 5. 2.1
Wheat kernel .... 46.1 43.4 5.8 2.6 2.4
Wheat straw > .. . :.... 48.4 38.9 oo A re,
Fodder beets=. .”.. . 42.8 43.4 5.8 7 6.3

Fodder-beet leaves . . 38.1 30.8 A 4.5 21.5

THE CHEMICAL ELEMENTS ) 21

Carbon constitutes a larger proportion than any other
element of the dry substance of plants of all species.
Oxygen stands next in order, followed by hydrogen and
then nitrogen. It is an important fact in the economy of
nature that those elements which, on the average, make
up 93.5 per cent of the dry matter of plants have as their
main source either the atmosphere or water. Only a
small percentage of the dry matter is drawn from the
soil, and it is this small part that sustains the most impor-
tant economic relations to the farmer’s business.

25. Elements in plant ash.—The elements of the ash
vary materially in relative quantity in different plants.
The following table gives the proportion of the ash ele-
ments in a number of agricultural products:

TABLE II
AsH ELEMENTS IN CEREAL GRAINS AND VEGETABLES*

m2
o n 2 a 5,
» ro) ~ a 3) mo
= ® 2 ~ ° 2 3 ro)
® = 2 a 3 ZI ae} |
S an ae S | © 2 3 ar sag
aes | fo) oie = O | bier ioe

Per | Per | Per | Per | Per | Per | Per | Per | Per
cent | cent | cent |} cent |} cent | cent | cent | cent | cent

Potassium, . . . .|.5) |.36 |.46 |1.25:)1.89 1168 ieosei2 7 las
podium . 7. . . |.029 |.012 |.039 | .029| .08 | .86 |1.14714-32 |, 053
Calcium = . .. . |.043 |.023 |.08 129} .07 | 44 | .77°(1.40 | 39
Magnesium .. .|.14 |.135 |.134 | .16 | .112| .14 | .13 | .63 | .163
Iron .... . .{|.017 |.008 |.026 | .012] .029] .038] .144] .38 | .038
Phosphorus . . .|.41 |.29 |.35 62: | 28 | .31 | .343] .74 | 412
Sulfur... . . |.0032].0044].022 | .049) .099) .14 | .19 | .45 | .101
Silicon. w:-... . 1.018. 1.014 |.57 -011} .036;} .06 | .031| .35 | .036
Chlorine. . . . . |.006 |.013 |.029 | .065| .131] .25 | .66 /|1.02 | .183

* Calculated from Wolff’s ‘‘Aschen Analysen.” It is realized that more modern
methods of analysis might modify the above figures to a small extent, but they
are sufficiently accurate for illustration of the variable composition of the ash of
different species.

26. Elements in animals.—The proportions of the
chemical elements of our larger animals have been deter-

22 THE FEEDING OF ANIMALS

mined through analyses made of the entire bodies of
steers and other domestic animals by Lawes and Gilbert,
of England, and the Maine Experiment Station, in this
country. These results, combined with our knowledge of
the constitution of the compounds of the animal tissues,
enable us to calculate very closely the proportion of car-
bon and other elements in the entire body of an ox:

TaB.LE III

Fat ox Two steers, 2 yrs.old
Lawes & Gilbert Maine Station

Per cent Per cent
5) TO Se ie ce 63 60
| 3. 9 aS ree 13.8 14.1
es ee 9.4 9.
EET) $3. ws ns se hee 5. 5.8
Mineral compounds (ash). . . 8.8 A!

A fat ox contains a much larger proportion of carbon
than a lean one, because the fats are richer in carbon than
any of the other compounds of the animal body. It is
seen that plants and animals are alike in containing much
more of carbon than of any other element, and that the
quantities of the remaining elements stand in the same
order of proportion in the plant and in the animal,
oxygen being in greater proportion in the plant, and car-
bon and nitrogen in the animal. The plant and animal
are alike, therefore, in consisting chiefly of elements
derived from air and water. Carbon, oxygen, and hydro-
gen constitute from 83 to 86 per cent of the bodies of fat
oxen. It follows that less than one-sixth of the animal is
built from elements that have, in part, a commercial value
for crop production. Nitrogen and certain elements in
the ash of the plant and animal bear a market value.

-

THE CHEMICAL ELEMENTS j 23

27. Ash elements in animal.—The proportions of the
ash elements are shown from analyses made of the fat
ox by Lawes and Gilbert. For comparison, the propor-
tions of ash elements in the human body are given:

TABLE IV
Ox Man
Percent| Percent

EI 7222.09 ee INE Vth PY OE AS NOY thy 1383) 1.93
EE og Be ry Lr 2.80 | 2.50
I ok a eg oy. OM Ls .26 12
hy aca Pye ha ae ag te .20 10
Os tg oss oo ae et et ee a OF
Pe ee eh hr 2S) een ine 3.29
CE IE Pe a ee .65 14

It appears that in the ash, other than oxygen, phos-
phorus and calcium take a leading place as to quantity,
although other elements, such as sulfur, potassium, and
sodium are essential to animal growth, even if present in
relatively small amounts.

28. Classes of matter—A common and familiar
phenomenon is the destruction of vegetable or animal
matter by combustion, with the result that only a small
portion of the original material is left behind in visible
and solid forms. Fuel, such as wood or coal, is largely
consumed when ignited, and we have as a residue the
ash. If we incinerate hay, corn, or wheat we get a
similar result. The gradual decomposition of exposed
dead vegetable matter that occurs in warm weather is a
process essentially similar to the combustion of fuel, only
more prolonged. In view of these facts, it is customary
to classify all the tissues of plants and animals into the
combustible and incombustible portions, the former being

24 THE FEEDING OF ANIMALS

that part of the ignited or, decayed substance which dis-
appears in the air as gases, and the latter the residue
or ash.

29. Combustion does not destroy matter.—It should
be well understood that combustion does not involve
a loss of matter; only a change into other forms. If we
were to collect the gases which pass off from a stick of
wood that is burned, consisting mostly of carbon dioxid,
vapor of water, and certain compounds of nitrogen, we
would find that their total weight, plus that of the ash
residue, is even greater than that of the dry wood, because
the carbon and the hydrogen of the wood have united
during the combustion with an increased amount of
oxygen. The carbon, oxygen, hydrogen, and nitrogen of _
the plant or animal tissue belong to the combustible |
portion, although small amounts of two of these elements
are found in the ash, as it is usually estimated. The
remainder of the fifteen elements previously named is
supposed to appear wholly in the ash, although in different
combinations from what they exist in the plant.

30. Relation of combustible to incombustible por-
tions.—The relation in quantity of the combustible and
incombustible parts of vegetable and animal dry matter
is illustrated below:

TABLE V F

Combustible ea ie

Per cent Per cent
Cloyvecringestes lw. CN 92.8 v2
Potatesuaee =. Cw. (we 95.5 4.5
Mavekcues::...... am 98.3 ben
Wheat: kermeanemeet ss. 0° >. ce 98. 2

Body of faijez. Ss . Cw OC. 91.2 8.8

THE CHEMICAL ELEMENTS : 25

The significance of these facts in their relation to
cattle-feeding is that the chemical change which we call
combustion is one of the phenomena of animal nutrition.
Substances which may suffer either slow or rapid oxida-
tion outside the animal body may undergo complete or
partial combustion in the animal; or, stated in another
way, the part of the plant which “burns up”’ in the fire-
place or crucible is the part which in general undergoes
the same change within the animal organism in so far as
the food is digested.

31. Organic and inorganic classes.—The terms com-
bustible and incombustible are less used, perhaps, than
two others which represent practically the same divisions
of plant or animal substance, viz., organic and inorganic.
In chemical literature, the portion of a plant or animal
which suffers combustion is called the organic, and the
ash is known as the inorganic part. These terms were
evidently based on the erroneous assumption that the
compounds which burn and break up into simpler ones
are peculiarly those which sustain necessary and vital
relations to life, and are formed only through the func-
tions of living organisms. To be sure, the dry substance
of the plant is organized chiefly by building up com-
pounds of carbon, oxygen, hydrogen, and nitrogen, which
suffer combustion; but compounds of sulfur, phos-
phorus, chlorine, potassium, sodium, and calcium are
also constant and essential constituents of the juices and
tissues of the plant and animal. They sustain important
relations to nutrition and growth. It is true, however,
that the portion of a food material which is commonly
spoken of as organic embraces those compounds that fur-
nish practically all the energy which is utilized by animal
life and much the larger part of the building-material.

CHAPTER IV
THE COMPOUNDS OF ANIMAL NUTRITION

Tue animal body consists primarily of elements, but
we ordinarily regard it as made up of compounds. These
are groups of elements united in such fixed and con-
stant proportions that they have as uniform properties,
under given conditions, as the elements themselves. In
discussing the composition and uses of cattle foods and
the structure, composition, and functions of the animal
as an organism, we refer chiefly to the compounds of
carbon rather than to carbon itself. In the language of
practice, we speak of proteins, carbohydrates, and fats.
Commerce recognizes these compounds also. These com-
pounds are the source of the energy that is manifested by
animal life, and, with the ash, of nearly all the materials
out of which animal tissues are built.

32. The classes of compounds.—The known com-
pounds that belong to life in all its forms are almost
innumerable. These sustain a variety of relations to
human needs, some serving as food, some as medicine, and
some in the arts. Comparatively few of these must be
considered in discussing the science and art of cattle-
feeding. Moreover, the compounds which play a leading
part in animal nutrition are designated, especially for
practical purposes, in classes rather than singly, which
tends to more or less looseness of expression and definition.
For instance, the popular understanding of the term pro-
tein doubtless is that it is a single compound.

(26)

COMPOUNDS OF NUTRITION : a7

The same classification is used for the compounds of
both the vegetable and animal kingdoms, which are
divided into the following groups:

Water,

Ash (mineral compounds),

Protein (nitrogenous compounds),

Carbohydrates (and related bodies),

Fats (or oils).

Variously named compounds partially theoretical
and unclassified: Enzyms, antigens hormones,
vitamines accessories, activators. (These terms
are in part synonyms.)

Accuracy is here sacrificed to convenience. These
class names have come to be regarded, more or less, as
representing entities having fixed properties and func- -
tions, whereas each class contains numerous compounds
differing widely in their characteristics and in their nutri-
tive value and office. Moreover, these terms have a
variable significance as used under different conditions.
No one of them, except water, uniformly represents just
the same mixture of compounds when applied to unlike
substances.

33. Distribution of elements.—It is well to gain a
clear understanding of the relation which the fifteen
elements previously mentioned sustain to these classes
of substances. This relation can be shown for the five
main classes of nutrients, but not for the unclassified or
theoretical bodies. Just what elements enter into these
is not known. So far as known they do not have a con-
structive function. The distribution of the elements can
be seen most readily by a tabular display:

28 THE FEEDING OF ANIMALS

Water... 20; eda
Incombustible stake
or inorganic Oxygen
matter .. Sulfur
Chlorine
Phosphorus
Silicon. Fluorine
Potassium
Sodium
All vegeta- Calcium
hic or ani Magnesium
mal matter Tron
Manganese

Ash

Carbon
Oxygen
: Hydrogen
Protein . -. . . Nitrogen
Sulfur (generally)
Phosphorus (sometimes)
Iron (in a few instances)

Combustible
or organic
matter.

and fats. . { Oxygen

Carbohydrates ( Carbon
Hydrogen

The ash which, on the average, constitutes about one-
twentieth of the plant, and never more than one-tenth
of the animal, may contain thirteen of the fifteen ele-
ments, while the larger proportion of living matter con-
sists mostly of the compounds of three or four elements,
in no case of more than six or seven. It is strikingly
evident that the dominant elements of life, quantity
alone considered, are those derived from the air and water.

WATER

Water fills a very important place in agriculture. All
plant substance, all animal tissue, foods, and nearly all
the material things with which man comes in contact in
his daily life are made up of more or less water, or are

COMPOUNDS OF NUTRITION 29

- associated with it. Sometimes this is very evident, as
with green plants or juicy fruits. It is not so evident
with straw and corn meal. If, however, we submit
almost any substance, no matter how dry it may appear,
except, perhaps, glass and metals, to the heat of an oven
at 212° F., we find that a material loss of weight occurs;
and if we so arrange that whatever is driven off is first
drawn through some substance that entirely absorbs the
water which has been vaporized, we learn that the decrease
in weight is nearly all accounted for by the water thus
collected.

34. Measurement of water-content.—This suggests
to us the chemist’s way of determining the proportion of
water which any particular material contains. He weighs
out a certain amount of the substance and then keeps it
in an oven at 212° F. for five hours perhaps, after which it
is re-weighed. The difference in the two weights, or the
loss, is assumed to be all water, and the percentage in the
original substance is easily calculated. That portion of
the material which is left behind after the water is evap-
orated is called the dry substance.

35. Hygroscopic water.—Water is associated with
plant and animal substances and tissues in two ways,
hygroscopically and physiologically. It is easy to illus-
- trate the former way. If an ounce of corn meal were to
be dried in an oven as described, it would, as stated, lose
in weight. If it were subsequently allowed to remain
exposed in the open air in a barn or out-of-doors, it would
regain part or all of its original weight. The loss would
be due to water driven away by heat, and the gain to
water absorbed from the atmosphere, which we call
hygroscopic moisture.

All solids attract moisture up to a certain proportion —

30 . THE FEEDING OF ANIMALS

which varies with the substance and with the conditions
that prevail. The-surfaces of the particles of matter are
ordinarily covered with a thin film of water, which is
thicker on a cold, wet day than on a warm, dry day, and
so the same quantity of hay or grain weighs less at one
time than at another, because the percentage of hygro-
scopic water varies. An equilibrium will always be estab-
lished between the attraction of a substance for moisture
and the tension of the vapor of water in the surrounding
air, which accounts for the effect of temperature and of
the degree to which the air is saturated with water-vapor.
As all substances do not have the same attraction for
moisture, therefore, under similar atmospheric conditions,
one feeding-stuff may retain more water than another.

36. Physiological water.—Water that is held physio-
logically is that which is a constant and essential part of
living organisms, in which relation it is necessary to life
and performs certain important functions. These func-
tions are of three kinds: (1) The presence of water in the
tissues of plants and animals gives them more or less firm-
ness or rigidity combined with elasticity; (2) water acts
as a food-solvent; (3) water is the great carrier of food
materials and of waste products from one part to another
of the vegetable or animal organism.

37. Water in living plants.—Water constitutes a large
proportion of the weight of all living plants, especially
during the period of active growth. The cured hay weighs
much less than did the green grass when it was cut, and
this loss in weight is due almost wholly to evaporation of
water from the tissues of the plant under the influence of
the sun and wind. This water, which is contained in the
cells, tubes, and intercellular spaces of the stalk or leaf, is
pure water and has no more physiological value for the

~

COMPOUNDS OF NUTRITION ; 31

animal than water from any other source excepting that
it is pure and is not subject to the contamination which
sometimes occurs in streams and wells. There is no such

thing as the so-called natural water of plants, which has

a peculiar nutritive value or function.

38. Sap or plant juice.—Vegetation water should be
distinguished from sap or plant juice. Sap is more than
water; it is water holding in solution certain substances
such as sugars and mineral salts. When the plant is

_dried, these soluble compounds do not pass off, but remain

behind as part of the dry matter.

39. Proportion of water in plants.—The proportion of
water in plants varies greatly in different species, and in
the same species according to the stage of growth or the
surrounding conditions. These facts have more impor-
tance than is generally recognized, because the food
value of vegetable substances is largely determined by the
proportion of dry matter. It is always necessary to know
the percentage of water in a green plant before we can
estimate its worth for feeding purposes.

The variations in water-content of the living tissues of
different species of plants or parts of plants are well illus-
trated by the following average figures: (See Pars. 304—
306.)

TasLe VI. Water IN GREEN PLANTS Per cent
Pastere grass: (mixed) |. . Meares lee 80.
rey OPASS 4. |. So oe sss pe 61.6
Paden 0". |. A es ge 62.2
Peer... ee Se 76.6
PeeeeTOGeT) ..- . . . . eRe | exe 79.4
Fodder corn, dent, kernels glazed ........ 73.4
ereimeeeer. ye 8. 8 ee he, 70.8
i i na re 71.8
Elore-Déean,. med... TOR 84.2
Petatocs: (iene). 44. . fee ok a 78.9

ormnips ee 90.5

32 THE FEEDING OF ANIMALS

40. Effect of stage of growth on water-content.—
Immature plants contain more water than older or mature
ones. Young pasture grass is more largely water than the
same plants would be after the seed is formed. This fact
is consistent with the very rapid transference of building-
material during the active stages of growth. Analyses of
samples of timothy grass cut at the Maine State College,
in 1879, and at the Pennsylvania State College, in 1881,
show the marked influence of the stage of growth on
the water-content of the living plant:

TasBLE VII. Trwotruy

Maine State College Rencenaes
Mommy headed out... 265 2.2 e ei ee 78.7
Meee blossom =. 22 ee ee See eee 71.9
Sommer blossom: 5.2 eo ft Los sey ee 65.2
Pee Tipe a Sais SAS eo ee ee 63.3

Pennsylvania State College Percentage of water
ighl

gnly °
manured manure

Cut June 6, heads just appearing ... 79.7 76.5
Cut June 23, just beginning to bloom . 69.7 69.1
Cut July 5, somewhat past full bloom . 61.4 60.

What is true of timothy is probably true of all forage
crops in the perfectly fresh state. We have here an expla-
nation of the difficulty of curing early cut grass. When
the farmer begins haying, at least two drying days are
needed in order to secure a product that will not ferment
in the mow, while later in the season, grass cut in the
morning may be safely stored in the mow before night.
At the Maine State College, in 1880, immature timothy
grass lost 56.7 per cent weight in curing and the ripe
grass only 12.9 per cent. The extreme succulence of
immature corn and other crops previous to the formation
of seed is a fact which the dairyman who feeds soiling-

COMPOUNDS OF NUTRITION , 33

crops must consider if he would uniformly maintain a
ration up to the desired standard.

41. Influence of soil moisture-——The proportion of
water in plants is influenced also by the lack or excess of
soil moisture. The soil and not the atmosphere is the
source of supply of vegetation water, which, taken up by
the roots, traverses the plant and passes into the atmos-
phere through the leaves. If the supply is abundant, the
tissues are constantly fully charged, but if, by reason of
drought, the soil becomes very dry, the outgo of water
by evaporation may exceed the income. During a drought
vegetation water often falls below the normal, or below
what is necessary to maintain the tissues in their usual
condition of rigidity or to perform fully their physio-
logical functions.

42. Supply of water to plants.—This leads to the
observation that the water in a growing plant is that
which is in transit from the soil to the air. This liquid
stream enters the plant with its load of building-materials,
takes into solution the compounds elaborated in the ~
leaves and aids in transporting them to the points of
rapid growth, finally passing into the air from the sur-
face of the foliage. Throughout the entire growing sea-
son the plant acts as a pump, drawing from below through
the roots the water which it needs for various purposes,
and discharging it into the air. It was found that in
Wisconsin 309.8 tons of water were evaporated by the
plant for each ton of dry matter in the crop. Four tons of
dry matter to the acre is not an unusual product with
maize, requiring 1,239.2 tons or 10.4 inches of water for
its growth, the equivalent of about five-eighteenths of an
average annual rainfall. This is a fact of great significance
to the stock-feeder. His success begins with proper hus-

Cc

34 THE FEEDING OF ANIMALS.

banding of the plant-food resources of the farm, of which
water is an important factor. |

43. Water in feeding-stuffs.—Cattle foods, whether
in the green or air-dry condition, always contain more
or less water. The proportion is greatly variable, depend-
ing upon several factors. With the green foods, the range
of percentages is similar to that of the living plants pre-
viously noted. As, however, forage plants are used at
varying lengths of time after cutting, and as a loss of
moisture begins immediately after the plant is severed
from its source of water-supply, the amount of dry matter
in a green forage crop is somewhat uncertain, unless a
water-determination is made in the material exactly as
it is fed. In all experimental work this precaution is
necessary to accuracy. Roots and potatoes contain a
large proportion of water, which, owing to their struc-
ture, is slowly evaporated. In a cool, moist cellar, their
water-content will remain practically unchanged for a
long time; in a warm, dry room, evaporation occurs and
they shrivel and lose weight.

44, Conditions affecting water-content of feeds.—
The water-content of air-dry foods varies with the con-
dition in which they were stored, the length of time after
storage, and the percentage of moisture in the air. Early
cut hay often goes to the barn less perfectly cured than
the late cut, and all hay dries out more than is generally
realized during the first few months of storage. Con-
cerning these points, the writer has obtained data through
experiments at the Maine State and Pennsylvania State
colleges. Fourteen lots of hay, some early cut and some
late cut, were weighed when stored and again after
remaining in the barn for several months. The results
follow:

4s C

‘

COMPOUNDS OF NUTRITION 35

TABLE VIII
[ —_——_—___ ______________ ll ES
) Early cei Late |Late cut s
cut after Percent} cut after |Percent
a eeerl loss as several| loss
stored manthe stored | months] ©
Pounds} Pounds Pounds} Pounds
Timothy .. .:. 1881 | 3634 | 2307 | 36.5 | 4234 | 3390 | 19.9
Timothy ... .° 1882 | 3634 | 2556 | 29.7 | 3802 | 3168 | 16.7
Timothy ... . 1881 | 5000 | 3922 | 21.6 | 5270 | 4035 | 23.
Timothy ... . 1882 | 3570 | 3037 | 14.9 | 4017 | 3413 | 15.
Giggerss oy. . a. 1882 | 2910 | 1215 | 42.4 |} 1520) teao)) 256
Timothy ... . 1888 | 2815 | 2470 | 12.2 | 2790 | 2420 | 13.3
Timothy ... . 1889 | 5070 | 4225 | 16.6 | 6208 | 5086 | 18.1
Average ... 24.9 18.8

General average loss, 22.2 per cent.

It is probable that hay seldom loses less than one-
eighth of its weight during storage, and often much more.

As illustrating the variations in the proportions of
water in hay due to changes in air moisture, reference is
made to observations by Atwater. He found that dry
hay hung in bags in a barn varied in water-content
between 7.5 per cent and 13.6 per cent during the
months of May, June, and July. Hay in large masses
would change less, but would be affected, doubtless, by
long periods of very dry weather or very wet.

45. Relation of water to preservation of cattle foods.—
The proportion of moisture in coarse foods and grains
has much to do with their preservation in a sound con-
dition. New hay and grains when packed in large masses
are subject to fermentations which injure their quality
and diminish their food value. This is due to the fact that
sufficient moisture is present to allow the growth of low
forms of life with certain attendant chemical changes.
Feeding-stuffs containing 20 per cent or more of water—
and this is likely to be the case with clover, rowen, field-

36 THE FEEDING OF ANIMALS

cured corn fodder and stover, new oats and new corn—
when stored in large quantities are almost certain to heat
and become musty or moldy, always involving a loss of
nutritive value. (See Par. 306.)

46. Water in the animal.—Water is an important and
abundant constituent of animal organisms, from the
lowest to the highest forms. The blood, which is from
one-thirtieth to one-twentieth the weight of the bodies of
farm animals, is at least four-fifths water, while the soft
tissues have been found to contain from 44 to 75 per
cent, according to the species, age, and condition of the
animal. The most extensive and complete analyses so
far made of the entire bodies of animals were performed
by Lawes and Gilbert at Rothamsted, England. In this
country, four steers were analyzed at the Maine Experi-
ment Station, and in the study of human-nutrition
problems many determinations of water have been made:

TaBLeE TX. Water in ENTIRE Bopy Per cent
Ox, well fed, Lawes & Gilberts. 2 sw Se 66.2
Ox; half fat, Lawes'& Gilberpemees ss ww wt tS 59.
Ox, fat, Lawes & Gilberplgeeee tt wt tw 49.5
Steer, 17 months old, medium fat, Me. E.8..... 59.
Steer, 17 months old, medium fat, Me. E.S..... 56.3
Steer, 27 months old, fat, Me. E.8...... . . €- dIs
Steer, 27 months old, fat, Me. E.S8......... 522
Calf, tae Lawes & Gilbertieeneeeess we 64.6
Sheep, lean, Lawes & Gilbert .....2.2.2.2.4 67.5
Sheep, well fed, Lawes & Gilbert. ........ 63.2
Sheep, half fat, Lawes & Gilbert ......... 58.9
Sheep, fat, Lawes & Gilbert ........... 50.9
Sheep, very fat, Lawes & Gilbert. ......... 43.3
Swine, well fed, Lawes & Gilbert ......... 57.9
Swine, fab, Lawes:& Gilbertuweme.’. . . . -4. 43.9
Chickenyifiesh: 0... RRR sh 74.2 -
Fowl Meanie... Am a. Me. 65.2
Goose; flesh . . . . . . een. RPA s sisia 0 42.3

Turkey, flesh) *.°. -i:. SG eae ee

COMPOUNDS OF NUTRITION 37

It is very evident that, in general, considerably more
than half of the weight of the bodies of our domestic ani-
mals consists of water, the limits observed in all species
and conditions here mentioned being 42.3 and 74.2
per cent.

47. Variations of water-content of animal bodies.—
The percentage of water varies with the species, age, and
condition. Swine carry a notably small proportion. The
calf’s body, even though fat, is comparatively watery.
It is very noticeable that with oxen, sheep, and swine the
lean animals contain a much larger proportion of water
than the fat. This does not necessarily mean that in the
process of fattening the fat is substituted for water, and
so expels it from the organism, but that the increase has
a much smaller percentage of water than the body in its
original Jean condition. This is well illustrated by the
data from two independent investigations at Rothamsted
and at the Maine Experiment Station. The former investi-
gation showed that when swine, sheep, and oxen were
fattened the increase contained from 20 to 24 per cent
of water, this being half the proportion found in the entire
bodies of the lean animals. The Maine Station results
established the fact that in the increase of two steers
from the age of seventeen to twenty-seven months, dur-
ing which time a fattening ration was fed, there was 42
per cent of water, the bodies of the younger steers hav-
ing 58.2 per cent. It is a common remark among unscien-
tific people that beef from mature animals “spends”
better than that from young, the same observation being
made in comparing lean and fat beef. Modern investiga-
tion shows clearly that the reason for this lies partly in
the difference in water-content. Dry matter, and not
water, is the measure of food value.

38 THE FEEDING OF ANIMALS

ASH

The ash or mineral part of plants and animals has
occupied a minor place in the discussions which pertain
to the principles and problems of animal nutrition. In the
past chief attention has been given to the carbon com-
pounds of living organisms, while the compounds of the
mineral world, in their relation to foods and to nutritive -
processes, have generally been passed by with too brief
discussion. It is desirable to gain a clear understanding
of the combinations, distribution, and functions of the
constituents of the ash, for their importance in animal °
nutrition is no less than pertains to the carbon compounds.

48. Mineral compounds in the ash of plants and
animals.—As previously stated, the mineral portion of a
plant or animal is measured by the ash or residue after
combustion, the principal ingredients of which are the
following:

TABLE X
Acids Bases
Hydrochloric acid . . . HCl. oiten ws K;0
Sulfuric acid ..... HSOpeeoee 8. ee Na,O
Phosphoriclacid . . . HePsOpyaiimmew 2 Re CaO
Pcie ACI. ay. SiOz Miaenema |... Oe MgO
Carbonic acid ... .CQOsz co a |S Fe:O3

Other mineral compounds are found in the various
forms of vegetable life, but those mentioned are all that ~
we need to discuss at length.

The acids and bases do not exist in the ash as shown,
but they are united to form salts, and so we have the
chlorides, sulfates, phosphates, and carbonates of potas-
sium, sodium, calcium, magnesium, and iron. ‘These
are nearly all familiar objects in common life, as, for
instance, sodium chloride (common salt), potassium

COMPOUNDS OF NUTRITION 39

chloride (the muriate of potash of the market), potassium
sulfate (the sulfate of potash of the market), calcium sul-
fate (of which gypsum or land-plaster is composed), cal-
cium phosphate (burned bone is chiefly this compound),
potassium phosphate (a compound of phosphoric acid
and potash found chiefly at the druggist’s), and calcium
carbonate (limestone).
| 49. Rearrangement of ash elements during ignition.—
It should be remembered that the compounds in the ash
are not necessarily those of the plant or animal. During
the ignition of plant or animal substance, organic com-
pounds are broken up, certain acid and basic elements of
which enter into other combinations in the salts of the
ash. Much of the lime in the ash is in union with carbonic
acid, which in the plant may have been associated with
vegetable acids, such as oxalic and tartaric, and part of
the sulfur and phosphorus of the ash comes from cer-
tain carbon compounds.

The salts of the ash differ greatly in their properties.
Some are soluble in water, others are not. To the former
class belong all the chlorides, and the potassium and
sodium sulfates and phosphates. The normal phosphates
of calcium and magnesium are insoluble in water, but
soluble in various acids. These facts are important in
showing what salts may be found in the plant and animal
juices, and what effect leaching with water or other sol-
vents might have on the inorganic portion of cattle foods.

50. The ash compounds of plants.—Upon incinera-
tion, all plants and feeding-stuffs yield an ash residue
which has been termed the mineral part of the plant. The
ash elements are important in this connection because
they are the main source of the same elements of the
animal body. These may be held in plant tissue in three

40 THE FEEDING OF ANIMALS

ways: in organic combinations and as the inorganic salts
of plant solutions, crystals and incrustations. Outside
of phosphorus and sulfur, little is known of the relations
to plant structure of the important ash elements, such as
potassium, calcium, and magnesium. Their place as
bases in organic structures is not fully understood.

51. Variations of plant ash.—The ash from different
plants and feeding-stuffs is by no means uniform in com-
position and quantity, even in the same species or class
of materials, although with the grains there is some degree
of uniformity in this respect. Certain factors cause varia-
tions, such as species, stage of growth, fertility, the part
of the plant, and changes due to manufacturing processes.

52. Variations of ash due to species.—Different species
of plants, and consequently different feeding-stuffs,
are greatly unlike in their content of mineral matter.
The figures of Table XI illustrate this fact:

TABLE XI
Number of| Per cent

analyses ash
Mixed grasses?™-. . .°. . . 2 ee: 106 He
Timothy grass’. . ....... . 7 9 6.8
Hinglish ray tases . . . .. >) 11 12.1
Red clover, in bloom ee 113 6.9
eeradella in blogm ....... 3 9.8
Buckwheat (oom... J... ee 17 8.2
Potatoes’ fame... ... .. i: =z 59 3.8
Sugar-beets {3usgw .-. . >. . ne 149 3.8
Furnips) oa) ae sw et 32 8.
Carrots 2. eee. «Cw (C(“(s S 11 5.8
Winter wheat) 700. S.-y Lee 110 2.
Oats. =. SDS. (ee 57 Be |
Maize (0. 04882... . ee 15 1.4

‘ploy oy} JO pvoy OY ‘“[] ALVIg

COMPOUNDS OF NUTRITION 41

-

As a rule forage crops contain a higher percentage of ash
than do the grains. These variations pertain not alone to
the quantity of ash but to the proportions of compounds
which it contains:

Tap te XII. Toe MiInerat CoMpounnDs OF PLANTS AND FEEDING-
Sturrs (PER CENT IN THE Dry MatTrTeER)

Chlorine

Mixed grasses . ce. .| 1.86] .26 | 1.11 | .48] .11 .50 | 36 | 2. 43
iamotiy hay cee. .| 2.37 | 12) .55 | .22] .06 80 | 49) }.2.19 |” .35
Red clover in bloom .| 2.21] .13] 2.39] .75]| .07 .66 | .22 18 | .26
Wihtterclover ih. .14.57 | .53:12.21 | .69°]'.15 94] .54 ESat roe
Arata =... Freel ted4 | ole | oe 236. | 214 .63:'[> .43 47 (00 eee
Buckwheat -ig. . . 25t Ne SON Sio2 |. LOS eae -50 | .30 .09 | .06
Roots
oUaLOeS» .. . ae. : aa 7 oy ered O71" 19° 204: 64] .25 [OS8eie ole
pupar-peets “sam. . .| 2.031 .34 | .23]. .80] .04 AC) AG .09 | .18
Hodder beets". . .| 3.96 11.23 | .28]| .83 | .06 "65 1 c2e Ba hn 5
urnips:. : Say . wag eee! 79 85 B00 206) [. 1202 +1.,.96 ol Sale
@arvots.c iG oS; 2:02) 1.16 62 24} .05 MO 285 Lawl eee
Grain

Winter wheat .... 61 .04 -06 24] .03 93 | :O8 .04

Mites Pee yo .06 -05 Sk 22} 04. 00 | .Spr} 1.22 | .03
Summer bDamey.. ..| .56] .06| .07 | .23 | .03 -92 | .05 -68 | .03
Mame kerne o>. =| 4431 02: |) .03\]) 322°) con -66 | .01 2034) 208
[Reon iene ae Ray (oA bel bo -03 13 BW Te a | Pe -98 | .09 .02 | .04
Bield beans#. :._: .. -|- 1.51 .04 18 26 | .02 11.41 4get2 028206

These figures show that potash, lime, magnesia, and
phosphoric acid are the prominent mineral compounds
of the plant ash, and it is with them that we find the
important variations. The true grasses differ from the
clovers and related plants in containing much less lime
and greatly more silica, the phosphoric acid and potash
not being greatly unlike in the two cases. As a source of
lime, then, the clover hay is superior. Potatoes and roots
have an ash richer in potash and poorer in lime than are

42 THE FEEDING OF ANIMALS

the coarse fodders. The grains with hulls contain much
silica, and those like wheat and corn but little. The seeds -
of the legumes are richer in potash and lime than those
of the grasses. The maize kernel is especially poor in
lime.

53. The distribution of mineral compounds in the dif-
ferent parts of the plant.—Because the farmer separates
his crops into grain and straw, and the manufacturer goes
farther and divides the grain into parts, thus modifying
the character of feeding-stuffs, especially by-products,
it is necessary to consider just how the mineral compounds
are distributed in the stalk, leaves, and fruit, especially
of the cereal-grain plants. A comparison of the straws
and grains shows striking dissimilarities:

‘

TABLE XIII. Per CENT IN THE Dry MATTER

aS)
oO oO
4 a | 3 |e Mae
ig a @ | 8 | ao le ¢
= Q o | ° aS 5 3 .?)
$ $ 4s g = 5 oo a 3 2
i) a - fa)
SRN aa esas | NR aw wo Beto
Wheat—
Straw.) 2.41 o4 73 07 Sti ote .03 26 .13);| 3.62 |. .09
Kernel) 29.) 2. .61 | .04 06 | .24 .03 .93 .O1 .04
Oats—
Straw vse dee | 2.07 24 50] .26 |} .08 33 2301" S.0 31
Kernel . 3%] 3.1 56 | .05 Ji | .22 | .04 80 06 | 1.22] .03
Maize—
Straw is beuem 5.0 11.93 | .06 58 | 280 id [4 28 1.538 OF
Kernel ...] 1.4 .43.| .02 .03- | 222me OL -66 | .01 .03 | .O1
Peas—
Strawe iu. see | 217 21 | 1.89] .41 .09 41 32 35 29
Kernel mat | 1.18 03 13s) 222 .02 98 09 02 04

The straws contain more mineral matter than the
grains. In the straws there is much more potash, lime,
and silica than in the grains, while phosphoric acid exists
in larger proportions in the latter.

COMPOUNDS OF NUTRITION ; 43

The roots and leaves of beets and turnips present a
striking difference in mineral-content:

TABLE XIV. PER CENT IN THE Dry MaTTEeR

iS
o LSS 9
4 = De a m4 ©
s << o S eaten 7-34 &
4 | Goes | & | 6 | BS leer s\| 6
5 | o ae s-| S| 8 |s% |e | Sy] a
= oY a 4 = & | A I D O
Sugar-beets—
LE 3'6) * en are 3.8 | 2.03 .o4 -23 30 | .04 AT .16 -09 18
Leaves .. .]| 14.8] 3.90 | 2.05 | 3. 1.69 08 ae aot ROE E26
Fodder beets—
Heo --. 7a. “6: | 3.96-]))23 28 83 | .06 -65 5} 15 By 5
eaves oem . | 15.3 | 4.71 12.98 |. 1.63 | 1.46 | .22 } 1. 86 .56 | 2.45
Turnips—
Ineots. 2 2 | 8. 3.64 79 85 230"! 206.1102 .90 Ae 41
eaves. . 222 | 11.6 | 2.73 | 1.10 | 3.83 46] .18 .85 | 1.09 45 | 1.18

There appears to be a tendency for mineral compounds
to accumulate in the leaves of plants, and leafy plants
are, as a rule, those which appropriate these most freely.

The ash of the outside of the stem and of the husks of
seeds is in relatively large proportions, due sometimes to
an excess of silica. Husked rice kernels contain not over .5
per cent of ash, while the husks contain 39 per cent or over.

54. Influence of manufacturing processes on the ash
constituents.—The cattle-food market is abundantly
supplied with by-products from certain manufacturing
industries, such as milling, brewing, and starch produc-
tion. One prominent by-product is wheat bran. As this
is the outside of the kernel, we would naturally expect,
in view of the previous statements, that it would be rich
in mineral compounds, and we find such to be the case.
The wheat kernel contains about 2 per cent of ash, wheat
bran about 6 per cent, and wheat flour about .5 per cent.
Bran is rich in needed mineral compounds.

44 THE FEEDING OF ANIMALS

In brewing, the kernels of barley are subjected to a
leaching process which results in taking out the soluble
mineral salts, chiefly the salts of potassium, calcium, and
sodium, leaving behind, in part, the compounds of lime
and magnesium. This fact is made clear by comparing the
analysis of the ash of barley with that of brewers’ grains:

TABLE XV. ParTIAL COMPOSITION oF ASH (PER CENT)

Phos-

Potash | Soda | Lime Se phori

Summeribgriey . .... ..| .56 .06 .07 .23 92
reweTm reams. we all 64 | 9.45 -| 1.69

As a source of phosphoric acid and lime the brewers’
grains are more efficient, pound for pound, than the
original barley grains.

55. The mineral compounds of animal bodies.—The
mineral compounds of animals are nearly similar in kind
to those of plants, but are very different in relative pro-
portions. This is made plain by a comparison of the
figures given below:

TABLE XVI. ASH IN PLANTS AND ANIMALS

Ss
== =
3 ha
“ fe) fe ©
a rb) ay == A
| 2/4/2186 |83| 2a se
° ie) iS te | S Sie | = fa]
Selita |i ries n |e} Oo
Per | Per | Per | Per | Per | Per | Per | Per | Per
Dry substance cent | cent | cent | cent | cent | cent | cent | cent | cent
Timothy hayes. | 6.8 | 2.4 2 255) |) eze 80} 19 [R222 <o0
Maize kernel . . .| 1.4 43} .02 .03 |. .22 -66 | .01 L081} 208
Wheat kernel .. .| 2. -61 | .04 .06 | .24 -93.| 01 .04
Fresh bodies—
Fat ox)... °Seeaemee 3.9 o14.| .12) oe gaaeeS | 1.56 .O1
Fat sheep dl eeD 14]. .13 | PSR O04 se). 1.45 .02

Fat.swine —. i). 7igep 1.8 10 | .07 77 | .03 .73

COMPOUNDS OF NUTRITION 45

Potash is much less prominent in the composition of
the animal than is the case with plants, and phosphoric
acid and lime are much more so. In general, more than
80 per cent of the ash of the animal body consists of phos-
phoric acid and lime in combination as calcium phosphate,
whereas these two compounds constitute less than one-
fifth of the ash of hay and less than one-half of the ash
of maize and wheat kernels.

56. The distribution of inorganic compounds in the
animal body.—The bones contain a very large proportion
of the ash constituents found in the animal body, the soft
parts being poor in mineral salts. Between 60 and 70
per cent of the ash comes from bone, and the bony frame-
work is from 6 to 9 per cent of the entire bodies of domes-
tic animals. Williams and Emmett found that the total
ash in the bodies of pigs forty to forty-three weeks old
was distributed among the parts as follows: about four-
fifths in skeleton, one-ninth in the boneless meat and
about one-sixteenth in the offal, blood, and the jowl and
intestinal fats. Of the water-soluble ash, only about one-
twelfth was found in the skeleton, with about three-fifths
in the boneless meat. This distribution of the ash was not
the same in pigs forty to forty-three weeks of age as for
pigs eighteen weeks of age. The offal and carcasses of
the younger animals contained practically twice as much
as those of the older pigs, while the skeletons contained
only about three-fourths as much. More than 80 per
cent of the ash of bone is calcium phosphate, which is
associated with calcium carbonate, calcium fluoride, cal-
cium chloride, and magnesium phosphate.

The bones of all species of animals show a remarkable
similarity of composition, the average of which would not
be far from the following:

46 THE FEEDING OF ANIMALS

TABLE XVII. In 100 Parts or THE Asu or BonE (AVERAGE)

Calcium phosphate.) 2 (98s 802 8. BS a. 0 iin 83.9
Sealeaum ‘Carpemene. ». Seas) | GR ORpeee eee y <. 43.
(Calcium mother ‘combinations . =. 6. ee oo
SMIOTINe (me, Mes. ee 23
BOOTING A were, SN LO MRT) 18
97.66

57. Ash elements in the soft tissues——The muscular
tissue and other soft parts of the animal body contain
less than 1 per cent of incombustible materials. The ash
of flesh is mostly phosphoric acid and potash, accompanied
by comparatively small amounts of soda, lime, and mag-
nesia and minute quantities of chlorine and iron. Unques-
tionably, potassium phosphate is the predominating salt
in flesh, as calcium phosphate is in bone.

58. Ash elements in the blood.—The blood contains
a variety of mineral substances, the chief of which is
sodium chloride, or common salt, although a minute
amount of iron is present, having a most important func-
tion. In the bile, soda is abundant, combined mostly
with the peculiar organic acids of this secretion. Chlorine
is a constant constituent of the gastric juice, its presence
as chlorhydric acid being essential to digestion. The
preceding are some of the prominent facts concerning
the inorganic compounds of the animal body, but they
are only a brief suggestion of the knowledge which per-
tains to this part of animal chemistry.

CHAPTER V

THE COMPOUNDS OF ANIMAL NUTRITION,
CONTINUED—THE NITROGEN COMPOUNDS

Tue nitrogen compounds of the vegetable and animal
kingdoms have received much attention from scientific
investigators and writers during the past fifty years. It
has been generally taught that certain members of this
class of substances are the ones most important in the
domain of animal nutrition, and many writers have given
to these a prominent place in discussing the relative
value of feeding-stuffs and have almost ignored the other
nutrients. It is now conceded that relatively the func-
tion and value of protein have been unduly magnified.
The present tendency is toward a fuller discussion of the
office and value of the non-nitrogenous bodies.

59. The importance of protein.—There can scarcely
be any disagreement, however, concerning the general
proposition that the proteins play a leading part in the
processes and economy of animal nutrition. This is true
for several reasons:

(1) The nitrogen compounds are those fundamental
to the energies of the living cells which make up the tis-
sues of plants and animals. The basic substance of the
active cell is protoplasm, a complex nitrogenous body,
which Huxley called “the physicai basis of life.’”” Around
this primal substance seem to center all vital activities,
especially the transformation of the raw materials of the
inorganic world into the organized structures of life.

(47)

48 THE FEEDING OF ANIMALS

(2) These compounds are structurally essential to the
growth of animal tissues and to the formation of milk.
The significance of this fact is intensified by their paucity
in many of the feeding-stuffs that are ordinarily pro-
duced on the farm.

PROTEIN

For the sake of brevity and convenience, the nitro-
gen compounds of cattle foods, both vegetable and
animal, have been designated as a class by the single
term protein. When, therefore, it is stated that a feeding-
stuff contains a certain percentage of protein, reference
is made to the total mass of nitrogen compounds present,
which may be many in number and of greatly differing
properties.

60. How protein is determined.—The proportion of
protein (total nitrogen compounds) in a feeding-stuff as
given in tables of feeding-stuff analyses is ascertained by
determining the percentage of total nitrogen and then
multiplying this by the factor 6.25. This method is based
on the assumption that the average percentage of nitro-
gen in protein compounds is 16, which is not true to so
close a degree of approximation as was formerly believed
to be the case. It may happen in some instances that a
determination made in this way is sufficiently accurate,
while in other cases the margin of error is large. Recent
investigations with perfected methods show percentages
of nitrogen in the numerous single protein substances
found in the grains ranging from 15.25 to 18.78. These
are largest in certain oil seeds and lupines and smallest
in some of the winter grains. Ritthausen, a prominent
German authority, conceded that the factor 6.25 should
be discarded, and suggests the use of 5.7 for the larger

THE NITROGEN COMPOUNDS 49

number of cereal grains and leguminous seeds, 5.5 for
the oil and lupine seeds, and 6 for barley, maize, buck-
wheat, soja-bean, and white bean (Phaseolus), rape and
other brassicas. Nothing short of inability to secure
greater accuracy justifies the longer continuance of a
method of calculation which is apparently so greatly
erroneous.

61. So-called proteins greatly unlike.—As previously
stated, protein is the accepted name for a class of com-
pounds. Just how there came about such a grouping
of a large number of substances under a single head it is
not necessary to consider in this connection, but it should
be made clear that the individual compounds which are
included under this term are greatly unlike in their
chemical and physical properties; and it is known that
they differ materially in their nutritive functions.

62. Classification of proteins.—It is very evident that
it is not only convenient, but necessary, to classify such
a heterogeneous group of bodies into subdivisions more
nearly alike in their characteristics.

The most recent classification is one recommended by
committees representing certain scientific bodies.* Doubt-
less this classification is only temporary and will be
modified as our knowledge of the compounds of nutrition
is enlarged. The grouping now agreed upon is based on
chemical constitution; at the same time the lines of cleav-
age appear to have reference to nutritive function. As will
be noticed later, other bodies are related to metabolism
and growth which it is not now possible to classify as
they have not yet been isolated and their chemical con-
stitution is undetermined. The terms used in this classi-
fication are explained in the text which follows:

* Am. Jour. Phys., Vol. X XI.

D

50 THE FEEDING OF ANIMALS

Albumins
Globulins
Glutelins

; Simple ._. -{ Alcohol solubles
Albuminoids
Histones
Protamines

Nucleo-proteins
Glyco-proteins
Proteins J] Conjugated { Phospho-proteins
Hemoglobins
Lecitho-proteins

Primary Proteans
derivatives. . {et proteins
Coagulated proteins
Derived
Proteoses
Secondary Peptones
derivatives. . (peptides
Extractives
Non-proteins< Amides
Amino acids

Certain changes in terms and classifications should be
noted. The term proteid is abandoned, and the term
albuminoid is made to refer to the bodies formerly classed
as collagens or gelatinoids. The newer classification
groups the proteins on the basis of constitution and char-
acteristic properties.

Other nitrogen compounds are included with the pro-
teins by the present methods of chemical analysis, such as
alkaloids and nitrates, but these are so uncommon in
foods, or are present in such small quantities, that they
may be safely ignored.

63. The true proteins.—The proteins are the main and
important nitrogen compounds either in the plant or in
the animal. The nitrogenous bodies of seeds are little else
than such proteins, while young plants, and especially

ah sae eee
pean
PN

. ee ity ee ; Be ‘ }
. ‘ ne - a i ; ;

THE NITROGEN COMPOUNDS ; 51

roots, such as beets and turnips, contain more nitrogen
in the non-protein form. Proteins are the chief constit-
uents of muscular tissue. Their chemical constitution is
not definitely known, but it is generally considered
to be very complex, .even to the extent of several
thousand atoms. These bodies are constructed from
the simpler ones of the inorganic world through the
vital energies of plants, and in order to serve the
purposes of nutrition they must come to the animal fully
organized.

64. Ultimate composition of proteins—The ultimate
composition of proteins, that is, the proportions of the
elements which they contain, has been carefully studied,
and while there are material differences among them in
this respect, the limits of variation are not especially
-wide, as can be seen from the following figures according
to Osborne:*

TaBLE XVIII. ComposITION OF SOME TYPICAL PROTEINS

Hydro-| Nitro- Phos-
Carbon onl BS Oxygen | Sulfur} Iron pines

Per cent} Per cent} Per cent| Per cent|Per cent|Per cent| Per cent

Egg-albumin . .. | 52.75 | 7.10 | 15.51 | 23.02 | 1.616
Lact-albumin . . | 52.19 7.18 | 15.77 | 23.13 | 1.73
Leucosin . . . . | 53.02] 6.84 | 16.80 | 22.06 | 1.28
Serum-globulin . | 52.71 | 7.01 | 15.85 | 23.82 | 1.11
Myosin 2: . - .52.82| 7.11 |16.67 | 22.03) 1.27
Edestin . . .| 51.50 | 7.02 | 18.69 | 21.91] .88
Legumin . . .| 51.72 | 6.95 | 18.04 | 22.90} .385
asen pe. .. , | 53:13 | 7.06. |15.f8 1) 22.3711 80 86
Ovovitellin .. . | 51.56} 7.12 | 16.23 | 23.24 | 1.028 82
Cream gee... . | 52.72 | .6.86 | 17.661 21.73 [1.027
Zein .’. , | 55.23.| 7.26 | 16:13 p20 60

Oxyhemoglobin . | 54.64] 7.09 |17.38]20.16| .39 | .335

*“Chemistry of Food and Nutrition,’’ Sherman, page 35.

52 THE FEEDING OF ANIMALS

We see that the number of elements ordinarily found
in the proteins is five, nitrogen and sulfur being those that
chiefly distinguish these bodies from all others which
make up the mass of combustible matter. Two other
elements are found in certain of these bodies, as, for
instance, phosphorus in casein and ovovitellin and iron
in a constituent of blood.

65. Familiar examples of proteins.—Proteins are
familiar objects, and their properties are matters of
common observation. The tenacious cud of gum from
wheat gluten, the strings of coagulated albumin which
separate from the cold-water extract of fresh lean beef
that is brought to the boiling-point, the hardening of the
white of an egg into a tough mass as it is dropped into
boiling water, the stiffening of the muscular tissue of the
slaughtered animal or the rapid formation of strings of
fibrin in the cooling blood—in all these instances there
are manifested certain chemical or physical properties
which pertain to these most important and widely uti-
lized compounds.

SIMPLE PROTEINS

66. The albumins.—The albumins have several sources.
They are found in the juice of plants, in certain liquids
- of the animal body such as the serous fluids, in the cell
substance of muscular tissue, in blood and milk,
and abundantly in eggs. Unlike other proteins,
these compounds are freely soluble in pure cold water,
and when such a solution is heated to the boiling-
point, they separate from solution by coagulation and
become insoluble unless acted upon by some strong
reagent.

Lie” a
eas eat OP

THE NITROGEN COMPOUNDS : 53

When macerated beef is treated with cold water the
albumin in it goes into solution, and if this extract is
boiled the albumin separates in clotted masses.

The clear serous fluid that is left after removing the
clot from blood contains albumin. After the casein is
removed from milk by acid or rennet, the albumin of the
milk remains in the whey. It is this which in part causes
milk to clot if brought to the boiling-point. As stated, one
example of this class of proteins is the white of an egg,
which, when cooking in boiling water, becomes a hard,
coagulated mass. Albumin in the serous fluids and in
blood is called serum-albumin; in milk, lact-albumin, and
in eggs, ova-albumin.

A small proportion of the proteins of plants is found to
be albumin; for instance, Osborne found .3 to .4 per cent

~ in wheat, .43 per cent in rye, .3 per cent in barley, .5 per

cent in soja-beans, and some in most seeds. ‘This possesses
essentially the same characters as the animal albumin
described previously. Whenever a vegetable substance
is leached with water, it is probably this protein which
would be the first to suffer removal or destructive
fermentation.

67. The globulins—These proteins are usually asso-
ciated with albumins. When animal tissues are treated
with water, but a small part of the proteins dissolve. If,
however, we add to the water a mineral salt, especially
common salt (sodium chloride), sufficient to secure a
10 per cent solution, an additional and considerable
amount of protein may be extracted. Certain compounds
so extracted are called globulins, and differ from the
albumins in being practically insoluble in pure water and
in a saturated solution of certain mineral salts, such as
sodium chloride. The so-called globulins form an impor-

* Oe ee sk
Ng Spe 4

54 THE FEEDING OF ANIMALS

_ tant part of the protein-content of plants and of animal
tissues, both in quantity and in having a maximum
nutritive usefulness.

68. Plant globulins.—In plants these proteins seem
to be especially abundant and widespread. Our most
recent and most reliable knowledge of plant proteins
comes from investigations by Osborne. In these researches
the seeds of many species of agricultural plants were
studied, all of which were found to contain globulins.
In some the proteins consisted largely of these com-
pounds. The percentage content in certain seeds was
determined approximately:

TABLE XIX. GLOBULINS IN CERTAIN SEEDS

Per cent Per cent
Hidmeywean . .'.°. © 20. mente >; 13.
Cottonseed meal .. 15.8 Sioree bean. .. .# tv:
eRe gee eo i, 10. Migiger sn Sk. A
LON) aa aro 26.2 Soybean .... chiefly globulin
WV RESG UM ye cece 6

The seeds of the legumes, as a rule, contain the larg-
est proportion of these proteins, the cereal grains
having only a very small part of their protein in this
form.

From present knowledge, many seeds appear to have
characteristic globulins which differ among themselves
in their chemical properties. ‘These have been given
names derived from the general names of the species in
which they are found. Thus we have amandin in almonds,
avenalin in oats, corylin in walnuts, excelsin from the
Brazil-nut, phaseolin in several species of beans, glycin
in the soybean, maysin in maize, vicilin in horse beans,
lentils, and peas, vignin in the cowpea, and tuberin in
the potato. One globulin called edestin appears to be

THE NITROGEN COMPOUNDS “ 55

quite generally distributed in the seeds of agricultural
plants, having been found in a larger number than
any other protein yet discovered, including all the
cereals, castor bean, cottonseed, flaxseed, hemp, squash,
and sunflower, although it is not abundant in any of
these.

69. Animal globulins—The animal globulins exist
abundantly in muscle and blood. If finely divided, well-

washed muscle (lean meat) is treated with a 10 per

cent salt solution, first by rubbing it in a mortar with
fine salt, and then adding enough water to secure the
proper strength of solution, a globulin is dissolved which is
derived from a muscle protein designated by some authors
as myosin. It is believed that myosin coagulates in the
muscle upon the death of an animal forming a clot some-
times called myosin-fibrin. The theory has been proposed
that myosin acts as a “mother’”’ substance in the muscle
from which myosin-fibrin is formed in much the same
way as fibrin is developed in clotting blood from a pre-
existing body, but no single view as to exactly what
occurs is fully accepted. Other terminology has been
proposed, viz., that the mother substance shall be named
myosinogen to correspond to fibrinogen, myosin being the
coagulation product. Much confusion and indefiniteness
exist with reference to the chemistry of muscle proteins.
There is, nevertheless, a general agreement that rigor
mortis is due to a clotting of the muscle, accompanied by
marked chemical transformations. It is held that fer-
ments are present in the muscle, to the influence of which
these changes are due, and without which they do not
occur.

Another prominent globulin is the fibrinogen found in
the blood. When blood is drawn from the veins and cools,

56 THE FEEDING OF ANIMALS

it clots, which is nothing more than the formation of
strings of fibrin, perhaps through the influence of a fer-
ment, which has been named thrombin. Fibrin as such is
not found in living blood. A remarkable fact is that so
long as the blood is retained in the arteries and veins,
even if the animal dies and grows cold, this clotting does
not appear.

Serum-globulin is a collective name for several globu-
lins, which exist in blood-serum and in the other fluids of
the animal body, such as lymph and its allies, including
those exudations which pertain to diseased conditions,
especially dropsical.

One more protein has been generally classified as a
globulin, although differing in some respects from the
other members of this class, and more recently is classed
as a phospho-protein. Reference is made to vitellin,
which is the principal protein in the yolk of eggs. It is
there intimately mixed with certain peculiar phosphorized
bodies, which we shall notice later.

70. Glutenins.—These form a large part of nitrogen
compounds of the cereal grains and possibly of other
seeds. They are insoluble in water, alcohol, and neutral
salt solutions, but readily dissolve in very dilute acids
and alkalies. ‘The glutenin of wheat, found in the
tenacious substance that is left after washing the starch
out of wheat flour, is the best-known protein of this
class and is an important constituent of wheat flour,
existing there on the average to over 40 per cent of the
total protein.

71. Alcohol-soluble proteins.*—Alcohol-soluble pro-
teins have been found in all the cereal grains so far exam-

* Osborne and others propose the name prolamins. Science, Vol.
XXVI, pages 417-427.

THE NITROGEN COMPOUNDS ; 57

ined. The principal ones to be mentioned are gliadin
from wheat, zein from corn, and hordein from barley.
Gliadin is more abundant in the wheat kernel than is the
glutenin with which it is associated, the two together
constituting over 80 per cent of the total proteins of that
cereal. The proportion of gliadin in wheat flour has much
to do with its quality for bread-making purposes. It ap-
pears that the best bread flour contains about twice as
much gliadin as glutenin.

72. Albuminoids.—This term, according to the classi-
fication still in more or less use in the United States, has
been understood as including various proteins such as
the albumins, and globulins. The classification now
recommended confines the term to proteins found chiefly
in the animal body in such parts as the cartilages, bones,
feathers, hair, hoofs, horns, and nails. These proteins
are also obtained from the threads of silkworms and from
sponges. The albuminoids have group names, such as
collagen in cartilage and bone, keratins in feathers, hair,
hoofs, horns, nails, and similar exterior tissues, fibroin
in the threads of silkworms, and spongin in the frame-
work of sponges.

Gelatine, so well known to the housewife, is derived
from collagen. When meat containing tendons (cartilage)
is submitted to the action of boiling water, there is
obtained in the extract a gelatinous substance which
becomes evident when the extract is cooled. This gela-
tine is insoluble in cold water, but dissolves in hot. As a
dry commercial article, it is a tenacious substance which,
when prepared in thin layers, is transparent. When col-
lagen and gelatine are acted upon by tannic acid, as, for
instance, when the skin of an animal is treated with an
extract from hemlock or oak bark, the result is a sub-

DS THE FEEDING OF ANIMALS

stance which does not putrefy and which gives to the
tanned hide the properties of leather. Gelatine is much
used in various food preparations.

It is characteristic of the keratins such as hair and horn
that they contain a relatively large proportion of sulfur,
the analysis of horn and hair showing as high as 5 per
cent, the average amount in horn being 3.3 per cent. The
keratin bodies serve to give rigidity and wearing a
ties to certain exterior animal tissues.

73. Histones, protamines.—The proteins in these
two groups do not occur as such in nature, and are ob-
tained only by separating them from some combination.
The two groups are alike in being basic in character
and in being found in the spermatozoa of fishes.
Histones have also been obtained from the blood cor-
puscles of a goose and from the white blood corpuscles
of thymus glands.

CONJUGATED PROTEINS

74. Nucleo-proteins.—These are complex, phosphorus-
bearing proteins that sustain an important nutri-
tive function. They are regarded as a combination of
nuclein with an albumin, the nucleins being compounds
of nucleic acid and albumin, and nucleic acid yielding on
cleavage phosphoric acid, certain nitrogenous bases known
as purins, and a carbohydrate.

The nucleo-proteins are associated with the nuclei of
the cells that make up both plant and animal tissues.
They are relatively abundant in glandular tissues such as
the spleen, pancreas, thymus gland, and liver. The
spermatozoa masses of fishes are especially rich in these
compounds. Because certain bases known as purins

- THE NITROGEN COMPOUNDS ; 59

which arise from the cleavage of nucleo-proteins are
regarded as the progenitors of uric acid, persons with
uric-acid tendency have been advised to avoid eating
certain animal foods such as beef and liver, or any others
known to contain these compounds abundantly. Experi-
ments show that the feeding of certain tissues rich in
nucleo-proteins increases the output of uric acid, while
adding to the diet a large amount of purin-free proteins
such as albumin does not have this effect.

75. Glyco-proteins.—These are bodies that upon cleay-
age are decomposed into a protein and a carbohydrate.
The best-known glyco-proteins are the mucins that are
secreted by the mucous membranes of the air passages
and of the alimentary canal and by certain glands such as ,
the salivary. Certain of these compounds contain phos-
phorus and others do not.

76. Phospho-proteins.—Like the nucleo-proteins,
these compounds contain phosphorus, but on cleavage
do not yield the purin bases. The best-known phospho-
protein is the casein of milk, a compound exceedingly
important in human nutrition, especially with the
young.

This compound is a secretion of the mammary gland
of many species of animals, and doubtless originates in
the gland cells. The casein from different species of
mammals differs somewhat in chemical and physical
properties. Casein is insoluble in water, but exists in
milk in suspension. It is not coagulated by heat but
curdles when a weak acid is added to milk, as, for instance,
vinegar. The same result is produced by a generous quan-
tity of common salt. When milk is received into the
human stomach, the casein coagulates (the milk curdles)
through the action of a ferment in the gastric juice and

60 THE FEEDING OF ANIMALS

this coagulation is mechanically unlike, at least, with |
milk from different species. The action of this ferment
on casein is utilized in cheese-making in the development
of a curd which, with its inclosed fat, is separated
from the whey and pressed into compact masses and
later allowed to undergo certain changes due to other
ferments.

Other phospho-proteins exist, one being the vitellin
in the yolk of eggs which, as prepared, contains
lecithin. |

77. Hemoglobin.—Blood contains a peculiar com-
pound known as hemoglobin. When decomposed, it
separates into a protein, globin, and a coloring matter
heemochromogen, which, when charged with oxygen, is
called hematin. This oxidation changes the hemoglobin
to oxy-hemoglobin. This hemoglobin in the blood of
mammals contains, besides carbon, nitrogen, oxygen, and
hydrogen, sulfur and iron. The latter varies in per cent
from .34 to .48, and sustains an essential relation to the
functions of the blood. The blood pigment has the
property of taking up and releasing oxygen with great
readiness, carrying its load of oxygen out of the lungs,
giving it up to oxidation processes in various parts of the
body, and bringing to the lungs in its place the result-
ing carbon dioxid to be discharged into the air. The
blood changes color with the acquisition and loss of the
oxygen.

78. Lecitho-proteins—From the yolk of eggs, the
mucous membranes, and the kidneys, and doubtless from
other sources, are obtained a conjugated protein con-
taining lecithin. The constitution and special function
of this body are not well understood.

THE NITROGEN COMPOUNDS - 61

DERIVED PROTEINS

These are divided into primary and secondary protein
derivatives. Primary protein derivatives are those that
have been slightly modified by the action of water, very
dilute acids, or enzyms, or are the result of the action of
acids and alkalies whereby products soluble in weak
acids and alkalies are formed. Coagulated proteins
resulting from the action of heat and alcohol are classed
in this division.

Secondary protein derivatives are those in which the
modifying changes (hydrolytic, or the taking up of water)
through the action of acids or enzyms, have proceeded
beyond the incipient stage with the formation of bodies
that are soluble in water. In this division, the most
important compounds are the proteoses and the peptones,
the latter having suffered a greater change by hydrolysis
than the former.

1. PRIMARY PROTEIN DERIVATIVES

79. Proteans and metaproteins.—When proteins are
acted on by acids or alkalies, they are modified in
proportion to the strength of the reacting acid or alkali
and the length of time that the action continues. With
acid or alkalies of sufficient strength, there are formed
products soluble in weak acids and alkalies (meta-pro-
teins).

80. Coagulated proteins——There are several agents
which convert albumins and other proteins into a coagu-
lated mass, such as a boiling heat, alcohol, and certain
neutral salts and the action of an enzym. For instance,

62 THE FEEDING OF ANIMALS

with albumin from flesh or the white of an egg, boiling
water converts it into a coagulum that is insoluble in
water and is rendered soluble only by such agents as
acids and alkalies upon heating.

Dropping a soluble protein into alcohol has the same
effect. Globulins are, as a rule, affected in the same way.
The nature of this modification is not known.

2. SECONDARY PROTEIN DERIVATIVES

81. Proteoses, peptones.—When various proteins such
as albumin or globulin are subjected to the action of a
weak acid or of certain enzyms, they undergo what is
known as hydrolysis. This change involves a cleavage
(splitting) of the protein body accompanied by the taking
up of the elements of water. In this way are formed pro-
teoses and peptones, the latter being proteins that are
soluble in water. A proteose is an intermediate stage
between the original protein and a peptone, and it receives
a name according to its source, as albumose, globulose,
and caseose, according as an albumin, a globulin, or casein
is its source.

Peptone was formerly regarded as the final product of
enzym action in digestion, but we now know that the
. digestion of the proteins proceeds much farther. These
hydrolyzed bodies are found abundantly in the digestive
tract during digestion, the proteoses as’ stated being an
intermediate stage of digestion between the original pro-
teins and the peptones. This means that the formation
of the final products of protein digestion is a progressive
step. Proteoses and peptones may also be obtained by
laboratory methods. It should be noted that commercial
peptones are largely proteoses.

THE NITROGEN COMPOUNDS : 63

82. Important properties of the proteins.—The pre-
vious description of the various groups of proteins cannot
be understood to its fullest extent except by those who
have a good knowledge of the fundamentals of organic
chemistry. Nevertheless, the facts given serve to impress
the important chemical and physical properties which
these bodies possess, and point. to the necessity of study-
ing them individually in their relation to foods and nutri-
tion. It is not rational to speak of protein as if the |
term represents an individual entity, but the members
of this general class of compounds must be considered
by sub-classes at least, in discussing their place in
nutrition.

A fact of importance is the varying constitution of
the protein molecule, and consequently the possible
variation in the nutritive function of the individual
proteins.

83. The unlike constitution of the various proteins.—
We have already seen that certain proteins are particu-
larized in part by containing phosphorus, others sulfur,
and others iron. A phosphorus-bearing protein may have,
and undoubtedly does have, a nutritive function that
cannot be exercised by an albumin not carrying
phosphorus.

84. Cleavage products of the proteins.—It is well
known that when proteins are submitted to the action
of acids, alkalies, and certain ferments (enzyms) they
break up into simpler compounds which we speak of as
cleavage products, chiefly amino-acids which are some-
times designated as the building-stones of the proteins.
It is very significant that the kinds, and especially the
proportions, of these products differ greatly with different
proteins. For instance, the purin bases, which certainly

~ Ww ma YX. . aoe

64 THE FEEDING OF ANIMALS

sustain important physiological relations, are present
in beef and certain glands used as food, but absent in
milk and eggs. The variations in the decomposition prod-
ucts of certain vegetable proteins are striking, as also
are the differences in this respect between vegetable and
animal proteins, and these differences have an important
bearing on the value of the inividual proteins for the
purposes of growth. The following table taken from
Hammarsten’s “‘Text-book of Physiological Chemistry,”
seventh edition, is worthy of attention:

TABLE XX. CLEAVAGE PRODUCTS OF THE PROTEINS

Plant Proteins

Edestin | Legumin | Hordein | Gliadin Zein

Capeseen 6 tS eS 238 .68

Aranines =... 3.6 2.08 A438 2 9.79
Veaine Wms a fas Oe i 13 3.04 1.88
ence ta . | 20.9 8. 5.64 6.62 19.55
eemnee. sl, 33 03 ae 13 1.02
Aspartic acid -... 4.5 5.3 vay. 58 1.71
Glutamic acid .. .| 18.74 | 13.8 43.19 | 48.66 | 26.17
cs ies 25 har sf bs 45 we
Phenylalanine .. . 2.4 BaD) 5.03 Zao 6.55
ivece@em.. 2... |- 2.) 1:55 1.67 1.2 |3.55-10.1
POM LO 3.22 -| 18.73 | 13.22 9.04
Oxyprolime, ....| 2. Sie Eee ce e.g
Tryptophane 38 fe tgs 1. te
Histidine La 2.42 1.28 61 82
Arginine Tis: 10.12 2.16 3.16 1.55
ibysie? aie s).. 1 4,29

Tes. (a ae 149 | 4.87] 522| 3.61

THE NITROGEN COMPOUNDS - 65

Animal Proteins

lace Sadaeaa Ova ae Fibrin | Casein | Vitellin

Glycocolly... . . 3.5 : x
memos. .. .| 25 Dok 2.2 2.2 : 15 5
Se 9 er. 2.5 Ste ‘ 7.2 2.4
Leucine ... .|19.4 | 20. 1 CU By oe tai to ag . 9.35 | 11.

Peorevcmer . . |... oat Bi Hf wet 1.43] .

— i ae ae 2 ARN ah ae Bie : BRAT os
Aspartic acid . .| 1. Fs Re bee Aire : 1839] 2.13
mimiameacid .. .|10.1 4 7.7 | 9.1 | 85 15.55 | 12.95
mime. . . | . . | 2.5 ii aad al vin Wawa
Phenylalanine . .| 2.4 | 3.1 | 5.17| 3.8 ; RA e};, 28
aiyfosie 2... Naty cee Ie dan i a ar : 4.5 | 3.387
Proline nero Ba 1.04} 3.56] 2.8 ; 6.7 4.18
Ete PRS IRS Seas (aaa (Mees aaa Ue tl ane sa VAS mek
aeypromnane . .| 3.07), ... ere fai uN 165 are
die . |. eee Pare: ome 2.5 1.9
Mes | Sl! Aor. of 3. | eee
Sppiemy. ....|.. ae 3.76 ce : 5.95| 4.81
meena... |. CC “ae Te |. ue 1G is

In view of later discussions it is well to note in this
connection certain marked differences in the kind and pro-
portions of the cleavage products (building-stones) of the
individual proteins.

For example, glutamic acid is found in the plant
proteins in much larger proportion than in animal pro-
teins; lysine is absent from the alcohol-soluble proteins
hordein, gliadin, and zein, and proline is found in much
larger proportion in these than in any others. It is safe to
conclude that certain plant proteins cannot be rebuilt
into an equal quantity of animal proteins.

It should be noted, however, that a comparison of
vegetable and animal proteins shows in general a close
resemblance in the kind of building-stones out of which

E

66 THE FEEDING OF ANIMALS

they are constructed, although the proportions are
unlike. Bs

NITROGEN COMPOUNDS THAT ARE NON-PROTEINS

In the usual method for determining the proteins of a |
food by multiplying the total nitrogen present by a fac-
tor, there is included in the calculation nitrogen that does
not come from true proteins, but from compounds that
possess physical and chemical properties greatly removed
from those which characterize albumin and other true
proteins. Their office as nutrients is probably less com-
prehensive than that of the proteins.

85. Amino-acids and amides.—These compounds re-
sult from the union of organic acids and the group NH2.
Whether the resulting compound is an amino-acid or an
amide depends upon the manner of combination. Cer-
tain of the amino-acids may be produced in the labora-
tory by synthesis, but in the main they are obtained
from the cleavage of protein through the action of acids
or alkalies or ferments (enzyms). ‘They are found abun-
dantly in the alimentary canal during the digestion of food
as a result of the action of the digestive enzyms on pro-
teins. Amides occur in plants. Asparagine is an amide of
amino-succinic acid, first found in young asparagus shoots,
and glutamine is an amide of amino-glutaric acid, found in
germinating pumpkin seeds. They are soluble in water, and
consequently are diffusible throughout the plant tissues.
It is believed that such amides are forms in which the
nitrogen compounds of the plant are transferred from one
part to another, as, for instance, from the stem to the seed.
It has generally been held that these bodies are more abun-
dant in young plants than in mature. A larger part of the
nitrogen of roots and tubers is found in these compounds

~

THE NITROGEN COMPOUNDS 67

than in other foods, the proportion in grains being the
least, and is very small indeed. Such investigations as
have been conducted point to the conclusion that amides
do not function wholly as do the proteins. This is one
reason for regarding the protein of certain vegetable foods
as of less value than that of the grains and grain products.

86. Extractives.—These are bodies found in the extract
obtained from beef with cold water. After the albumin
has been removed from such an extract by boiling, these
compounds known as creatin and creatinin chiefly con-
stitute the nitrogenous solids that remain. Their food
value is small, for they appear to be largely eliminated
from the body in the urine without change.

CHAPTER VI

THE-COMPOUNDS OF ANIMAL NUTRITION,
CONCLUDED—CARBOHYDRATES, ACIDS,
FATS, AND OILS ;

Mucus the larger proportion of the dry matter of cattle
foods consists of non-nitrogenous material. While these
nitrogen-free compounds have not been regarded as
fundamentally so important as are the proteins, in quan-
tity they unquestionably occupy the first rank. The
activities of plant life are largely devoted to their pro-
duction, and their use by animal life is correspondingly
extensive. They may properly be called the main fuel-
supply of the animal world. Other nutrients aid in main-
taining muscular activity, to be sure, but these compounds
are the principal storehouse of that sun-derived energy
which furnishes the motive power exhibited in all animal
life. They also fill a necessary office in the formation of
milk and in the fattening of animals. This class of com-
pounds greatly predominates in the usual farm crops,
even in those of the legume family.

87. Elementary composition of the non-nitrogenous
compounds.—The non-nitrogenous compounds contain
only three elements—carbon, hydrogen, and oxygen.
They may be derived, therefore, wholly from air and
water, and they constitute that portion of foods which is
drawn from never-failing and costless sources of supply.
The elementary composition of typical nitrogen-free
bodies is given in this connection:

(68)

CARBOHYDRATES, ACIDS, FATS, OILS — 69

~

TABLE XXI

Cellu- Saccha- - :
ra Starch |Glucose rae Stearin} Olein

ee ee ee

Percent} Percent|Percent| Percent] Percent} Per cent

oo 44.4 | 44.4 | 40. 42.1. \%GsRa C14

Pi~oromem . Nw 6.2 6.2 6.7 6.4 | 12.4 | 11.8

_- , 49.4 | 49.4 | 53.3 | 51.5] 11. | 108

88. Classification of non-nitrogenous compounds.—
The non-nitrogenous compounds of foods are usually
divided into two main classes, viz., carbohydrates and
similar bodies and fats and oils. The first class often
bears the name nitrogen-free extract, but the carbohy-
drates are its principal members. Crude fiber belongs in
this class. The second is known by the chemist as ether-
extract, because ether is used to extract the fats or oils
from the vegetable substances in which they are con-
tained. The actual fat obtained from vegetable foods is
always less, however, than the ether-extract, because the
ether takes into solution other compounds than the fats.
It should be noted that the last two compounds of the
above table, which are fats, are relatively richer in car-
bon and hydrogen and poorer in oxygen than the other
compounds mentioned, which are carbohydrates. This
fact has an important relation to nutritive value.

89. The carbohydrates.—In order to understand the
carbohydrates as individual compounds and in their
relations to each other and to the processes of nutrition,
it is necessary to consider them, in general outlines at
least, from the standpoint of the chemist.

The term carbohydrates, as it is used, like the term
protein, is collective and includes a great variety of com-
pounds. By their common names we know them as sugars,

70 [HE FEEDING OF ANIMALS

starches, celluloses, gums, and so on. Chemically we dis-
tinguish them by their structure and by their relation
to one another.

90. Classification of carbohydrates according to struc-
ture.—The structure of certain sugars is such that their
molecules cannot be divided into simpler compounds that
retain the carbohydrate character, and these are known
as mono-saccharides. To this class belong glucose (grape-
sugar) and fructose (fruit-sugar). On the other hand,
there are a large number of carbohydrates, one molecule
of which by treatment in certain ways may be converted
into two or more molecules of a mono- (simple) sugar.
For instance, one molecule of starch, when submitted to —
the action of an acid or of certain ferments, breaks up
into several molecules of glucose, and so starch is known
as a poly-saccharide. Other poly-saccharides are sucrose
(cane-sugar), maltose (malt-sugar), lactose (milk-sugar),
cellulose, and the gums, all of which may be split up into
mono- or simple sugars. The poly-saccharides are sub-
divided into di, tri, and so on, according as they break up
into two, three, or more molecules of a simple sugar.

There are subdivisions of the mono-sugars also, on
the basis of carbon atoms in their molecules and thus we
have the names diose, triose, tetrose, pentose, hexose,
heptose for sugars having two, three, four, five, six, or
seven carbon atoms in the molecule. It may be remarked
here that it is among the hexose (six-carbon) sugars or their
multiples that we find the carbohydrates most important
to human nutrition.

91. The mono-saccharides or simple sugars.—The
simple sugars that are most important in animal nutri-
tion are dextrose (grape-sugar), levulose (fruit-sugar),
and galactose (from milk-sugar). These are hexose (six-

ap heh PP Ay El
' iia 2.
:

| CARBOHYDRATES, ACIDS, FATS, OILS Tt

carbon) sugars. The pentoses are also simple sugars, but,
as we shall see, they scarcely occur in nature, being
obtained chiefly by splitting up certain gums.

92. Dextrose.—An important simple sugar is dextrose
or grape-sugar, or what is known in the market as glu-
cose. Except in the hands of the chemist it is seldom
seen as crystals, although these appear in the “candying”
of honey and raisins. It is a constituent of molasses and
the sirups. Dextrose is found in practically the same
plants that contain saccharose, such as sorghum, maize,
and the fruits. So far as known, it is always associated
with some other sugar. On account of its difficult crystal-
lization and a lower degree of sweetness, it is less valuable
for commercial purposes than cane-sugar. That which
appears in the market is largely made from starch by the
use of an acid, and it is often utilized for adulterating the
more costly saccharose. Many seem to regard glucose as
a substance deleterious to health, but in consideration of
the fact that, in digestion, starch and most other sugars
are reduced to this compound before entering the circu-
lation of the animal, this view does not seem to be sus-
tained. There is a lack of evidence to show the ill effect
of glucose either upon man or animals.

93. Levulose.—Another simple sugar is levulose or
fruit-sugar, the composition of which is identical with
dextrose, but which has a different chemical constitution.
It accompanies dextrose and is found in some fruits in
considerable quantities, and especially in honey. It is as
sweet as cane-sugar, but does not form crystals with the
same readiness.

94. Galactose.—This is obtained by a cleavage of
milk-sugar (see later) into this sugar and dextrose. It
may also be obtained from certain gums.

1

TZ THE FEEDING OF ANIMALS

95. The pentoses.—There are several pentoses, none
of which occurs in nature, but which are prepared by chem-
ical methods from the gums. Thus, from gum arabic,
containing araban, arabinose may be obtained, and from
zylan (wood-gum), zylose may be prepared. Certain of
these sugars have been isolated from animal compounds.
They also have been found to appear in human urine.
They are important in the nutrition of herbivorous
animals.

96. Di-saccharides.—These carbohydrates are all
sugars which may be decomposed into two molecules of
a simple sugar, or one molecule of each of two simple
sugars. They are only three in number—saccharose or
sucrose (cane-sugar), maltose (malt-sugar), and lactose
(milk-sugar). When acted on by weak acids or cer-
tain ferments, they break by cleavage (hydrolysis)
as follows:

Saccharose-++ water—dextrose-+levulose.
Maltose -+water—dextrose-+ dextrose.
Lactose -+water=dextrose+ galactose.

These are the changes that occur during the digestion
of food.

97. Saccharose.—The most important of these, com-
mercially considered, is saccharose, which is the ordinary
crystallized sugar of the markets. As a human food it is
widely used, is especially valuable, and its manufacture
and sale constitute a prominent industry. This sugar is
obtained mostly from two plants, sugar-cane and the
sugar-beet. It also exists abundantly in sorghum, pine-
apples, carrots, and in considerable proportions in the
stalk of ordinary field corn. The first spring flow of sap
in one species of maple tree is richly charged with it.

CARBOHYDRATES, ACIDS, FATS, OILS © 73

The fruits generally contain saccharose, mixed with
other sugars and organic acids, and upon the relative
proportions of these compounds depends the character
of the fruit as to acidity or sweetness.

98. Maltose.—This sugar is intimately related to the
first growth which occurs in the germination of seeds. It
stands as an intermediate product between the store of
starch in the seed and the new tissues of the sprout. The
solution that the brewer extracts from the malted grains
contains this compound as the principal ingredient, and
through succeeding fermentations in the beer vats it is
broken up into alcohol and other compounds. It sustains
an important relation, therefore, to the production of
beers and other alcoholic liquors. Glucose sirups some-
times contain small quantities of this sugar. It is also
found as an intermediary product in the intestinal canal
during the digestion of food, being derived from starch
and other carbohydrates through the action of ferments.
Maltose is similar to cane-sugar in ultimate composition,
but not in constitution, although as a nutrient it evidently
has an equivalent value.

99. Lactose.—The only sugar of animal origin which is
abundant in farm life is the lactose that is found in milk,
which is known in commerce as milk-sugar. The milk of
all mammals contains sugar, which appears to be the same
compound with every species so far investigated. When
they are fed wholly from the mother, this is the only
carbohydrate which young mammals receive in their
food. The average proportion of sugar in the milk of
domestic animals varies from three to six parts in a hun-
dred, cow’s milk containing about five parts. When the
cream is removed, much the larger part of sugar remains
in the skimmed milk, and in cheese-making it is nearly all

74 THE FEEDING OF ANIMALS

found in the whey, from which the milk-sugar of com-
merce is obtained. Very soon after milk is drawn, unless
it is heated to the point of sterilization, or is treated with
some antiseptic, the lactose begins to diminish in quantity,
being converted into lactic acid through the action of
lactic-acid organisms (bacteria). Sour milk, therefore,
is different from sweet in containing less sugar or none
at all.

100. The sugars as a class.—When considered from
the standpoint of efficiency, the sugars are among the
most valuable of all the carbohydrates, although in quan-
tity they are less important than the starches, at least
in raw food materials.

Unlike starch, they are found in solution in the sap of
growing plants. It is probable that these are the forms in -
which carbohydrate material is transferred from one part
of the plant to another. It is easy to see that some such
medium of exchange is necessary. The actual production
of new vegetable substance takes place in the leaves.
When, therefore, cell-walls and starch grains are to be
constructed in the stem and fruit, the building-material
must be carried from the leaves to these parts in forms
which will readily pass through intervening membranes.
Excepting certain soluble compounds, closely related to
starch, the sugars appear to be the only available bodies
fitted for this office.

It is very seldom that a plant contains only a single
sugar. Generally two or more sugars are found together.
This is especially the case in the corn plant, sorghum, and
the fruits, and the proportions of each depend somewhat
on the stage of growth of the plant.

101. Other more complex poly-saccharides.—This
group includes a large number of carbohydrates that may

bee at a
ee) Py >) Mi
tear @ r 7
ae »t))
A }
; Lah
-, ¥

CARBOHYDRATES, ACIDS, FATS, OILS ~ 75

be considered as complexes of the simple sugars already
described. Indeed, they make up the principal bulk of
the carbohydrate-content of cattle foods. These poly-
saccharides may be divided into three subgroups: the

starch group, the gum and vegetable mucilage group, and

the cellulose group.

102. The starches.—Starch is a widely distributed and
abundant constitutent of vegetable tissue. Food plants,
especially those most used by the human family, contain
it in generous proportions, in some seeds as much as 60 or
70 per cent being present. Probably only water and cellu-
lose are more abundant in the vegetable world.

Starch does not exist in solution in the sap, but is
found in the interior of plant cells in the form of minute
grains which have a shape, size, and structure character-
istic of the seed in which they are found. Potato starch
grains are large, about zoo inch in diameter, and are kid-
ney-shaped, while those of the wheat are smaller, about
toow inch in diameter, and resemble in outline a thick
burning-glass.’ Corn starch grains are angular, being
somewhat six-sided, and those of other seeds show marked
and specific characteristics. These differences in size
and shape furnish the most important means of detecting
adulterations of one ground grain with another, a method
much used in the inspection of human and cattle foods.

Unless modified by some chemical change, starch is
not dissolved by water. The starch grains are not affected
at all by cold water, and, in hot water, at first only swell
and burst. Prolonged treatment with hot water causes a
chemical change to more soluble substances. For this
reason the simple leaching of a food material removes no
starch by solution. At the same time, the cooking of a
ground grain so breaks up and liberates the starch grains

‘ 3 1s
. 4

t y ; or: ears ether
= ‘ t 2% -
+ jee Ls
ey Fy
t

76 THE FEEDING OF ANIMALS -

that they a are probably acted on more promptly by
ferments in the digestive fluids.

The proportion of starch in plant ces varies
greatly. The dry matter of many seeds, such as rice and
the cereal grains, wheat, maize, barley, or oats, is largely
made up of starch. The same is true of potatoes and
other tubers. Johnson quotes the following figures from
Dragendorff :*

TABLE XXII. Amount or StTarcH IN Dry MATTER

Per cent Per cent
Wheatkernel . ... 68.5 Pease a Ae 39.2
Ryekernel ..... Gf; Beans. .445.3:4.04. one 39.6
Oat kermel -~. ... . 52.9 Flaxseed” 6 sea 28.4
Barley kernel . . . . 65. Potato tubers ° : . eG25

It appears that in grain plants starch forms most
abundantly during the later development of the seed. At
the Maine Station none could be found in very imma-
ture field corn cut August 15, while on September 21
the dry matter of the whole plant on which the kernels
had matured to the hardening stage contained 15.4 per
cent. In general, the stem and leaves of forage plants are
poor in starch.

The distribution of starch in seeds is worthy of note.
The grain of wheat has been carefully studied in this
particular, and it is found that this body does not nor-
mally exist in the seed coatings, this tissue consisting
largely of mineral matters, proteins, cellulose, and gums.
On the contrary, the germ and interior material deposited
around it are rich in starch. To be sure, wheat bran,
which is now very largely the outer seed coats of the
grain, has more or less, but this is due to imperfect milling.

Starch is an important commercial article, and is

*How Crops Grow,” page 52.

CARBOHYDRATES, ACIDS, FATS, OILS - 77

mainly obtained from corn and potatoes. Special forms of
starch used in cookery are sago, tapioca, and arrowroot.
Tt is used as human food, as a source of dextrin, and in
other ways. By treatment with an acid, corn starch is
converted into the glucose of our markets, dextrin and
maltose being intermediate products.

103. Glycogen.—This is the only uncombined carbo-
hydrate found in the animal body in appreciable quan.
tity outside the forms that are in the blood circulation.
It is sometimes called animal starch. It is a white pow-
der, soluble in water, and may be extracted in small
amounts from the muscles and liver. It is formed out of
the sugars that are taken into the circulation from the
digestive tract, and, as we shall see, is held a reserve store
of fuel for the maintenance of muscular energy, and in
this way it performs a very important office in nourishing
the animal body. (See Par. 214.) It was formerly believed
that another carbohydrate exists in muscle called inosite,
but it is now known that this substance belongs to a
different class of compounds.

104. The pentosans.—These bodies are very widely
distributed in nature, being found in the leaves, stem,
roots, and seeds of a great variety of plants, in alge and
in beets and turnips. Certain pentosans are known as
gums, such as gum arabic, gum tragacanth, and cherry
gum. Pentosans, on hydrolysis, yield pentose sugars,
among which are arabinose and zylose. These gum-like
substances exist in beets and turnips and probably in all
herbaceous plants that serve as cattle foods.

105. Galactans, mannans, levulans, dextrans.—These
are compounds of some importance that are more or less
associated in the framework of a great variety of plants
or parts of plants, including seeds, beets and turnips,

rte

78 THE FEEDING OF ANIMALS —

tubers and bulbs, alge, lichens, molds, and the wood and
bark of many species of trees. On hydrolysis they yield
galactose, mannose, levulose, and dextrose respectively.
The compounds are designated as hemi-celluloses.

They make up the least valuable part of certain vege-
table foods. ;

106. The pectin bodies.—Another class of compounds
much like the gums and perhaps related to them chemi-
cally, is the pectin bodies. Some of these substances are
gelatinous in appearance. The jellying of fruits, such as
apples and currants, is made possible by their presence.
They exist in greater abundance in unripe fruit than in
the ripe, consequently the former is selected for jelly-
making. When such fruits are cooked, the pectin which
they contain takes up water chemically and is transformed
into a gelatinous substance known as pectose. Mucilages
not greatly unlike the gums and pectins exist in certain
seeds and roots, the most notable instance being flaxseed.

107. Dextrin, which is sometimes spoken of as a gum,
is made by heating starch to about 200° C. It may also
be produced by treating starch with a dilute acid. Dex-
trin is formed on the outer part of the loaf when wheat
bread is baked. It is soluble in water.

108. Cellulose.—This is found in the tough or woody
portion of plant tissue. In tables of food analyses we
find the term crude fiber, which consists largely of cellu-
lose, a familiar example of which in a nearly pure form is
the cotton fiber used in making cloth. Crude fiber is
separated from associated compounds by the successive
treatment of vegetable substance with weak acids and
alkalies, and as so determined is sometimes improperly
taken to represent the amount of cellulose in a plant.
While crude fiber is mainly cellulose, it contains a small ,

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, ~. Hi) ;
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maa oy 2! Z
‘CARBOHYDRATES, ACIDS, FATS, OILS 79

proportion of other compounds, and besides, more or less
cellulose is dissolved by the acid and alkali treatment,
so that the percentages of crude fiber given in food tables
only approximately measure the cellulose present.

All plant tissue is made up of cells, the walls of which
are chiefly or wholly cellulose. It is this substance out of
which is built the framework of the plant, and which
gives toughness and rigidity to certain of its parts. The
more of this plant tissue contains, the more tenacious it
is, other things being equal, and the more difficult of
mastication.

The proportions of cellulose in the different parts of a
plant are greatly unlike. It is usually most abundant in
the stem, with less in the foliage and least in the fruit.
With vegetables like potatoes and turnips, the leaves are
much richer in fiber than the tubers or roots, which con-
tain a comparatively small proportion. Of the grains or
seeds, considerable is present in the outer coatings, while
but little is found in the interior. Vegetables such as
celery, lettuce, beets, and turnips are relatively rich in
crude fiber, while tubers, flours, and meals contain only
small amounts. In certain by-products from the grains,
like bran, which is made up mostly of the seed coatings,
fiber is present in fairly large proportions, while in flour
derived from the inner parts of the grain, the percentage
is almost negligible.

The stage of growth at which a plant is used for food
purposes has a marked influence upon the proportion of
crude fiber. In young, actively growing vegetable tissue,
the cell-walls are thin, but, as the plant increases in age,
these thicken chiefly through the deposition of cellulose.
In general, the toughness and hardness of mature plants,
as compared with young are due to the increased pro-

ae ae 4

>.
80 THE FEEDING OF ANIMALS

portion of woody fiber, although the decrease in the
relative amount of water in the tissues and the deposition
of other substances have more or less effect.

109. The acids.—Other substances besides those of a
carbohydrate character are included in the nitrogen-
free extract. Chief among these are the organic acids,
compounds which are found mostly in the fruits, although
they appear in certain fermented products, such as silage
and sour milk. The most important and well known of
these are acetic acid, found in vinegar, citrie acid in
lemons, lactic acid in sour milk, malic acid in many
fruits, such as currants and apples, and oxalic acid in
rhubarb. Sometimes these acids are free, that is, not
combined with any other compound. In the main they
are united with lime or some other base, forming an
acid salt. Excepting the fruits, only fermented foods
contain acids to an appreciable extent. When milk sours,
the sugar in it is changed to lactic acid under the influence
of a ferment. The acids of silage are formed at the expense
of the carbohydrates that are in the material which is
subjected to fermentation.

110. Fats and oils—When any finely ground food-
stuff, either vegetable or animal, is submitted to the
leaching action of ether, chloroform, or certain other
solvents, several compounds are taken into solution, the
main and important ones being fats or oils. These bodies
make up the chief portion of such an extract from seeds,
while the extract from other vegetable materials also
contains a considerable amount of wax, chlorophyl, and
other substances. Tables that show the composition of
foods have a column which is sometimes designated
“ether-extract,”’ and sometimes “fats or oils.” The former
is the more accurate term, because the compounds which

_ CARBOHYDRATES, ACIDS, FATS, OILS _ 81

it is the intention to describe are often no more than half
fats or oils. The real value of the ether-extract from
different foods is partly determined, therefore, by its
source. When it is all oil, or nearly so, it is worth much
more for use by the animals than when it is made up to
quite an extent of other compounds.

111. Fats or oils in grains and seeds.—The propor-
tions of fat or oil in cattle foods vary within wide limits.
In general, seeds and their by-products contain more than
_ the stem and leaves, the differences in the percentages of
actual oil being greater than is indicated by the ether-
extract. But little is found in the dry matter of roots
and tubers. Among the cereal grains and other more
common farm seeds, corn and oats show the largest
amounts, the proportion in dry matter being from 5 to 6
per cent, while wheat, barley, rye, peas, and rice contain
much smaller percentages, wheat having about 2 per
cent, and rice sometimes not over one-fifth of 1 per cent.
Agricultural seeds that are especially oleaginous are
cottonseed, flaxseed, sunflower seeds, and the seeds of
many species belonging to the mustard family, such as
rape. Peanuts, coconuts, and palm nuts are also very
rich in oil. The average percentages in these seeds and
nuts are approximately as given below:

TaBLE XXIII. Om 1n CERTAIN SEEDS

Per cent Per cent
Tol. Sin 34 Peannts *<-. 2. 46
Conmemmped. |. .°. 30 Gorenmis- 26. . 67
Sunflower seed ... 32 Paleaia() ...-- 49
Hapemeed. . 1. 42 Popmyceear . . & >: 44
Mustard seed... . 32

The oils from all the above are important commercial
products, being used in a great variety of ways in human
: |

82 THE FEEDING OF ANIMALS

foods and in the arts. In many cases, the refuse from this
extraction goes back to. the farm as food for cattle. This
is especially true of linseed and cottonseed.

112. Nature and kinds of fats——The vegetable and
animal fats and oils may, for convenience’ sake, be dis-
cussed in two divisions, the neutral fats, or glycerides, and
the fatty acids. The neutral fats are combinations of the
fatty acids with glycerin. When, for instance, lard is
treated at a high temperature with the alkalies, potash
and soda, glycerin is set free, and an alkali takes its place
in a union with the fatty acids. This is the chemical
change which occurs in soap-making. There are several
of these neutral fats, the ones most prominent and impor-
tant in agriculture being those abundant in butter and
in the body fats of animals, viz., butyrin, caproin, cap-
rylin, caprin, laurin, myristin, olein, palmatin, and
stearin, the last three being the most abundant and impor-
tant in human foods. Butyrin is a combination of buty-
ric acid and glycerin, stearin of stearic acid and glycerin,
and so on. Because these are combinations of three
molecules of a fatty acid radical with one of glycerin,
they are sometimes named tri-stearin, tri-palmatin, and
tri-olein, and so on. Some single fats (glycerides) are
compounds of two or three fatty acid radicals united with
glycerin in the same molecule. As glycerin is an alcohol,
and. as combinations of an alcohol and acids are ethers,
the neutral fats are really ethers (esters), although they
differ greatly from the common conception of an ether
which is gained from ethy] ether or the ether of drug-stores.

113. Physical properties of the fats and oils—These
individual fats possess greatly unlike physical properties.
They are all soluble in benzine, chloroform, and ether,
and insoluble in water. At the ordinary temperature of

NA Sead ee eer
1 S ‘ ya “ay

es

CARBOH YDRATES, ACIDS, FATS, OILS - 83

a room, some are liquid and some are solid, olein belong-
ing to the former class, and palmatin and stearin to the
latter. Butter, lard, and tallow differ in hardness at a
given temperature, and it may easily be discovered that
their melting-points are not the same. As the animal
body fats are in all cases chiefly mixtures of olein, palma-
tin, and stearin, stearin and palmatin being a solid at
ordinary temperatures, and olein a liquid at anything
above the freezing-point, it is evident that the relative
proportions of these compounds will affect the ease of
melting and the hardness of the mixtures of which they
are a part. Stearin melts at 71.7° C. and palmatin at
62° C. Tallow, having much more stearin than lard and
less olein, is consequently much more solid on a hot day.

The composition and physical properties of the fat
from a beef animal seem to vary according to the age of
the animal and the locality of the body from which the
fat is taken. Fat from an old animal melts at a lower
temperature than: that from a young animal, and the
same is true of fat taken from the outside of the body as
compared with that taken from the inside. Fat from
the herbivora is in general harder than that from the
carnivora.

114. Milk-fat—This contains not only the three
principal fats, but also the others mentioned, butyrin,
caprion, caprylin, caprin, laurin, and myristin, in small
proportions, and these latter tend to give butter certain
properties that distinguish it from the other animal fats,
which are almost wholly palmatin, olein, and stearin.
These special butter-fats are liquid at ordinary tempera-
tures. Doubtless the flavor, texture, and resistance of
butter to the effects of heat, are much influenced by the
proportions of the numerous fats it contains.

4

84 THE FEEDING OF ANIMALS

115. Fatty acids.—Free, fatty acids exist in nature.
They are not found in butter, lard, and tallow unless
these substances have undergone fermentations and
become rancid. The characteristic flavor of strong butter
is due to free butyric acid, which, because of fermenta-
tions, has parted from the glycerin with which it was
originally combined in the milk. In plant oils, on the
other hand, are found considerable proportions of the
free fatty acids, some of which have not been discovered
so far in animal fats, either free or uncombined.

116. Ether-extracts.—Stellwaag investigated the in-
gredients of the ether- and benzine-extracts from plants.
His results show that not only do these extracts include
substances which are not fats, but that a considerable
proportion of free, fatty acids is always present, sometimes
in quantities exceeding the neutral fats:

TABLE XXIV. ComposITION oF ETHER-EXTRACTS

Neutral Free fatty |Material not
fats acids saponifiable

Per cent Per cent Per cent
Pobatoes: 3. 3° 0S ee 16.3 56.9 10.9
Bees oo. ee 23. ‘ da.3 10.7
NMeaizeskemely. .\°:\. ete 88.7 6.7 3.7
Pape. o. . . ———e 73. 14 6.1
ee BR 61.6 21.6 2.4

It appears, as before stated, that ether-extract, espe-
cially that from vegetables, may consist, to some extent, of
materials which should not be classed among the fats.
The extracts from the grains proved to be nearly all oil.
Moreover, the grain oils were made up principally of gly-
cerides, and those from potatoes and beets consisted
largely of free, fatty acids.

CARBOHYDRATES, ACIDS, FATS, OILS - 85

117. Lecithins.—These are often called the phos-
phorized fats. It has previously been stated that neutral
fats are combinations of fatty acids and glycerin (glycerol).
Lecithins are compounds in which one of the radicals
of a fatty acid is replaced by a compound of phosphorus.
They are widely distributed in nature. They appear to
be an active component of every cell, both of vegetable
and animal tissue, and they are especially abundant in
seeds, in the nerve system, in fish, eggs, and in the yolk
of eggs. These compounds evidently fill an important
place in plant and animal nutrition. There are good
theoretical reasons for suggesting that lecithins serve as
a stepping-stone to the synthesis of the nucleo-proteins.
In digestion they behave like the true fats.

118. Enzyms, anti-bodies, hormones, vitamines
(accessories).—The science of nutrition must now deal
with a class of bodies which have not been isolated, some
of which have merely a theoretical standing, and all of
which are known chiefly by their reactions.

Certain of these bodies are formed within the animal
organism and others are associated with foods.

The subject of enzyms is treated in Par. 128.

Anti-bodies are bodies which in some manner neu-
tralize or hinder the specific action of some other body,
as for instance the anti-enzyms. It is held that an anti-
pepsin exists in the mucous membranes of the stomach
and an anti-trypsin in the mucous membrane of the
intestine which render these linings immune to the
action of the digestive juices.

Hormones, or “chemical messengers” are represented
by secretin (see Par. 161) which reacts upon certain
secretory glands, as for instance the pancreas, causing a
flow of the digestive fluid. The formation of secretin is

x

86 THE FEEDING OF ANIMALS

believed to be due to the reaction of certain food sub-
stances on the inner membranes of the stomach.
Vitamines, or food accessories, are regarded as being
attached to foods, and may properly be styled growth-
promoting substances. These bodies of an unknown
nature seem to fall into two classes (Hart and McCollum),
the fat-soluble accessory attached to butter fat, egg yolk
fat, pig kidney fat, and certain vegetable fats, and a
water-soluble accessory attached to the wheat embryo,
egg yolk, milk-powder, and other foods. These accessories
are not destroyed by heat, even when subjected to the
action of steam for two and one-half hours. The fat
soluble accessory may be concentrated in butter oil by
fractional crystallization of the harder fats.

CHAPTER VII
THE DIGESTION OF FOOD

WE have accepted so far without discussion the almost
self-evident fact that the food is the immediate source
of the substance and energy of the animal body. It now
remains for us to consider the way in which nutrition is
accomplished. The first step in this direction is the diges-
tion of food. It is necessary for food ingredients to be
placed in such relations to the animal organism that they
are available for use. This involves both condition and
location. The various nutrients in the exercise of their
several functions must be generally distributed, and so
their compounds, in part at least, must be brought into
soluble and diffusible condition, in order that they may
pass through the membranous lining which separates the
blood vessels and other vascular bodies from the cavity
of the alimentary canal.

119. Digestion vs. assimilation—In discussing physio-
logical relations of food, two terms are employed, viz.,
digestion and assimilation. Digestion refers to the
preparation of food compounds for use, by rendering
them soluble and diffusible—changes which are accom-
plished in what we call the alimentary canal, a passage
that begins with the mouth, includes the stomach and
intestines, and ends with the anus. Assimilation signifies
the appropriation of nutrients, after digestion, to the
maintenance of the vital processes and to the building
of flesh and bone—processes taking place in the tissues,

(87)

88 THE FEEDING OF ANIMALS

to which the nutritive substances are conveyed by the
blood. The two terms are entirely distinct in meaning,
although they are confused in popular speech.

120. General changes in food through digestion.—
In digestion, food undergoes both mechanical and chemi-
cal changes. It is masticated, that is, ground into
finer particles, after which, in its. passage along the
alimentary canal, it comes in contact with several
juices which profoundly modify it chemically. That
portion of it which is rendered diffusible is absorbed
by certain vessels that are embedded in the walls of
the stomach and intestines, and is conveyed into the
blood. The insoluble part passes on and is rejected by
the animal as worthless material, and constitutes part
of the solid excrement or feces. The forms in which the
nutrients are conveyed into the circulation are believed
to be the following: The proteins, previous to absorption
into the blood, are converted into soluble bodies, at
first proteoses and peptones, and finally into simpler
nitrogen compounds (amino acids) resulting from a more
extensive cleavage; the carbohydrates enter the blood
as sugars, chiefly as dextrose. The fats are changed into
a finely divided form, either as such or as fatty acids and
soaps. A study of digestion includes, then, a knowledge
of mastication, of the sources, nature, and functions of
the several digestive juices, and a consideration of the
various conditions affecting the extent and rapidity of
digestive action.

FERMENTS

The changes involved in rendering food compounds
soluble are intimately connected with a class of bodies »

Well-fed Hereford heifer.
PuatEe III. Two good bovine types.

THE DIGESTION OF FOOD 3 89

known as ferments, and it seems necessary before proceed-
ing to a consideration of digestion as a process to learn
something of the nature and function of these agents, which
are actively and essentially present in the digestive tract.

121. Definition of ferments.—A ferment may be
defined in a general way as an agent which causes the
decomposition of certain vegetable or animal compounds
with which it comes in contact under favorable condi-
tions. In the past, ferments have been classified into two
kinds, organized and unorganized. The so-called organ-
ized ferments are low, microscopic forms of vegetable life,
generally single-celled plants. The unorganized ferments
are not living organisms, but are simply chemical
compounds.

122. Organized ferments.—When milk is allowed to
remain in a warm room for several hours, it becomes
sour. An examination of it chemically shows that its
sugar has in part disappeared and has been replaced by
an acid. A study of the milk with the microscope, before
and after souring, reveals the fact that there has been a
marvelous increase in it of single-celled organisms or
plants. The presence of this form of life is regarded as
the cause of the change of the sugar into lactic acid. We
have here a so-called lactic-acid ferment, which may
typify the organized ferments known as bacteria. Numer-
ous other fermentations of the same general kind are
common to everyday experience, such as the changes in
the cider barrel and the wine cask, the spoiling of canned
fruits and vegetables, and the heating of hay and grain,
which are all illustrations of what is accomplished by these
minute organisms.

123. Structure and distribution of organized ferments.
—The organized ferments are classed in the vegetable

90 THE FEEDING OF ANIMALS

kingdom. As a rule, each individual plant is a single
cell and so minute as to be invisible to the unaided sight.
It corresponds in its general structure to the cells which
make up the tissues of the higher vegetable species, 1. e.,
it consists of a cell wall inside of which are protoplasm
and other forms of matter. These organisms are dis-
tributed everywhere—in the air, in the soil, on surfaces
of plants, and in the bodies of animals. Whenever the
right opportunity offers itself, they multiply and bring
about all the results attendant upon their growth.

124. Conditions of growth of organized ferments.—
The conditions essential to their development are the
proper degree of moisture and temperature and the neces-
sary food materials. Animal and vegetable substances
supply the necessary nutrients, but when thoroughly dry
do not ferment. Flour and meal that have been dried to
a water-content of 10 per cent will keep a long time with-
out loss from fermentative changes. The heat in a mow
of hay or in a bin of new grain, with their subsequent
musty condition, is due to the fermentations that are
made possible through the presence of considerable
moisture. Thorough drying is a preventive of these
destructive fermentations.

There is a temperature at which each vegetable ferment
thrives best, and there are limits of temperature outside
of which the growth of these forms of life does not occur,
or is very slight. Numerous species thrive between 75° and
100° F. Fermentable materials like fruit and meat at
the freezing-point or below are not subject to fermenta-
tions. The boiling-point of water kills most bacteria,
and temperatures above 150° F. retard or entirely pre-
vent their growth.

THE DIGESTION OF FOOD 5 91

125. Results of fermentation.—Like all life, these
organisms must have food. Many species find this in
acceptable forms in vegetable and animal products.
Because these products contain the sugar, proteins, and
mineral compounds which nourish bacteria, many of
them are the prey of ferments under proper conditions of
moisture and temperature. The prevention of fermenta-
tion in cattle foods is desirable because it occasions a loss
of nutritive value and often produces undesirable flavors.
The loss becomes evident when we consider the nature of
the chemical changes that occur. For instance, when the
sugars in cider are broken up through the influence of a
bacterium, carbon dioxid and alcohol are formed through
the appropriation of free oxygen. This means that com-_
bustion occurs, causing the liberation of energy which
otherwise would have been available if the sugar had
been taken as food. Many other fermentations involve
oxidation, all of which are destructive of food value.

126. Manner of action of ferments.—These little
plants use sugar and other compounds as food, deriving
energy and growth therefrom, the carbonic acid, alcohol, ~
and other new bodies being the by-products of this use.
It now appears probable that these organisms develop an
unorganized ferment which brings about these fermen-
tative changes. Indeed, it is definitely proved that it is
possible to separate from the cells of the yeast plant a
substance that, in the absence of the yeast plant itself,
converts sugar into carbon dioxid and alcohol. This
shows that the effective agent in bacterial fermentations
is, after all, a chemical substance, or an unorganized
ferment. These later discoveries tend to remove the dis-
tinction that has been made between the so-called organ-
ized and unorganized ferments. Certain ferments are

92 THE FEEDING OF ANIMALS

among the most useful agencies with which we deal and
some are harmful. The yeast plant is useful in bread-
making, but the putrefaction of meats under the influence
of another ferment causes loss.

127. Bacteria in the digestive tract.—The digestive
tract of animals is inhabited by countless numbers of
bacteria. These inhabit both the stomach and the intes-
tines, especially the colon. They also form a part of the
feces. The two main types in which we are interested in
their relation to digestion are (1) the fermentative or those
that attack the carbohydrates, especially the sugars, and
(2) the putrefactive, or those that cause decomposition of
the proteins. Under certain conditions such as a sudden
change of food to large amounts of young and succulent
herbage, especially the legumes, bacterial fermentations
may endanger the life of the animal through the exces-
sive formation of acids and gases.

128. Unorganized ferments.—There is another class of
ferments which is termed unorganized, and to which the
general term “enzym” is given. These are the ferments
especially important in digestion. They are merely chemi-
cal compounds, formed within the living cells of the
plant or animal, which produce a peculiar effect upon
certain bodies with which they come in contact. If a
thin piece of lean beef be suspended in an extract from
the mucous lining of a pig’s stomach, to which has been
added a small proportion of hydrochloric acid, the liquid
being kept at about 98° F., the beef will soon begin to
soften, afterwards swell to a more or less jelly-like con-
dition, and finally dissolve. The same general result
would occur with fish, blood fibrin, or the coagulated
white of an egg. When starch is placed in a warm-water
solution of crushed malt, it soon dissolves, leaving a com-

THE DIGESTION OF FOOD - 93

paratively clear liquid. A chemical examination of these
preparations will reveal the fact that the compounds of
the meat are present in solution in somewhat modified
forms, and that the starch has been changed to a sugar
or other soluble bodies. In both cases substances insolu-
ble in water have become soluble and diffusible.

129. Enzyms and their action.—The cause of these
changes is the presence, one in the pig’s stomach and one
in the malt, of ferments of the enzym class, the former of
which renders proteins soluble, the latter producing a
similar result with the insoluble carbohydrates. This
action is not entirely like that caused by the presence of
the organized ferments, where oxidation occurs in many
cases. The enzyms simply induce the proteins and starch
to take up the elements of water, a change which is termed
hydrolysis. How this is done cannot be explained in
simple terms, if at all. Our knowledge of the manner of
the change rests to some extent upon theoretical grounds.
Enzyms are regarded as catalyzers, that is, compounds
which by their presence cause chemical changes while
they themselves do not enter into the combinations
formed. A small quantity of an enzym may cause changes
in a large amount of material, the enzym itself under-
going no appreciable change. The digestion of food is
largely accomplished through the specific effect of enzyms,
of which every digestive fluid contains one or more. Exam-
ples of these are the pepsin and pancreatin of the drug-
store that contain enzyms mixed with more or less of
impurities. The various enyzms are often given names
according to their function: invertase, which inverts or
splits sucrose; glucase, that changes any carbohydrate
into glucose (also called maltase); lactase, that splits lac-
tose into simpler sugars. In general, the ferments acting

94 THE FEEDING OF ANIMALS

on starch are called diastases. Enzyms that split fats are
designated as lipases and those acting on proteins to pro-
duce proteoses are designated as proteases.

THE ALIMENTARY CANAL

The digestion of food is accomplished in the alimen-_
tary canal, a duct that extends from the mouth to the
anus.

130. Parts of the alimentary canal.—The succession of
the various parts of this canal is as follows: the esophagus,
stomach, small intestine (duodenum) and the large intes-.
tine (colon).

The length of the intestines in the several species of
farm animals is very great as compared with the length
of the body of the animal, as the following figures show:

Sheep, ratio length of intestine to length of body . 26 times

Ox, ratio length of intestine to length of body . . 20 times
Horse, ratio length of intestine to length of body . 12 times
Dog, ratio length of intestine to length of body . 8 times

The food is pushed along the intestinal canal by a
muscular movement of the walls of the intestines known
as peristalsis, which passes from stomach to rectum, being
slower in the large intestine than in the small. During this
passage there occurs both the digestion of food and the
absorption through the walls of the canal of the digested

materials.
THE MOUTH

131. Mastication.—The first step in the digestion of
fodders and whole grains is to reduce them to a much
finer condition. This is done in the mouth, the teeth being
the grinding-tools.* Sometimes the cutting or grinding is

*This is not true of hens, turkeys, and other fowls.

»

THE DIGESTION OF FOOD 95

partially or wholly performed for the animal in hay-
cutters and grain mills. This mastication is essential for
two reasons: (1) It puts the food in condition to be swal-
lowed, and (2) fits it for the prompt and efficient action
of the several digestive fluids. Dry whole hay or kernels
of grain could hardly be forced down the tube leading to
the animal’s stomach. It is necessary for these mate-
rials to be broken down and moistened in order that they
may be swallowed. Even if they could be conveyed to the
stomach in their natural condition the process of render-
ing their constituents soluble would proceed very slowly.
The more finely any solid is ground, the larger is the sur-
face exposed to the attack of the dissolving liquid and
the more rapid the action.

132. The teeth.—Prompt and rapid solution of food
is essential, because, if it is too long delayed, uncomforta-
ble and injurious fermentations are likely to set in, and,
because of imperfect digestion, the final nutritive effect
of the ration may be diminished. For these reasons,
animals with diseased teeth, or those that have lost teeth,
make poor use of their food, and require an unnecessary
amount to keep them in condition. These conditions
may often be a cause, especially with horses, of disappoint-
ing results from an ordinarily sufficient ration. The teeth
of our domestic animals differ somewhat in number and
arrangement. Authorities state the following to be the
usual number:

TABLE XXV
Total Incisors Canines Molars
SRE ieee SN 36-40 12 4 24
SRLS 4 oe a on 8 24
Sheep and goat. .... 32 8 24

Bo ON cM, 44 12 4 28

96 THE FEEDING OF ANIMALS

The incisors or front teeth are those which are used
for prehension, and by grazing animals for cutting off the
grass and other herbages. With the ox, sheep, and goat,
incisors are found only in the lower jaw. These move in
their sockets and shut against a tough pad on the upper
jaw. ‘They are constantly being pushed out of their
sockets and wearing off, and with old animals may be
sO worn away as to leave only the roots. Such animals do

Fig. 1. Glands secreting saliva in man,—parotid, sublingual,
submaxillary.

not graze successfully. With the horse and pig, incisors
are found in equal numbers in both jaws.

The molars are the grinding teeth. Those of the horse
sometimes need filing on the edges in order to prevent

irritation and soreness of the adjacent tissues. A diseased

.
* (2
i-iiee S

A

THE DIGESTION OF FOOD : 97

-molar may also occasion an animal much discomfort and
cause imperfect mastication.

133. The saliva.—During mastication there is poured
into the mouth a liquid called the saliva, which has two
important functions: (1) It moistens the food, and (2)
with several species of animals it causes a chemical
change in certain of the constituents of the food.

134. Origin of saliva.—The saliva has its origin in
several secretory-glands that are adjacent to the mouth
cavity, and from these this liquid is poured into the
mouth through ducts that open in the cheek and under
the tongue (Fig. 1). The chief of these glands are located in
the side of the face, below and somewhat back of the jaws
and beneath the tongue, and are called respectively the
parotid, the submaxillary, and the sublingual. Other
glands of this character are scattered in the cheeks and
at the base of the tongue. The proportions of these glands
in the several species of farm animals are as follows:

Taste XXVI
Horse Ox Sheep Pig Dog
meroud . 2.2 273 45 52 81 48
Submaxillary . 17 48 43 16 52
Sublingual .. 5 7 5 3

135. Properties and office of saliva.—The saliva is a
transparent and somewhat slimy liquid, and contains
generally not less than ninety-nine parts in one hundred
of water, and one part or less of solid matter. It is alka-
line in reaction, because of the presence of compounds
of the alkalies. One important organic compound present
is mucin. The specific chemical effect exerted by this
liquid on the food constituents may be illustrated by sub-
jecting starch to its action. When this is done, the starch
gradually disappears as such and is replaced by dextrin

G

98 THE FEEDING OF ANIMALS

and maltose, chiefly the latter. The agent which is active
in causing this change is an enzym (see Par. 128), to

which the name ptyalin has been given, and which is —

always present in the saliva of man and of some animals.
It is classed among the diastatic ferments, and has an
office similar to that of diastase in the germination of
seeds, viz., the transformation of starch into a sugar.
With man this change begins in the mouth and continues
in the stomach until the food becomes so acid that the
ferment ceases to act, for ptyalin is inactive except in an
alkaline medium. There is yet no reason for concluding
that with herbivora the saliva is as important in car-
bohydrate digestion as with man. Different observers
differ in opinion as to the diastatic value of saliva with
farm animals.

The saliva also moistens the food, which is a most
important office, for it is a necessary preparation to the
act of swallowing. The saliva is not the same from the
different glands, that from the parotid being watery with
no mucin and that from the other glands being rich in
mucin and therefore very viscid. ‘The former serves
chiefly to moisten the food while the latter aids in swal-
lowing.

136. Quantity of saliva excreted.—With large rumi-
nants, the quantity of saliva required is large, as is evi-
dent when we remember that an ox or cow may consume
in one day twenty-four pounds of very dry hay and grain,
and that rumination goes on much of the time while the
animal is not eating. It is estimated that oxen and
horses secrete from eighty-eight to one hundred and thirty-
two pounds daily, an apparently enormous quantity
of liquid for organs no larger than the salivary glands
to supply. The extent and character of the secretion of

a“

Me . / ; {
THE DIGESTION OF FOOD ‘ 99

saliva seems to be modified by the nature of the food
offered, dry materials stimulating the parotid gland and
moist foods only the submaxillary and sublingual. The
organic constituents of the saliva are the peculiar prod-
ucts of the secretory activity of the cells of the salivary
glands, and the water and inorganic salts are regarded
as the result of cell secretion.

THE STOMACH

When the food leaves the mouth, it passes down the
gullet (esophagus) into the stomach. The only modi-
fications it has suffered up to this point are its reduction

_to a finer condition and a possible action of the mouth

>

ferment upon the starch. After the food is swallowed,
changes of another kind begin sooner or later.

Before considering gastric digestion from a chemical
point of view, we should become acquainted with the
widely differing structure of the stomachs of the various
farm animals. Those of the ox and horse are greatly
unlike. The stomach of the ox, and of all other rumi-
nants, consists of four divisions or sacs, whereas with
the horse and pig it is made up of a single sac.

137. The ruminant stomach.—The ruminant stomach
is really quite a complicated affair, and the way in which
it disposes of the food is understood only after a careful
study of details. It has four divisions or sacs: the paunch,
honeycomb, many-plies, and rennet, or what the physi-
ologist has named the rumen, reticulum, omasum, and
abomasum. With the ox these cavities contain on the
average not far from twenty-five gallons, about nine- —
tenths of this space belonging to the rumen (Fig. 2).

138. Esophageal groove.—A gutter or canal with

100 THE FEEDING OF ANIMALS

an incomplete wall runs to the reticulum and omasum
from the entrance of the esophagus into the rumen. It
communicates both with the rumen and reticulum. The
interior of this canal is not visible in its passage along the
inner wall of the reticulum unless the lips with which it
is provided are separated.

Fic. 2. Stomach of ox. 7, rumen or paunch, showing attachment
of esophagus; C, reticulum or honeycomb; O, omasum or many-plies;
A, abomasum or rennet, showing attachment of small intestine.

139. The rumen.—The food, especially in its first
descent from the mouth, passes at first mostly into the
paunch through a slit in the gullet. This cavity, as stated,
is very large, and it may properly be considered as an
immense reservoir for the storage of the bulky materials
which the ruminants take as food. It is divided into
four sacs by constriction in its walls caused by strong
muscular bands. As is the case with the entire digestive
canal, the walls of the paunch are composed of three
layers of tissue, the.middle one being a very thick muscu-
lar coat, which seems necessary to produce the churning
movement of the large mass of food. The inner or mucous

THE DIGESTION OF FOOD - 1010:

layer is covered with numerous leaf-like projections, in
which the blood vessels are freely distributed. During
its stay in this reservoir, where it is held for remastica-
tion, the moist food becomes thoroughy softened and
besides undergoes a variety of changes, chiefly those due
to bacterial ferments which probably bring about the
extensive digestion of the cellulose, estimated at from 60
to 70 per cent. These fermentations are attended by an
evolution of gases, which under ordinary conditions are
absorbed into the blood current. It may be suggested
that hoven and the puffing up of the paunch of a
freshly-killed bovine are due to the partial or total failure
of the blood to take up these gases. Sometimes unnatural
and dangerous fermentations set in, induced often by the
consumption in the spring of a large quantity of easily
fermentable food such as green clover. This causes hoven,
and unless the gas pressure is at once relieved by an
opening the animal often dies, due sometimes to the
bursting of the rumen. Some authorities claim that
proteolytic and amylolytic changes occur in the rumen
brought about not by enzyms secreted by the rumen but
by those contained in the food.

140. The reticulum.—A portion of the food reaches
the reticulum either through the esophageal slit when
first swallowed, or through a large opening between the
rumen and the reticulum. That which goes directly to the
reticulum when swallowed is mostly fluid. The reticulum
also communicates with the third stomach by an opening.
This is the smallest division of the stomach, and derives
its common name from the fact that its interior surface
is divided by ridges of the mucous membrane into cells
which bear a close resemblance to a honeycomb. These
cells, which are several-sided and quite deep, appear to

102 THE FEEDING OF ANIMALS

be a “‘catch-all’’ for the foreign bodies which animals are
liable to swallow, such as small stones, pins, and nails.
The contents of this compartment of the stomach are very
watery, and by being forced into the esophagus and
rumen appears to aid the return of the food to the mouth,
portion by portion, for remastication.

141. Rumination.—Rumination, which is the re-chew-
ing of food previously swallowed, is peculiar to bovines,
sheep, and goats. In the case of these species, the masti-
cation of coarse fodder is not completed before it is swal-
lowed the first time, and they have the power of return-
ing to the mouth the material which has become stored
in the rumen and reticulum in order that it may be more
finely ground. This is what is termed “chewing the cud.”
It is an operation which greatly aids digestion by render-
ing the food mass finer and more susceptible to the action
of the digestive fluids. Animals fed on grain alone do not
ruminate. They “lose their cud,” a condition popularly
and erroneously supposed to be fatal to the animal’s
life. The bolus or “cud” of the bovine weighs approxi-
mately four ounces and requires for its mastication not
far from one minute, including preparation, transference
to the mouth, and return. It is essential to rumination
that the supply of liquid to the rumen be abundant, to
which the salivary glands contribute a large share.

142. The omasum.—After remastication, the food
does not return wholly to the first and second stomachs,
but is mostly carried along the esophageal groove to the
third stomach, the omasum. The finer portions may even
do this when first swallowed. The omasum is a cavity
somewhat larger than the reticulum, which has a most
curious interior structure. It is filled with extensions of the
mucous membrane in the form of leaves, between which

-

THE DIGESTION OF FOOD : 103

the food passes in thin sheets, an arrangement which
seems to have for its purpose the further grinding of the
food so that when it finally reaches the fourth and last
compartment it is in a very finely divided condition and
is thoroughly prepared for the action of the juices that
are subsequently poured upon it.

143. The abomasum.—lIt is at the last stage of the
journey of the food through this complicated stomach
that it is submitted to the true gastric digestion. As a
matter of fact, the abomasum, or rennet, is regarded as the
true stomach, the other three sacs being considered as
enlargements of the esophagus. In the calf, the rennet is
only partly developed, the other divisions not coming into
use until the animal takes coarse foods in considerable
quantity. The fourth stomach is larger than either the
second or third. It receives directly from the omasum
the finely divided food, upon which it pours the gastric
juice, a liquid that is secreted in large quantity by glands
located in its inner or mucous membrane.

144. The gastric juice.—This juice, like all the diges-
tive fluids, is mostly water, the proportion being between
ninety-eight and ninety-nine parts to less than two parts
of various compounds. The latter consist of ferments, a
certain amount of free hydrochloric acid and a variety of
mineral compounds, prominent among which are calcium
and magnesium phosphates and the chlorides of the
alkalies, sodium chloride being especially abundant.

145. Artificial digestion—Especial interest pertains
to the ferments of the gastric juice, one of which, in con-
nection with free hydrochloric acid, causes a most impor-
tant change in the proteins of the food by reducing them
through hydrolytic and other cleavages to soluble forms.
We know quite definitely about this action, because it can

104 THE FEEDING OF ANIMALS

‘

be very successfully produced in an artificially prepared
liquid. If the mucous lining of a pig’s stomach, after
carefully cleaning without washing with water, is warmed
- for some hours in a very dilute solution of hydrochloric
acid, an extract is obtained which has the power of dis-
solving lean meat, wheat gluten, and other proteins. The
active agent in causing this solution is pepsin, an unor-
ganized ferment or enzym (see Par. 128) which is present
in the gastric fluid of all animals.

146. Changes in stomach digestion—This juice
changes proteins to peptones, bodies soluble and diffusible.

The change to peptones is not a single step, for the pro- .

tein passes through successive stages as acid proteins and
proteoses before it reaches the peptone form. This is

largely what may be styled progressive hydrolysis. An-

other ferment present in the gastric juice is the one which
gives to rennet its value as a means of coagulating the
casein of milk in cheese-making, and is called rennin. The
action of this latter body is especially prominent in the
stomach of the calf when fed exclusively on milk, and it
is the calf’s active stomach, the fourth in the mature
animal, which is the source of commercial rennet. Lipase,
an enzym that acts in the fats, is also possibly present
in the gastric juice of herbivore. (See Par. 129.)

147. Hydrochloric acid essential in stomach diges-
tion.—The free hydrochloric acid in the gastric juice is
also actively concerned in protein digestion. It is found
that a solution of pepsin has a limited effect in the absence
of free acid, for when, during artificial digestion, the
supply of this acid is used up, it must be renewed or
digestion is checked.

148. The stomachs of the horse and pig.—These con-
sist of a single sac, so that digestion with these animals is

THE DIGESTION OF FOOD c 105

a much simpler matter mechanically than with ruminants.
Chemically, the results are essentially similar, i.e., the
protein is in part changed to peptones. The food, after
being swallowed, is not returned to the mouth, but is
very soon brought under the
action of the gastric juice with-
out so long-continued preliminary
preparation by remastication and
trituration. For this reason the
horse fails to digest coarse fodders
so completely as the ox does.
Besides, the stomachs of the horse
and pig are too small to admit of
so large an ingestion of hay of. | ,
similar material, as is the case Fic. 3. Stomach of
with ruminants of similar size. In {ithment; dopsloie cod
all species, however, the chemical ei con
result of stomach digestion is

essentially the same, i. e., the protein is in part changed
to peptones. (Fig. 3.)

A =

THE INTESTINES

The most extended portion of the alimentary canal,
though not the most capacious in all cases, is the intes-
tines. They consist of a tube differing in size in its vari-
ous portions, which begins with the stomach and ends
with the anus.

149. Form and length of intestines.—This tube is
not a straight passage between the points named, but
presents curves and folds, so that when straightened out
it appears surprisingly long. Its average length with the
ox is given as 187 feet, sheep 107 feet, horse 98 feet, and

106 THE FEEDING OF ANIMALS

hog 77 feet, lengths which are from twelve to twenty-six
times that of the body of the animal. The intestines are
divided into large and small, the latter being from three
to four times as long as the former.

150. Food in the small intestine-—When the food
leaves the stomach, it enters the small intestine. At this
point it is only partially digested. The fats are probably
so far mostly unchanged and, without doubt, the larger
proportion of the proteins and carbohydrates that are
susceptible of digestion is still in the original condition.
Hardly has this partially dissolved material passed into
the small intestines before it comes in contact with two
new liquids which are poured on it simultaneously or
nearly so, viz., the bile and the pancreatic juice, and the
changes which began in the mouth and stomach, with
others which set in for the first time, proceed vigorously.

151. The bile.-—The bile has its source in the liver. It
is a secretion of this organ, and after elaboration a reserve
is stored, until required, in a small sac attached to the
liver which is called the “gall bladder.” Gall is conveyed
to the intestines through a duct opening very near the
orifice leading out of the stomach. The rate of secretion
of bile, according to experiments by Colin, is as follows:
Horse, eight to ten ounces an hour; ox, three to four
ounces an hour; sheep, one-fourth to five ounces an
hour; pig, two to five ounces an hour. The secretion and
flow of bile are continuous but the flow is not uniform.
Bile is a liquid varying when fresh from a golden red color
in man to a grass-green or olive-green in certain herbiv-
orous animals. It is alkaline, bitter to the taste and
without odor. The specific and characteristic constitu-
ents of the bile are two acids, glycocholic and tauro-
cholic, that are combined with sodium and are associated

THE DIGESTION OF FOOD - 107

with two coloring matters, bilirubin and biliverdin.
Numerous other compounds are present in very small
proportions, such as fats, soaps, and mineral compounds,
but they appear to have no important relation to diges-
tion. If any ferment is present at all, it is only as a trace,
and therefore the bile is incapable of effecting decomposi-
tions of the proteins and carbohydrates, such as occur in
the mouth and stomach.

152. Function of bile-—Nevertheless, this liquid must
be regarded as having an important function, which it
exerts in two ways, (1) by preparing the chyme (partially
digested food from the stomach) for the action of the
pancreatic juice and (2) it acts in conjunction with the
pancreatic juice in preparing the fats for absorption.

Pepsin, the stomach ferment, acts upon proteins only
in an acid medium. The opposite is true of the ferments
which the food meets in the intestines, for these require
an alkaline medium. The bile neutralizes the acidity of
the chyme, and so prepares the way for the pancreatic
juice to do its work. It is shown that when the entrance
of the bile into the intestines is prevented the fat of the
food largely passes off in the feces.

Bile has very little, if any, direct digestive action, but
it may be said to codperate with the pancreatic juice
in accomplishing the digestion of fats. It emulsifies fats,
especially in the presence of the pancreatic juice. When
the fats are split by a ferment in the pancreatic juice we
get as a result fatty acids which combine with the alka-
lies present to form soaps. Both the fatty acids and the
soaps are dissolved by the bile. In this way the fats are
prepared for absorption. In experiments by Vail on dogs,
cutting off the supply of bile reduced the absorption of fat
from 99 to 40 per cent.

108 THE FEEDING OF ANIMALS

‘It has been asserted that the bile has more or less
antiseptic influence and so prevents the intestinal con-
tents from undergoing putrefactive fermentation. A
more rational explanation is that because the bile acts as
a natural purgative the food residues pass promptly out
of the intestinal tract before the putrefactive fermenta-
tions set in which would occur in the absence of bile.

153. The pancreatic juice.—This secretion has the
most comprehensive action on the food nutrients of any
one of the intestinal liquids. It originates in the pancreas
(sweetbread). Its flow is intermittent, being induced by
the reaction especially of the acids in the partially digested
foods from the stomach. The amount secreted and
its composition appear to change with the kind of food.
It contains with the horse about 98.2 per cent of water
and 1.8 per cent of solid matter. With the dog the per-
centage of water is about 90. This secretion acts upon all
classes of nutrients, as it contains a variety of ferments
greatly unlike in function.

154. The enzyms of the pancreatic juice.—The three
enzyms present in the pancreas secretion are: a protein-
splitting enzym, trypsin (or its progenitor), a starch-
splitting enzym, amylopsin, and a fat-splitting enzym,
steapsin. Trypsin, like pepsin, hydrolizes the protein by
progressive stages to proteoses, then peptones, after
which, in conjuction with erepsin (see later), breaks the
peptones into simpler bodies known as the amino acids.
(See Par. 84.) Trypsin acts in neutral or in alkaline solu-
tions, a free mineral acid like hydrochloric completely
stopping its operation. Organic acids, like lactic, do not
seem to have this effect.

155. Steapsin.—The pancreatic secretion acts vigor-
ously on fats, not only splitting them into fatty acids and

THE DIGESTION OF FOOD - 109

glycerin, but, in conjunction with the bile, also effects
their emulsification, this latter result being aided, doubt-
less, by the soaps which are formed from a union of the
fatty acids and the alkaline bases (mostly sodium) in
the bile. The cleavage of the fats is due to an enzym to
which the name of steapsin is given, also ealled “lipase.”
(See Par. 128.)

156. Amylopsin.—We have seen that starch is acted
upon to a small extent by the saliva, and that this action
is not prolonged in the stomach beyond the time when the
stomach contents become fully acidified. Starch diges-
tion is therefore carried on mainly in the intestines,
chiefly, if not wholly, by a diastatic ferment in the pan-
creatic juice which has the power of hydrolyzing the
starch mostly into maltose. This pancreatic diastase,
called amylopsin by some authors, is not found in the
digestive tract of young animals as abundantly during
the period of milk-feeding as after vegetable foods are
taken, for milk does not require the action of a diastatic
ferment. The presence of bile is very favorable to the
action of amylopsin. (See Par. 128.)

157. Intestinal juices—Mention has been made of
juices that are secreted by small glands distributed in
the walls of the small intestine. These are quite impor-
tant factors in digestion, as they supplement the action
of the ferments of the pancreatic juice. It appears to be
shown that an enzym, erepsin, is found in these juices
that is unable to act upon any of the native proteins
except casein, but has the power of decomposing proteoses
and peptones into simpler compounds, particularly the
amino-acids. These secretions contain, also, the ferments
that hydrolize sucrose, maltose, and lactose into dextrose.
It is held also that trypsin does not exist as such in the

\

110 THE FEEDING OF ANIMALS

pancreatic juice when poured into the small intestine, but
that this enzym is formed from a mother substance in the
pancreatic juice (trypsinogen) after it comes in contact
with the intestinal juice, this result being accomplished
through the action of a body probably secreted from
the intestinal walls and called by Pawlow “enterokinase.”
(See Par. 154.)

158. Intestinal bacteria.—So far, in presenting the
relation of ferments to digestion, only the unorganized
ferments or enzyms have been considered. While these
are chiefly concerned in normal digestion, organized
ferments are present throughout the entire intestinal
canal and play a part in food changes. They are very
abundant and active in the rumen and large intestine.
They act upon the proteins, causing putrefaction, dissolve
cellulose, and cause a decomposition of the carbohydrates.
The products of these fermentations include, among other
compounds, indol and skatol, which have the character-
istic fecal odor, volatile fatty acids, and gases, some of
which are carbon dioxid, hydrogen, marsh gas and hydro-
gen sulfide. The evolution of these gases appears to occur
constantly and normally with farm animals, particularly
the bovines, the quantity depending somewhat upon the
kind of food. (See Par. 127.)

159. Effects of intestinal fermentations.—Under cer-
tain conditions, fermentations of this character, which
are in part normal and may be beneficial, proceed so
far as to be deleterious. Gorging with a very succulent
food, such as immature clover, after a period of dry
foods, or anything which retards digestion, such as
imperfect mastication, excessive eating, and failure of the
organs secreting the digestive fluids to supply these fluids
in sufficient abundance, give these bacteria a better oppor-

THE DIGESTION OF FOOD Ait ULE

tunity to act on the food residues, and increase their
effect. Recent results appear to indicate that the syn-
thetic activities of intestinal bacteria may be a matter of
some importance in the utilization of amides (Par. 273).

160. Stimuli to digestion.—The gastric juice is not
constantly poured into the stomach to accumulate there,
but is secreted as it is needed under the influence of cer-
tain stimuli. These stimuli may be classed as psychic and
chemical. Appetizing odors when there is a strong desire
to eat, and the agreeable taste of food in the mouth of a
hungry person are important psychic or “nervous”
influences that promote gastric digestion through stimu-
lating the secretion of an adequate supply of the digest-
ing fluid. Other stimuli that may be called chemical
result from the indirect reaction of certain substances
upon the secretory glands. With man, meat extracts,
- proteoses, acids, sugars, alcohol, and condiments seem to
be effective in this way. This stimulus comes later than
the psychic, but is more prolonged.

161. Secretins.—The more. recent researches indicate
that the first products of digestion, reacting on the inner
membranes of the stomach and duodenum, cause the
formation of substances called secretins that belong to
the general class of excitants known as hormones, which,
carried by the blood stream to the cells of secretory glands,
excite the secretion of the digestive juices. It now seems
possible that sometime we shall have a definite dietetic
method of influencing human digestion, at least, other than
a medicinal, for it appears that certain food compounds
may stimulate and others retard the activity of digestion.

162. The psychic factor.—The psychic factor is no
less important. This being so, it is seen how necessary it
is that eating shall be pleasurable. Satisfaction with the

112 THE FEEDING OF ANIMALS

diet, even with an animal, undoubtedly is a determina-
tive element in good digestion. Moreover, condimental
stimulation is a poor makeshift for the effect of a healthy
liking for food. There are good reasons for believing that
psychic stimulation is an important factor in digestion
with farm animals. Whether the theory of chemical
stimuli applies to this class of animals is less certain.

163. Digestion of food as a whole.—From what has
preceded we learn that several liquids and certain organ-
isms participate in producing the complex changes that
food undergoes during digestion. Some of these liquids
have certain common functions, as, for instance, pro-
teins are acted upon both by the gastric and pancreatic
juices. Moreover, the various digesting fluids appear to
act codperatively. This is made plain by following the
course of the food changes.

164. Stomach digestion.—After the food has remained
in the stomach for a certain period of time, it is gradually
discharged into the small intestine, the rate of discharge
varying with the kind of food, that is, with the prompt-
ness and rapidity of digestion, which differs with different
foods. The progress made up to this point in food trans-
ference, so far as we have definite knowledge, is chiefly the
cleavage of the proteins into various stages of hydrolysis,
the resulting bodies being proteoses and peptones. All
proteins appear to be acted on in the stomach, but to
different degrees and probably at different rates. Starch,
already somewhat dissolved by the saliva, is not further
acted upon by the stomach enzyms, neither are the solid
and liquid fats affected to any material extent. Simple
sugars are not acted upon by the gastric juice, but it seems
possible that the di-sugars may be split into simple cnes
by the hydrochloric acid.

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THE DIGESTION OF FOOD Pr OHS

165. Digestion in intestines.—It appears, then, that in
the intestines protein digestion must be completed with
the cleavage of peptones into the simpler amino acids,
the larger part of the starch transformed to sugar and the
digestion of the fats wholly accomplished or mainly so.
As a matter of fact, the partial solution in the stomach of
the proteins and the swelling of the undissolved part to a
gelatinous mass may be considered as a preparation of the
food for intestinal digestion, for through these changes
the proteins present a larger surface to the attack of
trypsin and other intestinal enzyms and digestion pro-
ceeds more promptly than would be the case with the
freshly ingested food. Moreover, the compounds in the
chyme, especially the acid, indirectly react on the liver
and pancreas, and cause an abundant flow of digestive
fluids from these glands.

166. Digestive fluids act together—As soon as the
chyme mixes with the bile and pancreatic juice, the mass
is changed from an acid to an alkaline condition. This
seems to be essential to the effective operation of the
pancreatic ferments. While the pancreatic juice will
carry on digestion by itself, this is not satisfactory in the
absence of bile, one reason for this being that when the
latter is not permitted to enter the small intestine, the
digestion of fats is very imperfect. It seems essential that
these two liquids act together. The bile aids in rendering
the digesting mass alkaline, contributes to the formation
and solution of the fatty acids and soaps, and in these
ways promotes the activity of the pancreas enzyms.

167. Action of intestinal juices.—The juices that flow
from the small glands in the intestinal walls appear essen-
tially to supplement the work of the bile and pan-
creatic juice. In the first place, they probably contain a

H

114 THE FEEDING OF ANIMALS

substance that activates the mother substance of tryp-
sin; in the second place, they aid in splitting the pep-
tones into simpler bodies, and, lastly, they convert cer-
tain sugars into the final form (dextrose) in which they
are absorbed into the blood circulation.

168. Summary of changes in digestion.—If we con-
sider the digestion of the food compounds by classes, the
following is a summary of the ways in which they are
acted upon: pepsin, trypsin, and erepsin secreted by the
stomach, pancreas, and intestinal glands act on the pro-
teins; ptyalin in the saliva, amylopsin from the pancreas,
and lactase, maltase, and sucrase in intestinal secretions
act on the carbohydrates, and the fats are acted on
mainly by the lipase of the pancreatic juice. |

The bacteria are not surely known to have necessary
specific digestive functions, unless it be their solvent action
on the cellulose. __

It should be observed that the above is a presenta-
tion of the general scheme of digestion, and takes no
account of differences between the various species of
farm animals of which our knowledge is incomplete.

ABSORPTION OF FOOD

From the time the food enters the stomach, during
nearly its entire course along the alimentary canal, there
is a constant production of soluble compounds, which
progressively disappear into other channels, so that when
the anus is reached only a portion of the original dry
matter is found in the residue. In some way, not wholly
explainable in all its details, the digested food has been
absorbed and received into vessels through which it is
distributed to the various parts of the body.

sch THE DIGESTION OF FOOD TAS
169. Function of lacteals and blood vessels in absorp-
tion (Figs. 4, 5).—A merely casual observation shows us
that the inner surface of the walls of the small intestine is
covered by numerous projections, called villi. In these are
imbedded the minute branches of two systems of vessels,

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showing capillaries and lacteals. (Gerrish.)

the lacteals, belonging to the so-called lymphatic system,
and the capillaries, which are minute branches of the
blood system. The lacteal is in the center of each villus
and this is surrounded by a network of capillaries. The
lymphatic vessels lead to a main tube or reservoir, the
thoracic duct, which extends along the spinal column

116 THE FEEDING OF ANIMALS

and finally enters one of the main blood vessels. Any
material, therefore taken up by the lacteals ultimately
reaches the blood. The capillaries all converge to a larger
blood vessel, known as the portal vein, which enters the
liver, transferring to that organ whatever material the
capillaries have absorbed.

170. Manner of food absorption—The manner in
which the soluble food is absorbed has been explained in
part on common physical grounds.
When two solutions of different densi-
ties, containing diffusible compounds,
are separated by a permeable mem-
brane, diffusion through this membrane
from the denser to the lighter liquid
= will always occur. Such a condition
fe 1“ as this prevails in the intestines, we
1 may believe. The intestinal solution,
the denser one, is separated from a
i less concentrated liquid, the blood,
which is constantly flowing on the
| ie other side of a thin dividing mem-
yi brane. Under these conditions there

vie occurs the passage into the blood of
certain parts of the digested food. It

Fic. 5. Intestinal 18 held that in this way water, soluble
ck ee mineral salts, and sugar pass directly
laries; ¢, lacteal ves- into the blood vessels, chiefly from
ae the small intestine.

171. Changes in the walls of the intestinal tract.—
In the absorption of peptones and fats, at least, forces are
encountered other than the osmotic transference of sub-
stances in solution, the operation of which is still more or
less unexplained.

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THE DIGESTION OF FOOD g 117

The ingested proteins are changed in the stomach and
intestines to peptones, and in part, perhaps mainly, to
amino acids resulting from the cleavage of peptones. The
fats are split partly, or entirely, into fatty acids and glyc-
erin, with the subsequent formation of soaps by the union
of the free acids with alkaline bases. It has been held that
in the passage of these new compounds through the walls
of the intestine changes occur of a synthetical character,
with a partial or total reconstruction of the proteins and
fats into forms similar to those in the ingested food. This
view as to the proteins has been modified somewhat by
the demonstration of the existence of amino acids in the
blood showing that, if a synthesis of proteins occurs in the
intestinal walls, it is at least not complete. Amino
acids may exist in the blood even if synthesis occurs in
the intestinal walls. The rebuilding of fats and their
transference into the lacteals is regarded as being
accomplished through the activity of cells lying in the
mucous lining of the intestine. This seems to be proven.
It seems, then, that the vital forces residing in these
cells probably play a part in the transfer of the nutrients
into the blood circulation, and that this absorption
can not be explained wholly on the basis of osmotic
pressure.

172. Place of maximum absorption of food.—Absorp-
tion of digested food takes place to a limited extent
from the stomach of man and the dog, but not from the
stomach of the herbivora. The main transference of the
products of digestion into the blood is from the intestines,
particularly the small intestine. Much of the water that
passes into the large intestine is absorbed there, together
with the products of digestion not already absorbed and
those products that result from bacterial action.

|
118 THE FEEDING OF ANIMALS

THE FECES

The soluble and insoluble portions of the intestinal
contents become separated gradually, and the undissolved
part arrives finally at the last stage of its journey along
the alimentary canal, and is expelled as the solid excre-
ment, or feces.

173. Constituents of feces.—The feces is made up of

the undigested food, residues from the bile and other
digestive juices, mucus, and more or less of the epithelial
cells which have become detached from the walls of the
stomach and intestines. Dead and living bacteria also
appear to constitute a material portion of the fecal mat-
ter. These organisms are not taken in with the food to
any great extent, but are the result of their continuous
growth in the digestive tract. Small quantities of fer-
mentation products, particularly indol and skatol, are
present, which give to the feces its offensive odor. The
incidental or waste products may properly be considered
as belonging to the wear and tear of digestion.

174. The feces not wholly undigested food.—The
ordinary conception of the fecal residue is that it is only
the part of the food that has resisted the action of the
digestive fluids, but in fact it is much more than that. Not
only does it include the various waste products previ-
ously referred to, but also compounds that have been
absorbed into the blood circulation and returned to the
alimentary canal for excretion. It has been shown, for
instance, that when a phosphorus compound was in-
jected. subcutaneously into a sheep, the phosphorus was
excreted in the feces in another combination. It is also
proven that mineral compounds absorbed from the intes-
tinal tract may afterward appear in the feces.

~

THE DIGESTION OF FOOD 119

The physical condition of the feces is characteristic
with each species of animals, the differences in consistency
being due largely to variations in the amount of water
present. The amount of water in feces depends more
upon the character of the food eaten than upon the
amount of water drunk.

THE RELATION OF THE DIFFERENT FOOD COMPOUNDS TO
THE DIGESTIVE PROCESSES

Numerous digestion experiments with a large variety
of foods have abundantly established the fact that these
materials differ greatly in their solubility in the digestive
juices. This is an important matter, and one which should
be well understood, for we must consider both the weight
of the dry matter eaten and its availability in determin-
ing its nutritive value. Variations in digestibility are
caused primarily by variations in composition; therefore,
we must deal fundamentally with the susceptibility of the
various single constituents of food to the action of the
several digestive ferments.

In this connection, we need to pay little attention to
the mineral compounds that exist in the inorganic form
in the food. They do not undergo fermentative changes
in the way that the carbon compounds do, but are brought
into simple solution either in the water accompanying the
food, or in the juices with which they come in contact.

175. Digestibility of the proteins.—As has been noted,
protein is a mixture of nitrogenous compounds. The gluten
of wheat contains at least five of these bodies, and other
seeds as many. What is the relative susceptibility of these
single proteins to the digestive enzyms either as to rapid-
ity or completeness of change does not appear to be known.

120 THE FEEDING OF ANIMALS

Some proteins are pratically all digested by artificial
methods, and probably are in natural digestion. It is
known definitely that protein is much more completely
dissolved from some foods than from others. That of
milk and meat is practically all digestible, that of some
grains very largely so, while with the coarse foods quite a
large proportion escapes solution. Whether this is due to
differences in the characteristic protein compounds of the
various foods is not quite determined. The fact that
highly fibrous materials show the lowest proportion of
digestible protein suggests as an explanation that the
nitrogen compounds of plant tissue are so protected by the
cell-walls that they escape the full action of the digestive
juices. It is certain, however, that the protein in plant
tissue is less fully digested than that from milk and
meat products.

176. Digestibility of the carbohydrates.—In the case
of the carbohydrates, our knowledge of the relative sus-
ceptibility of the individual compounds to enzym action
is more definite. First of all, the necessary modification
of the sugars, which are already soluble, is slight, and they
are wholly digested. In the second place, we have learned
in two ways that the starches are wholly hydrolized, first
by submitting them in an artificial way to the action of
various diastatic ferments, and, second, by discovering
a complete absence of starch or its products in the normal
feces. Under normal conditions the unprotected starches,
like the sugars, are completely digestible.

177. Starches unlike in rate of digestibility—Digesti-
bility must be considered, however, from the standpoints
both of rapidity and of completeness. As to the former
factor, starches from unlike sources exhibit some remark-
able differences. Investigations by Stone, who sub-

THE DIGESTION OF FOOD ; 121.

mitted a number of these bodies to the action of several

diastatic ferments, show that “‘this variation reaches such
a degree that, under precisely the same conditions, cer-
tain of the starches require eighty times as long as others
for complete solution.” The potato starches appear to be
acted upon much more rapidly than those from the
cereal grains.

178. Digestibility of cellulose and gums.—Other car-
bohydrates, cellulose and hemicelluloses, such as pento-
sans, galactan mannan, and related bodies, show great
variations in digestibility according to their source,
these variations ranging in observations by Swartz from
0 to 100 per cent. The extent to which these latter sub-
stances disappear from the alimentary canal appears
to be dependent on their susceptibility to attack by
bacteria.

179. Digestibility of the fats.——The actual extent of
the digestion and absorption of the fats or oils is also not
definitely known. If we were to accept the figures given
for ether-extract in tables of digestion coefficients as
applying to the real fats, we would believe that their
digestibility varies from less than one-third to the total
amount. It is unfortunately true that these coefficients
mean but very little. The ether-extract from some foods
is only partially fat or oil, as we have seen, and the inac-

curacy of a digestion trial is still further aggravated by

the presence in the feces of bile residues and other bodies
which are soluble in ether, so that the difference between
the ether-extract in the ingested food and that in the
feces does not give accurate information as to what has
happened to the actual fats. It seems very probable that
pure vegetable fats and oils and all mixed animal fats are
quite completely absorbed.

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122 THE FEEDING OF ANIMALS

The foregoing statements make it plain that when the
general composition of a food is known, it is possible to
predict with a good degree of certainty whether its per-
centage of digestibility is high or low. Feeding-stuffs
with a high percentage of starch and sugar and a small
percentage of fiber have a relatively high digestibility, as,
for instance, corn meal, while the coarse foods like timo-
thy hay and straw, with a high proportion of gums and
fiber, have a relatively low digestibility.

FACTORS WHICH MAY INFLUENCE DIGESTION

Digestion has an important relation to the nutritive
efficiency of food because only that portion of the food
that is digested and absorbed can serve the purposes of
growth and the maintenance of the vital functions.

180. Meaning of ‘‘digestibility.’—In discussing the
factors that may influence the digestion of food, it is
essential to understand clearly what is involved in the
term digestion as it is used in science and in common
speech. This term includes at least two elements, com-
pleteness of solution of the food nutrients and rate of
digestion. The figures that are given for the digestibil-
ity of various cattle foods refer to the completeness or
extent to which the food is dissolved and transferred to
the circulation. But different foods from which come the
same proportion of undigested dry matter may differ
materially in the rate at which they undergo digestive
changes, and in this sense their digestibility is unlike.
The ultimate completeness of solution in the digestive
fluids may not be influenced by the rate at which the
process goes on.

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CHAPTER VIII
CONDITIONS INFLUENCING DIGESTION

THE chemical changes and other phenomena consti-
tuting digestion, which have been described as occurring
in the alimentary canal, are practically outside the con-
trol of the one who feeds the animals. They proceed in
accordance with fixed chemical and physiological laws.
It is, however, within the power of the feeder to so
manipulate the food or vary the conditions under which
it is fed that the extent or completeness of digestion is
modified, and this must be regarded as an important
matter when we remember that only the digested food
is useful.

181. Palatableness.—It is entirely reasonable to
believe that a thorough relish for food is conducive to
good digestion. The secretion of the digestive juices is
not a mechanical process, but is partly under the control
of the nervous system. With man, at least, the enjoy-
ment of eating, even its anticipation, stimulates the
secretory power of the salivary glands and those in the
mucous lining of the stomach, and it is evident that this
holds true with animals. Palatableness is, therefore, an
important factor in successful feeding, for it tends to pro-
mote a state of vigorous activity on the part of the diges-
tive organs. The experienced feeder knows well the
value of stimulating the appetite of his animals by means
of attractive mixtures. An agreeable flavor or taste adds
nothing to the energy or building-capacity of a food, but

(123)

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124 _ THE FEEDING OF ANIMALS

it does tend to secure a thorough appropriation of the
nutrients which enter the alimentary canal. Without
doubt, the success of one feeder as compared with the
failure of another may sometimes be due, in part, to a
superior manner of presenting a ration to the animal’s
attention and to manipulations that add to the agreeable-
ness of its flavors. (See Par. 162.)

182. Influence of quantity of ration—Early experi-
ments by Wolff, in which he fed larger and smaller rations
of the same fodder to the same animals, have been made
the authority for the statement that a full ration is as
completely digested as a scanty one, provided the former
does not pass the normal capacity of the animal. It must
be said, however, that the testimony concerning this

point is not unanimous. Since Wolff’s experiments, ~

Weiske, in feeding oats to rabbits, found the digestibil-
ity to be inversely as the quantity of food taken. In
experiments with oxen, by G. Kuhn, at Méckern, when
the grain ration was doubled the digestibility of the malt
sprouts used was decreased about 9 per cent. Results
at the New York Experiment Station from feeding full
and half rations to four sheep showed uniformly higher
digestion coefficients with the smaller ration, the differ-
ences being too large and too constant to be considered
accidental. Other experiments give varying and con-
flicting figures. If we assume that the constituents of
feeding-stuffs have a certain fixed solubility in the
digestive fluids, then within reasonable limits the amount
of food should have no effect upon the proportions of
nutrients digested, but such an assumption cannot safely
be made.

Doubtless no single statement concerning this point
will be found applicable to all animals and all rations.

{ : : !
- CONDITIONS INFLUENCING DIGESTION’ 125

Certainly, over-feeding may lessen the extent of solution
and is never wise, while under-feeding for the sake of
securing a maximum digestibility would not be good
practice. It is reasonable to suppose, however, that the
relation in quantity between the enzyms and the food
compounds has an influence, at least, upon the rapidity

of digestion; and indeed investigations by Stone very

strongly point to such a conclusion, for he found that the
rate of ferment action was proportional to the concentra-
tion of the ferment solution.

183. Effect of drying fodders.—At one time the belief
became very firmly fixed in the public mind that curing
a fodder. causes a material decrease in its digestibility.
Because this drying is often carried on under conditions
that admit of destructive fermentations or of a loss of
the finer parts of the plant, this view is probably correct
for particular cases; but, if it is accomplished promptly
and in a way that precludes fermentation or loss of leaves,
it is doubtful if curing has any material effect upon
digestibility.

The point has been the object of six American diges-
tion experiments, Hungarian grass, timothy, pasture grass,
corn fodder, crimson clover, and winter vetch being the
experimental foods. With four of these, slight but unim-
portant differences were observed in favor of the dried
material, while the reverse was decidedly true of the
crimson clover and the corn fodder. German experiments
show in a majority of cases greater digestibility for the
green fodders. It seems probable that in general prac-
tice, because of greater or less unavoidable fermentations
and a loss of the finer parts of the plant, dried fodders have
a somewhat lower rate of digestibility than the original
green material, a fact not due directly to drying, but to

|

126 | THE FEEDING OF ANIMALS

: ;
a decrease, either of the more soluble compounds or of —

the tender tissues. (See Par. 306.)

184. Influence of the conditions and methods of

preserving fodders.—In comparing the conditions and
methods of preserving fodders in their relation to digesti-
bility, we may safely rest upon the general statement
that when, for any cause, leaching occurs or fermenta-
tions set in, digestibility is depressed. The explanation
of this statement is that those compounds of the plant
which are entirely soluble in the digestive fluids, notably
the sugars, are the ones wholly or partially removed or
destroyed by leaching or fermentations, while the more
insoluble bodies remain unaffected. When, therefore,
hay is cured under adverse conditions, such as long-con-
tinued rain, digestibility is decreased, and the same
effect is inevitable from the changes which occur in a
fermenting mass, such as a mow of wet hay, a pile of
corn stalks or the contents of a silo. Experimental
evidence of the truth of these statements is not wanting.
German digestion trials with alfalfa and _ esparsette,
green, carefully dried, cured in the ordinary way, fer-
mented after partial drying and as silage, show a grad-
ually decreasing digestibility from the first condition to
the last. A single American experiment, comparing the
same fodder both green and as silage, gives testimony in
the same direction. On the other hand, field-cured corn
fodder, according to nine out of eleven American experi-
ments, is considerably less digestible than silage coming
from the same source, although the results of field curing
vary greatly according to the conditions of exposure.
Here it is largely a question of the relative loss by fermen-
tation in the two cases, and it is to be expected that the
outcome would not be wholly one way. |

CONDITIONS INFL UENCING DIGESTION — 127

185. Influence of the stage of growth of the plant.—
Another generalization, which certainly must hold good
with reference to the digestibility of fodder plants, is that
any conditions of development which favor a relatively
large proportion of the more soluble carbohydrates, viz.,
starches and sugars, and accompanied by a minimum of
gums and fiber, promote a high rate of digestibility, and
reverse conditions produce the opposite result. It is well
known that, in general, as the meadow grasses mature
the relative proportion of fiber increases and the tissue
becomes harder and more resisting. Numerous Ameri-

’ can and European digestion trials unite in testifying

almost unanimously to a gradually diminished digesti-
bility as the meadow grasses increase in age. The matur-
ing of maize seems to produce quite the contrary effect.
The testimony of experiments conducted at the Connec-
ticut, Maine, and Pennsylvania experiment stations
justifies the statement that the corn plant, cut when the
ears are full-grown, furnishes not only a larger amount
of digestible material, but a larger relative proportion
than when cut before the ears have formed; and this is
strictly in harmony with our general principle, for the
mature plant, on account of the storage of starch in the
kernels, has by far a larger proportion of the more digesti-
ble carbohydrates. (See Par. 102.)

186. Influence of methods of preparation of food.—
Much labor and expense have been expended by farmers
in giving to feeding-stuffs special treatment, such as wet-
ting, steaming, cooking and fermenting, in order to
secure a supposed increase in nutritive value, an increase
which must come chiefly, if at all, from a more com-
plete digestion. It is plainly noticeable that these methods
of feeding have lost in prevalence rather than gained.

128 THE FEEDING OF ANIMALS

Practice does not seem to have permanently ratified
them, and, so far as digestibility is concerned, this out-
come is in accordance with the results of scientific demon-
stration. The conclusions of German experimenters have
been that these special treatments have no favorable
influence, their effect being either imperceptible or
unfavorable.

187. Wetting food.—It should occasion no surprise
that the mere wetting of a food is without influence upon
its solubility in the digestive juices, because it becomes
thoroughly moistened during the mastication and in the
stomach. It is not rational to expect that previous
wetting would have the slightest effect unless it induced
more complete mastication, which certainly would not
be the case with ground grains. The extensive trials by
Kiihn and others with a hay and bran ration, the bran
being fed in several conditions, such as dry, wet, moist-
ened some hours before feeding, treated with boiling water,
and fermented, gave results adverse to all of the special
methods of preparation as either useless or harmful, and
no testimony so thorough and convincing has been fur-
nished on the other side.

188. Cooking foods.—German and American experi-
ments unite in condemning the cooking of foods already
palatable, because this causes a marked depression of
the digestibility of the protein, with no compensating
advantages. Digestion trials with cooked or steamed
hays, silage, lupine seed, corn meal and wheat bran, and
roasted cotton seed, uniformly show their protein to be
notably less digestible than that in the original materials,
a fact which may explain the lessened productive value
of cooked grains which has been observed in certain
experiments. It must be conceded, of course, that when

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CONDITIONS INFLUENCING DIGESTION 129

cooking feeding-stuffs by steaming or otherwise renders

them more palatable, and thereby makes possible the
consumption of material otherwise wasted, the influence
upon digestibility is a minor consideration.

189. Influence of grinding foods.—Few points are
more frequently questioned than the profitableness of
grinding grain. There seem to be only two ways in which
such preparation can enhance the nutritive value of a
feeding-stuff, viz., by diminishing the energy needed for
the digestive processes and by increasing the digesti-
bility. While not many experiments bearing upon the
digestion side of this question are on record, their evi-
dence is quite emphatic. In three trials with horses, with
corn and oats, grinding caused an increase of digesti-
bility varying from 3.3 to 14 per cent. A single experi-
ment with maize kernels gave a greater digestibility of
about 7 per cent from grinding, and with wheat, in one
trial, the increase was 10 per cent. In one test with
sheep, the unground kernels were as completely utilized
as the ground. It is reasonable to expect that with
ruminants the danger of imperfect mastication is less
than with horses and swine, although whole kernels of
grain are often seen in the feces of bovines. The profita-
bleness of grinding grain turns, in part at least, upon the
relation of the cost of grinding to the loss of nutritive
material from not grinding. If the miller’s toll amounts
to one-tenth the value of the grain the economy of grind-
ing it may be doubtful, especially with ruminants. The
utilization of the undigested kernels of grain by pigs is a
business point to be considered.

190. Effect of common salt.—It is the custom of
many feeders to allow their animals an unlimited supply
of salt, and others furnish it in definite and regular quan-

I

130 THE FEEDING OF ANIMALS

\

tities. The belief prevails more or less widely that an
abundant consumption of salt is beneficial. If this is
true, the advantage arises for other reasons than an
increased digestibility. The verdict from earlier experi-
ments by Grouven, Hofmeister, and Weiske that the
addition of salt to the ration does not increase the digesti-
bility was confirmed through later tests by Wolff. In-
deed, if we give to the data collected a literal and per-
fectly justifiable interpretation, salt diminished rather
than raised the proportion of digestible nutrients.

191. Influence of frequency of feeding and watering
animals.—Experiments relative to this point are not
numerous. One by Weiske and others, relative to fre-
quency of feeding, and another by Gabriel and Weiske,
in which the effects of the time of watering and of the
amount of water were tested, gave no indication that the
completeness of digestion is materially affected by varia-
tions in these details of practice. According to Smith,
horses should be watered before being fed. He argues
that water does not stop in the stomach but passes
directly through it and freshly ingested food would be
washed into the intestine before any stomach digestion
occurs, an opinion which tallies with the popular view.
On the other hand, Tangl asserts, on the basis of extended
investigations, that horses may be watered either before
or after eating without depressing digestion, except that
a horse long deprived of water should be watered before
eating. The thing chiefly important is that the plan of
feeding and watering should not be varied. It seems
probable that the nutritive importance of these minor
points in managing animals has been much overesti-
mated by some, especially as affecting the utilization of
the food.

CONDITIONS INFLUENCING DIGESTION © 131

192. Influence of season and storage.—It is well

_ known that the composition of fodder crops grown on the

same soil may vary somewhat from year to year accord-
ing as the season is wet or dry, cold or warm. Such varia-
tions may influence digestibility, though no actual
demonstration of this fact appears to be on record. The
question is often asked whether the storage of hay for
a long period affects its nutritive value. The data from
four series of experiments touching on this point indicate
that there is a perceptible, though not marked, decrease
in digestibility of hay during long-continued storage.

193. Influence of the combination of food nutrients.—
Among the apparently important and freely exploited
conclusions drawn from investigations in animal nutri-
tion is the statement that the digestibility of food is
influenced to a marked degree by the relative propor-
tions of the several classes of nutrients. It is taught that
if more than a certain percentage of starch and sugar, or
of feeding-stuffs rich in carbohydrates, like potatoes
or roots, is added to a basal ration, the digestibility of
the latter is decreased, the protein and fiber being especi-
ally affected. The conclusions, as stated by Dietrich and
K6nig, on the basis of a critical study of the data involved
are that if pure carbohydrates are used to the extent of
more than 10 per cent of the dry substance of a basal
ration, or if potatoes and roots are fed equivalent in dry
matter to more than 15 per cent, a depression of digesti-
bility occurs, which increases with the amount of carbo-
hydrate material added. Kellner taught that if the crude
protein in a ration falls below one part to eight of digesti-
ble non-nitrogenous nutrients (carbohydrates + fat X 2.25)
a depression digestibility occurs. It is suggested that
when much easily digested carbohydrate material is

Bis p- THE FEEDING OF ANIMALS

fed the activity of the cellulose digesting bacteria is
diverted from the crude fiber to the more readily avail-
able starches or sugars. A modifying conclusion is, that
if the addition of the carbohydrate material is accom-
panied by correspondingly more protein, the depression
of the digestion coefficients is much lessened or does not
occur. Many data are cited in support of these generali-
zations which are worthy of careful consideration.

It is not unreasonable to suppose that the relative
quantity in a ration of the several classes of nutrients
may have an influence upon the digestive processes, and
we should accept the verdict of previous observations in
so far as they will bear critical discussion and further
investigation. But it should be said, by way of comment,
that the carbohydrate material in the experiments cited
has usually been fed in addition to a basal ration, thus
increasing the amount of food consumed, and, as we have
seen, this may have an influence upon the proportion of
total dry matter digested. In this particular, the experi-
ments have not been logical. Again, in these experi-
ments, no allowance has been made for the metabolic
wastes in the feces, 1. e., that material not belonging to
the true undigested residue. As this appears to be inde-
pendent of the amount of protein fed and stands more
nearly in relation to the total digested nutrients, it fol-
lows that the smaller the proportion of protein in the
digested food, the larger the error caused in the coeffi-
cient for protein by the waste nitrogen products. A careful
study of this point in the light of more recent knowl-
edge might modify the conclusion reached as to the
depression of protein digestion through feeding starch
or starchy foods. In all or nearly all the experiments
where this effect is apparently shown, the digestible dry

CONDITIONS INFLUENCING DIGESTION - 133

_ matter of the ration was largely increased and the pro-

tein remained constant or was diminished. However,
the depression of the digestibility of the crude fiber is
not easily explained on any other ground than that of
the influence of the greater proportion of starch.

What is claimed as the effect of a disproportionate
addition to the supply of carbohydrates does not appear
to be true of a similar increase in the ration of fat and
easily digested protein. Several experiments in which

_ oils and albuminoids have been added freely to a basal

ration did not indicate that such addition had any mate-
rial effect upon digestibility.

194. Influence of work.—Such evidence as has been
secured with both man and farm animal indicates that
even severe labor has no material influence upon diges-
tion one way or the other. Scheunert’s work with horses
leads him to conclude, however, that exercise Improves
digestion.

195. Influence of species, breed, age, and individual-
ity—The conclusion reached by the early experimenters
in the field of animal nutrition that the digestive efficiency
of the several species of ruminants was practically uni-
form has not been set aside by more recent observations.
The number of experiments upon which this conclusion
was based was large, and their verdict is not likely to be
reversed by observations less extensive or less complete.

The following coefficients were obtained from German
trials with meadow hay:

Dry Susstance DicEsteD FRoM Mrapow Hay (PER CENT)

Samples Best Medium Poor
SG (i eh: 7 ana * a, 42 67 61 55
Oxen . awe lor" 67 - 64 56

Horse “segs 8 wees 18 58 50 46

134 THE FEEDING OF ANIMALS

In nine American experiments the digestive efficiency
of large and small ruminants has been studied, steers
being compared with sheep and cows with goats. In
five cases, the large animal digested from 5 to 14 per cent
the more, in three cases the excess for the small animal
varied between 7 and 17 per cent, and in one case there
was little difference. The general effect of such conflict-
ing results is to confirm the older and more numerous
observations.

196. Lower digestibility with horses for coarse
foods.—The horse and ruminants differ in digestive
capacity to a marked extent. The comparisons which
have been made show a uniformly lower digestive effi-
ciency for coarse fodders on the part of the former. It
appears that because of less perfect mastication, or for
some other reason, the horse dissolves much less of the
crude fiber than the steer or sheep, and the effect of this
is prominent with hays and other fibrous materials.
With the grains, ruminant and equine digestion is not
greatly unlike, eight samples of oats with sheep and
twenty-four with the horse showing almost identical
digestion of the dry matter. With maize the case is the
same. In experiments with beans, the advantage was
slightly with the ruminant. The difference between
bovine and equine digestion is certainly least with highly
digestible rations containing a minimum of fiber. So
far as we are able to judge, swine digest concentrated
food about as do ruminants. How this is in the case of
fodders we do not know fully, but it is shown that the
swine digest crude fiber quite freely.

Past experiments have not revealed any influence of
breed upon digestive capacity. There is no reason for
supposing that Shorthorn cattle, Southdown sheep, and

a
CONDITIONS INFLUENCING DIGESTION ~- 135

Chester White pigs would digest rations differently from
Jerseys, Merinoes, and Yorkshires.

Young animals seem to digest high-quality coarse
foods and grains as efficiently as older ones of the same
species, which is probably contrary to the popular belief.
There is doubtless a variation in the digestive power of
individual animals, but the data so far collected do not
show this with any degree of definiteness. In those in-
stances where the same four or more steers or sheep have
been used in determining the digestibility of several
feeding-stuffs, the highest coefficients were obtained
sometimes with one animal and sometimes with another.

197. Determination of digestibility—If we accept
as the undigested food the dry matter of the solid excre-
ment, which is practically in accordance with the fact, we
have only to subtract the dry fecal residue from the dry
matter of the ingested food in order to ascertain the
amount and proportion digested. All digestion experi-
ments have proceeded on this basis. Animals have been
fed at regular intervals a uniform quantity of carefully
analyzed food and the feces have been collected, weighed,
and analyzed. From the data thus obtained, the digestion
coefficients have been calculated. The method and the
mathematics of such experiments are so simple that cor-
rect results seem very easy to obtain and they do possess
an accuracy sufficiently approximate to truth to render
them useful in practice. As digestion trials are usually
conducted, the coefficients of digestibility obtained for
the dry matter and total organic matter represent, we
have reason to believe, very nearly the actual digestible
matter in the particular material studied. The propor-
tions secured for particular classes of nutrients may be
less accurate, for reasons that will appear. We cannot

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136 THE FEEDING OF ANIMALS

be sure, either, that the digestibility of one hay applies
to another produced and cured under totally differ-
ent conditions. The truth of this latter statement is
clearly seen in the effect of the various factors upon
digestibility.

198. The inaccuracies of digestion coefficients.—The
inaccuracies of digestion coefficients are in part those
for protein and fats. The errors in the figures for protein
are caused by the presence in the feces of nitrogen com-
pounds which are not a part of the undigested food pro-
tein. (See Pars. 173, 174.) These are waste compounds
which are residues from the bile and other digestive juices,
epithelial cells and mucus which are carried along from
the walls of the intestines during the passage of the food.
Their quantity seems not to be proportional to the pro-
tein fed, but appears to be influenced more or less by the
amount of food digested. Their source is in part the
“wear and tear” of the digestive apparatus. It follows then
that the less protein there is in a ration, the larger the
percentage error caused by these metabolic products.
In certain experiments with oat straw, the fecal nitrogen
has been more than that of the food, although without
question much of the straw protein was digested. It has
been found, using the best methods known for extracting
these waste products, that they cause a much. larger
error for the protein of the straws than for that of the
legume hays. Under some conditions, at least, ten should
be added to the coefficients of digestibility of the protein
of coarse fodders as usually given in the tables that have
been compiled.

Errors are caused in determination of the digestibility
of fat in much the same way. Certain of the bile residues
in the solid excrement are soluble in the ether which is

CONDITIONS INFLUENCING DIGESTION — 137

~ used to extract the fats and consequently the undigested
fat appears to be much larger than it really is.

Reference has been made to the return to the intes-
tinal tract of material that was absorbed into the circula-
tion and is in part returned to the intestines for excre-
tion, as, for instance, the phosphorus of phytin and other
compounds. Such material is not a part of the undigested
food residue.

CHAPTER IX

THE DISTRIBUTION AND USE OF THE
DIGESTED FOOD

Tue digested food, after absorption, all passes into
the blood, either directly or indirectly, and mixes with
it. The materials which are to serve the purposes of
nutrition are now taken up by a stream of liquid that is
in constant motion through the minutest divisions of
every part of the animal. Flowing in regular channels
the blood reaches not only the bones and muscular tis-
sues, but it passes through several special organs and
glands where the nutrients it is carrying and certain of
its own constituents meet with profound changes. It is
here that we discover the manner in which food is applied
to use and what are some of the transformations which
the proteins, carbohydrates, and fats undergo in perform-
ing their functions.

In order to follow intelligently this most interesting
phase of nutrition, we must know something of the blood
and of the organs—the lungs, liver, and kidneys—through
which it passes.

199. The blood.—The blood, which makes up from
3 to 4 per cent of the total weight of the live animal,
when in a fresh state, is apparently colored and opaque,
but if a minute portion is examined with a microscope, it
is seen to be a comparatively clear liquid in which float
numerous reddish disk-like bodies. These bodies, which
are known as corpuscles, give to the blood its bright red

(138)

USE OF THE DIGESTED FOOD /- 189

color. The liquid in which they are suspended is called
the plasma.

200. The blood corpuscles (Fig. 6).—The corpuscles
are not mere masses of unformed matter, but they are
minute bodies having a definite form and structure. They
make up from 35 to 40 per cent of the blood, and con-
tain over 30 per
cent of dry
matter. This
dry matter con-
sists mostly of
hemoglobin, a
compound that
is peculiar to the
blood and equips
it for one of its
most important
offices. Hemo-
globin, when
broken up in the
absence of oxy-
gen, is found to

be made up of a Fic. 6. Red and white corpuscles of blood
protein (globin- (magnified). A, zed conpuseles; , white cor
histone) and a coemned F, G, white corpuscles, more mag-
coloring matter aicay:

(hemochromogen) in the latter of which is combined a
definite proportion of iron. When broken up in the pres-
ence of oxygen we get globin and hematin, as hemo-
chromogen when oxydized becomes hematin. The peculiar
property of hemoglobin which renders it so useful a con-
stituent of the blood is its power of taking up oxygen
and holding it in a loose combination until it is needed

140 THE FEEDING OF ANIMALS

for use. When thus charged, it is known as oxyhemo-
globin. Because of this function of their most prominent
constituent, blood corpuscles become the carriers of
oxygen to all parts of the body. The blood corpuscles
are also concerned in gathering up one of the waste
products of metabolism, viz., carbon dioxid, and convey-
ing it to the point where it may be thrown off from the
body. (See Par. 77.)

201. The blood plasma.—The plasma is a liquid
having a very complex composition. It is about nine-
tenths water, so that it easily holds in solution whatever
soluble nutrients are discharged into it from the alimen-
tary canal. Among its constituents are found members of
all the classes of compounds that are important in this
connection—ash, protein, carbohydrates, and fats. The
proportion of ash is about 1 per cent, three-fourths of it
being common salt, and the remainder consisting of
phosphoric acid, lime, and other important mineral com-
pounds. The solid matter of the plasma is rich in pro-
teins, including the fibrinogen which is the mother sub-
stance of fibrin and several albumins and _ globulins.
These proteins make up about 80 per cent of the total
dry substance of plasma. Sugar and fats are also present,
their proportions undoubtedly varying somewhat with
the extent to which they are being absorbed from the
digestion of food. It is evident that the blood is charged
with those materials which we recognize as necessary to
the construction and maintenance of the animal body.

202. The heart.—The blood is contained in the heart
and in two sets of vessels, one set called the arteries lead-
ing from the heart by various ramifications to all parts
of the body, and the other set called the veins, leading
from all parts of the body back to the heart. Through

USE OF THE DIGESTED FOOD ; 141
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=

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RIGHT

AURICLE
Fic. 7. Heart and lungs of the human subject.

BRONCHIAL
TUBES

142

THE FEEDING OF ANIMALS ~

these vessels the blood is mov-
ing in a constant stream, which
we call the circulation. It does
not move of itself, but is forced
along by a very powerful pump,
the heart. This is a_ highly
muscular organ divided into
four chambers, which are sepa-
rated by valves and partitions,
the two upper chambers being
called the right and left auri-
cles, and the two lower the right
and left ventricles. The right
auricle is above the right ventri-
cle and is separated from it by
a valve, and the same is true
of the left auricle and ventricle.
(Fig. 7.)

203. Circulation of blood.—
Out of the left ventricle the
blood is pumped into the arteries
and, after reaching the arterial
capillaries throughout the entire
body, it passes from these into
the smallest divisions of the
veins and comes back to the
heart along the venous system,
entering the right auricle. It
is then carried to the lungs by

Fic. 8. Diagram of circulation. 1,
heart; 2, lungs; 3, head and upper
extremities; 4, spleen; 5, intestine; 6,
kidney; 7, lower extremities; 8, liver.
(Collins. )

reat ec ae wh. q \

USE OF THE DIGESTED FOOD ° ~ 143 -

way of the right ventricle and is returned from the
lungs to the left auricle to be sent to the left ventricle,
and from there to again start on its journey through
the body. (Fig. 8.)

The nutrients, as prepared for use by digestion, enter
the blood on its return flow to the heart, coming into
the venous cavity by way of the hepatic (liver) vein and
the thoracic duct as previously described. When, there-
fore, the right side of the heart is reached, a new acces-
sion of food material is on its way to sustain the various
functions of nutrition.

We are more interested in the object of blood circu-
lation than we are in its mechanism. Somehow the
digested food disappears into these constantly moving
blood currents, and the only evidence of its effect which
comes to us from ordinary observation is the warmth,
motion, and perhaps growth of the animal that 1s
nourished.

204. The lungs.—The first point where important
changes occur is the lungs. Here the blood loses the pur-
plish hue which it always has after being used in the body
tissues and takes on a bright scarlet, a phenomenon that
is more easily explained when we understand the lung
structure. (Fig. 9.)

Breathing is a matter of common experience. We all
know how air is drawn into the lungs at regular intervals,
an equivalent quantity being as regularly forced out.
The mechanism of respiration (breathing) we will not dis-
cuss at length. It will aid us, however, if we know that
the passage which the air follows to and from the lungs,
the trachea (windpipe), divides into two branches, one to
each lung, and these divide and sub-divide until they
branch into numerous fine tubes. Each of these tubes

144 "(HE FEEDING OF ANIMALS.

ends in an elongated dilation which is made up of air
cells opening into a common cavity. These cells are so |
numerous in the lung tissues that only a very thin wall
separates adjoining ones, and in this wall are carried the

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RicHT LUNG LEFT LUNG

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Fie. 9. Air-tubes of the human lung. (Gerrish.)

capillaries or fine divisions of the blood vessels leading

from the heart.
205. Object of respiration——The lung structure per-

mits the blood to take up oxygen as it flows along and
transfer certain wastes into the lung cavities, and thus be
made ready to go back to the body carrying a joint load
of digested food and oxygen. The air that passes out of

USE OF THE DIGESTED FOOD ; 145

the lungs is less rich in oxygen than when it was taken in,
and there have been added to it certain materials which
are noticed later.

206. The use of food.—The revivified blood now
passes to all parts of the body and is brought into the
most intimate relation with the minutest portion of every
tissue. Several things happen in the course of time.

In the first place, the new supply of nutritive sub-
stances is used by the living cells in a way we do not
wholly understand to rebuild worn-out tissue and to
form new growth. With the young animal, much material
is appropriated in the latter way. In the case of the milch
cow, there is furnished to the udder the nutrients out of
which certain constituents of milk are formed through the
special activities of that gland.

207. Nutrients are oxidized.—Moreover, it is in the
tissues that the oxygen which was taken up in the lungs
is used to burn slowly a portion of the food. This com-
bustion does not take place by the mere contact of the
oxygen and food in the large blood vessels, but it occurs
by progressive steps throughout the minute divisions of
the muscles and other parts of the whole body. Not-
withstanding this oxidation may be very gradual and
occupy much time, its ultimate products are, for the most
part, similar to those which result from the rapid com-
bustion of fuel. In the fireplace, starch, sugar, cellulose,
fats, and similar bodies would be burned to carbonic acid
and water, and this is what takes place in the animal to
the extent that these nutrients are not used for the forma-
tion of body substance. When the protein is not stored
as such but is broken up, the result differs somewhat in
the furnace andyin the animal because in the latter the
oxidation is not complete.

J

146 THE FEEDING OF ANIMALS

208. Oxidases.—The manner of this oxidation is one
of the difficult physiological problems. The present view,
and one based on very significant data, is that these
oxidations of the nutrients is the result of enzym action
and the oxidizing ferments are designated as oxidases.
The proteins, carbohydrates, and fats are first acted on
during digestion by the hydrolizing enzyms, and the
cleavage products are then further broken down, or
oxidized, by the oxidases.

209. Proteins not wholly oxided.—The proteins may
be partially burned to carbonic acid and water, but unless
used for tissue formation a portion of their substance
passes from the body principally in the form of urea and
uric acid, which are the prominent constituents of urine.
These compounds carry with them a certain proportion
of carbon and hydrogen which in ordinary fuel com-
bustion would more fully unite with oxygen. The heat
production from protein is therefore less in the animal
than in the furnace.

210. Rate of oxidation of nutrients.—This oxidation
in the animal is constant but not uniform. It varies with
the exercise the animal is taking and with the amount of
food that must be disposed of. The quantity of oxygen
needed is therefore variable, and when the demand for it
is largely increased the heart pumps faster, more blood
passes through the lungs, the breathing is more rapid and
the supply of oxygen is in this way augmented.

ELIMINATION OF WASTES

The various waste products from this combustion and
from the breaking up of the proteins within the animal
evidently must be disposed of in some manner. When

USE OF THE DIGESTED FOOD By PA

not eliminated from the body, they cause results of a
_ most serious character, as, for instance, when an accumu-

lation of urea in the body produces uremic poisoning.
The blood therefore not only carries to the tissues the

- necessary nutrients and oxygen, but it has laid upon it

the burden of taking into its currents the waste products
of combustion and growth and carrying them to the
points where they are thrown off. (See Par. 77.)

211. Elimination of urea.—One of the branches of the
arterial system of blood vessels runs to the kidneys, and,
by repeatedly rebranching, traverses all their substance.
The main function of the kidneys is to eliminate certain
products through the urine. It is in this way that all the
waste nitrogen from the digested protein finds its way out
of the body in the form of urea and similar bodies. The
blood that enters them carries with it the urea and uric
acid which have resulted from a breaking down of pro-
tein, and in a most wonderful manner these compounds
are filtered out so that they are not present in the out-
going blood. An excess of soluble mineral matters, espec-
ially the alkaline salts is also removed by the kidneys, as
well as the bile compounds which are absorbed from the
alimentary canal.

212. Elimination of carbon dioxid.—The carbon
dioxid must in some way also be eliminated from the
body. This is not accomplished to any extent until the
blood containing it reaches the lungs, where it is ex-
changed for a new supply of oxygen and passes off in the
expired air. In the case of man, the air “breathed out”
is nearly a hundred times richer in carbonic acid than the
air “breathed in.”

213. Elimination of water——Water may be regarded
from one point of view as a waste, for it is produced in

CF

Fic. 10. Portal system of veins in the human subject, showing how
absorbed nutrients are collected from intestinal tract and carried to
liver by portal vein.

(148)

USE OF THE DIGESTED FOOD ; 149

the oxidation of the food, and this passes off from the
_ lungs as vapor, through the skin as sensible or insensible
perspiration, and in considerable quantities through the
kidneys.

To summarize, it may be said that the blood is con-
stantly undergoing gain and loss. The gain comes from
the food (including water and oxygen), and the loss con-
sists of the compounds in the urine, carbonic acid, and
water given off through various channels.

THE LIVER '

214. Regulation of carbohydrate use.—One part of
the arterial system of blood vessels runs to the stomach
and intestines and is distributed over their walls in fine
divisions. These connect with the capillaries of the portal
vein which leads to the liver (Fig. 10). During this passage
of the blood from one system to the other, part of the
digested food is taken up. The quantity of material thus
absorbed must vary greatly at different times according to
the nature and amount of food supply and the activity of
the digestive processes. If, therefore, the blood from the
alimentary canal were allowed to pass directly into the
general circulation, the supply to the tissues of the sugar
resulting from digestion would be very uneven. Just here
comes in a liver function. In that organ there is found a
starch-like body known as glycogen, which appears in
increased quantity following the abundant absorption
of sugar from the intestines. It is believed, because of
this and other facts, that the liver acts as a regulator of
the carbohydrate supply to the general tissues of the
body, storing a temporary excess of the sugar in the form
of glycogen and then gradually giving it up to the gen-

150 THE FEEDING OF ANIMALS

eral circulation as it is needed. Glycogen is also stored in
the muscles in an amount equal to or greater than in
the liver. (See Par. 103.) No better illustration can be
cited of the nicety of adjustment of the animal organism
to the maintenance of its activities than this regulation
of its fuel supply to the areas of oxidation.

CHAPTER X
THE FUNCTIONS OF THE NUTRIENTS

Tue digestion, absorption, and distribution of food
are not its use—they are the preliminaries necessary to
use. Not until the nutrients have been converted to
available forms and have passed into the blood do they
in the slightest degree furnish energy or building-material
to the animal organism. We have followed to a certain
extent the chemical changes which the digested food
suffers, but no detailed statements have been made as
to the part taken by each class of nutrients in constructing
the animal body and in maintaining its complex activities.

215. General uses of food.—Animals use food in two
general ways, viz., for constructive purposes, which
involve the building or repair of tissue and the forma-
tion of milk, and as fuel for supplying different forms
of energy. The tissues which are to be formed are of
several kinds, principally the mineral portion of the bone,
the nitrogenous tissue of the muscles, tendons, skin, hair,
horn, and various organs and membranes, and the deposits
of fat which are quite generally distributed throughout
the body substance.

216. Uses of energy.—Energy in the forms in which it
is used by the animal organism may appear as muscular
activity, both internal and external, such as working,
walking, breathing, the beating of the heart, the move-
ments of the stomach and intestines, as heat, and as
chemical energy necessary for carrying on digestion and

(151)

152 THE FEEDING OF ANIMALS

other metabolic changes. The animal body is certainly
the seat of greatly varied and complex constructive and
destructive activities, which are sustained by the matter
and potential energy of the food. How this is done we
do not fully understand, but we know many facts which
are of great scientific and practical importance and which
the feeder must consciously or unconsciously recognize
if he would not come into conflict with immutable laws.
(See Pars. 236-241.)

217. Functions of water.—Water fills an impor-
tant place in the nutrition of all forms of life. In both
plants and animals it acts as a solvent of the building-
materials which it carries from one part of the organism
to another. It also serves as a carrier of wastes, particu-
larly those excreted through the kidneys, and the free
use of water is recommended as promoting thorough
cleansing of the tissues. It is proper to speak of water
as building-material for the animal body, for it is an
abundant constituent of animal tissue and takes part in
chemical changes such as hydrolysis. It fills an essential
office in regulating the heat processes of the body through
varying rates of evaporation from the surface of the body.

FUNCTIONS OF THE MINERAL ELEMENTS

218. Relation of mineral elements to vital processes.—
The life of an animal is maintained through chemical
reactions between substances in solution. These reactions
are brought about by means of electrical currents, and
the importance of the mineral salts in these relations is
seen in the fact that very dilute solutions of the mineral
salts in water increase greatly the electrical conductivity.
The organic compounds in the body have a low electrical

‘omysed ye ploy oy, “AT @LVIg

Sm seared te
wes Py,

le RS Sa

FUNCTIONS OF THE NUTRIENTS lita 155

conductivity or are inert, and it is the presence of the
mineral elements in solution carrying electrical charges
which makes possible the reactions involved in metabolism.
Without the mineral elements protoplasm would be dead.
219. Relation of mineral elements to animal struc-
ture.—The mineral elements are largely involved in the
structure of the animal body. They constitute the entire
amount of the ash in which the elements calcium and
phosphorus exist in the largest proportions. The follow-
ing table illustrates the kinds and distribution of mineral
elements in the bodies of five species of farm animals.

TaBLE XXVII
Ox Calf Sheep ~ Lamb Pig
Half Half Very

———— ee

tin 2a OM SOst. | G4ss sey (2325 | 35:6 || 45.5885 cata ae
Nitrogenous

mapter . . .|16.6 | 14.5 | 15.2 | 14.8 | 14. 12.2.) 10.9 Yi2:3 1 13.7.1 10:9
Minerals .. .| 4.66] 3.92| 3.8 | 3.16] 3.17| 2.81] 2.9 |) 2.94] 2.67| 1.65
Water Peer 2 bolcor |. 45:5. i Ga: 57.3 | 50.2 | 43.4 | 35.2 "47.8 155.1 1413

Contents of
stomach, etc. Bol iGs 3.2) :0: 9.1 | 6. 5.2) S-Di ole less

SN ee ee ee ee ee

Total. = . . . .| 100. | 100. | 100. | 100. | 100: | 100: | 10041400: || 1002 |' 100:

Minerals Per | Per | Per | Per | Per | Per | Per | Per | Per | Per

cent | cent | cent | cent | cent | cent cent | cent | cent | cent
Phosphorus . . .803] .677| .67 488] .524| .454] .484] .492| .465] .286
Calcium . . . . | 1.508] 1.281) 1.177) .944] .965], .846] #86] .915] .771] .455
Magnesium .. .051} .037|) .048} .034] .031) .029) 033] .031] .032! .019
Potassium ...| .17 .146| .171] .144| .14 2S) Mele ll ASS) 2163|) 2115
Sodium ja .-< - -108} .094} .109} .09 -077| .072| .096} .076| .082} .054
ron 3 cae: ee 028] .017} .015} .026] .029} .024!] .021)] .018} .015} .009

Live weight, lbs. | 1,232] 1,419] 258.8] 97.6] 105.1] 127.2] 239.4; 84.4] 93.9] 185.
Age... . srage 4yrs.|4 yrs.| 9.5 | lyr.| 344 | 144 | 13% |%yr.
wks. yrs. | yrs. | yrs.

s% NM AEN Rae Un a ML
ie BLA OUR a RD

i

154 THE FEEDING OF ANIMALS
,

220. Distribution of mineral elements in animal body.
—The bones carry the greater part of the ash elements.
Fresh bones are approximately one-quarter ash. The
muscles have between 1 and 2 per cent of ash, and the
blood from eight to nine parts in a thousand. The dis-
tribution of the mineral elements in the animal body is
somewhat as follows: phosphorus and calcium predom-
inate in the bones; sodium salts are found largely in the
blood, the serums, and lymph; potassium salts exist most
abundantly in the blood, muscles, brain, and liver. Iron
compounds are found most largely in the blood, lungs,
liver, and spleen; and magnesium in the lungs, muscles,
and nervous tissue. Sulfur, as has been seen, is asso-
ciated with many of the proteins and is found in espec-
ially large proportions in hair and horn.

221. Relation of mineral elements to elimination of
waste products.—In this respect, iron exercises a particu-
larly important function. As has been seen, it is con-
tained in the hemoglobin of the red corpuscles. In the
lungs, oxygen becomes lightly attached to this hemo-
globin and is carried to the various parts of the body
where it is used for the oxidation of the organic com-
pounds in the food. The red corpuscles seize upon the
carbon dioxid which is one of the products of this oxida-
tion and carry this to the lungs where it is eliminated.
As these oxidation processes furnish the energy for sus-
taining the activities of the animal body, it appears that
iron is a most important factor in animal metabolism.

222. Relation of mineral elements to a proper equilib-
rium between the acids and bases of the animal body.—
The cleavage processes which take place in the use of
food compounds give rise to sulphuric and phosphoric
acids, and these together with certain organic acids must

FUNCTIONS OF THE NUTRIENTS ~~ 155

be neutralized through the presence of certain basic ele-
ments. Sodium, potassium, and calcium function in
this relation. If this neutralization did not occur, the

animal would be seriously affected and in time die. As a

matter of fact acidosis (acid condition) has not been
demonstrated with farm animals. The acidity or the
alkalinity determines the function of the action of certain
enzyms in the digestion of food, as, for instance, while the
pepsin of the stomach acts most effectively in an acid
solution, the trypsin and other enzyms of the duodenum
act only in an alkaline medium.

223. Relation of mineral elements to osmosis.—
The transference of substances in solution from one part
of the body to another involves the passage of solutions

through various membranes and tissues, as, for instance,

from the alimentary canal into the blood and from the
blood into various tissues which are nourished through
such distribution. The penetrability of these membranes
seems to be dependent upon the presence of mineral salts.

224. Relation of mineral elements to muscular con-
trol— The contraction of both the voluntary and invol-
untary muscles seems to be dependent upon a certain
balanced chemical environment involving salts of calcium,
magnesium, sodium, and potassium.

225. Relation of mineral elements to tissue develop-
ment.—It has been shown that the eggs of certain marine
fishes segment normally only in water containing a mix-
ture of certain salts of a certain concentration, these
being the salts of the alkalies and alkaline earths.

226. General considerations.—It is easily seen that
the mineral salts sustain very complex relations to the
growth of animal tissue and to the maintenance of animal
life. It is a matter of common observation that when an

i

156 THE FEEDING OF ANIMALS

animal is given food free from the compounds of the
mineral elements, the animal suffers physical deteriora-
tion and finally dies. In considering the matter of a
sufficient supply of mineral element, the feeder should
consult tables showing the ash composition of the various
feeding-stuffs.

227. Supply of mineral elements (see Pars. 48-54).—
The supply of the mineral elements in the food of the
various classes of animals has not until a comparatively
recent time received extensive consideration. It has been
practically held that nature has made a generous provision
for supplying the animal’s needs for mineral substances
in our home-raised feeding-stuffs and that mixed rations
as usually fed contain in variety and quantity all that is
needful of these nutrients for the various kinds of pro-
duction. It was clearly proved sometime since that an
extra supply of mineral compounds is needed for laying
hens, especially calcium compounds for the formation
of egg shell, and it was also shown that the proper devel-
opment of the bony structure of swine is not secured
through feeding cereal products alone, particularly exclu-
sive corn-feeding, but the mixed rations for bovine pro-
duction have not been questioned in this direction.

It has remained for Forbes in a recent extensive and
exceedingly important investigation as to the mineral
supply of liberally producing cows to show that during
full milk production, even when the animals were fed
on rations that are regarded in practice as highly satis-
factory, there were important losses of calcium, mag-
nesium, and phosphorus from the cow’s skeleton. It is
suggested that the decreasing milk-supply during a
given period of lactation and the sometimes observed
failure of a highly producing cow to carry her high pro-

FUNCTIONS OF THE NUTRIENTS ~~ 157

duction successfully through two periods of lactation are

due to the removal from the body of these mineral elements
not supplied in sufficient abundance in food. It would
seem, however, that ordinarily there are periods during
which a milch cow recovers her loss of mineral elements.

Forbes calls attention to the importance of iodine in
animal metabolism. It has long been known that in the
cases of abnormal physical development accompanied
by inferior intellectual quality, such subjects being known
as cretins, the physical and mental conditions have been
improved by an extract of the thyroid gland which car-
ries iodine. An extensive investigation of many feeding-
stuffs shows an absence of iodine in some and only traces
or very small percentages in others. It would appear,
however, that under the ordinary system of feeding mixed
rations the iodine supplied to our domestic animals
is sufficient.

228. Relative efficiency of different phosphorus com-
pounds.—The mineral elements of foods may be supplied
to the animal in various forms. This is particularly true |
of phosphorus which is used so freely by growing animals
and milch cows. Because of the importance of this ele-
ment the problem of the relative nutritive! efficiency of
organic as compared with inorganic phosphorus com-
pounds has been much studied. The organic forms found
in foods are in part nucleo-proteins, phospho-proteins,
phytin, and similar compounds found in grains, and
lecithin and glycero-phosphates. In an admirable résumé
of the whole subject, Forbes shows that the data secured
on this question give conflicting testimony but that the
majority of evidence seems to favor the conclusion that
the organic phosphorus compounds are more efficient,
for some species at least, than the inorganic, such as cal-

. ae fr ‘ ri he Be ofa ie n \ ; * Epis
- i ;
L

158 THE FEEDING OF ANIMALS

‘cium phosphate. It seems clear, however, that growth
can be secured where only inorganic phosphorus is fed,
and in many experiments this form has seemed as efficient
as the organic. The synthesis in the animal of such com-
pounds as the nucleo-proteins can hardly be doubted.
The fact of such synthesis does not show that organic
phosphorus compounds may not be in general more
efficient than inorganic. This question has some economic
importance because it is well to know whether so cheap
a material as phosphatic rock may be a useful source for
fortifying the phosphorus supply of a ration.

FUNCTIONS OF PROTEIN

229. Proteins as tissue-formers.—While there are at
present many unsolved problems relative to the nutri-
tive offices of protein, there is no reasonable doubt that
the vegetable proteins are the primary and main source
of all similar substances in the animal body. From these
proteins are formed the muscles, the connective tissues,
the skin, hair, horn, and hoofs, and the major part of
the tissues of the secretive and excretive organs; in short,
that they are the source of a large proportion of the
working parts of the animal body. So far, scientific
research has not succeeded in demonstrating that a pro-
tein is ever synthesized (built up from simple compounds)
outside of the plant. It appears that bodies of this class
must in the main come to animal life fully elaborated.
This is a truth of great significance even in its relation
to the nutrition of farm animals. The nitrogenous tissues
are those that largely. determine the vigor and quality
of any animal, and as these are formed rapidly in the early
stages of growth, a normal and unrestricted develop-

™

FUNCTIONS OF THE NUTRIENTS ~~ 159

-ment demands an’ abundant supply of protein food. It
jis also true of mature animals that sufficient protein is

not only necessary to health and vigor, but it is essen-
tial to production that is satisfactory in quantity and
quality.

230. Protein as a source of fats.—The functions of
protein are not restricted, however, to the use already
described, for it is utilized in more ways than any other
class of nutrients. It was held at one time that outside
the vegetable fats it is the sole source of animal fats, and
this view was, not so very long ago, to some extent
accepted. Indisputable proof to the contrary is now in
our possession. Certainly we must be convinced that
nitrogen compounds of the food are, with some species,
not the most important source of animal fat, for various
investigators, such as Lawes and Gilbert, Soxhlet, and
others, have shown upon the basis of searching experi-
ments that sometimes over four-fifths of the fat stored
by pigs must have had its origin outside the food protein
and fat. Jordan showed that milk-fat may be largely
synthesized from carbohydrates. Besides all this, the
common experience of feeders that foods highly non-
nitrogenous are often the most efficient for fattening
purposes is good evidence that fat formation is not
greatly dependent upon the protein supply. Neverthe-
less, the possibility of producing animal fat from protein
now appears to be demonstrated.

231. Protein as a source of energy.—Protein can
unquestionably serve as fuel, or, in other words, as a
source of energy. The amount so used depends much
upon the animal fed and the character of the ration. In
the case of a dog eating an exclusive meat diet or of a
mature fattening animal which receives a ration liberally

160 THE FEEDING OF ANIMALS

nitrogenous, the greater part of the protein eaten is not
stored but, excepting the nitrogen compounds of the
urine, is used as fuel. With milch cows or young animals
growing vigorously a much larger proportion escapes
oxidation. The fuel value of protein will be discussed
later under another head.

FUNCTIONS OF CARBOHYDRATES

232. Carbohydrates the chief source of energy.—
Carbohydrates are usually characterized as the fuel portion
of the food, or that part which is oxidized to produce the
various forms of energy. This conception of the function
of these bodies is correct in the sense that in the case of
farm animals they constitute the larger part of the fuel,
although not the whole of it.

233. Proportion of ration used as fuel.—For instance,
in the case of a cow eating daily sixteen pounds of diges-
tible organic matter, giving thirty pounds of milk con-
taining 15 per cent of solids, and neither gaining nor
losing flesh, not far from five pounds of this organic
matter would be found in the milk and urine, leaving
about eleven pounds to be used as fuel, about a pound
and a half of which might be derived from the protein
and fat, the remainder, or nine and one-half pounds, con-
sisting of carbohydrates. If a fattening steer were eating
the same amount of the same kind of food and gaining
two pounds of live weight daily, the body increase and
urine would contain not over two and one-half pounds of
dry matter, leaving not less than thirteen and one-half
pounds to be oxidized, of which twelve pounds might
consist of carbohydrates and fat, mostly the former. It
is clear, then, that while other bodies serve as fuel, the

,
a ig

= mes be
giao

FUNCTIONS OF THE NUTRIENTS 161

carbohydrates furnish much the larger part of that which
is needed for this purpose.

234. Fats from carbohydrates.—Contrary to views
that held for a time, it is now well established that the
animal fats may have their source in the carbohydrates;
in other words, starch and sugar and related bodies may
serve the main purpose in feeding animals for fattening.
In many experiments, notably those with swine, the pro-
tein and fat of the food have fallen far short of account-
ing for the fat in the body increase, sometimes much the
greater part of the latter having no possible source other
than the carbohydrates. A practical expression of this
general conclusion concerning the fat-forming function
of carbohydrates is seen in the well-recognized value of
corn meal as a fattening food, a feeding-stuff nearly seven-
tenths of which consists of starch and its allies. Experi-
ments with milch cows leave no doubt that milk-fat may
also be derived from carbohydrates. These more recent
views tend to magnify the importance of the carbo-
hydrates as nutrients. |

FUNCTIONS OF THE FATS AND OILS

235. Fats and carbohydrates similar in function.—
So far as is at present known, the possible uses of the
food fats and oils and of the carbohydrates are similar.
In other words, both may serve as fuel and both may be
a source of animal fat. The differences are that the supply
of carbohydrates is much the larger, and the fuel value
of a unit weight of fats is over twice as great as that
of starch and sugar. Moreover, it seems possible for a
food fat to become deposited as such in the animal or
in milk without essential change, whereas fat formation

K

ae | | Sy ek
162 THE FEEDING OF ANIMALS

from carbohydrates involves complex chemical trans- |
formations not fully understood.

FOOD AS A SOURCE OF ENERGY

236. Work performed by the animal organism.—
The living animal, either as a whole or in some of its parts,
is constantly in motion. This means that the animal
mechanism is ceaselessly performing work. Even if the
body is apparently quiet, the heart beats, pumping
blood to all parts of the body, the lungs are expanded
and contracted, and the stomach and intestines keep up
the movements which are essential to digestion. Besides,
a living body is the seat of continuous, invisible and com-
plex chemical and physical changes that, if not work in
the common meaning of the term, are its equivalent.
Walking, trotting, pulling, lifting, pumping blood,
breathing, masticating, digesting and assimilating food
represent, then, a great variety of operations of those
living machines which we have named horse, ox, cow,
and sheep.

237. Work requires the expenditure of energy.—
Now work requires the expenditure of energy. The
projection of a rifle ball through space at the rate of 2,000
feet a second is work. The ball does not move of itself,
but is propelled by the application of the energy stored in
a powerful explosive. Back of every one of our great
mechanical operations, such as pumping, grinding, and
moving railroad trains, will always be found some sort
of energy, and what is true of machinery made of wood
and iron is equally true of that made of bone and muscle.
The fact that the mechanism is alive does not abrogate
a single physical law, so that the fundamental principles

~~ a es
‘ : y RY , ae
Seat t ‘ ¥ ne v

FUNCTIONS OF THE NUTRIENTS 163

of energy as applied to machines are as fully applicable
to the activities of animal life.

238. The animal organism does not originate energy.—
It is safe to go farther and say that the animal organism
does’ not originate energy. Among the fundamental
conceptions upon which all our knowledge of chemical
and physical laws rests is this, that energy and matter
are indestructible, and, moreover, that the sum total
of these in the universe is unchangeable. If, then, the

' horse expends the muscular energy necessary to draw a

load of one ton over 10 miles of road, the equivalent of
this must have been supplied to his body from some out-
side source. He could not create it. We know that this
is so, and we also know it is conveyed to the animal
in the food.

239. The nature of energy.—A definition of energy is
difficult. It can be illustrated by pointing out some of
its manifestations. It is a common observation to see a
blacksmith hammer an iron rod until it is red;hot. The
motion of the hammer-head descending with great veloc-
ity was suddenly arrested when it came in contact with
the rod. The hammer-head was driven by energy sup-
plied from two sources, gravity or the energy of position,

. and energy exerted through the blacksmith’s arm, that

is, energy supplied through oxidation in the blacksmith’s
body. When the hammer met the iron rod on the anvil,
the mass motion ceased. The operating energy was not
annihilated, but it appeared in another form. The motion
of the hammer-head (kinetic energy), a mass. of matter,
was communicated to the molecules of the iron rod, and
as the vibrations of the molecules increased in rapidity,
the rod grew hotter and hotter. Here we have another
manifestation of energy, viz., the motion of the molecule.

164 THE FEEDING OF ANIMALS

The iron rod might have been heated in another way—

by plunging it into burning charcoal. Somehow, when it
is deposited in the plant, there becomes stored in this
carbon, in a way about which we can only theorize, what
we may call chemical energy, which, when combustion
occurs, is changed into heat or molecular motion. From
these phenomena we learn that not only are there several
manifestations of energy, but that one manifestation is
transferable into another.

240. Transformations of energy through the use of
machinery.—Perhaps another illustration may still fur-
ther serve our purpose. A small dynamo is being run
by a pair of horses working in a tread-power such as is
used for threshing grain. The horses are constantly
climbing up a moving treadway and thereby communi-
cating motion to machinery. The energy thus applied
is the result of combustion in the body of the horse. This
motion, is, by the dynamo, converted into electricity,
which, by passing through the carbon film of an incandes-
cent lamp and there meeting resistance, is in part, at
least, manifested as heat. We have, then, in a chain,
muscular effort, motion of the mass (pulleys and wheels),
electricity, and heat, all manifestations of energy and
all transferable one into the other.

241. The horse a machine.—This is a fairly good pic-
ture of what goes on with the horse himself, externally
and internally, in sustaining life and performing labor
for his owner. It is now known that through the combus-
tion of the carbon compounds of vegetable and animal
origin, which serve as nutrients, chemical energy may be
transformed into those other forms that are manifested in
the activities of living beings, and it is a notable triumph
of science to be able to declare with certainty that the

FUNCTIONS OF THE NUTRIENTS — 165

ceaseless and multiple activities of life on this planet are
sustained by an energy which comes to the plant in the
sun’s rays and is stored there through the synthesis of
carbon compounds.

242. Measurement of energy.—It is obvious that if
the internal and external work performed by the animal
is sustained by the food, it is desirable to measure the
energy available in different feeding-stuffs, provided,
of course, that they differ in this respect. In order to
measure anything, we must have a standard or unit of
measurement. In this case it cannot be a unit of space
or of mass, that is, we cannot declare that corn meal con-
tains so many cubic feet or pounds ‘of available energy.
Energy has neither dimensions nor weight. If we meas-
ure it at all, it must be by units of temperature or of work
performed. Units of this latter kind are the ones applied
to the measurement of food energy. The one that has
been most commonly used is the Calorie, this being the
energy which in terms of heat is sufficient to raise the
temperature of one pound of water 4° F. Expressed in
terms of work, the Calorie (large) is very nearly 1.53
foot-tons, or in other words, it is equivalent to the work
involved in lifting one ton 1.53 feet. Heat units are
expressed in both the large Calorie and the small calorie.
When the former is indicated, the word begins with a
capital letter. The Calorie represents 1,000 calories.
Armsby proposes the use of the term therm, which repre-
sents 1,000 Calories, which renders less cumbersome the
figures given for the energy of a ration.

243. Determination of energy units in feeding-stuffs.—
The total energy or heat units developed in the combus-
tion of feeding-stuffs is determined in an apparatus
called a calorimeter. The latest form of this device is one

¢

166 THE FEEDING OF ANIMALS

in which the ground hay is burned under pressure in the
presence of pure oxygen, and the heat evolved is all
used in warming a known weight of water. Data are thus
obtained from which it is possible to calculate the Calories
in the particular material burned. The energy value of
single compounds, such as albumin, starch, and sugar,
may also be found in the same way, as has been done in
a large number of instances. These data show that the
heat resulting from the combustion of the compounds of
a given class is not the same in all cases. The value in
large Calories of one gram of several pure nutrients is
shown in the following table:

TABLE XXVIII

PROTEINS

Calories Calories
Wheat gluten... . 5.99 Ego albumin. ;. . . | ais
Gladding... oh ee Muscle (pure). . . . 5.72
Ghitenin 3. 3. 588 Blood fibrin .* = eae
Plant Gbrim (0)... 8.94 Peptone . .°.%) . 2) eae
Serumalbumin ... 5.92 Wook... 3) 209i
Milk casein. . 0 piog Gelatin: 0c
Walcot eee os. es BE Asparagin (amide) . 38.45

CARBOHYDRATES Fats

Calories Calories
Searcher |... 4.18 Of swine ts°2 423 eee 9.38
Gellulosevom .... . 418 Of oxen 20...
Cageose ne. BTA Of sheep’... 2. Gan
Cane-sugar#. ..... 3.95 Maize oil ... . . >. eos
Milk-sugar.-.... 3.95 Oliveol>... .°. : Seo ae
Maose me... .. 3.95 Ether-extract of oats. 8.93
Zylose.. 2m... 3.74 Ether-extract of barley 9.07

The heat values of a gram of the dry substance of
various cattle foods, which is a mixture of the several
nutrients, were found by recent determinations to be the
following, expressed in calories:

FUNCTIONS OF THE NUTRIENTS — ~ 167

TaBLeE XXIX
Calories Calories —
Bamed nay . oe 4.39 Commeanmeal 2°. 3 te 4.47
memliatay . . . 4.40 Linseed meal .... 5.04
eeitAW cs. ee 4.48 Flaxseed meal. . . . 6.93
Sugar-beets .... 3.93 Bicegueal . og 4.40

These figures mean that when a gram of each of
these materials is wholly burned the heat produced
is as stated.

244. Metabolizable energy—We must distinguish,
however, between the heat produced when any food
substance is wholly oxidized in a calorimeter and the heat
or energy which is available (metabolizable) when the
same material is applied to physiological uses. It never
happens that the combustible portion of a ration is
entirely oxidized in the animal.

245. Loss of food energy in feces.—In the first place,
the food of domestic animals is practically never all
digested and, as only the digested portion furnishes
energy, the available fuel value of a ration must be based
primarily, not on the total quantity of dry matter it
represents, but on the amount which is dissolved and
passes into the blood. If all feeding-stuffs or rations
were digested in the same proportion and with the same
ease, their total fuel values might show their relative
energy worth, but as digestion coefficients for dry matter
vary from less than 50 per cent with the straws to nearly
90 per cent with some of the cereal products, it is evident
that the fuel waste in the feces is not uniform.

246. Loss of food energy in urine.—In the second
place, the digested proteins are never fully burned. A
portion of these compounds always passes off in the urine
unoxidized, the fuel value of which is lost to the animal.

168 THE FEEDING OF ANIMALS

For this reason the available energy of the digested pro-
teins is about one-fourth less than the total.

247. Loss of food energy in gases.—In the third place,
there is, with ruminants and horses at least, an escape
from the alimentary canal of unconsumed gases, due to
the fermentations which take place during digestion.
These gases, mostly methane (marsh gas) with some
carbon dioxid and from green leguminous plants some
hydrogen sulfide and nitrogen, have their source in the
carbohydrates and crude fiber, and Kellner found them
to represent from 10 to 20 per cent of the total energy
value of the dry substance digested from various materials.
From twenty experiments, upon five different animals,
- Kin found the loss in methane to be over one-seventh
the energy of the digested crude fiber and nitrogen-free
extract.

248. Recent determinations of metabolizable energy.
—The most accurate and extensive determinations of
metabolizable energy that have been made in this coun-
try, or perhaps anywhere, are the result of recent inves-
tigations by Armsby and Fries with the aid of a respira-
tion calorimeter. These involved analysis of the feeds
used and determinations of the total energy of the feeds
and of the losses through the various avenues indicated
above. In carrying on this work, nine steers were used,
involving 3,401 experiments. Without giving any atten-
tion to the technics of the work, which required a costly
and extensive equipment of men and apparatus and
involved thousands of accurate chemical analyses of
foods and the different forms of excreta, the following may
be cited as an example of the necessary computation of
losses of chemical energy from..a ration through the
excreta and the methane:

FUNCTIONS OF THE NUTRIENTS 169

TaBLE XXX
Period 2. Period 3
Calories Calories
Total energy of feed—
Menguey lay . .. cee... . 12,477 12,618
rain mixture, No, ieee... ee... 12,549
Pie iy. | ee. ee oS... COE. 615
Energy of excreta—
_ .. Se ra ef 5,247
ee mre Wars é 627
eee |, Cee fe ON Oe 1,057
NS SS ity S'S 6,931
Metabolizable energy. .......... .14,021 5,687

The above computation is for a mixed ration contain-
ing both coarse fodder and grain. In order to ascertain
the losses from the grain itself, those for the hay having
been determined by other experiments, the following
computation was necessary :

TABLE XXXI

| Chemical energy of excreta

Chemical |__— ee
energy | lizable
of feed | Feces Urine | Methane| energy

ee ee

Calories | Calories | Calories | Calories | Calories

Total ration . . . . | 25,026]. 7,371, | 2546 | 2 0GRer i027
Computed for hay . . | 12,477 | 5,254 591 | 1,003 | 5,629

Grain mixture oe dif-
ference ... » . | 12,5494-23nee 945 | 1,095 8,392

249. Distribution of losses of food energy.—In the
next table there are given for eight individual feeding-
stuffs and several mixed rations and grain mixtures the
percentage of losses through the different avenues and

A

170 THE FEEDING OF ANIMALS

the percentage of metabolizable energy, or in other words, :

that which may be applied to use by the animal, from the
several materials involved in the experiments:

TABLE XXXII.
Percentage losses Perea
2 metabol-
sect 1 te | in | an | ible

feces | urine CH,

“imotiy Hay... kk 48.13| 3.57 | 6.94 | 41.36

Hemcuvemmny. 6... 40.95 | 6.82 | 5.95 | 46.28
Wine A Se 43.92} 5.17 | 7.35 | 43.56
PUM, se eS Og 47.54} 5.58 | 5.94 | 40.94
Pea EM eS ope . .|42.01] 5.89 | 6.11 | 45.99
MAMMURIRIMER a. le a ea ey 42.82 | 4.24 | 7.88 | 45.06
Riine CMP "sa le ee 14.74) 3.32'| 9.75 | F249
cree Ameer SSS care ae 31.77 | 5.38 | 7.44 | 55.41
Crain muxmire, No.1): ‘soe. Se EG F.20 |..7.84 | S0g
Crean aimaire, INO. 2.5) he . | 22.03 | 4.54 | 9.06 | 64.387
iorneey GOP. ss ka nae 12.15 | 3.84 | 9.20 | 74.81
Alfalfa hay and grain mixture, No. 2.] 30.27 | 4.83 | 7.98 | 56.92
Mixed hay and maize meal . . . . | 24.22] 3.87 | 8.89 | 63.02

Mixed hay and hominy chop . . . | 28.02, 4,44 | 8.15 | 59.39

It will be noted that the main loss is by way of the
undigested food residue. The energy loss in the urine
ranged from 3.3 to 7.2 per cent. The loss from methane
ranged from 5.9 to 9.7 per cent of the total dry matter,
or from 4.2 to 5.1 grams to 100 grams of digestible car-
bohydrates, the average being 4.8 grams. Kellner found
4.2 grams, and these figures may be taken as a basis for
the estimate of the probable loss of chemical energy
through fermentations. The undigested residue varies
greatly according to the nature of the food. These authors
have investigated the influence of the quantity of the
ration upon the losses of chemical energy.

hin aes i x
FUNCTIONS OF THE NUTRIENTS HS OF iy |

250. Influence of size of ration on losses of methane.—
The losses through gas evolution were found to be greater
in twenty-nine cases out of thirty-one with the lighter
ration and tended to be somewhat greater on the mixed
ration with a very much larger proportion of readily
soluble carbohydrates. This simply means that the
“bacterial fermentation of the carbohydrates in the di-
gestive tract of cattle proceeds to a distinctly greater
extent on light than on heavy rations.”

251. Influence of size of ration on losses in the un-
digested residue.—As is well known, this loss will be by
no means uniform as this residue is proportionately much
larger with coarse foods than with grain foods. In these
comparisons there seemed to be practically no difference in
the proportion of loss as between heavy and light rations,
these results not agreeing with former observations.

252. Influence of individuality on energy losses.—
Comparison was made between a pure-bred Shorthorn
steer and a so-called scrub. Practically no difference in
the loss of chemical energy was discovered as between
these two animals.

253. Estimates of metabolizable energy on the basis
of digestible organic matter—It is discovered that the
metabolizable energy in a unit of digestible organic
matter is fairly uniform as between the different coarse
fodders on the one hand and the various concentrates
on the other. Various investigators have studied this
question and their results show a satisfactory agreement.
It appears that the metabolizable energy which may be
derived from the several feeding-stuffs will vary quite
directly with the proportion of digestible dry matter.
The following table shows the figures reached by several
investigators:

i hi) THE FEEDING OF ANIMALS

TABLE XXXIII.

Coarse Feeds

Armsby and Fries: pa nile
Mamothy hayre. + . 2-24 te i, . 3849
men clover hagas: .. Uae... . aoe. _ 8.49
Piixed hay Awe S. \ ae OY. OL) Ge. etree
Alfalfa hay andmeal. . 7... . ae a 3.61
BEM OVER OS . wee Se oe ieee
PRS ete ee Oe 3.48

Kellner and Kohler:

2) LEE Sepa RL phate 3.50

MEIC ae eto et NY Mee SO me . 38.74

SPT tay ete rae EOS AS Ne Nou

MMC BLTAW. fe eo cee Geel =

SRS SR Porn te pat se ee
Concentrates

Armsby and Frics:

RViesiomrIICal os eae en ae meas 3.80
Wyrhieme Dram? i oo sync ss eee et cee eee 3.99
Gravmenrvure, No, 2 0/90 Se se 3.88
A VGTMEO: 5 Sas et ete Tele eee Cen ee eee 3.89
(rcureme x ture, NG. I Se So Ln hae ee ce 3.91
iets CHOP. 5"... (<a) is ye aes, eee Pe oh 4.08
Ro) os Soot ian el oa: 5 hs, See ee 4.00

Kellner and Kohler:

CEES POC S RE NESS ated ae ee ee, 3.47
Starch Ree) 2 oe REE ge 3.60
CMEEIGeN . me ea ee |

It is self-evident, of course, that the metabolizable
energy will be greatly influenced by the percentage of fat
or oil in a ration, as the fats have more than double the
energy value of the carbohydrates.

>
»
ne

Raped. (oh ae Se Es Aa a i ; Sele. Vereen
Behe gs San ae y
i ata Pa : t =
’ a j / -
a) 5 : a Pease \ /
* -
{ ’ ) o :
'

FUNCTIONS OF THE NUTRIENTS oan We:

254. Comparison of metabolizable energy in coarse

fodders and grains.—The following table selected from

the data of the same authors admits of a direct com-
parison of the proportions of metabolizable energy in
coarse fodders and grains.

TABLE XXXIV

Coarse Foods

Metabolizable energy
Gross Losses | _
energy per | energy per! por kilo Per kilo

kilo dry kilo dry = digestible

tt rganic

matter matter cater a ares

; Therms Therms Therms Therms
Gumothyhay.......) 4.51 2.66 1.85 3.49
Red cloverhay ..... .| 4.46 2.46 2.00 3.49
Migedmay .. . . 4.39 2.48 1.91 3.39
Alfalfa hay and meal . . 4.37 2.45 1.91 3.60
Miaizewtover ... 9. . . 4.33 2.38 1.95 3.45
_ 4.41 2.49 1.92 3.48

These data show that approximately 56 per cent of the
gross energy of the dry matter fed in coarse fodders is
lost in the feces, urine, and gases evolved. |

Grains

Metabolizable energy
Gross Losses a ca
energy per | energy peT | por kilo Per kilo

kilo dry kilo dry = digestible
matter matter tention ee
; Therms Therms Therms Therms
Mawetmemw ..... 4.44 ti 3.33 3.80
Wheat (': SSS 2 Rien 4.53 2.02 2 OF 3.95
Hominy chop. ee 4.71 1.19. 3.52 4.07

Average . °° (xf oe 4.56 1.44 a.12 3.94

174 THE FEEDING OF ANIMALS

The loss from the grains is relatively much less than
_ from the coarse fodders, being only an average of 31.5
per cent. This is easily accounted for by the greater
digestibility of the grains.

We are to understand, then, that the metabolizable
energy of a ration is represented by the fuel value of the
dry matter which is digested from it, minus the dry mat-
ter of the urine and that lost in gases.

If, however, we wish to know the actual energy gain

to the animal from a particular ration, we must go farther
than a determination of its available energy.

255. Net energy.— Within a comparatively short time
we have begun to speak of the net energy of foods, and as
this is a practical consideration which is likely to be the
subject of much future discussion, it is well to notice it
in an explanatory way. As we have learned, food is not
applied to use until it reaches the blood. Between the
time when it is taken into the mouth and when it passes
into the circulation, it must have work expended on it
in the way of mastication, solution, moving it along the
digestive tract and assimilation, and it seems probable
that the amount of this work for a pound of food must
vary greatly in different cases. In fact, this seemed to be
proven by the result of some masterly investigations con-
ducted by Zuntz and associates in Germany.

256. Work of mastication (Zuntz).—Zuntz determined
the oxygen consumption, that is, increased energy used,
during the mastication of several feeds by a horse as
compared with what occurred with the animal at rest.
In considering the data shown in Table XX XV it should
be remembered that mastication is only one factor of the
loss of enérgy involved in the appropriation of food, and
perhaps a minor one.

“ee “iA 9 - he bin \ ; 1 is .
s FUNCTIONS OF THE NUTRIENTS en ACO
TABLE XXXV
pape a ps sang ss Additional Equivalent
as experi- con- CO, energy
ants eeinad excreted
Liters Liters Calories
Oats and cut straw (6:1) 8 12.964 | 10.679 64.17
Oe ee aie 8 33.840 | 27.813 | 167.44
Hay, oats, and cut straw 8 20.072 | 17.677 | 100.79
Maize and cut straw (6: 2 1.133 6.205 35.12
Green alfalfa .. 7 6.171 4.980 30.42
Computed for oats alone 47.00
Computed for maize alone . 13.80

257. Difference in total energy use with different
rations.—Zuntz and Hagemann determined the oxygen
use and carbon dioxid excretion during an exclusive hay
diet as compared with a diet of mixed hay and grain.

TABLE XXXVI
H
Hay and eis
Time since lastfed ..... . .. hours 2.6 2.8
Ration—
PM yk co ea oo a. Klos! |Aboumeiis 4.75
arrose Pag) nS em 6.
Straw ... Ler ey 7 a 1.
Total digested nutrients (fat x 2.4) grams 4,125 5,697
Per kilogram and minute—
Oxygen consumed ... . cub. cent. 3.9837 3.6986
Carbon dioxid given off . . cub. cent. 3.6586 3.6695

Energy set free (computed). gr. Cals. 19.552 18.339
Energy katabolism per day and head
Calories 12,450 11,678

The comparison of the energy use for the consump-
tion of the exclusive hay ration and hay-and-grain ration
shows that the latter, carrying 5,697 grams of digesti-

176 THE FEEDING OF ANIMALS at

ble matter, used 1,213 gram-calories less energy than the
exclusive hay ration, carrying 4,125 grams of digestible
matter. The hay ration cost for consumption 4.7 Calories
per gram of digestible dry matter and the mixed ration

only 3.2 Calories. This increased use of energy can only —

be explained by assuming that the cost of consuming the
grain was proportionately less than that of the hay, a
difference presumably due to the greater cost of masti-
cating the hay.

The differences revealed by Kuntz’s figures are inter-
esting and important. Chewing green food cost in labor

only about 18 per cent of the effort required to masti-

cate its equivalent of dry hay, the proportions of labor
for hay, oats, and corn being in the ratio of 100, 28
and 814.

This author goes farther and calculates that the
work of mastication and digestion combined is 48 per
cent of the energy value of the digested material from hay
and 19.7 per cent of that from oats. He also makes the
statement that in general the coarse foods have 20 per
cent less net energy value than the grains. All these
deductions are based upon the excess of oxygen used by
the animal when engaged in the work of chewing and
digestion, over that used when at rest. It would follow
from these results that anything in the way of growth or
treatment of a fodder which tends to toughen or harden
the tissue reduces the net energy value.

258. The work of digestion—Armsby regards the
work of digestion outside of mastication as a small factor.
His experiments when he attempted to measure the work
of mastication by the increased heat elimination, showed
no distinct evidence of such inerease. He concludes that
there must have been an increased production of heat

FUNCTIONS OF THE NUTRIENTS —*+177

during mastication which was not given off promptly.
The Zuntz method of measuring the increase of oxygen
consumption would seem to be the more reliable.

The results of Kellner and of Armsby and Fries, which
follow, do not appear to ratify the conclusions of Zuntz
and Hagemann, although the work of mastication was not
determined as a separate factor.

259. Total energy expended in feed consumption.—
Extensive determinations of the total energy expended
in feed consumption have been made, both by Kellner
and by Armsby and Fries. The use of energy in this direc-
tion is determined by comparing the heat production of
two rations of unlike quantity, heat production being
equivalent to the energy expenditure by the animal.
The increased heat production for the larger ration should
be credited, therefore, to the increase of material in the

ration, whether a single feed or a mixture of feeds.
Results by Armsby and Fries follow:

TABLE XXXVII

Distribution of heat production

Quantity| Total

f dr h Risi

Satter ieoduee Stand- ade P 2008 ee

eaten tion ing lying $on Be

Grams | Cals. | Cals. | Cals. | Cals. | Cals.

ign 2 4,892 | 9,523] 1,438] 59 794 G2e2

lp. 7 2,974 |7,791}1,107} 40 498 | 6,146

Difference ... .| 1,918 |te2Peeolp as 296 | 1,086
Difference per kilo-

gram of dry matter 903| 173 9 154 567

The “remainder,” after deducting from the total

heat production that caused by standing, rising, lying

Nors.—In a recent publication by Armsby (Pennsylvania State
College Bulletin No. 142) the position is emphatically taken that the
consumption cost with concentrates is as great as with coarse feeds, and
suggests other factors which obscure differences caused by unlike
mechanical work.

L

178 ' ‘THE FEEDING OF ANIMALS

down, and fermentation, is that which should be charged
to the work of consumption. As the smaller ration was
less than the other by 1,918 grams and the heat produc-
tion was 1,086 Calories less for the smaller ration, it
appears that the work of consumption was 567 Calories
to a kilo of dry matter or 258 Calories to a pound. |

260. Calculation of net energy value.—The following is
an example of the calculation of net energy value:

TaBLE XXXVIII

Calories Calories Calories
Total chemical energy. ..... 4,408
Losses of chemical energy ae
WeeCe oc) soe we Bessy AO2
TM ri se afiyt Wiehe hs 243
GERMAINE 9, >. 40. Madu Rd 266

iver) i i res 2,571
Increased heat production ip been 1,202

eam lOsses. OP Ae ee 3,773
Net energy value .... 635

261. Net energy of various feeds.—In this way the
following table was derived from the data secured by
Armsby and Fries:

TaBLE XXXIX

L f ede yd d Net

Osses 8} expen e e
aaa cneray ,| Chemical [ia feed | aura

tion
~ | Perkilo | Perkilo | Perkilo | Per kilo

Calories Calories Calories Calories
Timothyay ... . . |; 4,518 2,664 782 1,072
Red cloverhay ... .| 4,462 2,461 962 1,039
*Alfalfiahaym. .... .| 4,872 2,451 1,169 752
Maize stover’ .....| 4,332 2,380 1,065 887
Maizemeal ......| 4,442 2115 1,434 1,893
Wheat brat. pi «> .-|_,.4,5382 2,021 1,177 1,334
Grain mixture, No.1 . .| 4,685 1,621 1,327 1,737
Hominy chop .. . .| 4,709 1,187 1,365 2,157

*Includes alfalfa meal.

Pee ae
By u- “ty woke i — aie + 4 *
nae wes ; peed . -

.

:

,*

7 aa

mt

FUNCTIONS OF THE NUTRIENTS ; 179

The values arrived at by Kellner are in the next table.
These differ, as would be expected, somewhat from the
values reached by Armsby and Fries because of a dif-
ference in the character of the materials fed.

TABLE XL

Energy

Gr Losses of | expended Net
Feeding-stuff ics chemical in feed energy
ee, energy consump- values
tion

Pameine | Perddlo ’| Per diaeeeee ale

Calories Calories Calories Calories
Meadow hay ..... .| 4,483 2,260 1,254 919
Pies: - . 5 . ..| 4336 2,848 1,014 574
Wheat straw... .. ..| 4,444 3,062 1,138 244
Extracted straw ....| 4,147 1,013 1,160 1,974
eee AY! oe 1,045 803
RMMEME 22S, ee atk 958 747
ae siraw ... . . > . 877 747
Memmeiay oe 932 811
RAMEE RR mets ari hae: 259 1,101 1,248 1,803
Peeelou 2 |. 9,457 4,165 1,727 3,565
Wee gluten .: >. .| 5,579 1,974 2,096 1,509

Beemmolasses . . .-. .|- 3,743 945 988 1,810

262. Computing net energy values of feeding-stuffs.—
It is very evident that it is not possible to make direct
determinations of the net energy values of all feeding-
stuffs, but these may be estimated with reasonable
accuracy. The following method of computing these
estimates may be followed, which is based on the total
digestible material, and the conclusion that each gram
of digestible organic matter contains 3.5 calories of
metabolizable energy. The energy used for feed con-
sumption is reduced to the percentage of dry matter in

the three feeds entering into the computation shown in
Table XLI.

180 THE FEEDING OF ANIMALS

TABLE XLI
Alfalfa Oat Wheat
hay straw bren
Per cent | Per cent | Per cent
Teedry matters... . gee. 91.6 .| 90.8 88.5
Digestible—
> wee ee. OR 1.2 12.01
Mameagnvirates: . 5... . 3/400 38.64 41.23
Ll ae aa Beton ee 1.38 76 2.87
DTotakdigestible ........ .| 49.29 | 40.6 56.11

Alfalfa hay, 1,169 calories X 91.6 per cent dry matter=1,071
calories per kilogram air-dry feed.

Oat straw, 1,014 calories X 90.8 per cent dry matter=921 calories
per kilogram air-dry feed.

Wheat bran, 1,138 calories X 88.5 per cent dry matter=1,007
calories per kilogram air-dry feed.

Alfalfa hay (3.5 calories X 492.9 grams digestible ‘matter)—1,071
calories=654 calories per kilogram=29.7 therms per 100
pounds air-dry feed.

Oat straw (3.5 calories X 406 grams digestible matter)—921
calories=500 calories per kilogram=22.7 therms per 100
pounds air-dry feed.

Wheat bran (3.9 calories X 561.1 grams digestible matter)—1,007
calories=1,181 calories per kilogram=53.6 therms per 100
pounds air-dry feed.

These methods of ascertaining net values of feeds may
be regarded as complex, but they are unquestionably
the most accurate of any methods so far developed.

The results of Armsby and Fries and Kellner do not
accord with a somewhat widespread teaching that the
energy expended in the consumption of coarse feeds is
greatly more for a unit of dry matter than is the case with
the concentrates. It is conceded, of course, that the
energy expended in the mechanical work of mastication
must be greater in the coarse foods than in the grain

FUNCTIONS OF THE NUTRIENTS _—‘181

feeds. It seems, from the later determinations, however,

that when all factors are considered, the difference in the

- total energy expenditure in the two classes of feeds is not

greatly unlike.

263. Estimation of production values proposed by
Armsby.—Instead of using net or production values as
experimentally determined for each individual feed,
Armsby has computed a table based largely on the
results of investigations by Kellner.

This investigator arrived at what is termed the pro-
duction values of pure nutrients, such as a single pro-
tein, starch, or one of the fats. His figures are as follows:

TaBLE XLII. PrRopucTION VALUES PER POUND
Calories

Mieestibic proces... 2 s.wews. ibe ko 1016
Digestible starch or crude fiber ........4 1071
mipesaale cane-suparo) 2 8. Se ek E 812
Digestible fat—
Snueoarse trodders and roots... ws ee ge 2041
im prains.and by-products)... 2: . -. « i 2273
In feeds with over 5 per centfat ........ 2585

In making up the tables of production values, these
values for pure nutrients are used in connection with a
given allowance for the expenditure of energy in mastica-
tion due to the presence of crude fiber. Kellner found it
was possible to estimate fairly. accurately the production
value of concentrated feeds by means of these factors, but
in the case of the coarse fodders carrying a much higher
proportion of fiber such a method of computation was
not reliable. He found, however, that if he deducted
from the figures obtained through the use of the produc-
tion values for pure nutrients 617 calories for each pound
of crude fiber in the coarse fodder the computed value

ee bey Oy THE FEEDING OF ANIMALS

was little different from the real value. In the use of
‘this method only the true proteins are brought into the
calculation, so that the values are based upon the digest-
ible true proteins and the total heat value of the nutrients
minus the energy expended on the crude fiber. The fol-
lowing table illustrates production values that have been
made up after this method, with the exception that the
deductions for crude fiber are less for the green fodders
and roots than with the dry coarse fodders.*

TaBLE XLIII

Total | Digest-
Feeding-stuff dry ible Energy
matter | protein

Pounds} Pounds} Therms

Green fodder and silage— 100 Ibs.
ee Vg as face ad ahha ene ey pee OR OD By
Corn silage ... 2h ape heme! 121 t Reee

Hay and dry coarse fodder
Clovermay, red...) Oo a ye eh
@orn 'stover es a a a GS

Straws—
Ont stram 0. ae OS

Roots and tubers—

Pigaparan . .). J ee 88 | 8.

Grains—
em, wf eS OT 7 Oi aaa
_ Se SEB 8.36 | 66.27

By-products—

Brewers’ grains, dried ....... . ..{| 92. | 19.04} 60.01
Cmoneeed meal... . .: . -| 91.8 35.15 342

ixitemremaodry.... . . ... . SaRiee) 91.9 | 19.95) 79.32
Linseed meal, new process. ..... .. .| 90.1 | 29.26 | 74.67
Wiheapteees, | ww... |. oe. k LO 2) ae ae

* Since writing the above, Armsby has published a newly computed
and very full table of production values, based upon the composition of
feeding-stuffs as found in ‘‘Feeds and Feeding,’’ by Henry and Morrison.
This table, computed by a simpler method than the above, may be found
in the Appendix.

FUNCTIONS OF THE NUTRIENTS ~~ 183

ENERGY RELATIONS.—HEAT REGULATION

As has been pointed out, the animal body is the field
of numerous mechanical activities. What is the rela-
tion of the several nutrients to these manifestations of
vital energy is an interesting and in some ways an in-
tensely practical matter.

264. Relation of protein to muscular activity—The
belief prevailed at one time that muscular contraction
caused a wasting of the muscle substance which must be
replaced by the protein compounds of the food; in other
words, protein alone was believed to sustain the work of
the animal body, both internal and external. It would
follow from this that the more work is done the more
protein is needed. This view is no longer held. The more
exact methods of modern research have revealed the
fact that an increase of muscular effort, even up to a
severe point, increases but little, if any, the nitrogen
compounds of the urine, these being the measure of the
protein that is destroyed.

265. Energy chiefly from carbohydrates and fats.—
There has come to light a corresponding fact that the
consumption of fuel in the body other than proteins
increases proportionately with the increase of work.
This means that as animals are ordinarily fed mechanical
work is largely sustained through the combustion of
carbohydrates and fats, although a fairly generous
amount of protein seems to promote the well- being of
a draft animal.

266. Heat regulation—As no energy is ever lost,
into what is the energy converted that is applied to
muscular contraction? It is concluded that muscular
energy used by the animal is partly transformed into

184 THE FEEDING OF ANIMALS

external motion (work) and partly into heat, and this
certainly is consistent with facts as observed. Violent
exercise by the animal greatly increases the production
of heat. We know this is so because under these con-
ditions an increased amount of blood is thrown to the
surface of the body, thereby greatly increasing the loss
of heat by radiation; perspiration sets in and with it the
consequent evaporation of much more moisture, thus
disposing of much heat. The dog, and sometimes other
animals, pants and thereby causes a large loss of heat
from the expanded surface of the moist tongue. All this
occurs without reducing the body temperature below
the normal. In fact, nature adopts these various devices,
such as increased circulation of the blood and perspira-
tion, in order to regulate the body temperature and pre-
vent its rising above the proper point. The explanation
of this greater heat during labor is that the mechanical
energy manifested by the muscles is converted to heat,
which under circumstances of severe exercise is more
than enough to keep the body at its usual temperature
and maintain the usual radiation. When it is severely
cold, on the other hand, vigorous exercise is sometimes
necessary in order to keep sufficiently warm.

267. Animal heat a secondary or waste product.—
The view now obtains that under certain conditions
body heat is wholly a secondary product, that combustion
first supports muscular activity with heat as a by-prod-
uct; in fact, that at usual temperatures no food is
burned primarily to keep the animal warm. Under cer-
tain conditions there may be combustion of food for the
specific purpose of warming the body. In any case,
animal heat is sustained either directly or indirectly by
the oxidation of the nutrients.

: - PUNCTIONS OF THE NUTRIENTS 185

268. The critical temperature.—Recent investigations
show that under given conditions there is an air tem-
perature, called the “critical temperature,” at which meta-
bolism (oxidation) reaches a minimum. If the air tem-
perature falls below this point thus causing a greater
radiation of heat from the body surface, increased oxida-
tion occurs. If the temperature of the air rises above this
point there is no diminution of oxidation but rather a
slight increase, hence the conclusion that there is a mini-
mum oxidation necessary to the maintenance of the vital
functions which must go on however much the demands
for the radiation of heat may be lessened by a rise of the
air temperature. It is evident then that at the higher
air temperatures there is an excess of oxidation above
that which is required for warming the animal, so that
some heat must be thrown off as a waste product. Which-
ever way the air temperature moves from the critical point
there is heat regulation, this being chemical for the lower
temperatures and physical for the higher.

The critical temperatures for our various farm animals
have not been determined, so that we are not yet able to
draw therefrom conclusions as to the influence of given
temperatures upon production. The opinion is ventured,
however, that with animals protected by a coat of hair,
that are kept under comfortable winter conditions, the
temperature of the surrounding air does not fall below
the critical point.

THE NUTRITIVE INTER-RELATION OF THE FOOD COMPOUNDS
AND THE NEED OF COMBINING THESE IN THE RATION

As we have seen, the conclusion reached by many
extended and severe investigations is that the compounds

_-

186 THE FEEDING OF ANIMALS —

of foods have certain functions in common. For instance,
the proteins, carbohydrates, and fats are all oxidized
wholly or in part to supply the necessary energy for
muscular activity. The proteins then serve both construc-
tive and fuel purposes. Carbohydrates and fats’ are
alike in being sources of energy through oxidation, and
in being utilized for the deposition of animal fat. In
view of these facts, the question arises whether the physi-
cal welfare of the animal requires the mixture of nutrients
that commonly exist in the average ration and that is
enforced in the standards that are recommended by
students of animal nutrition. It is certain that some
species of animals may exist wholly on a flesh diet which
is practically devoid of carbohydrates, but this is not
true of farm animals.

269. Protein physiologically necessary.—The neces-
sity of protein in the ration is abundantly demonstrated.
Many investigations have shown that when the food
contains no protein, the waste of body nitrogen continues,
no matter how abundant is the supply of carbohydrates
and fats. In other words, a continuous protein cleavage
is demanded by the animal organism, and no other
nutrients can serve as a substitute for protein in meet-
ing this demand. If the food contains no protein,
body tissue will be depleted. It cannot be said that
either carbohydrates or fats are an essential part of the
diet in the sense protein is, because it is possible to sub-
stitute the one for the other as energy-producers and pro-
tein for both.

270. Carbohydrates physiologically economical.—In
spite of these facts, it is safe to assert that the welfare of
the animal organism demands a food carrying a mixture
of the three classes of nutrients. The larger part of the

- \ ; : 7

FUNCTIONS OF THE NUTRIENTS _—187

~ animal’s food is used for the production of energy, and it

is physiologically economical that this energy be largely
supplied by the non-nitrogenous nutrients, particularly
carbohydrates. If the proteins are broken down to
supply energy, there is always a definite proportion of
urea and uric acid residue that must be eliminated through
the kidneys. An unnecessarily heavy protein diet bur-
dens these organs and floods the system with these nitrog-
enous wastes. On the other hand, the carbohydrates,
when not stored as fat, are completely oxidized to the
simplest compounds, carbon dioxid and water, which are
eliminated through the lungs and skin, part of the water
so formed acting as a solvent of the urinary compounds.
Investigation seems to prove conclusively that the
animal body has a physiological preference for carbo-
hydrates over the fats or other nutrients as a source of
energy. After the free ingestion of sugar, the respiratory
quotient in certain experiments has become 1.00 when
just previously it was much less than 1.00. This demon-
strates that while fat was being oxidized before the sugar
was taken, the oxidation immediately changed wholly to
the sugar. This indicates the physiological adaptability
of starches and sugars for maintaining muscular activity.

271. Protein-sparers.—The carbohydrates and fats
are sometimes classed as “‘protein-sparers.” This means
that, with an adequate supply of these bodies in the food,
protein destruction may be reduced to the lowest pos-
sible limit. To illustrate, if a man doing moderate work
were maintaining an energy balance when eating of
digestible nutrients 218 grams of protein, 400 grams of
carbohydrates, and 56 grams of fat, and 100 grams of
digestible carbohydrates were added to the daily food,
approximately 100 grams of digestible protein could

188 THE FEEDING OF ANIMALS

undoubtedly be withdrawn from the daily food without
causing any drain upon body protein to meet the demands
of the organism. As stated, however, such a substitution
cannot be carried beyond certain limits without depress-
ing the protein-supply below the body needs for main-
tenance. Fats are not as efficient protein-sparers as are
carbohydrates. To be more explicit, fats and carbo-
hydrates do not replace protein in proportion to their
energy equivalents, carbohydrates being the more effi-
cient. In brief, then, experience and science both indicate
that carbohydrates are the most healthful, and physiologi-
cally the most economical, source of a large proportion
of the food energy. There is every justification for the
relative abundance of starch foods in the rations of
farm animals.

272. Nutritive value of the gums.—The question has
been raised as to whether the gums (pentosans) which
exist so abundantly in many coarse foods and in some
grain products like wheat bran are not inferior as sources
of energy to the other more soluble carbohydrates. It
has been observed that the sugars which result from the
action of ferments on these bodies have, in some in-
stances, not been oxidized, but have passed off in the
urine as such. It appears that under normal and usual
conditions this does not occur to any extent with herbiv-
ora. Pentosans are present in all rations for farm
animals, and we have no reason for believing that the
pentose sugars are constant ingredients of their urine.
Muccollum and Brannon studied extensively the fate
of various pentosans in the digestive tract of bovines.
They found that these compounds are not equally diges-
tible from all sources. Those from the corn, oat, and wheat
plants were studied and the range of digestibility was 46

FUNCTIONS OF THE NUTRIENTS — 189

to 67 per cent. The corn-plant pentosans were digested
most fully and those from the wheat plant least so.

Swartz concluded from extensive investigation that
the water-soluble hemicelluloses are resistant to the
action of enzyms and disappear from the digestive tract
only in proportion as they are attacked by bacteria.
Pentosans and mannans which are hydrolized by bacterial
action were found to be almost wholly digested, while
galactans were largely excreted as such. In considering
their digestibility the groups of hemicelluloses evidently
must be considered separately. In any case, digestibility
should not be considered as a measure of nutritive
value.

273. Relative importance of the nitrogen compounds
of feeding-stuffs.—What is known as the crude protein
of feeding-stuffs is the total nitrogen multiplied by the
factor 6.25. As has been stated, protein as so estimated
contains a variety of nitrogen compounds that are unlike
in character and exist in various cattle foods in greatly
unlike proportions. For example, a much larger part of
the crude protein of coarse fodders and roots consists of
amides than is the case with grains, the latter being cor-
respondingly richer in true proteins. If, therefore, it is
found that the true proteins differ from the amides in
function and value, we have established one point of
unlikeness between grain foods and roots or the coarse
fodders. We have convincing proof that the true pro-
teins are the main flesh-formers found in cattle foods.
Are the amides such as glutamin and asparagin also flesh-
formers? Earlier experiments with these compounds led
to the conclusion that they may exercise a protective
function toward the true proteins and thus reduce the
minimum of such proteins necessary to satisfy the needs

190 THE FEEDING OF ANIMALS

of an animal under given conditions of production. Some
of the more recent investigations indicate that the amides
should be classed as to function with the true proteins, or,
in other words, that they may take part in the synthesis
of the proteins that are used constructively in the animal
body though probably with not the same percentage of
efficiency. Evidence exists, moreover, that the different
amides are not of equal value. (See Par. 85.)

274. Relative nutritive efficiency of the true pro-
teins.—Notwithstanding possible function of the amide
compounds in the synthesis of animal proteins, the true
proteins of our cattle foods must be regarded as the main
flesh-formers. There are, however, many true proteins
which are unlike in their constitution. It is desirable
to know whether these single proteins differ in nutritive
value for specific purposes, like growth or milk forma-
tion. Are the alcohol-soluble proteins, such as gliadin
and zein of equal value with an albumin, a globulin, or
casein? Reference has been made to the fact that while
the cleavage products of these various proteins (amino
acids), or what are called the building-stones, are to a
great extent similar as to kind, these building-stones are
not found in the same proportions in the several proteins,
and with some proteins certain building-stones are lack-
ing. The investigations of Mendell and Osborne, pre-
viously mentioned, indicate great unlikeness in nutritive
function and value. It is found, for instance, that the
gliadin of wheat and rye does not function as does the
casein in milk and that zein is particularly inefficient as a
means of even sustaining life, and it is significant that
the gliadin is deficient in lysine, and that zein is further
lacking in tryptophane, whereas the proteins of the animal
body contain both of these animo acids. (See Par. 85.)

Ree ic keene Bits oe) SOK, ee ET Be tT ak ane * a
Rak i Cao PAS? ae i ay LN
Ph he ag Oy he” sz : peta SS ind

es

FUNCTIONS OF THE NUTRIENTS -~ 191

| 275. A single amino acid a limiting factor —Evidence

on this question is seen in experimental work carried on
by Osborne and Mendell. These authors brought rats to
full size and kept them in health when the diet contained
18 per cent of casein. When the casein was reduced to 12
per cent, growth fell below the normal. When reduced to
9 per cent, growth was promptly limited by the protein
factor. If, however, cystine was added to the 9 per cent
of casein, the ration was rendered much more efficient
for growth, showing that the presence of an insufficient
quantity of this one building-stone was the limiting
factor. Similar results were secured in experiments with
edestin. When 15 per cent of the ration consisted of
edestin, normal growth was secured, but not with 9 per
cent. The addition of lysine to the 9 per cent of edestin
caused an improvement. Lact-albumin was efficient
because all the building-stones, including lysine and trypto-
phane, are relatively abundant in this protein.

McCollum has determined, through a series of experi-
ments in which he fed single foods to pigs, the proportion
of protein used by the animal for building protein tissue.
His conclusions are as follows:

Per cent

deposited
Oil meal ‘proteins’: 242022 “tes 40 eee 16-17
heat protems 3.05 SA 4 ee 20
Morn proteins: 2-5. . 2. bd se we 24
Mati provemsno ss. wt eee ee ee 25
PRCA: PCE Ot 4 ne. belie) ee 40
tee hs oe EO. a ee 45
Seeomed milk proteins . . . 2 eael si... ee 63

The author also gives figures showing that the proteins
of one food supplement those of another in producing
more growth when the two foods are combined than when
fed singly:

192 THE FEEDING OF ANIMALS

; Per cent _
: deposited /
Corn proteins 90 per cent, oil meal proteins 10 per cent . 31
Corn proteins 75 per cent, oil meal proteins 25 per cent . 37 ©
Corn proteins 60 per cent, oil meal proteins 40 per cent . 32

Those proteins are most efficient, evidently, whose
building-stones correspond most nearly in proportion to
those of animal proteins.

276. Nutritive value of the gelatinoids.—The gelati-
noids which belong to the class of non-proteins cannot
be regarded as taking the place of proteins. It has been
found that they protect protein from cleavage and thus
make a minimum protein-supply more efficient but they
do not function in the synthetical processes as the true
proteins do. Gelatin also is lacking in certain building-
stones, namely tyrosine, cystine, and tryptophane. This
consideration of the protein compounds on the basis of
their building-stones is a new and interesting point of
view and leads to the conclusion that those proteins are
most efficient for constructive purposes whose building-
stones correspond in kind and proportion most nearly to
those of the proteins in the animal body.

277. Synthesis in the animal of phosphorus-bearing
proteins.—One interesting question which has been con-
sidered is whether the nucleo-proteins and _ phospho-
proteins which are found so abundantly in eggs and in
milk must be supplied as such in the food, or whether
they may be built up in the animal from the simple pro-
teins and phosphates. If we could learn that the food
must contain these peculiar proteins all ready for use,
then we would have a valuable suggestion for feeding
cows and poultry. It now seems that this is not the case.
The sea salmon, which, during its stay up the river, is
believed to take no food, undoubtedly produces large

. FUNCTIONS OF THE NUTRIENTS i 193

masses of eggs from the body substance, and it seems
unlikely that so much nuclein as is needed exists in the
flesh. If a cow gives thirty pounds of milk daily, nearly
or quite a pound of casein must come from somewhere,
and there is no evidence that any ordinary ration would
contain so large a quantity of phospho-proteins of like
constitution. Hens’ eggs are rich in nuclein, beyond any
amount which the food seems likely to supply. Experi-
mental evidence supports these general inferences.

278. The function of certain unidentified bodies.—
An important addition to the science of nutrition is the
recent demonstration that certain compounds are asso-
ciated with animal foods which have a growth-promoting
function and in the absence of which either artificial or
natural foods fail to sustain growth and even life. (See
Par. 118.) It has been known for some time that some
such substance was associated with the shells of rice which,
when given to animals afflicted with beri-beri from eating
polished rice, would restore them to a normal condition.
Substances of this class were named vitamines by Funk.

An enlargement of the knowledge of bodies of this
class was led up to through studies by American
investigators as to the relative nutritive value of single
proteins. Heretofore the attention of investigators in
animal nutrition has been focussed chiefly upon the con-
structive and energy functions of the various classes of
nutrients, and it was expected that when the proteins,
carbohydrates, and ash compounds, supposedly necessary
to complete nutrition, were all supplied to an animal,
satisfactory results would be accomplished. It was dis-
covered that, when there was fed a combination of puri-
fied nutrients artificially prepared with great care and in
accordance with the best knowledge of the needs of the

A eV) it WRT, Ae is yo ae yg raat Fee Medan
- ah ¥ ‘ Bi IG: nay ¥ wll ae Aa
ria \ abe Teal LL ear Nee Le on

J \

194 THE FEEDING OF ANIMALS

animal, growth was not secured. When, however, what,
was termed “protein free” milk was used in connection
with such a preparation, normal growth resulted. This
result, observed by Mendel and Osborn, led up to a
series of investigations in which Hart and McCollum have ©
taken a prominent part. It now appears from abundant
data that two classes of growth-promoting substances
exist, which have been termed Fat-soluble A and Water-
soluble B, terms which are temporary until these bodies
have been identified. The proof of the existence of these
bodies has been illustrated as follows (McCollum): If to
a mixture of purified proteins, carbohydrates, and salt
mixtures containing all the salts found in the animal
body there is added either a small amount of egg yolk
or milk powder, growth proceeds normally; whereas the
mixture of nutrients before such addition fails to produce
growth. If the dried egg yolk is extracted with ether to
remove the fat, the addition of the residue does not give the
desired result. The addition of the fat alone also is shown
to be futile. If, however, there is added to the nutritive
mixture along with the extracted egg-fat a water-extract
of the fat-free yolk residue, growth is normal. Similar
results occur with other substances, such as milk powder.
This is the basis for the classification into Fat-soluble A
and Water-soluble B, both of which are essential to
growth. It appears that the milk of an animal which has
been fed on purified nutrients fails to sustain her young,
showing that these growth-promoting substances are
transferred from the food to the mother’s milk and are not
synthesized within the body.
It seems certain that the disease known as beri-beri,
brought about by a restricted diet of polished rice, is due
to the absence of one of these classes, and it is probable '

FUNCTIONS OF THE NUTRIENTS —‘195

that pelagra, prevalent in the South where the diet of

many individuals is considerably restricted, is due to the
absence or insufficient supply of one or both of these
classes.

These accessory substances appear to be abundant in
egg, milk, and the forage portion of many plants, Fat-
soluble A being deficient in the body fats of animals and
absent from the fats or oils of many species of plants.
The knowledge of the presence or absence of these growth-
promoting substances in cattle foods will undoubtedly be

enlarged as investigation proceeds.
It is shown in experiments by Hart and McCollum

that when the rations of animals were restricted to a single
‘plant, that the wheat germ contains a toxic body. Ani-
mals fed wholly on the corn plant or its products developed
normally and produced young. Those fed on the wheat
plant or its products, without the addition of other food,
failed to make satisfactory growth and to produce vigor-
ous young. Similar results were obtained with wheat
products when fed to swine. Such results with the wheat
plant were evidently not due to a lack of nutrients but
investigation showed that the operating cause was a
poisonous principle located in the fat of the wheat, this
principle being removed when the wheat oil was extracted.
We have here, then, an example of a toxic body con-
tained in one of the most common of our feeding-stufts,
the effect of which has been less observed because wheat
by-products have constituted only a portion of the food
of the animal.

279. Relation of production values to profit from
feeding animals.—The production from a given quantity
of food varies greatly under unlike conditions. It can
scarcely be doubted that the proportion of the available

196 THE FEEDING OF ANIMALS.

nutrients which are consumed, that is, burned as fuel,
increases as the ration increases above what is needed
for maintenance, and inversely the proportion of the
nutrients stored in the body as flesh and fat undoubtedly
is less the greater the quantity fed is in excess of the
demands for maintenance. A large excess over mainte-
nance is relatively less efficient than a small one in the
production of flesh or milk. There comes a point where
additional food produces no additional gain, but only
additional consumption. The age of the growing animal
and the condition of a fattening animal also modify the
efficiency of the food for production purposes, as does
individuality, and with a cow the stage in the period of
_ lactation. With all these variations no averages are pos-
sible which express with any definiteness fixed production
values for the different nutrients.

we ‘ds
se a ee

CHAPTER XI
LAWS OF NUTRITION

THE preceding pages have been devoted to a
discussion of the origin of cattle foods, what they are
in substance, how their nutrients are made available and

- how used. So far no attempt has been made to bring

together in a concise form what may be called the funda-
mental principles or laws of nutrition. It is desirable, how-
ever, before passing to the consideration of the practice
of cattle-feeding, to summarize the principles on which
the science of cattle-feeding is based.

280. All energy and building-material applied to the
maintenance and growth of the animal body come from
the food, water, and oxygen being included in this term.
The animal originates neither energy nor matter.

281. Only that portion of the food which is digested,
i. e., that which is rendered soluble and diffusible by the
digestive fluids so that it passes into the blood, is avail-
able for any use whatever.

282. The unutilized food and the wastes pass from the
body in several directions. The undigested part mainly
constitutes the solid excrement or feces. The urea and
other nitrogenous compounds which are the unoxidized
portion of the protein, pass out wholly in the urine. All
digested nitrogen not stored is found here. The carbon

- dioxid is eliminated through the skin and lungs, chiefly

the latter, and water is disposed of through the pee
skin, and lungs.

(197)

s ve -

Ae ~

198 THE FEEDING OF ANIMALS

283. The digested food is used in two general directions,
(a) for the production of energy and (6) for constructive —

purposes.
(a) The food energy is made available through com-
bustion, i. e., the oxidation of the carbon compounds of

the food to simpler substances, carbon dioxid and water,

thus liberating the energy stored in the plant during its
growth. Protein is never fully oxidized, but carbohydrates
and fats may be. All the organic nutrients may be oxi-

dized to produce energy, the phycological energy values ©

of protein, carbohydrates, and fats being approximately
as 1, 1, 2.25. The larger part of the energy used by farm
animals comes from the carbohydrate portion of the food.
This liberated energy finds expression in the animal
organism in various ways, as heat, mechanical energy or
motion, and chemical transformations. The total energy
of food is never all available to the animal because of a
loss in the excreta and gases. Moreover, the productive
energy is much less than the available energy, because
much energy is used in the work of appropriation of the
food.

(b) The food compounds are used for constructive
purposes, either without changing their general charac-
ter, as, for instance, the building of muscular tissue from
the plant proteins, or they may be reorganized into bodies
of a very different character, as in the formation of
animal fats from starch and sugar. Protein is used to
construct muscular tissue, in fact, all the nitrogenous
parts, and is a source of fat. Carbohydrates can only be
used constructively for the formation of fat, and the same
is true of food fats or oils. Mineral matter is needed for
the formation of bone, enters into the constitution of the
soft parts, and has important metabolic functions.

Ly,

=~
oS
i
=

LAWS OF NUTRITION eX 99

284. The matter of the digested food, including water
and oxygen, is exactly equal to that stored in the body or
in milk, or both, plus that in waste products—feces,
water, carbonic acid, and urine solids. Such a balance

may not be maintained for any particular day, but will

ultimately be found to exist.

285. Under given conditions of species, sex, climate,
and use, a definite amount of digested organic matter is
necessary to maintain a particular animal without gain

_or loss of body substance. This means simply that tis-

sue wastes must be replaced, and the fuel-supply must
be kept up.

If the animal receives no food, or less than the amount
needed for maintenance purposes, tissue waste and the
production of energy do not cease, but go on wholly or
in part at the expense of the body substance.

286. Food supplied above a needed maintenance quan-
tity may be utilized for the production of new substances
or work or may be eliminated in part increasing the
waste. Within limits, both things generally occur. In
the proper sense of the term, no production ever occurs
without an excess of food above maintenance require-
ments. Milk formation may sometimes go on at the
expense of the body substance, but with proper feeding,
milk, flesh or muscular work are produced at the expense
of food supplied in excess of that needed for maintenance.

287. Regard must be had to the supply of particular
nutrients as well as of total food. Even with an animal
doing no work and giving no milk a certain amount of
protein will be broken up constantly into urea and simi-
lar compounds, an amount which will be withdrawn from
the body tissues to the extent that it is not supplied by
the food. In addition to this, a milch cow, for instance,

200 THE FEEDING OF ANIMALS —

must have protein for the formation of the nitrogen com-
pounds of the milk, or a steer for the growth of flesh, in a
quantity proportional to the production, and food must
supply it. There is, therefore, a minimum supply of pro-
tein, which, in a particular case, is necessary for the
maintenance and for constructive purposes, less than
which ultimately diminishes production to the extent of
the deficiency, or else requires the use of body tissue.

288. The different classes of nutrients are to some
extent interchangeable in their functions. That is to say,
all the organic nutrients may be burned to supply energy.
Protein may be so used even to withdrawing it from the
purposes to which it is necessary unless the carbohydrates
or fats are sufficient to protect it from being consumed as
fuel. A proper supply of the non-nitrogenous nutrients
is required, therefore, to insure the application of the
necessary minimum of food protein to its peculiar uses.
The carbohydrates and fats are the physiologically eco-
nomical source of the main part of the energy used by
farm animals.

CHAPTER XII
SOURCES OF KNOWLEDGE

Tue foregoing chapters embody many statements of
principles and facts which have been made positively
and without modification. To quite an extent these
are based upon the conclusions of scientific men, i.e.,
conclusions which have been reached after such study
of the problems involved as is competent to secure ac-
curate information. In some cases this study has been
severe and long continued, having been carried on by
the use of methods and apparatus capable of the most
precise measurements. Moreover, in the investigations
of science an effort has been made to proceed logically,
so that the results attained shall not be fallacious. Not-
withstanding the fact that a great deal of our knowledge
is the result of an earnest and impartial search after
truth, under conditions especially favorable to its dis-
covery, many persons are disposed to give more credit to
traditions and conclusions of practice than to the care-
fully prepared verdicts of science. It may not be out of
place, therefore, to present in this connection some of the
considerations and methods which have to do with the
acquisition of knowledge concerning animal nutrition,
for this may aid us to appreciate the value of well-estab-
lished facts and to exercise caution in accepting the
verdicts either of science or of practice before they are
thoroughly justified.

There are three general ways in which we may be

(201)

202 THE FEEDING OF ANIMALS

said to have acquired knowledge in regard to feeding
animals: | .
1. The observation of ordinary practice.
2. Practical experiments, so called.
3. Scientific investigation.

289. Conclusions from feeding practice.—Until within
recent years, the practice of cattle-feeding has been
entirely governed by the conclusions drawn from ordi-
nary practice. Among the many men engaged in animal
husbandry, certain ones possessed of more than average
powers of observation and business ability have secured
good results with certain feeding-stuffs and methods of
feeding, and their practice has been accepted by their

neighbors with no further demonstration than that these —

successful farmers sold fat cattle and obtained large
returns from the dairy. During the centuries that man
has had domestic animals under his care, certain results
have appeared to follow from certain systems of feeding
or the use of certain foods, and upon these so-called
practical observations the feeder has built his creed.

In these ways there have come to be accepted, some-
times locally and sometimes generally, standards of
feeding as to quantity, kind of ration, and times of feed-
ing. At the same time, it was necessary only to attend
a farmers’ convention fifty years ago to become con-
vinced of a great variety of opinions as to the best
methods of practice. In fact, opinion was the court of
last resort. ‘There were then no known, well-estab-
lished fundamentals to which appeal could be made as
a basis for discussion. While many false notions were
entertained, many of the beliefs then prevailing were
undoubtedly correct or contained a germ of truth. It
is generally safe to assume that when an opinion is

yr . A | y /
SOURCES OF KNOWLEDGE ee OORE*

widely and persistently held it is not altogether with-
out reason or foundation. It is often the expression, in
more or less correct terms, of some important principle.
No one should lightly turn aside from widespread tra-

_ ditions and convictions in regard to any line of practice.

A knowledge of the precepts governing the feeder’s art
that are the accumulation of experience in the care of ~
animals is to be respected and is, to a great extent, essen-

' tial to successful practice. It is also true that little sub-

stantial progress can be realized in any art if its under-
lying truths are not understood, for when this is the case
the results of experience under one set of conditions do
not serve as a guide under circumstances entirely different.

290. Practical feeding experiments.—With the advent
of modern science and of the efforts to utilize it in agri-
culture, an attempt has been made to search for impor-
tant truths more systematically, an effort undertaken
chiefly by experiment stations. As one means of gain-
ing knowledge, these institutions, and to some extent
private farmers, have conducted many so-called practical
feeding experiments in order to verify present beliefs,
test theories, and solve existing problems. The relative
value of various feeding-stuffs and rations for producing
growth and milk and the influence of different fodders
and grain foods upon the quality of the product have
been the subjects of numerous feeding tests. Much
valuable information has been secured in this way, but
there has not always been a full recognition, even by
experiment stations, of the limitations which should be
observed in drawing conclusions from this manner of
experimentation.

291. Inconclusiveness of ordinary feeding experi-
ments.—In order to view this matter more in detail, let us

\

204. THE FEEDING OF ANIMALS

consider experiments in testing rations for growth and —
milk production. The usual method of procedure with
such feeding trials is either to feed two lots of animals
on the rations to be compared and note the compara-
tive growth or milk yield, or to feed the same lot
on one ration for a time and then change to another
ration.

If these tests are made with growing or fattening
animals, the increase in live weight is taken as the meas-
ure of the relative efficiency of the rations compared.
It should be said of these experiments that their appar-
ent verdict is to be accepted with great caution, and
definite conclusions are not justified until repeated
extended trials of two rations or of two systems of feed-
ing, made with the use of all possible precautions against
error, and under a variety of conditions, give uniform
and consistent results in the same direction. There are
several reasons why this is so, the main one being that
the increase in the weight of an animal is an uncer-
tain measure of actual growth. Variations in the con-
tents of the alimentary canal due to the irregularity of
fecal discharge and to a lack of uniformity in the water
drank may cause temporary variations in the live weight
of considerable magnitude. Moreover, the nature of the
growth of body substance is revealed neither by the mere
weighing of an animal nor by his general appearance.
Even if the changes in weight are due to an increase of
body tissue, this may be more largely water in one case
than in another, so that the real contribution of the food
to the dry substance of the body may not be shown.
Nor is the character of the solids deposited in the animal
discovered by merely weighing him. In fact, by such
practical experiments we simply learn that one set of

\ SOURCES OF KNOWLEDGE — “205

animals has gained more or less pounds of weight than
another set, but the why and the how are not explained.

Practically the same considerations pertain to feed-
ing tests for milk production. When the milk flow from
one ration is larger than from another, we can easily
satisty ourselves as to the comparative yield of milk
solids, which is the real test of such production; but we .
are not able to decide whether the cow either may not
have contributed to the milk secretion from the substance
of her own body, or may not have gained in body sub-
stance, the extent of such loss or gain being greater,
perhaps, with one ration than with another.

Even if these uncertainties did not exist, we have
the still greater disadvantage of not learning by this
means why a particular combination of feeds has superior
qualities for causing growth or sustaining milk secretion.
The mere data showing that an animal ate so many
pounds of food and produced so many pounds of beef or
milk are important business facts, but they reveal noth-
ing concerning the uses of the several classes of nutrients
and of themselves furnish slight basis for developing a
rational system of feeding. We must somehow learn the
function of protein, carbohydrates, and fats in main-
taining the various classes of animals and the real effect of
varying the source, quantity, and relative proportions of
these nutrients before we can draw safe general conclusions.

292. Chemical and physiological studies——As pre-
liminary to more comprehensive and convincing methods
of investigating feeding problems, there has been going
on during many years a necessary study of the compounds
which are found in plants and animals. Much has been’
learned about the ultimate composition and the consti-
tution of the proteins, carbohydrates, and fats, their

iy

206 THE FEEDING OF ANIMALS

physical and chemical properties, the compounds into
which these bodies break under certain conditions, the
chemical changes to which they are subject through cer-
tain agencies, and their relation to one another. Investi-
gations along these lines have for years occupied the
time of some of our ablest scientists, and, while such
researches when they were conducted may have seemed
to the extreme utilitarian to be of little value, we now see
how directly they are contributing to human progress _
and welfare.

To the above information has been added through
physiological investigations a knowledge of the ways in
which the several food compounds are transformed in
digestion and in other metabolic changes, the avenues
along which these compounds travel, and the ways in
which their products of decomposition are discharged
from the animal organism. We have learned how to dis-
tinguish between the digested and undigested food, have
demonstrated that all the nitrogen of the decomposed
proteins passes off in the urine, have measured the com-
bustion of the nutrients and have learned how to strike a
balance between the income and outgo of the animal-
body. It is now possible to determine with reasonable
accuracy just how much substance is retained or lost
from the body of the experimental animal while eating a
given ration, and what is the nature of the gain or loss.
Very recently means have also been devised for measur-
ing the heat given off by a man or an animal in order to
ascertain the actual physiological values of different
feeding-stuffs.

- 293. More accurate methods of investigation than
practical feeding tests.—In applying the principles and
facts of chemistry and physiology, the first advance from

SOURCES OF KNOWLEDGE Ce BOL

the ultra-practical feeding experiment in the direction
of an accurate history of what occurs when the animal
is eating a particular ration is the measurement of the
digested nutrients and the determination of the gain or
loss of nitrogen. This is accomplished, as heretofore
stated, by ascertaining the quantity of various com-
pounds eaten and the amount of the same in the feces,
the difference being the digested portion. The urime is
also collected, and if the nitrogen in it is less or more than
that in the digested protein, then the animal is either
gaining or losing nitrogenous body substance, unless
the measurement is with a milch cow, when the nitrogen
in the milk must be taken into account. By an experi-
ment conducted in this way, with careful and continued
weighings of the experimental animal, it is possible to
secure a probable relation between a unit of digested dry
matter and a unit of production. Such a method has been
used to determine what is a maintenance ration for ani-
mals of several classes, and in those cases where the
experiments have been continued for a sufficient length
of time and have shown on repetition a reasonable agree-
ment, we are justified in accepting the results as a close
approximation to fact. When a ration keeps an animal in
nitrogen equilibrium for one or more months and no
material gain or loss of weight occurs, we may safely
regard it as approximately a maintenance ration under
the conditions involved. Experiments of the same kind
are equally useful in testing the productive power of
various food combinations, and whenever by such con-
tinued tests one ration shows no superiority over another,
it is safe to assume that no differences exist which would
be especially important to the farmer’s pocketbook. This
may be accepted as a business fact.

208 THE FEEDING OF ANIMALS

294. Studies of food sources of animal fats.—Another
class of experiments somewhat more severe in their
requirements are those designed to give information as
to the relation between the constituents of the food and
the growth of the various tissues in the animal body or
the formation of milk solids. The experiments conducted
by Lawes and Gilbert on the formation of fat with swine
may be cited in illustration of the methods used. These
were planned so as to learn the amounts of digested pro-
tein, carbohydrates, and fat consumed by the animal and
also the quantities of protein and fat stored in the body
during a given period. “In experiment No. 1, two pigs
of the same litter, of almost exactly equal weight, and, so
far as could be judged of similar character, were selected.”
One was killed at once and its composition determined,
and the other was fed for ten weeks on a fattening ration
of known composition and then slaughtered and analyzed.
The quantity of protein and fat which the pig’s body had
gained during the ten weeks as ascertained from the com-
position and weight of the two pigs was then compared
with the food-supply of similar compounds. It was |
assumed that a pound of food fat could produce a pound
of body fat and that 51.4 per cent of all the protein not
stored in the body as such could be used for fat formation.
Even with the most liberal allowances it was found that
the protein and fat of the food could not possibly have
been the sole source of the new body fat, thus forcing the
conclusion that the carbohydrates are fat-formers. Prac-
tically the same plan has been followed in studying the
source of milk-fat. Several cows were fed on carefully
weighed and analyzed rations extremely poor in fat, and
the amount and composition of the feces, urine, and milk
were ascertained during sixty to ninety days. The fat

SOURCES OF KNOWLEDGE - 209

digested from the food and the theoretical fat equivalent
of the decomposed protein as measured by the urine
nitrogen were charged up against the milk-fat, and a large
quantity of the latter could be accounted for only as
having had its source in carbohydrates.

Another method of investigating fat formation has
been used with dogs. It is well known that when an
animal is deprived of food the expenditure of energy
by the body is maintained at the expense of body sub-
stance. Both muscular tissues and fatty substance are
broken down and used in this way, the latter being
regarded as furnishing the most natural and available
supply of fuel. It was found in the case of dogs that
after a certain number of days of starvation there oc-
curred a sudden and large increase in the waste of nitro-
gen compounds as shown by the urine excretion, the
explanation for this being that the body fat had become
exhausted and a demand was at once made upon the
protein tissues for the necessary supply of energy. As
soon as this rise of nitrogen waste appeared, then the
dog was allowed to eat, and whatever fat was found in
the body at the end of the feeding-period was regarded as
having been formed from the food taken after the star-
vation period. If, for instance, the ration was wholly
protein and fat was found to have become deposited in
the body, this was regarded as proof of the formation of
fat from protein. Such experiments as these have not
always been conclusive, although they are regarded by
some scientists as having furnished proof that protein
may be a source of fat.

295. The respiration apparatus.—After all, the investi-
gations of the kinds described fail to furnish data so
accurate and so complete as are necessary for entirely

N

,

210 THE FEEDING OF ANIMALS

safe conclusions. In every instance, one or more assump- |
tions are involved where definite proof is not furnished.
Nothing short of a complete record of the income and
outgo of the animal organism during the experimental
period is conclusive evidence as to whether there has been
a gain or loss of body substance and what is the kind and
extent of the growth or waste. The securing of such a
record is an expensive and laborious task. It requires not
only complete information in regard to the quantity and
composition of the food, but also an acccurate measure-
ment of the excreta, including the feces, the urine, the
respiratory products, and the matter given off through
the skin. Such measurements are taken by means of a
respiration apparatus, a costly and complicated mechan-
ism, a detailed description of which would be of little use
to most readers. It is sufficient to state that this appa-
ratus makes possible the collection and analysis of all the
excretory products, whether solid or gaseous. ‘The
experimental man or animal lives in a closed chamber
into which is introduced food and fresh air and from
which is pumped the vitiated air, the water and carbon
dioxid of which are absorbed and weighed.

All conclusions drawn from experiments with the
respiration apparatus are based largely upon the in-
come and outgo of nitrogen and carbon. As carbon
is a constituent of all possible compounds of the ani-
mal body except the mineral, it is certain that when
the body gains in carbon it gains in organic substance
of some kind, and if it loses in carbon there is a waste
of organic body substance. The general character of
the gain or loss can be determined by the nitrogen bal-
ance. If more nitrogen is taken in by the experimental
animal than is given off, it is clear that the nitrogen

SOURCES OF KNOWLEDGE Mae 24

compounds of the body have received an accession.
Knowing as we do the proportions of nitrogen and car-
bon in the various tissues of the animal, we can calculate
how much of the gain or loss of carbon belongs in the
nitrogenous substance deposited or wasted. If more
carbon is gained or lost than can possibly be associated
with the nitrogen gained or lost, then there has been a
gain or loss of fat, because protein and fat being the main
constituents of the animal carcass, any considerable
retention of carbon must be in one of these forms. If
there has been nitrogen equilibrium, all excess or deficit
of carbon belongs to a deposit or waste of fat. By such
searching methods as these, it is possible to ascertain
with a good degree of accuracy how food is used and what
quantity and kind of nutrients are needed in maintain-
ing an animal under given conditions.

296. Determination of energy values.—We have
reached a point in our study of animal nutrition where
we realize that food values are to some extent commen-
surable with energy values and that it is desirable to
know the energy product of different compounds and
feeding-stuffs. Moreover, we cannot possess sufficiently
full knowledge concerning the energy needs of the several
classes of animals until we have measured energy use in
terms of heat given off under the various conditions of
work and of production. The mere determination of the
income and outgo of the animal body does not neces-
sarily measure energy needs or use. We may go so far
as to ascertain that a certain amount of carbon from a
certain source was consumed in a given time, but from
this alone we do not learn the extent to which this com-

bustion has supported the internal and external work
of the body.

212 THE FEEDING OF ANIMALS

297. Calculation of the energy value of a ration.—
Three methods may be adopted for determining the
energy expenditure by an animal eating a given ration.
The one of these most easily carried out is largely a
matter of mathematical calculation. By the use of
average digestion coefficients it is possible to ascertain
approximately the amounts of digestible protein, carbo-
hydrates, and fats contained in any ration which is
apparently accomplishing a desired result. We have
learned from previous determinations what are the calorific
values of individual compounds such as albumin, starch,
sugar, stearin, and olein and these compounds are assumed
to represent the energy value of the classes of nutrients to
which they belong. If, then, we multiply the calculated
quantities of digestible protein, carbohydrates, and fats by
their respective assumed energy factors, we get a number
which has been taken as an expression of the available
energy of the ration under consideration. This method
must now be regarded as greatly inaccurate, because
the metabolizable energy of the digestible material
of feeding-stuffs is found to be much below the calorific
value of the pure nutrients to which energy measure-
ments have been applied. See Tables XXVIII and
XXXII. The older theoretical method by computation
might give the relative, but not the actual, units of
metabolizable energy in the several feeding-stuffs, for the
results by means of combustion in a Zuntz calorimeter
of pure nutrients do not measure physiological results
with complex mixtures.

298. Energy value of digested nutrients.——A second
method, which is probably a step in the direction of greater
accuracy, is to determine by the use of a calorimeter the
heat units of the ration and also of the urine and feces.

he? weed, Je”

SOURCES OF KNOWLEDGE : 213

The differences between the food heat units and those
found for the excreta might seem to represent the energy
value of that portion of the ration digested by the animal.
This would be an accurate measurement of the available
or metabolizable energy of the ration if it were not for the
loss of unoxidized gases, chiefly methane, which contrib-
ute nothing to the maintenance of the animal. Accurate
work requires that these gases be measured. But even
then it does not appear to what extent the digested
nutrients have been oxidized with a corresponding radia-
tion of heat or whether there has been a gain or loss of
body substance. If there has been a gain of body sub-
stance, then the ration is productive, but if there has been
a loss of body substance, then the ration is below the
required standard for the maintenance of the particular
animal under investigation. In a study of energy rela-
tions, it is therefore even more necessary to resort to a
respiration apparatus of some sort than in determining
food balances. We must learn the actual extent of the
food combustion which occurs if we would have all the
data necessary for measuring energy used, and here we
come to the third and most accurate method of determin-
ing energy expenditure, viz., experiments with a respira-
tion apparatus.

299. Measurement of food combustion.—There are
two general ways of ascertaining the extent to which
food is burned by any living organism. One is to measure
the products of combustion and the other is to measure
the amount of oxygen used. It is self-evident that no
combustion can occur without the use of oxygen, and so
if the experimenter is able to learn just how much of this
element is taken up in uniting with the carbon and hydro-
gen of the food, he has a direct and accurate means of

-

214 THE FEEDING OF ANIMALS

measuring actual energy production. The older forms of
respiration apparatuses simply allowed an estimation of
the carbon dioxid and water given off by the animal.
How much of the water was formed by the oxidation of
the hydrogen of the food and how much was simply
evaporated from the store taken in as water, it was
impossible to know by direct determination. This could
only be calculated. The carbon dioxid was, on the other
hand, a direct and accurate measure of the combustion
of carbon. Later devices, as, for instance, the one used
by Zuntz, allow a direct determination, not only of the
products of combustion, but of the oxygen absorbed by
breathing. This method of work seemed to have advan-
tages, as one measurement not only checks the other, but
makes it possible to ascertain the actual oxygen consump-
tion during any given period of the experiment, as, for
instance, when the animal is at rest, when masticating
food, or when performing a given amount of external
work. In this way, Zuntz made his masterly demon-
strations of the differences in oxygen use with different
foods during the period of mastication.

300. Respiration calorimeter.——None of the older
apparatuses, whether allowing the determination of
oxygen consumption or not, measured the heat radia-
tion from the animal body, or, in other words, the amount
of energy actually evolved from internal combustion.
Professors Atwater and Rosa first devised a respiration
apparatus which was at the same time a calorimeter.
The quantity of heat radiated from a man or other
animal confined in this calorimeter is absorbed by a
known volume of water and is thus determined. ‘This
is a great advance towards certainty, because direct
measurements of the energy production of a ration are

SOURCES OF KNOWLEDGE Sige |:

thus made possible and the necessity for theoretical
assumptions is largely removed.

301. Study of the efficiency of individual proteins.—
The type of investigation in animal nutrition upon which
much emphasis is now placed is a study of the function
and relations of individual compounds. The proteins
have been especial objects of studies of this kind, studies
which have been made possible through the isolation and
identification of many individual vegetable and animal
proteins. The general plan of work has been to feed only
one well-identified protein in connection with a sufficient
supply of all the other nutrients necessary to maintenance
and growth. In this way it has been demonstrated that
the individual proteins are greatly unlike in their nutritive
value and relations, it being found that some will not
sustain growth or even maintenance, while other single
proteins constitute an efficient protein-supply for any
known protein use.

It is already made clear to the reader, doubtless, that
the demonstration of facts and principles in the domain
of animal nutrition is exceedingly difficult. It should
be equally clear that when conclusions are reached in ways
which have been briefly described, they are worthy of
respect and should have greater weight than the neces-
sarily imperfect observations of common practice. Science
often errs in her deductions, but the efforts of her workers
are constantly directed toward the elimination of false
conclusions, so that unsound theories are not likely to be
accepted for a great length of time.

CHAPTER XIII
CATTLE FOODS—NATURAL PRODUCTS

Tue number of cattle foods now available for use
is very large, and the list appears to be constantly in-
creasing. Not only have several fodder plants been
added to those formerly grown, but we have now a great
variety of waste products from the manufacture of oils,
- starch, and human foods that are being placed upon
the market as feeding-stuffs. At one time farmers pro-
duced all their cattle ate, and this was done without
going outside a very limited list of forage plants and
grains. All this is changed, especially in the older, more
thickly-settled portions of the United States, so that
considerable knowledge is now needed regarding the
composition and specific characters of the numerous
kinds of feeding-stuffs if they are to be used intelligently.

302. Classification of cattle foods.—It will aid in
discussing this branch of our subject if we first note the
divisions into which the materials used for feeding farm
animals are grouped. There is more than one basis upon
which it is possible to make these divisions—botanical
relations, the portion of the plant used, whether stem or
fruit, and chemical composition. As a matter of fact, all
these. and other distinctions are involved in the classi-
fication of the cattle foods in common use at the pres-
ent time. 3

The feeding-stuffs of vegetable origin are generally
divided into four classes: (1) Forage crops, consisting

(219)

220 THE FEEDING OF ANIMALS

of the stem and leaves of herbaceous plants, either in
green or air-dry condition, to which is attached in some
cases the partially formed or wholly mature seed or
grain; (2) roots and tubers, or the thickened under-
ground portions of certain plants; (3) seeds or grains;
(4) parts of a plant which are the by-products from the
removal of other parts by some manufacturing process.
These are the commercial by-product feeding-stuffs.

FORAGE FOODS

303. Classes of forage crops.—The valuable forage
plants of the United States belong mostly to two families,
the grasses (Graminew) and the legumes (Leguminosz).
June grass, red-top, timothy and the cereal grain plants
are types of the former; and the clovers, alfalfa,
the vetches, and peas, of the latter. Whether in the
pasture or in tilled fields, few plants outside of these
divisions contribute materially to the supply of high-
class fodders. The most essential difference between the
members of these two families of plants when considered
as feeding-stuffs is the larger proportion of nitrogen com-
pounds in the legumes. It is characteristic of all legumes
that their proportion of protein is high as compared with
any other forage crops, and for this reason they are
greatly prized on dairy farms. The fact that they are
regarded as increasing materially the nitrogen supply
of the farm from sources outside the soil also adds to
their value.

304. Green vs. dried fodders; conditions of drying.—
Nearly all of the herbaceous plants that are grown for
consumption by farm animals may be fed either in a green
or dry state. Oats, maize, clover, alfalfa, and other spe-

CATTLE FOODS—NATURAL PRODUCTS ~ 221

cies which serve so useful a purpose as soiling crops for
summer feeding are also dried that they may be success-
fully stored for winter feeding, although mazei, and, to
some extent, other crops, are now preserved in a green con-
dition through the process of ensilage. (See Pars. 37-41.)
305. Effect of drying fodders.—The advantages and
disadvantages of green as compared with dry fodders
have been much discussed. It is safe to assert that the
compounds of a dried fodder which has suffered no
fermentation are practically what they were in the
green, freshly cut material, excepting that nearly all of
the water contained in the green tissues has evaporated
and that in drying there is a possible loss of an imper-
ceptible amount of volatile compounds, whose presence
in the plant affects its flavor more or less. It is certain
that curing a plant generally diminishes its palatable-
ness and increases its toughness, or its resistance to
mastication, although with many crops, as for instance
the early cut native grasses, these changes do not affect
nutritive value to a material extent. There is no ques-
tion but that the mere matter of being green or being dry
has very little influence upon the energy value of a fodder
or upon the extent to which it will sustain growth or milk
formation. We must, however, take into account the
desirability of the highest state of palatableness. !
306. Losses through curing fodders.—Drying fodders
under perfect conditions is not always possible. The
long-continued and slow curing of grass in cloudy weather,
especially when there is more or less rainfall, is accom-
panied by fermentations that result in a loss of dry sub-
stance more or less extensive, and which oxidize some of
the most valuable compounds, principally the sugars.
The tissues of certain plants, maize for instance, are so

222 THE FEEDING OF ANIMALS

thick that rapid curing in the field is never possible, and
fermentative changes are unavoidable. It is probable.
that maize fodder and stover are never field-dried with-
out a material loss in food value, for it is found that even
when the stalks are finely chopped, drying by artificial
heat is necessary to a complete retention of the dry mat-
ter. The extent of the loss from curing fodders must be
very variable. So far as we know, grass, which in “good
haying weather’’ is well stirred during the day and packed
into cocks over night so as to avoid the action of heavy
dew, suffers practically no deterioration, while dull
weather or rain may cause a serious loss. It is doubtful,
however, whether night exposure during good weather is
sufficiently injurious to justify the expense of cocking
partially cured hay. On the other hand, the economy of
using hay caps during unfavorable weather is without
question. The over-drying of hay before raking into
winrows and “‘bunching” so as to cause a loss of the leaves
and the finer parts through brittleness may be as wasteful
as under-drying and the consequent fermentation. Over-
_ dried hay does not pack well in the mow and is less pala-
table. The leguminous hays, such as clover and alfalfa,
are expecially subject to loss from over-drying before
handling. Fodder crops, if dried at all, should be dried
to such a percentage of moisture that they will not “heat”
to discoloration after being packed in large masses and
lose value from the same general causes that operate in
field-curing under bad conditions. (See Par. 45.)

307. The harvesting of forage crops.—The result to be
achieved in the growing of forage crops is the produc-
tion on a given area of the maximum quantity of digesti-
ble food materials in a palatable form. The age or period
of growth at which a forage crop is harvested is an impor-

CATTLE FOODS—NATURAL PRODUCTS —~ 223

tant factor in this relation and may affect the product in
three ways: (1) in the quantity of material harvested, |
(2) in the composition of the crop, and (3) in the palata-
bleness of the resulting fodder. In discussing this ques-
tion we must recognize the fact, first of all, that in these
respects no general conclusion is applicable to all crops.
What would be wisest in the management of the meadow
grasses might be wasteful in handling the legumes, and
especially so in harvesting maize.

308. Maximum yield of forage crops at maturity.—
It is safe to assert that in general the maximum quan-
tity of dry matter is secured when forage crops are
allowed to mature fully and ripen. The only exception
to the rule is found in the legumes such as the clovers
and alfalfa, where at maturity the leaves unavoidably
rattle off and are lost, either before or during the process
of curing. The fact that growth of dry matter takes
place up to the time of full maturity is well illustrated by
the results of experiments conducted on the farms of the
Pennsylvania State College, the New York Experiment
Station, and the University of Maine, in cutting timothy
grass, clover, and maize at different stages of growth.
These results are summarized in the accompanying tables:

Taste XLIV. Timoruy Grass (YIELD oF Dry Hay To THE AcrRE)

. : Results in Pennsyl-
Rieoulte tm Mains vania—two farms

Stage of growth ee
Av. 3 years| 1 year Av. 2 years

1878-1880 1889 1881-1882
Pounds Pounds Pounds
Hearn head... ..... 3,720
ee eS, 4,072 4,225 2,955
Out of bloom or nearly ripe .| 4,136 5,086 3,501

CS) 5 Os 3,832

224 THB FEEDING OF ANIMALS

Maize FoR SILAGE (YIELD oF Dry MATTER TO THE ACRE)

New York Maine

Stage of growth 1889 1893
Pounds Pounds

Tasseled to beginning ofear........ 1,620 3,064
Silked to some roasting ears ........ 3,080 5,211
Watery kernels to full roasting-period. . . .| 4,640 6,060
Peapeeeene eee www a 7,200 6,681
rieeeeetiewere we ee cl ej 920 7,040

Rep Cover (YIELD or Dry MaTTER TO THE ACRE)

Stage of growth See
Pounds
ae ter tr ene 3,680
SRM Hen) 5500 EEO Sk a 3,428
ELSS 3 2)5) TERY) RRR MRD a oe a Ao: 3,361

These data are convincing testimony as to the growth
of dry substance in certain forage crops up to and in-
cluding the period of ripening. Clover is an apparent
exception, but is probably not really so because after
the heads begin to die there is an actual loss of dry mat-
ter from the shedding of the leaves.

309. Value of crops not proportional to yield.—It does
not follow when a plant increases in its yield of dry matter
that its nutritive value has proportionately increased.
The end to be sought is the largest possible quantity of
available food compounds, and it is entirely possible
that changes in texture and in the composition of the
dry substance may partially or fully offset the greater
yield. With the meadow grasses this undoubtedly hap-
pens. The dry matter of mature grass contains a larger
proportion of fiber than the immature. The progressive

CATTLE FOODS—NATURAL PRODUCTS ~ 225

increase of fiber as the plant approaches ripeness is well
illustrated by analyses made at the Connecticut Experi-
ment Station of a sample of timothy grass cut at different
periods of growth:

Taste XLV. Composition oF Dry Susstance (PER CENT)

Nit
Stage of growth of timothy Ash |Protein oo cores Fats
extract
Welrheades out. . . . ja0 4.7 oH ep tess 43 50.8 | 1.9
ial bieesom =... . - eee 4.3 A .| 3&:3/ | Siee 1~2:
When out of blossom ....| 4.1 TAL [SRS | aoa. See
Meatamepe- . .-. ¢ sae 3.6 | 6.8 | 35.4 | 52.2 | 2.

These analyses show that the changes are not con-
fined to an increase of fiber. The relative proportions of
ash and protein grow less as the plant matures. An
examination of the nitrogen-free extract would prob-
ably show an accompanying decrease of the soluble
carbohydrates.

The combined effect of these changes is to cause the
plant to harden in texture and become less palatable and
more difficult of mastication.

310. Age decreases digestibility—The digestibil-
ity is naturally affected by age. Three American diges-
tion experiments with timothy hay cut in bloom or
before show an average digestibility of the organic mat-
ter of 61.5 per cent, the average from four experiments
with timothy cut when past bloom being 55.4 per cent.
Doubtless the increase in dry matter when timothy
stands beyond the period of full bloom no more than
compensates for the decrease in digestibility. Using
the average coefficients of digestibility and the average
yields, as given in this connection, the yield of digestible

O

~

226 THE FEEDING OF ANIMALS

organic matter would be in full bloom, 2,306 pounds, and
when out of bloom or nearly ripe, 2,350 pounds. If one
considers the decrease in palatableness the advantage is
with the earlier cut hay.

These facts do not pertain to timothy alone. Other
meadow grasses are similar in their characteristics of
growth. The clovers, and especially alfalfa, deteriorate
to a marked degree from the same cause when allowed
to ripen too fully before cutting.

It is probable, all factors considered, that if the grasses
and clovers which are cut for hay could be harvested when
in full bloom a desirable compromise would be effected
between quantity and quality. Alfalfa should be cut no
later than when the first bloom makes its appearance.

311. Maize unlike other grasses.—Conditions are
quite different with maize. This plant in maturing
gains not only in quantity but in quality. In support of
this statement data are cited from an experiment con-
ducted at the Maine Experiment Station.

The following is the composition of the dry matter
of the corn when cut at several periods of growth:

TABLE XLVI. In 100 Parts WaATER-FREE SUBSTANCE OF MAIZE

Total

Stage of growth Ash | Protein pee Sugar | Starch een teal Fat
extract

Very immature, Aug. 15 .| 9.3 15. 26.5 1 a | 46.6 | 2.6

A few roasting-ears, Aug. 28} 6.5 tb PSY 23.3 20.4 Pa | 55.6 AZo
All roasting-stage, Sept. 4 6.2 11.4 19.7 20.6 4.9 59.7 3.
Some ears glazing, Sept. 12) 5.6 9.6 19.3 21.1 5.3 62.5 Bliss
All ears glazed, Sept. 21 .| 5.9 9.2 18.6 16.5 15.4 63.35 | <3:

Here we see the same decrease in the proportions of
ash and protein as occurs with timothy, but, unlike

. CATTLE FOODS—NATURAL PRODUCTS ~ 227.

timothy, the maturing of the maize causes a decrease in
the percentage of fiber and a material increase in the
relative amount of the soluble carbohydrates, sugar,
and starch. .

These data give us every right to expect that the
dry matter of the mature corn plant is more digestible
than that of the immature plant, and experimental
tests show this to be the case. There follows a summary |
of American digestion experiments bearing on this point:

TaBLE XLVII. Dicestep From 100 Parts Orcanic MATTER

Corn fodder Corn silage

Max.} Min. | Av. | Max.| Min. | Av.

——— | ———<——.Ss§|§- ———<—.§s | ——————————_ | ———]|——_..

Cut before glazing, 13 experiments .. . | 71.4 | 53.6 | 65.7 | 77.8 | 56.6 | 67.4
Cut after glazing, 10 experiments . . . . | 74.2 | 61.2 | 70.7 | 80.2 | 65.2 | 73.6

The advantage is seen to be with the mature corn.
It is fair to conclude from all these observations that
harvesting ‘the corn plant when immature is injudicious
from every point of view.

312. Alfalfa—Alfalfa has become in many parts of
the United States one of our most important forage crops.
Its points of excellence are a high degree of palatableness,
large relative yield, its partial independence, at least,
of a soil-supply of nitrogen, and its efficiency as a soil-
renovating crop. From three to five cuttings may be
made annually; and the yield, according to records in
central New York, sometimes reaches the equivalent of
five tons of hay. The fact that it is a leguminous plant
indicates a useful place in farm cropping because of the
fact that the percentage of protein it contains is consider-
ably higher than that of the true grasses.

228 THE FEEDING OF ANIMALS

In order to successfully establish this plant in many
sections it is necessary to inoculate the soil with the bac-
terium that sustains a symbiotic relation with this
legume, and coapply some form of lime when the soil
has a high degree of acidity.

It should be stated that the relative feeding value of
alfalfa has been overestimated as compared with other
legumes, such as the clovers. It is doubtful whether
alfalfa hay cut and cured under the best of conditions is
superior in quality to the best quality of clover hay.

SILAGE

About forty years ago a new process for presery-
ing crops in a green condition was introduced into the
United States, viz., ensilage. This consists in storing
green material in receptacles called silos, in masses
sufficiently large to insure certain essential conditions.
Within a brief period after maize or other green material
is packed in a silo the mass becomes perceptibly warm,
and in the course of two or three days it reaches its maxi-
mum temperature, which is much above the average heat
outside. This rise in temperature is due to chemical
changes which involve the consumption of more or less
oxygen and the production of compounds not previously
existing in the fresh material.

313. Nature of the changes in the silo—— These changes
are very complex. They have been regarded as due to
the activity of a variety of ferments, principally those
which are believed to cause the formation of alcohol
and acetic, lactic, and other acids. Whether the oxida-
tions occurring in the silo are wholly induced by ferment
action or in part at least are the result of oxidations

CATTLE FOODS—NATURAL PRODUCTS ~ 229

brought about in other ways is a point over which there
has been some recent interesting discussion.

Babcock and Russell carried on at the University
of Wisconsin able and very suggestive investigations
concerning the causes of silage formation. They con-
clude that the theory that silo changes under normal
conditions are due wholly to bacteria “does not rest on a
sound experimental basis.”

Their data led them to regard respiratory processes,
both direct by the plant cells and intramolecular, as
the main causes of the chemical transformations which
produce carbon dioxid and the evolution of heat within
the ensiled mass. The direct respiration appropriates the
oxygen confined in the air spaces of the silo, and the
intramolecular respiration uses oxygen combined in the
tissues. Both forms of respiration go on only so long
as the plant cells remain alive. Concerning bacteria
the authors say: “The bacteria, instead of function-
ing as the essential cause of the changes produced in good
silage, are on the contrary only deleterious. It is only
where putrefactive changes occur that their influence
becomes marked.”

Doubtless intramolecular respiration is continued
longer in immature and succulent plant tissues than in
tissues where the cells have reached maturity, and so the
losses in the silo with immature plant substance are
greater than with mature. Analyses of silage from
frozen corn and feeding trials with this material show
that it is not economy to cut immature corn for fear of
frost, as the increase of dry matter much more than bal-
ances the loss from the freezing.

314. Losses in silo—Whatever are the inducing
causes, a careful record of what takes place in the silo,

'

230 °° THE FEEDING OF ANIMALS

shows that the silage contains considerably less dry
substance than the original fresh material. Loss occurs
through the formation of volatile products. An examina-
tion of the fresh corn and of the silage shows that the
latter contains much less sugar than the former, some-
times none at all. In the place of the sugar we find a
variety of acids, chiefly acetic and lactic. This is a change
similar to the formation of acetic acid in cider and lactic
acid in milk, in all cases sugars being the basal com-
pounds. Determinations of acidity in silage by Morse
during several years showed it to vary from .8 to 1 per
cent. Along with the development of these acids, carbon
dioxid and water are formed from the carbon compounds
of the ensiled material. In other words, combustion takes
place and more or less of dry matter is actually burned
up, thus generating heat and causing rise of temperature
of the fermenting mass. The amount of dry matter
thus lost is determined partly by the kind of crops and
the care with which the silo is built and filled.

Another important chemical change induced by fer-
mentation is a splitting up of a certain portion of the
proteins of the fermenting material into amino acids,
some of which compounds may have a more limited nutri-
tive function than the proteins. Investigation conducted
at the Pennsylvania State College showed that in some
cases over half the nitrogen of silage existed in the amino
acid or amide form, this being between two and three
times as much as was found in the original fodder. Proba-
bly the same change takes place in the field-curing of
fodder, but no data are available on this point. Starch
seems to resist the usual silo oxidations. In certain experi-
ments a considerable loss of nitrogen is reported. It is
hard to understand, though, how this can occur to any

j

CATTLE FOODS—NATURAL PRODUCTS ~- 231

large extent unless the conditions in the silo\are very
bad, so that putrefactive fermentations set in. An exten-
sive loss of nitrogen compounds certainly would indicate
very serious and long-continued destructive changes.

Steaming the corn seems to depress the fermenta-
tions and decrease the percentage of acids that form.
Knisely found .3 to .88 per cent acidity in steamed silage
and 1 to 1.6 per cent in unsteamed.

315. Corn an important silo crop.—The nature of
the changes and losses in producing silage have been
dwelt upon partly because corn, the principal silo crop,
is one of our most important forage crops, perhaps the
most so on a dairy farm, and partly in order to illustrate
the necessity and value of good management in preserv-
ing this crop by the silo method. Moreover, the loss that
is incident to the field-curing of maize is practically the
same in kind and is fully as large as that pertaining to
silage, so that the facts presented are pertinent to both
methods as well as to all circumstances where similar
oxidations and fermentations are likely to ensue.

316. Extent of loss in the silo.—The extent of the loss
of dry substance is important. It measures in a general
way the difference between the food value of the silage
and of the fresh material. The silo combustion reduced
the energy or heat value which the fermented fodder
will have whenever it is eaten by the animal. The
heat lost would supply energy to an animal were the
combustion to occur within the animal instead of in the
silo. It is desirable, therefore, to know the extent to
which dry substance is actually broken up in the prepara-
tion of silage. This loss has been measured by several
investigators, and, as was to be expected, it has been
found to depend greatly upon the conditions involved,

232 THE FEEDING OF ANIMALS

the figures reached varying from about 2 to nearly 40
per cent of the dry matter of the fresh crop. Ina majority
of cases the loss has been over 15 and less than 20 per
cent. King, of the Wisconsin Experiment Station, who
gave the production of silage much study, concluded
upon the basis of his observations that in good practice
the necessary reduction of dry matter in making corn
silage need not exceed 4 to 8 per cent, and with clover
silage from 10 to 18 per cent.

317. Necessary loss in silo.—The necessary loss is
explained as being that which occurs in the interior of
the mass where all outside air is excluded and other
favorable conditions prevail. Considering the contents
of the silo as a whole, it will require careful attention to
all details in order to reach King’s estimate with the best
conditions attainable.

This investigator found that 64.7 tons of silage packed
in a silo lined with galvanized iron, thus securing a per-
fect exclusion of air, lost an average of 6.38 per cent of
dry matter. This silo was filled in eight detached layers,
and the proportion of loss in these several divisions, as
affected by location, is most suggestive:

TaBLE XLVIII

Silage Te nate

Pounds Per cent
Surface Tagger = Bore 8,934 32.53
Seventh layeei: < (. ee 8,722 23.38
Sixth layer. ... .... 2 ee. 14,661 10.25
Fifth layers...’ . . 7 See 48,801 2.10
Fourth layer fg: .... . > \° Se 13,347 7.01
Third layer -3E-77 2... (eee 7,723 2.75
Second layer. 200.02. Sy - 12,689 3.53

Bottom layer .°.>.). |... 772 12,619 9.47

A crop of silage corn.

PuaTe V.

CATTLE FOODS—NATURAL PRODUCTS ~~ 233

_ The mean loss of dry matter in the lower six layers

was only 3.66 per cent. These figures show that it is
profitable to make the walls of the silo air-tight, even
at large expense. |

318. Financial importance of silo losses——The im-
portance of reducing the loss in the silo to the lowest
possible percentage is almost self-evident. As this point
is capable of mathematical demonstration, it will be
interesting and suggestive to calculate what might take
place in a hundred-ton silo. In many of the trials which
appear to have been conducted under not unusual con-
ditions, a loss as high as 20 per cent of the dry matter
put in the silo has been observed. In a hundred-ton silo
filled with corn containing 25 per cent of dry matter, or
50,000 pounds, this would amount to the destruction of
10,000 pounds of dry food substance. As the loss falls
chiefly on the sugars or other soluble bodies which are
wholly digestible, the available nutrients in the fresh
material are diminished by an amount of digestible dry
matter equivalent to what would be required by ten
milch cows during two months. If, therefore, by good
planning and extra care this waste could be reduced three-
fourths or even one-half, the food resources for carrying
a herd of cows through the winter would be materially
increased, from five to seven and one-half tons of timothy
hay being the measure of the saving in a hundred-ton
silo.

319. Ensiling vs. field-curing.—The question is often
raised whether ensilage or field-curing is the more waste-
ful method of preserving a forage crop. Considerable
study has been given this matter, and the results secured
have been taken as a justification of the statement that
one method is about as economical as the other, which

234 THE FEEDING OF ANIMALS

is correct if we consider only the outcome of certain com-
parisons. A general survey of the data accumulated

shows that on the whole the waste has been the larger |

in field-curing. Observations made in six states reveal
a loss by the old method as low as 18 per cent in only
one case, and from 21 to 34 per cent in all others. Pos-
sibly under favorable conditions of weather, field-cured
corn fodder may lose as little dry matter as silage, though
this is doubtful, but in bad weather the waste from the
exposed fodder is extensive. The greatest advantage in
silo preservation is that conditions can usually be con-
trolled with more satisfactory average results than are
possible in field-curing. Other advantages pertain to the
silo which are of a business nature and which need not
be discussed here further than to affirm that the cost of
a unit of food value is in general diminished by the use
of the silo.

320. Crops for silage.—The number of crops that may
_be successfully ensiled is not large. Maize is the most
valuable one for this purpose, and clover and alfalfa
are stored in this manner with a fair degree of success
although silage from these latter crops often, if not gen-
erally, carries an offensive odor. So are peas, especially
when mixed with corn. The true grasses and cereal
grains outside of corn are not desirable silo crops, first
because the silage from them is generally poor in quality,
and second because usually they may be successfully and
more cheaply stored in an air-dry condition. Any crop
with a hollow stalk, giving an inclosed air space—oats,
for instance—is not adapted to silo conditions, and there
is no justification for ensiling any fodder which is sus-
ceptible of prompt and thorough drying in the field,
because in such cases there is an unnecessary waste of

ye ao ee Ey ¥ dpe rs m Ww
; Beet na tah ieee

7

CATTLE FOODS—NATURAL PRODUCTS ~ 235

food substance by fermentation and an unnecessary
_ handling of many tons of water contained in the green
material, with no compensating advantages. But any
crop used for the production of silage should be managed
“in the most efficient manner. A few general facts may
be discussed in this connection. ’

321. Construction of silos.——Silos that are of proper
construction and shape have air-tight perpendicular
walls and a height considerably in excess of either of
the horizontal dimensions. These conditions are essen-
tial to the completest possible exclusion of air and to
the closest possible packing of the material, with a mini-
mum of exposed upper surface.

Silos may be either round, square, or rectangular,
provided that in the latter case one horizontal dimen-
sion is not too greatly in excess of the other. The shape
of a silo which is most economical and efficient is not the
same for all conditions, although the round and square
forms hold most in proportion to the wall area. Many
farmers desire to have the silo in the barn, and generally
there the square or rectangular form is more economical
of space than a round one. When built outside the barn,
the round form, according to the opinion of many, may
be used to advantage both as to expense and results. If
a square or rectangular silo is built the corners should
be cut off inside in order to prevent an access of air and
the decay which occurs at those points when this is not
done. Several kinds of materials have been used suc-
cesfully in building silos, wood, brick, and stone. If the
walls are of masonry the inner surface must be cemented
not only air-tight but so smoothly as to allow easy and
uniform settling of the silage without leaving air spaces.
If wood is used, which is the more common material, the

236 THE FEEDING OF ANIMALS

inside construction must meet the same requirements.
Lining a wooden silo with iron has been suggested as
practical and economical. Cement is used successfully
in the same way. Economy demands that as a preventive
against decay the inner woodwork should at least be
treated with some preservative, which may also serve the
purpose of obviating excessive swelling and shrinking of
the lining boards.

322. Filling the silo.—The condition of the crop and
the manner of filling a silo determine to a great extent the
character of the silage. Obviously it should be so done
as to reduce the loss of food compounds to the lowest
possible point. Three points are prominently discussed
in this connection: (1) the condition of the crops, (2) the
preparation of the material, and (8) the rate of filling.

323. Mature corn desirable for silage.—Experience
has thoroughly demonstrated that the maturity of a
crop influences its value for silage. This is known to be
especially true of the corn crop. An immature corn
fodder, which always carries a high percentage of water
with less of the matured products, such as starch, is
always certain to change to very acid silage. On the
contrary, mature corn, when properly handled, is con-
verted into a product with the minimum acidity and with
an appearance and aroma much superior to that from the
immature plant. Neither are satisfactory results secured
from material that is overdry. It may be stated in gen-
eral terms that the best results are obtained when the
proportion of dry matter falls between 25 and 30 per
cent. If corn is harvested for the silo after the kernels
have begun to glaze, while the leaves are still green and
before they show dryness, other conditions being favora-
ble, it will meet every requirement for good silage.

\

CATTLE FOODS—NATURAL PRODUCTS © 2at

324. Cutting and shredding ensilage material.—
Whether the material with which a silo is filled shall be
put in whole or after cutting or shredding depends to
quite an extent upon its degree of coarseness. It is prob-
able that clover, and even the smaller varieties of maize,
are often successfully preserved without cutting, but no
one professes that this can be done with the coarser
varieties of maize. It is generally admitted that, with
maize, cutting or shredding it increases the probability
of satisfactory preservation, because the finer mechanical
condition allows more uniform packing and prompter
and more uniform settling. The highest grade of silage
with the minimum loss is undoubtedly more surely made
from cut or shredded material.

325. Rate of filling silo.—In the early days of silos it
was taught that to insure the least possible waste by
fermentation, the silo should be filled with the maximum
rapidity and then promptly weighted. Following this
view was the conclusion on the part of some that very slow
filling with no packing other than that given by the weight
of the mass, was the proper way to make silage of the
highest quality. This method was advocated for produ-
cing sweet (?) silage. It allowed violent fermentation at
first with resulting high temperatures, by which means
bacteria were supposed to be killed and subsequent
fermentations prevented, a conclusion so far not sus-
tained by scientific observations. Moderately slow and
continuous filling, rather than very rapid, has been
advocated by leading authorities. Two advantages were
claimed for this method, one being that more material
can be stored in the silo and the other is that silage of a
higher quality is produced with a smaller loss of dry
matter. The first point must be conceded and the second

238 THE FEEDING OF ANIMALS

claim may be true, although in part it lacks proof. It is
hard to understand why slow filling, especially if inter-
mittent, should not increase rather than decrease the
losses of food compounds. Certainly the less compact the
mass the more intense the oxidation and the higher the
temperature, the latter condition indicating with cer-
tainty the extent of the combustion. This point is illus-
trated by results reached at the Pennsylvania State
College when the chemical changes in two large tubs of
sorghum silage were studied, one of which was com-
pactly filled and weighted at once and the other loosely
filled and weighted after five days. The temperature
rose 17° higher in the latter than in the former, with a
loss of two and one-half times as much organic matter
from the loosely filled tub. It follows from the theory of
Babcock and Russell, previously noted, that the less the
oxygen available in the air spaces and the quicker the
plant tissue dies the less will be the combustion or loss
of organic matter. ‘These authors suggest as a prac-
tical application of their theory that the air be excluded
from the silo as rapidly as possible and only mature corn
be ensiled, because such tissue will die sooner than im-
mature, having less vitality. Their data seem to prove
conclusively, also, that the evolution of much heat when
a fodder is first ensiled is not essential to the formation
of first-class silage. The repeated exposure of a loose
upper stratum, which occurs with slow, intermittent
filling, must cause extensive loss from portions of the silo.
It must be held, in view of the experimental data now at
hand, that the more promptly the air is excluded and
expelled by the reduction of the contents of the silo to a
condition of maximum compactness, the less will be
the fermentation losses. The term “sweet silage” me ins

a se
5 Sap

L bo NF Ua Meet
Pee A>. Se re.
4h - y

\

CATTLE FOODS—NATURAL PRODUCTS - 239

but little as indicating completeness of preservation, for

' it may even be the result of extensive fermentations, a

condition expensively secured. Its significance is entirely
different when the sweetness is due to proper maturity
of the fodder plant.

THE STRAWS

326. When the grain plants which produce seeds
valuable for cattle and human foods are threshed, or
in some way manipulated to remove the seeds, the other
parts of the plant constitute what we call straw in the
case of the cereal grains and legumes, and stover in
the case of maize. These fodders differ from the same
plants, when cut in a less mature condition for hay or
fodder, in being more tenacious and less palatable, with
a smaller proportion of the more digestible, and there-
fore more valuable, compounds. The most useful of these
materials for feeding purposes are corn stover, oat straw,
and the legume straws. These are better relished by farm
animals than wheat and barley straws, which are utilized
mostly for litter.

ROOTS AND TUBERS

327. Certain species of plants, more especially beets,
mangel-wurzels, turnips, rutabagas, carrots, and pota-
toes, are agriculturally valuable because of the store of
nutrients which they deposit in subterranean branches
or in roots. The original purpose of this deposit is, in
the case of potatoes and artichokes, to nourish the young
plants of the next generation, or, in the case of bien-
nials like beets, to supply the materials for the seed-
stalk and seeds of the second year. Potatoes are not
grown primarily as food for cattle, but roots have for

240 THE FEEDING OF ANIMALS

many years been a standard crop for feeding purposes.
This class of crops has the advantage of furnishing very
palatable, succulent food, which may be kept in per-
fect condition during the entire winter season, an advan-
tage which is not wholly measured by the actual quan-
tity of nutrients supplied by these materials.

The disadvantages of these crops are that they are
somewhat expensive to grow and necessitate the hand-
ling of large weights of water. A ton of turnips or man-
gels may furnish even less than 200 pounds of dry sub-
stance, to secure which 1,800 pounds of water must be
lifted several times. The percentage of dry matter in
roots and tubers varies in American products, on the
average, from 9.1 per cent in mangel-wurzels and tur-
nips to 28.9 per cent in sweet potatoes. Potatoes are
more nutritive pound for pound than roots. The dry
matter of this class of cattle foods is principally carbo-
hydrate in its character, though the proportion of pro-
tein is as large and in some cases larger than in certain
grain foods.

Two conditions are essential to the winter storage of
roots without deterioration, viz., a low temperature,
as near freezing as possible, and abundant ventilation.
Large masses of roots unventilated are apt to “heat,”
and sometimes decay, with a resulting large loss in nutri-
tive value.

GRAINS AND SEEDS

328. The conditions which provide for the mainte-
nance of plant life also subserve the interests of the animal
kingdom. We have seen that this is true of the store
of starch and other compounds in tubers and roots,
and it is a fact of much larger significance in the produc-

~ xa
\ &

“40
7
* J

fan

CATTLE FOODS—NATURAL PRODUCTS 241

tion of seeds, especially those of our cereal grains, includ-
ing barley, maize, oats, rice, rye, and wheat. Other
seeds, such as buckwheat, cottonseed, flaxseed, beans,
and peas, also contribute an important addition to our
animal feeding-stuffs. In all these species there is de-
posited in the seed coats and either around the chit or
embryo or in the seed leaves of the embryo, a store of
protein, starch, and oil, the purpose of which is to supply
materials for growth during germination. This deposit
of plant compounds represents the highest type of vege-
table food, whether we consider concentration, palatable-
ness, or nutritive efficiency. Besides, it is in such form
that with ordinary precautions it is capable of indefinite
preservation, without loss.

329. Storage of grain.—It often occurs that when
newly-harvested grain is stored in bulk it heats and
grows “musty.” This condition is due to fermentations
that are made possible by the high water-content of the
fresh grain and which involve a loss of dry substance. It
is very desirable that grain shall be thoroughly dried
before threshing, and it is generally desirable to secure
additional drying after threshing before storing it in
large bins.

The agricultural value of the cereal grains is much
enhanced by their adaptability to a great range of soil
and climatic conditions. They are the American farmer’s
great reliance for the production of the highest class of
cattle foods. Maize, especially, is grown from Maine to
Florida and from the Atlantic to the Pacific. These
crops are useful, not only for their seeds but as fodder
plants. For soiling purposes, as well as a source of dried
forage they are highly important.

Ly

CHAPTER XIV

CATTLE FOODS—COMMERCIAL FEEDING-
STUFFS

Tue cereal grains and other seeds are the source of
a great variety of by-product feeding-stuffs which have
a large and widespread use, especially in the dairy sec-
tions of the United States. In the preparation of a
great variety of human foods and of other materials
important in industrial life, certain by-products are
obtained which represent particular parts or compounds
of the grain or seed. Whenever the methods of manu-
facture are such as not to injure the palatableness or
healthfulness of these waste products, they may be
utilized as cattle foods. As a matter of fact, a large
proportion of our commercial feeding-stuffs is of this
general kind and because these materials differ greatly
in composition and nutritive value, the purchaser should
clearly understand their source and character. Changes
in methods and new manufacturing enterprises are
constantly modifying the composition of old products
and introducing new ones, consequently the facts as
they exist at one time may not be applicable for a long
period. There is need therefore of constantly keeping
informed in regard to the various cattle foods found in
the markets, if they are to be economically purchased
and wisely used.

330. Classes of commercial by-product feeding-
stuffs.—For the purposes of description, the various

(242) >

COMMERCIAL FEEDING-STUFFS ~~ 243

by-product feeding-stuffs may be classified according
to their origin. Their sources are mainly as follows:
1. The milling of wheat and other grains.
2. The manufacture of oatmeal and a variety of
breakfast foods.
3. The manufacture of beer and other alcoholic drinks.
4. The manufacture of starch and sugars, chiefly
from corn.
5. The manufacture of beet-sugar.
6. The extraction of oils, chiefly linseed oil and cotton-

seed oil.

7. Screenings from the milling of wheat, and other
refuses.

8. Compounded feeds made up from a variety of
by-products.

331. Wheat offals—No commercial feeding-stufis are
regarded with greater favor, or are more widely and
largely purchased by American feeders than the by-
products from milling wheat. Wheat bran and mid-
dlings are cattle foods of standard excellence, whether
we consider composition, palatableness, or their relation
to the quality of dairy products. These feeding-stufis
consist of particular parts of the wheat kernel, a knowl-
edge of the structure of which aids greatly in under-
standing what they are and why they possess certain
chemical and physical properties.

332. Structure of the wheat grain—To ordinary
observation the wheat grain appears to be merely a
seed, but it is really a seed contained in a tightly-fitting
seed pod. This pod, which is woody and tough, con-
_ stitutes the outer coating of the kernel. On the seed
itself are two more hard and resisting coatings, one of
which is double, that serve to protect the softer parts.

-

244 THE FEEDING OF ANIMALS

We find, then, that in every wheat kernel there are three
coats entirely unlike the rest of the grain, because they

consist of hard, thick-walled cells containing but little

starch, if any, with a much larger proportion of cellulose
or fiber than is found in the inner portion of the kernel.
(Figs. 11 and 12.)

Just inside the innermost of the three outer coats
is a layer of material very rich in protein compounds,

One MILLIMETER

Fig. 11. Section of entire wheat kernel (enlarged 16 diameters). 7, seed
pod and seed coatings; 4, gluten layer; 6, mass of starch cells.

which may properly be called the gluten layer. The
great bulk of the wheat kernel is made up of cells closely
filled with starch grains.) This is the soft white por-
tion of the seed and is that which furnishes the flour. All
of these parts serve to protect, and, in germination, to
nourish the essential portion of the seed, the germ or
embryo which lies ‘‘at the lower end of the rounded back
of the kernel.’ Bessey, in an admirable description of

COMMERCIAL FEEDING-STUFFS — 245

the wheat kernel, tells us that the percentage propor-
tions of its various parts are as follows:

Per cent Per cent
aanmes Le 5 Starch cells ... . 8486
Gluten layer ..... 34 Geeta: i. ee 6

333. The milling of wheat.—We are now prepared to
understand the significance of the statement that in mill-
ing wheat the flour of various grades comes from the
starch cells, the other
portions passing into
the bran, shorts, and
middlings, which col-
lectively are termed the
offal. If only the coat-
ings, gluten layer, and
germ went to make up
the offal it would in-
clude only about 14 or
15 per cent of the )

—— ae pee One Fig. 12. Partial scetion of wheat kernel
the remainder, but, aS (enlarged 155 diameters). 1, seed pod;
Gi istter of fact, no 7 out th cont; S.mmema ams
milling methods so far

used completely separate the starch cells from the
inclosing tissue, so that the offal is perhaps never less
than 25 per cent of the whole grain. In milling tests con-
ducted by the Minnesota Experiment Station, the offal
from several lots of wheat, good and bad, varied from
25 to 40 per cent. If four bushels of wheat are consumed
per capita by the population of the United States, which
is below the estimate, and if only one-quarter of this is
converted into offals, the amount of bran and middlings
annually consumed by our domestic animals is not less

246 THE FEEDING OF ANIMALS

than 3,000,000 tons, barring the quantity which may. be
exported.

334. Composition of milling products of wheat.—It
is a fact worthy of special comment that because of
a somewhat irrational standard of excellence for bread,
certain parts of the wheat kernel best adapted to the
nourishment of young and growing animals are separated
with great care to be used by the brute life of the farm
rather than by the farmer and his family. A comparison
of the composition of the whole wheat kernel, white
flour, and the various parts of the offal emphasizes this
point. The figures given are taken from the results of
an investigation by Snyder, of Minnesota, in which he
compared the composition of different grades of wheat
with that of the flour and products obtained from them:

TABLE XLIX. ComposITION OF WHEAT AND ITs MILLING
Propucts (PER CENT)

Protein Nitrogen-| Starch
Water | Ash |————————— Fiber free and Fat
Total | Gluten extract |dextrine

—_———— | | | | | SS Ee

Wheat kernel . | 10.2 | 1.8 | 13.7| 13.5 | 3.2!- 69. 64.9 | 2.

Wheat flour .| 10.6 oe: Ay Beh Is Ie oy wid ieee 70.4 5
Memeawecem . | 10.4 | 2.7.1 15.7|-15.3 ). 4 6n7 : le aoe
Wheapeuprs,. | 10.1.) 3.1 | 138.1) 12.9 | 5.4) 65.3
Wheat bran .| 10.4 | 5.9 | 15.4) 14.8 | 10.2} 52.9 Lge a

The greater richness of the coatings of the kernel
in mineral matter, protein, fiber, and oil is made plain
by this comparison. There is four times as large a per-
centage of mineral matter and of oil in the whole wheat
as in the flour, nearly one-third more protein and con-
siderably less starch. On the other hand, the bran is not
less than ten times richer in mineral compounds and oil

‘COMMERCIAL FEEDING-STUFFS _ 2A7

than the flour, one-third richer in protein, with corres-
pondingly less starch. “Graham” flour, which contains
more or less of those parts which pass into the offal in
milling white flour, does not differ so much from the
whole kernel. Middlings differ from bran in containing
less of the hard, tough coatings and more of the finer
parts of the kernels, and this feeding-stuff varies from
the coarser kinds to the fancy middlings, according to
the proportion of starchy material present. Red Dog
flour is counted among the offals from milling wheat, and
it represents the dividing line between the middlings and
the high-grade flour.

335. Milling processes compared.—There is a belief
more or less prevalent that bran from the old milling
processes which contained more of the starchy part of
the kernel than is now the case, was more valuable than
roller process bran is. It is probable that a greater pro-
portion of starch increases the digestibility of bran, and
in this sense the old process bran was superior to the
roller process product; but, on the other hand, the latter
is more nitrogenous than the former and is therefore
more efficient as a protein supplement to home-raised
foods.

336. Screenings.—Wheat, when sold to the mills, con-
tains besides inferior wheat grains a certain percentage
of foreign materials such as other grains, weed seeds,
chaff, bits of straw, and even particles of grit. Before the
wheat is milled these materials are removed and in com-
merce are known as screenings. While the percentage
of this foreign matter in wheat is small, the aggregate
quantity of this offal put on the market is very large.
Screenings contain ingredients of greatly varying qual-
ity, some of which are very inferior, This offal is almost

248 THE FEEDING OF ANIMALS

wholly used as a part of the so-called compounded
feeds, a fact to be reckoned with by purchasers of these
mixtures.

Recently millers are mixing these screenings with the
bran. Unquestionably the bran thus suffers deteriora-
tion proportionate to the quantity and quality of the
screenings. The guarantee accompanying such mix-
tures generally specifies “wheat bran with the mill run
of screenings.” This is
a part of the growing
practice to foist upon
the consumer a great
variety of by-products
and refuses, some good
and some bad.

337. Residues from
breakfast foods.—In

Sci the manufacture of
ae were breakfast foods, the

Fic. 13. Section of entire oat grain :
(enlarged 16 diameters). 0, hull; 1, seed use of which has be-

coat; 4, gluten layer; 5, mass of starch eoQmeso prevalent, cer-
me tain by-products are
obtained which are now found in the market as cattle
foods. The preparation of oatmeal and similar materials
involves the selection of the finest oat grains, i. e., those
having the largest kernels, from which the hulls are
removed. These hulls and the smaller oat grains, and
perhaps bran, constitute by-products which, after being
finely ground, are sold as oat-feed and in various mix-
tures. As the sale of oat hulls as such, or in a fraudulent
way when mixed with other substances, is likely to occa-
sion a financial loss to feeders, it is desirable to clearly
understand the situation. We shall accomplish this by a

COMMERCIAL FEEDING-STUFFS 249

study of the relation of the oat hulls to the kernel in
quantity and composition. (Figs. 13 and 14.)

338. The oat grain, oat hulls—It is common knowl-
edge that the oat grain consists of a hull and kernel,
which are easily separated. The former is fibrous and
tough, and the latter ae

soft with very little fiber. s¥ojse\ley ay e)(o roe) iC e
The hull forms a con- ED) dg fe (eels

: lay Nae
siderable portion of the ie pushy. ay”
grain. In 1894, the Ohio eS: Oe Ee
Experiment Station ee

SS
—$

made a study of numer-
ous varieties of oats. It
was found that with
sixty-nine varieties the
hulls constituted from
24.6 to 35.2 per cent of
the whole grain, the aver-
age being 30 per cent.
It did not appear, con-
trary to the general Z
opinion, that the pro- ON eae
portion of hull was larger (.ciatged’170 diameters). 0, hulls 1
with light oats than with seed coat; 4, gluten cells; 6, starch
heavy, although observa- °C"S:

tions elsewhere have sustained the popular view. At the
Mustiala Agricultural College twenty-eight samples of
Finnish oats and twenty samples from five other coun-
tries gave from 28 to 32 per cent of hulls. Wiley states
that the average proportion of hull to kernel is as three
to seven, which varies with locality. The figures in the
next table show the composition of the dry matter of
whole oats, oat hulls, and the hulled kernel:

250 THE FEEDING OF ANIMALS

Taste L

Nitrogen-
Ash |Protein| Fiber iree Fat
extract
Per aae Per cent} Percent] Per cent |Per cent
Whole oats, 30 samples . . .| 3.4 | 13.2 | 10.8 | 67. 5.6
Hulls, New Jersey .... . 7.2 3:5 lees 56.3 t;
Sieaeligs Vermons pore.” . 6.9 4.4} 29.5 | 57.2 2.
Hulls, Wisconsin... . . 7.8 2.3. | 50D | -30. 8

Hulled kernels, 179 analyses .| 2.3 | 154| 1.5] 721 | 87

The inferiority of the hulls as compared with the whole

grain or with the hulled kernels is very apparent, because .

of their smaller proportion of protein and oil and their
much larger percentage of fiber. If hulls are purchased
at all the price should be on a par with that at which the
coarsest and cheapest grades of fodders are sold.

339. Oat clippings——Oat clippings is an offal intro-
duced into the market at a later date than oat

hulls. This waste consists of the hairs, oat dust, ~

and light oats mostly separated from the oat kernel by
the clipping process. Such material is inferior both as
to composition and digestibility. It is now much used
in compounded feeds. Farmers will do well to carefully
inquire into the character of the so-called oat feeds and
compounded feeds offered to them. These articles are
often oat hulls, poor oats, and other refuse mixed with
corn or with by-products of another class and are dis-
tinctly inferior to the whole grains. Such low-grade
mixtures are not wisely purchased at prices nearly equal
to those ruling for whole cereal grains of any kind.

340. Barley feed.—This is a by-product from the
manufacture of pearled barley, and like oat feed consists
of the hulls and portions of the grain and contains more

nf Png ‘ 2 5 3 1. f j

COMMERCIAL FEEDING-STUFFS _ 251

fiber and less starch than the original grain, its value
being proportionately less.

341. Hominy feed.—Hominy is made from corn and
consists of the hard portions of the kernel, leaving as a
residue the hull, germ, and part of the starch cells, which
collectively are sold as hominy feed or chop. This differs
from the whole kernel but little In composition and is
practically as digestible.

342. Brewers’ grains; maltsprouts.—Sugar in some
form is at present essential to the production of alcoholic
beverages, a cheap supply of which is obtained by con-
verting the starch of certain cereal grains into maltose,
which afterward passes into fermentable sugars. This
result is accomplished by placing barley and other grains
under such conditions of moisture and temperature that
they germinate. We have already seen that during ger-
mination the starch of a seed is converted into maltose
through the action of a diastatic ferment (see Par. 94),
and the maltster arrests this germination at a point
which gives the maximum quantity of sugar. The malted
grains are subsequently dried and the sprouts after
removal appear in our markets in an air-dry condition,
constituting one of our valuable nitrogenous feeding-
stuffs. The malted grains are then crushed, the sugar is
extracted from them, and the residue is known in com-
merce as brewers’ grains, a by-product feeding-stuff fairly
rich in protein. The high proportion of protein is due to
the fact that the starch has been largely removed,
leaving the other constituents behind in a more concen-
trated form. ‘These grains are mostly dried and may
then be shipped to distant markets in a perfectly sound
and healthful condition.

~

253 THE FEEDING OF ANIMALS

343. Residues from starch and glucose manufacture.—
The gluten meals, gluten feeds, corn bran, and the like
are residues obtained in the manufacture of starch and
glucose from the maize kernel. This kernel, like that of
wheat, is not homogeneous in structure and composition,
a condition which makes it possible, through mechanical
or chemical operations, to secure a variety of by-products
greatly unlike in texture and in their proportions of
nutrients.

344. Structure of the maize kernel.—All this is made
plain through a consideration of the structure of the
maize kernel. This seed is in some respects similar to
that of wheat. We have first an outside husk or skin
made up of two distinct layers, one less than we find in

Fig. 15. Section of entire maize kernel (enlarged 10 diameters). 1,
outer layer of husk or skin; 2, inner layer of skin; 4, gluten layer;
6, mass of starch cells.

wheat. This skin is rich in fiber, scarcely any being found
in the other portions of the kernel. Next on the inside
is a layer of cells rich in gluten. The body of the kernel
surrounding the germ or embryo consists of closely com-
pacted starch cells, though some of this interior tissue on

COMMERCIAL FEEDING-STUFFS 253

the sides of the kernel next to the walls is flmty. We
may properly speak of the maize kernel, then, as consist-
ing of four parts—the husk, the gluten layer, the germ,

Sear ne starchy “ate -eee
SS OOO OO Sas Jsgeime

hard part. (Figs. 15 a Se
and 16.) At the New | epee
Jersey Experiment Sta- ae gs ee
tion one hundred grains
of the maize kernels
were separated as nearly
as possible into the
skin, germ, and main or
starchy and hard por-
tions. These parts were
analyzed, and below

Fic. 16. Partial section of maize

Saya their COMPO- kernel (enlarged 170 diameters). 1,
sition: outer layer of skin; 2, inner layer of
skin; 4, gluten cells; 5, starch cells.

Taste LI. Composition oF Dry SussTANceE OF Maize KERNEL

(PER CENT)

Nitrogen- Propor-

Ash _ | Protein] Fiber free Fat tion

extract of parts

Original kernel . . .| 1.7 | 12.6] 2. 79.4 4.3 | 100.
i ea ae 1.3 6.6 | 16.4 | 74.1 1.6 5.5
COST SER eae eae ee et eA a 2.9 | 34.7 | 29.6 10.2
Starch and hard part.| .7 | 12.2 6 | 85. 1 e828

These figures are essentially similar to those obtained
by other investigators, including Salisbury, Atwater,
and Balland.

345. Manufacture of starch.—The separation of starch
cells (see Par. 102) from other parts of the kernel is
accomplished mechanically. Either before or after soak-

ben dl | A ot Wo oy (ROU
{ ‘

gua f
254 © THE FEEDING OF ANIMALS

ing in warm water, the maize kernels are crushed into a
coarse powder. The various parts separate in water by
gravity, the hulls floating on the surface and the germs
sinking to the bottom. The starch and harder portions
of the kernel remain in suspension in the water, which is
conducted slowly through long troughs, where the starch
settles to the bottom and the more glutinous portions
float off and are recovered.

It is now easy to see how these various by-products
may differ widely. When made up largely of the hulls
or bran they are characterized by a relatively high pro-
portion of fiber with comparatively low percentages of
protein and fat. The presence of the germs increases the
relative amount of protein somewhat and of the fat very
greatly. The fine glutinous part, that is finally separated
from the starch, when unmixed with other materials is
distinguished by its high content of protein.

As found in the market, the principal brands are corn
bran, gluten meal, that comes from the flinty portion of
the kernel, and gluten feed, which is now a mixture of
hulls, the gluten part, and the steep water residue. When
unmixed with other parts of the kernel, the hulls are also
known as corn bran and the germ portion from which the
oil has been pressed is called, when ground, germ oil meal.
The corn bran contains the least protein and the gluten
meal the most, while the gluten feed and germ oil meal
occupy a position between these.

In recent years the practice has been adopted of add-
ing to the gluten feeds the solids found in what is known
as the steep water, that is, the water in which the maize
kernel and its parts have been soaked during the process
of separation of one part from another. This steep water
contains all that is soluble in ‘the maize kernel or has

b
COMMERCIAL FEEDING-ST UFFS : 259

become so through the treatment it receives, including
soluble proteins, amino acids, and the soluble mineral
salts of the corn. This steep water residue darkens the
color of the feed and renders it acid in varying degrees,
which at first caused an unwarranted prejudice against
gluten feeds with these characteristics. |

346. Residues from the manufacture of beet-sugar.—
An industry apparently now established in the United
States, the manufacture of beet-sugar, is offering to
farmers two waste products, sugar-beet pulp and sugar-
beet molasses. The former is the extracted beet tissue
from which all the sugars and more or less of other solu-
ble compounds have been removed. This pulp as it
leaves the factory has been found to contain an average
of scarcely 10 per cent of solids. One ton of pulp sup-
plies, then, not over 200 pounds of total dry substance,
or perhaps 160 pounds of digestible dry substance. This
means that it would require six tons of wet pulp to supply
as much of digestible nutrients as one ton of good hay.
The solids of the pulp must be regarded as inferior to those
of the beets before extraction because consisting more
largely of fiber and gums whose productive value is below
that of sugar. Experiments at Cornell University in-
dicated that the pulp is worth about one-half as much
as corn silage, which would be approximately the rela-
tion of digestible matter in the two materials.

Sugar-beet pulp is, however, a useful, succulent food,
and may be fed to advantage in quantities from seventy-
five to one hundred pounds daily to full-grown animals,
provided it can be purchased at a price proportional to
its value.

The pulp is not adapted to transportation for long
distances because of the heavy expense of freight and

\

256 THE FEEDING OF ANIMALS

handling, but is most available for consumption near the
factories. It may be preserved in pits or silos.

Dried beet pulp is now on the market. Its protein-
content is low, and the carbohydrate-content high. The
rate of digestibility is fairly high. Cattle-feeders should
bear in mind that the use of this material only intensifies
the already high carbohydrate-content of the home-raised
feeds.

The molasses is generally four-fifths or more dry
substance and contains from 40 to 50 per cent of sugar,
which is all digestible and which gives to this product
its only value for feeding purposes.

This material has been fed successfully to bovines
and swine. When given as an addition to coarse foods
and home-raised grains it obviously should be combined
with some nitrogenous feeding-stuff like gluten meal
or the oil meals.

347. The oil meals in general.—Ma terials of this class
may properly be regarded as among the standard feed-
Ing-stuffs. Because of their uniformity in quality and
composition, their general usefulness in compounding
rations and their value in maintaining soil fertility,
their use has had the sanction of scientific men and of
successful practice. The oil meals are so called because
they are the residues left after the extraction of the oil
from certain seeds and nuts, among which are cotton-
seed, flaxseed, hemp and poppy seed, rape seed, sesame
seed, sunflower seed, coconuts, palm nuts, peanuts, and
walnuts. Of the residues from these sources, those from
cottonseed and flaxseed are most common in the United
States; in fact, no other oil meals have become greatly
important in our cattle-feeding. A description, therefore,
of the production of cottonseed meal and linseed meal

‘“

COMMERCIAL. FEEDING-STUFFS ~~ 25%

will not only cover the points of practical interest to
American feeders, but will serve to illustrate the main
facts that pertain to the manipulation of these oil
seeds. |

348. Methods of extracting oils.—It may be stated
in a general way that two methods have been used for
removing vegetable oils from seeds, expressing by pres-
sure and extraction with a solvent. With the first method,
it was formerly the custom to express the oil from the
cold crushed seed, but now the seed is more generally
submitted to heat, either by boiling or steaming, after-
ward applying the pressure to the warm material. More
oil is obtained by the latter process. The second or
extraction method involves the use of a solvent, gen-
erally a light naphtha, which leaves less oil behind than
either cold or warm pressure. Before extraction the
crushed seed is heated just as when pressure is used.

349. Cottonseed meal.—The cotton seed as gathered
from the plant consists on the exterior of a mass of long
white fibers that are attached to the outer coat or hull,
inside of all of which is the kernel or meat. The seed
is first delinted by running it through a gin, which removes
the lint or cotton of commerce. After this operation
there is still attached to the seed a soft down, which
is subsequently removed and which constitutes what is
known as “‘linters,” a short lint that is used in making
cotton batting. The remaining portion is that from
which cottonseed oil and certain by-product feeding-stuffs
are produced.

350. Cottonseed hulls.—The first process in the manu-
facture of the oil is to remove the hull from the inside
meat. This is done by a sheller, which breaks the seed
coat and forces it from the kernel. These seed coats,

Q

a7 »s vy oe ‘“ oi¢
\ : =,’ C \ a . Ly
t

258 THE FEEDING OF ANIMALS

which constitute from 45 to 50 per cent of the delinted
seeds, are known in commerce as cottonseed hulls, and
are used to some extent as a feeding-stuff. They are
characterized by a very low proportion of protein and a
very high content of fiber. Twenty-two analyses show a
range of protein from 1.6 to 4.4 per cent, and of fiber
‘from 35.7 to 66.9 per cent. Such material as this belongs
with the. very lowest grade of coarse fodder, as both
composition and experience demonstrate.

351. Extraction of oil from the cottonseed kernels.—
The hulless kernels make up from 50 to 55 per cent of
the delinted seed, and from those the oil is obtained.
These meats are first cooked twenty or thirty minutes
in large, steam-jacketed kettles in order to drive off the
water and render the oil more fluid, and then after being
formed into cakes in wire cloths, they are submitted to a
pressure of 3,000 to 4,000 pounds to the square inch.
This removes at least four-fifths of the oil and leaves the
cakes very solid, which after drying are cracked and
ground into a fine meal, known in commerce as cotton-
seed meal. Formerly a ton of ginned seed yielded the
following quantities of the different parts:

Pounds
ee ace eh Se Ta a ine Ne ae 20
EN en aren ea nL Sp LS ih? 891
ee a a i Ct 800
oo TLV SEE SE SS a ae ca 289

Since the above estimate was prepared the manufac-
turing process has been so improved that from forty
to forty-five gallons of oil are now obtained from a ton
of seed, giving a correspondingly smaller amount of cake.
Cottonseed meal at the present time is less rich in oil
than was the case a few years ago.

Fis

= Se

(COMMERCIAL FEEDING-STUFFS ~ 259

352. Composition of cottonseed oil by-products.—
The composition of the cottonseed oil emi is

the following:
TaBLe LII
: : Nitrogen-
Water | Ash /Protein| Fiber free Fat
extract

SNe nn ee ee

Per cent|Per cent|Per cent|/Per cent} Per cent |Per cent

Mantonseed .. .... Bao - | 49.4 | 22.6| Bae 19.4
Cottonseed hulls . . .| 11.4 me 4.2 | 45.3 34.2 piel
Cottonseed kernels . . 6.9 | 6.9 | 30.3 4.8. +. 21.4 19m

Cottonseed cake ... Rint 7. 44.1 49: So 14.2

These figures represent the composition of the several
materials when the separations are fairly complete.
Cottonseed products are sometimes sold, however, in a
more or less mixed condition. There has been found
in the market undecorticated cottonseed. meal, or the
meal with all the hulls ground in without removal from
the seed. The meal that is free from hulls should be
light yellow in color and have a slightly nutty flavor. It
should show few or no black specks, because the presence
of these indicate either accidental or intentional adul- -
teration with hulls. Cottonseed meal now contains less
protein than was formerly the case, which means, un-
doubtedly, that a larger proportion of hulls or lint, or
both, is present. Cottonseed feed is a finely-ground mix-
ture of cottonseed hulls and cottonseed meal, and its value
is less than that of the pure meal.

353. Linseed meal (oil meal).—The original source of
this feeding-stuff is the flax plant. This plant serves
a very useful purpose in producing a valuable fiber,
and oil which now seems indispensable as a constituent
of paint and a high-class stock-food. Flaxseed, of which

260 THE FEEDING OF ANIMALS

the annual production in this country was about 19,500,-
000 bushels in 1909, contains a very high percentage of oil,
ranging in the analyses so far made from 22 to 40 per
cent. The average is variously stated by different com-
pilers at from 33 to 37 per cent, and the mean of these
two numbers is probably fairly correct. On this basis
a bushel of flaxseed, weighing fifty-six pounds, contains
nineteen and one-half pounds of oil and thirty-six and
one-half pounds of other substances.

354. Extraction of linseed oil.—Linseed oil is obtained
from the seed by both the pressure and extraction methods.
The oldest method was to subject the cold crushed seeds
to a heavy pressure, which expressed from 70 to 80 per
cent of the oil, leaving a cake containing from 10 to 15
per cent. Later the warm pressure process was intro-
duced, which consists of moistening the crushed seed,
heating it to from 160° to 180° F., and submitting it to a
pressure of 2,000 to 3,000 pounds to the square inch. This
improvement increased the output of oil from a given
quantity of. seed, the amount expressed being about
90 per cent of the whole, leaving a cake containing from
6 to 7 per cent. The latest and most effective process is
the extraction of the oil by a light naphtha. The seed is
crushed and heated as in the warm pressure method, and
the oil is then extracted by repeated leachings with
naphtha until the residue when dry contains only about
3 per cent of oil. The naphtha is thoroughly driven from
this residue with steam so that the resulting meal is
entirely free from odor and is as palatable as the residue
from the pressure process.

355. Old process vs. new process linseed meal—
The terms “old process” and “new process” are now
applied to linseed meal, the former referring to that made

COMMERCIAL FEEDING-STUFFS : 2652

_ by the cold and warm pressure processes, and the latter
to the residue from naphtha extraction. The composi-
tion differences between the two are seen in the following
average of several analyses of each kind which were

made by Woll:
Taste LITI

’ : Nitrogen-
Water | Ash | Protein} Fiber free Fat
extract

Percent|Percent|Percent|Percent|} Per cent |Percent
Old process linseed meal) 9.4 | 5.4 | 35.6 | 7.1 35 45
New process linseed
Mice. <2 0 oe A 9.2 5.4 | 36.6 | /8.6 37 az

These averages show 1 per cent more protein and 3
per cent less fat in the new process meal.

The old process samples analyzed by Woll were
doubtless from the warm pressure methods and do not
fairly represent the linseed meal which was found in the
markets when it first came into general use. Four hundred
and twenty-eight analyses of old process cake compiled
by Dietrich and Konig, which were made previous to
1888, show an average of only 28.6 per cent of protein
and 10.6 per cent of fat. An average by the same authors
of 179 analyses of the meal shows 30 per cent of protein
and 9.9 per cent of oil, those samples taken previous to
1880 being poorer in protein and richer in fat than those
analyzed after that date. The average of twelve samples
of linseed cake made prior to 1883 and compiled by
Jenkins, gives 29.7 per cent of protein and 11.2 per cent of
fat. There is no question but that the meal now found in
the markets is considerably richer in protein and poorer
in fat than that with which American farmers were first
acquainted.

262 THE FEEDING OF ANIMALS

The relative values of the old and new process meals
are much discussed. Many farmers are prejudiced in
favor of the former, possibly because anything which has
been treated chemically is regarded with suspicion when
considered as a food. No good evidence exists, however,
that new process meal is less palatable or less healthful
than the old process product, nor has practice demon-
strated that in a general way it is less nutritious.

A very useful inquiry by Woll into the characteristics
of the two kinds of meal showed certain differences which
are interesting in this connection. ‘Two points were
studied: the digestibility and the property of swelling to
a mucilaginous condition when stirred up with water.
Experiments with animals both in Germany and in this
country have shown a quite uniformly lower coefficient
of digestibility for the protein of the new process than
for the old process, meal. Woll tested this matter by
artificial digestion with a solution of pepsin, and his
results verified those secured with animals, the protein
of the old process sample proving to be 10 per cent the
more soluble. This difference is believed to be caused by
the additional cooking with steam which attends the
driving out of the naphtha from the new process meal, for
it seems to be well proven that the digestibility of vege-
table protein is diminished by cooking. American experi-
ments do not indicate a lower digestibility of total dry
matter for the new process meal, which is contrary to
the verdict of German digestion trials.

The property of swelling to a mucilaginous condi-
tion is one well known to pertain to flaxseed. This is due
to mucilage cells found in the seed coat. When this
mucilaginous matter has once been swollen, it will not
repeat the process after drying. Woll’s tests showed

@ TEST" oe “i y ~ A 4 f A . 3 : As s
. - 4 —

COMMERCIAL FEEDING-STUFFS ~ 263

that the old process meal responded to the swelling test,
but not the new process, a result due probably to the
steam cooking of the latter. This may serve as a means
of determining the method used in manufacturing a
given lot of meal, but probably has no special signifi-
cance as to feeding value, unless it indicates the new pro-
cess meal to be less useful in making a porridge for feed-
ing calves.

CHEMICAL DISTINCTIONS IN CATTLE FOODS

The classes of cattle foods as arranged in the previous
discussion have had reference to several factors, chiefly
those relating to origin and texture. Chemical facts have
not been considerd in these divisions. There are, how-
ever, certain chemical differences among the various
groups of feeding-stuffs, a knowledge of which is helpful
in selecting materials for compounding rations.

356. Coarse foods vs. grains and grain products.—In
comparing hays, straws, and other fodders with grains
and grain products there are points of chemical unlike-
ness which bear an important relation to problems of
nutrition. In the first place, the nitrogen compounds
differ. In the grains we find the nitrogen combined mostly
in the form of true proteins, while in the fodders and
roots a proportion of it, and sometimes quite a large
one, exists in amides. This is a point in favor of the
grains, for the nutritive function of amides is probably
more limited than that of the true proteins. Again, the
non-nitrogenous material of the grains is in general
superior to that of the herbaceous cattle foods. In the
former, especially in the cereal grains, there is but little
fiber and the nitrogen-free extract is made up largely of

264 THE FEEDING OF ANIMALS

starch and other bodies, whose net value in nourishing an
animal is quite surely greater than that of fiber and gums
found in such abundance in the hays and other fodders.
The work of masticating fibrous materials is greater than
with sugar or starch, and less is digested. The terms
protein and carbohydrates do not signify the same com-
pounds or the same values when applied to different
feeding-stufts.

357. Classification of feeds according to the propor-
tions of nutrients.—The relative proportion of nitrog-
enous and non-nitrogenous compounds in feeding-stuffs
is greatly varied. There is no fixed proportion in the
same species, even, but it varies to some extent with the
season, period of cutting, and other conditions. At the
same time, there are differences of composition between
several groups of feeding-stuffs that are constant within
not very wide limits, and which it is important to recognize.

358. Misleading terms for feeding-stuffs.—There
are a few terms that are popularly used to differentiate
_ feeding-stuffs which are misleading. For instance, corn
meal is often spoken of as “‘carbonaceous” in contrast
to cottonseed meal, which is called “nitrogenous.” It may
be seen by reference to preceding data that there is a
higher proportion of carbon in the proteins than in
starch or sugars. Cottonseed meal is more carbonaceous
than corn meal, rather than less so. Such a distinction is
therefore absurd.

“Heat-forming” is another term often applied to
foods rich in carbohydrates, while the more highly nitrog-
enous materials are characterized as “muscle-forming,” a
distinction apparently based upon the facts that carbo-
hydrates are usually largely burned in the animal body,
and that the food proteins are the source of the body

e \

COMMERCIAL FEEDING-STUFFS s 265

proteins. But, as a matter of fact, the potential heat
value of the digestible part of an oil meal is certainly
greater than that of digestible corn meal. Under certain
conditions one feeding-stuff is no more fully used than
the other for tissue-forming purposes, and both may be
utilized outside of the usual wastes in the production of
some form of energy, ultimately heat.

359. Classification of feeding-stuffs——The satisfac-
tory division of feeding-stuffs into as few as two classes,
according to their composition, is not possible by the use
of any terms whatever. Such a division is necessarily
based upon the relation in quantity of the protein to the
non-nitrogenous part, and there is an almost uniform
gradation of foods in protein-content from those contain-
ing the least to those most highly nitrogenous. Any
division into groups with reference to the percentage
amount of protein must be entirely arbitrary and should
take account of at least four classes of materials, other-
wise the extremes of each division are too widely apart.
Probably no more convenient and rational classification
of grains and grain products can be suggested than the
one proposed by Lindsey:

Class I. Thirty to 45 per cent protein, 30 to 45 per
cent carbohydrates. The oil meals and gluten
meals and certain distillers’ dried grains.

Class II. Twenty to 30 per cent of protein, 60 to
70 per cent carbohydrates. Gluten feeds, the lower
grade distillers’ dried grains, dried brewers’ grains,
maltsprouts, buckwheat middlings, and beans
and peas.

Class III. Fourteen to 20 per cent protein, 70 to 75
per cent carbohydrates. Wheat brans and mid-
dlings, rye bran, and mixed feeds.

266 THE FEEDING OF ANIMALS

Class IV. Eight to 14 per cent protein, 75 to 85 per
cent carbohydrates. Barley, corn, oats, rye, wheat,
cerealine, hominy, oat feeds, corn and oat chop,
and corn bran. The fodders and roots properly
belong with Class IV.

By reference to these groups it is possible to ascer-
tain about what place a particular feeding-stuff will
take in making up a ration, for instance, to what extent
it will serve as a protein amendment to a mixture of
materials composed largely of carbohydrates.

FOODS OF ANIMAL ORIGIN

360. The principal materials of animal origin that are
used in feeding domestic animals are milk, dairy by-
products, and offals from slaughter-houses. They are
mostly characterized by their large relative proportion
of protein and their high rate of digestibility. The net
nutritive value of their solid matter is very high, because
it is practically all utilized and a minimum amount of
energy is required for its mastication and digestion.
Practice has long recognized the peculiar efficiency of
feeding-stuffs of this class, which is due to the directly
available forms of the nutrients.

361. Milk.—Whole milk has a greatly varying food
value according to its proportion of solid matter. Its
composition is determined by several factors. The milks
of different species of domestic animals are greatly unlike
both in their proportions of total solids and in the rela-
tion in quantity of the different constituents.

The table of the average composition of the milk of
several species, given herewith, is taken mostly from
figures given in Richmond’s “Dairy Chemistry;”

aL i / “d 7 re MOA Ae ay
F Yi 4 ‘ a

. id . : ree Pee
‘ is
A / ‘ &

i
4

COMMERCIAL FEEDING-STUFFS : 2604

Taste LIV. ComposiTioN OF THE MILK oF MAmMats (PER CENT)

Species Water | Dry matter| Ash |Casein Albumin! Sugar | Fat
Peete) 75.44} 24.54 Cel 3 5.05} 3.09 | 9.57
23s 79.46 | 20.56 97 15.23 1.45) 4.28 | 8.63

_
Sow 84.04] 15.96 {1.05 a 23 3.13: 4.55
0 a 86.04| 13.96 .76 |3.49 .86) 4.22 | 4.63
_—_—————— oOo
eo 2! 87.1 12.9 7 a2 5.L fae
Woman 88.2 11.8 gee 9 5 | 68 13.3
oe
oe ae 89.8 10.2 oO 1.84 6.89 | 1.17
*Van Slyke.

The milks are arranged in the order of their richness,
the dry matter present varying from 24.54 to 10.2 per
cent. Those containing a high proportion of total solids,
particularly those from the bitch and the ewe, are espe-
cially rich in proteins and fat, the percentages of sugar
being less than half those in the poorer milks. It is note-
worthy that the proportions of proteins and fats in the
milk decrease, and the percentage of sugar increases, as °
the total solids diminish. Two-thirds of the ‘solids of
mare’s milk is sugar, the proportion of this constituent
in the dry matter of an ewe’s milk being only about one-
eighth.

If we assume that the milk of each species is best
adapted to its own progeny, it follows that when the
young of other species is fed the milk of the cow, as
is so often done, this milk should be modified so far
as possible to simulate that provided under natural con-
ditions. When, for instance, cow’s milk is fed to a colt,
it should be diluted and have its content of milk-sugar
increased; or when lambs are given cow’s milk it may
‘well be made richer, by the addition of cream, perhaps.

268 THE FEEDING OF ANIMALS

362. Milk of several breeds.—The milk of the cow
varies with the breed, the individual, and the period of
lactation, and in its use for feeding purposes these varia-
tions should be considered.

Taste LV

Ash* | Solids | Casein |Albumin|Sugarst| Fat

——<—. | —_ << | —————___ | _ _____ J ——_______ |

Holstein-Friesian 7 \118> (Sz 64 | 5 3.26

Ayrshire ere. || Cot | 12.75 2246 61-|\ 3222 } 3:76

phonons CC sd|:«COS «114.38 «| 2.79 .64 | 5.79 | 4.28

Devon eeeraree. | 8 | 14.5.1. Sik 83 | 4.88 | 4.89

Guernsey . 8 {14.9 | 2.91 .65 | 5.16 | 5.38

Jersey .| 8 115.4 | 3.03 65 | 5.44 | 5.78
*Assumed. +Calculated.

While we have few or no data on the subject, it is
probable that the same causes operate in affecting the
milk of all species.

363. Dairy by-products.—These by-products are three
in number, skim-milk, both from the gravity and the
separator processes, buttermilk, and whey. Their aver-
age composition, as taken from compilations by several
authors, is as follows:

TasLe LVI. Composition oF Datry Orrats (PER CENT)

Water Total Ash Casein and

solids albumin Sugar| Fat

Skim-milk, general average, Cooke| 90.25 | 9.75| .8 3.5 5.15

a
Skim-milk, gravity, Fleischman .| 89.85 |10.15| .77 4.03 4.6 AEE
Separator-milk, Richmond .. .| 90.5 9.5 78 3.57 4.95 | .1
Butteemilloi@opkes-). A... 90.5 9.5 ah, 3. Dil ae
Buttermilk Wretite. 3 2. 90.39 | 9.61] .75 3.6 4.067) .5
Whey, Cooke =m... . . ssf 929 Taos <6 93 5 2
Wihey,-Van Slyketacs heen. : 93.07 | 6.93] .6§ 83 5.16 | .34

*Probably includes the lactic acid. +.80 per cent lactic also present. §Assumed.

COMMERCIAL FEEDING-STUFFS e269

Skim-milk and buttermilk are not greatly unlike in
richness in solid matter or in general composition. In
case the skim-milk is sweet, buttermilk differs from it
because in the latter the sugar has changed partially or
wholly to lactic acid. Whey is considerably poorer in
solids than the other dairy by-products and also differs
from them in the proportions of the.several constituents.

Skim-milk is the residue left after removing the
cream. It differs in composition according to the com-
position of the original whole milk and the thoroughness
of the creaming. The percentage of solids which it con-
tains is proportional in a general way to the richness of
the whole milk. At one time a contrary notion prevailed
and the skimmed milk of the butter breeds, especially
the Jersey and the Guernsey cows, was popularly sup-
posed to be of inferior quality. Numerous analyses have
been made of this by-product from several breeds, and
the succeeding figures give the proportion of solids and
fat in skimmed milk from the gravity process:

TasLE LVII
Skimmed milk
Bolts ine
whole mi
Za | 2
Per cent |Percent;Percent
iim Or ee eS ond 12.22 9.5 e574
Runetemin ee oes... a 12.98 |10.4 | .85
eeeeS fen ee Se py 15.24 |10.5 | .37

These figures show most clearly that the Jersey prod-
uct is more valuable than that from Holstein cows,
volume for volume.

Skim-milk is also affected by the manner or thorough-

:

270 THE FEEDING OF ANIMALS

ness with which the cream is removed. The more per-
fectly the fat is taken out, the less the percentage of solids
left behind, and the less their unit value as a source of
energy. For these reasons gravity-process skimmed milk
is often more valuable for feeding than that from the
separator, though under the best conditions of skimming
in both cases the difference is small.

Buttermilk, which is the residue after extracting
butter from cream, varies in composition from such causes
as the composition of the cream and the perfectness of
the churning. The more fat that is left in it the more
it is worth for feeding purposes. Its feeding value is
‘but little less than that of skim-milk.

Whey solids are mostly sugar. In good cheese-making
practice, whey retains scarcely any of the casein and fat
of the milk. It therefore takes a place in the ration quite
different from that of skim-milk, as it is essentially a
-_ carbohydrate food.

The dairy offals are peculiarly valuable as food for
young animals and swine. It is safe to say that for calves
and pigs no other materials can fully take their place
in their relation to health and vigor.

364. Slaughter-house and other animal refuses.—The
offals from slaughter-houses and from fish, which have a
somewhat limited use in feeding domestic animals, are
meat scraps, meat meal, dried blood, and dried and ground
fish. The materials serve admirably as a supplement to
the home-raised feeds which are largely of a carbohydrate
character, especially in feeding poultry and swine. In the
case of meat-scraps it is desirable to distinguish between
those having a large proportion of bone and those mostly
meat. The accompanying analyses display their composi-
tion, which is subject to great variations:

COMMERCIAL FEEDING-STUFFS oy Bf

Taste LVIII. Composition oF SLAUGHTER-HovusE AND OTHER
ReEFusEs (PER CENT)

Water | Ash |Protein| Fat

Animal meal, N. Y. station .... . 22.1 38.7 | 375) 132

Meat meal, German analysis ... .| 10.7 | 4.1 | 71.2 | 13.7
Fish scrap, German analysis. . . . ./| 13.9 | 31.3 | 48.4] 6.4
meer plood, Fenty . 2° Sie... 8.5 4.7 | 844] 2.5

The meat and fish offals vary greatly according to
proportion of bone which they contain. The percentage
of protein is always large, nevertheless. Dried blood is
much less rich in mineral matter and fat than other
slaughter-house offals are generally, and the proportion of
protein is correspondingly larger. All these materials
are excellent poultry foods when used as a part of the
ration. They may be fed to swine also as an amendment
to cereal grains when dairy by-products are not available.

y

CHAPTER XV
THE PRODUCTION OF CATTLE FOODS

Tue farmer, in deciding what forage and grain crops
he shall grow, should take into consideration several
factors, of which the following are the main ones: (1)
The adaptability of the various crops to the soil and
climate; (2) the adaptability of the various crops to the
kind of business which is to be followed, whether dairy-
ing, stock-growing, or sheep husbandry; (3) the capacity of
the various crops for the production of digestible food;
(4) the protein supply; (5) the maintenance of fertility.

365. Adaptability of crops to environment.—Con-
cerning the adaptability of crops to the great variation
of soil and climate in this country, it is not possible to
treat extensively in this connection without going too
fully into questions of agricultural botany. There are
however, a few general facts worthy of mention. In the
first place, few farmers have accurate information con-
cerning the species of grasses which are growing on their
farms. Only occasionally is one found who carefully
observes what species are most prosperous under his con-
ditions. This is equivalent to the statement that but
little attention is given to the matter of the adaptability
of forage plants to the environment under which they
must be grown. While it may be said that nature carries
on for the farmer more or less of a selective process, it
must be remembered that the rotation of crops, involy-
ing of necessity an artificial selection of species, inter-

(272)

PRODUCTION OF CATTLE FOODS ; 273

feres with this process. The old practice of maintaining
mowing fields for ten to twenty years without breaking
the sod might allow the grasses most congenial to the
soil and climate to establish themselves, but successful .
farming on this basis is now scarcely possible. It is essen-
tial, therefore, especially in dealing with meadows and
pastures, to know what members of the grass family
or other forage plants find the environment congenial.

366. New vs. old species of plants.—It is commonly
remarked, with much reason, that more is to be gained
by the proper selection and proper care of the forage
crops which have maintained successful, though perhaps
unrecognized, existence among us for years, than by seek-
ing for better results from some introduced species. No
cultivated plant possesses qualities that will defend the
farmer against the evil effects of poor or ill-directed cul-
ture, and when intelligent, thorough methods prevail,
many of the familiar species will do for us all we can
reasonably expect. Occasionally an introduced species
may serve a useful purpose, as is true of alfalfa, but in
general a more economical production of cattle foods will
be reached most surely through an improvement of
methods in growing what we already have.

367. Adaptability of crops to kind of animal produc-
tion.—It is obvious that the home production of feed-
ing-stuffs must be adapted to the kind of stock kept.
A herd of dairy cows can hardly be most successfully
managed on the old basis of exclusive pasturing in the
summer and exclusive dry food in the winter. To attain
the best results the pasture must be amended by soiling-
crops, at least during late summer and early autumn, and
a succulent food is a decided improvement to a winter
ration. On the other hand, the successful growing of

R

274 THE FEEDING OF ANIMALS

steers, sheep, or horses requires in many localities only a
good pasture and plenty of dried fodder and grain,
although some succulent foods are desirable with any —
class of animals. Every feeder, no matter what his line
of business, should have at command quite a variety
of fodders.

368. Productive capacity of crops.—The productive
capacity of the different crops used: as cattle foods is
greatly unlike. A satisfactory crop of maize or alfalfa
contains greatly more dry matter an acre than one of
oats, peas, or any of the usual meadow grasses, and in
order that land may yield a maximum supply of feeding-
stuffs it is necessary to step outside grass and grain farm-
ing, where long rotations are practised and where a
major part of the farm is kept in meadow grasses and
only small areas are devoted to cultivated crops. Rapid
rotation and the use of the more grossly feeding crops
are necessary to a vigorous development of the resources
of any land for the maintenance of animal husbandry.

Other things being equal, the most desirable crop
is the one producing the largest amount of digestible
dry matter. This will not be the same crop for all locali-
ties. In one section it may be maize, in another alfalfa,
or in another roots. The selection must be determined
by circumstances, and no rule of general application is
possible. Of course, other things outside of quantity of
production are not generally equal. The cost of pro-
duction varies so that the largest yielding crop is not
necessarily the most economical. This is a local matter
also, concerning which no safe general statement can be
made. It would be convenient if some correct, universal
standards of production and cost could be formulated
for the guidance of farmers, but both growth and cost are

PRODUCTION OF CATTLE FOODS ; 275

much modified by locality and other circumstances and
data are not available, and doubtless never will be, from
which useful averages may be obtained.

The most that it is possible to show is the relative
productive capacity of different crops when the yield is
what is regarded as highly satisfactory in favorable
localities under good culture. This is done in the accom-
panying table. Attention is again called to the fact that
judgment should be based upon the amount of digestible
dry matter produced:

TasBLE LIX

Yield Dry Dry Digestible
per acre} Dry | matter | matter
fresh | matter} per | digesti-

. per
material acre ble TORE

matter

Pounds|Percent| Pounds|Percent} Pounds

JTLT “Gh a aM ee net tart 35,000 25 8,750 69 5,162
Maize, whole plant... . 30,000 | 25 7,500 61 5,025
Red clover, about 34 tons new i 18,000 | 30 5,400 57 3,070
Wntsramd peas} \. 4.5. 2 3 OY 20,000} 16.2 3,240 65 2,106
Timothy, about 234 tons new hes 11,500} 38.4 4,416 57 Pay Wf
Hungarian grass. . 19,000} 25 4,750 67 3,182
Mangolds’ 006°... \. Be COL000 10 6,000 88 5,200
Sugar-beets .... ae: . | 32,000} 20 6,400 88 5,632
OCS ee ee) eee O18 OOO.) .. 25 4,500 85 3,825

The estimates here given may not coincide with the views
of all as to what constitutes a fair crop, but from the data
shown, anyone can easily make a calculation on the
basis of his own estimate.

369. Crops of high productivity.—The foregoing figures
emphasize the relative high productivity of alfalfa,
maize, and roots, as compared with certain cereal grains
and the meadow grasses. The former crops fill an impor-
tant place in intensive stock husbandry. Probably no
species of forage plants are known that are more economi-
cal sources of high-class cattle food than alfalfa and

276 THE FEEDING OF ANIMALS

maize. While the latter crop is no more productive than
mangolds and sugar-beets when these are at their best,
the corn crop costs much less in labor.

Crops of such large productive capacity are espe-
cially adapted to dairymen located on limited areas of
high-priced land. They occupy a place in intensive cul-
ture which will become more and more important as
grazing and long rotations are replaced by soiling and
stable feeding during the entire year.

370. Home supply of protein.—The protein supply
of the farm may be augmented by the growth of legu-
minous crops, such as peas, beans, alfalfa, and the clovers.
In so far as climate and soil permit the economical pro-
duction of this class of fodders, there will be a corres-
pondingly less necessity for the purchase of nitrogenous
feeding-stufts.

371. Legumes and fertility—The leguminous crops
are regarded as sustaining an important relation to
fertility in acting as nitrogen-gatherers, and for this
reason they are believed to be a valuable adjunct of any
system of farming. Just what proportion of the nitro-
gen in a crop of clover, for instance, comes from outside
the soil is not known, however, either for particular con-
ditions or as to the average.

SOILING-CROPS

372. Soiling-crops a necessity—The production of
green crops as an amendment to the pasture, or as a
substitute for it, is a practice essential to the highest suc-
cess in dairying on many farms, and is to some extent
desirable in other branches of stock husbandry.

There are few pastures, perhaps none, that afford

PRODUCTION OF CATTLE FOODS ‘ At

grazing in August and September of such a quality as to
maintain a satisfactory flow of milk. In many instances,
moreover, farmers owning a limited area of high-priced
tillable land wish to keep the maximum number of ani-
mals an acre, and to do this they must cultivate soiling-
crops for stable feeding.

It is no longer a debatable question, whether or not
soiling is profitable under most conditions. Unlimited
testimony can be furnished showing the great gain from
every point of view of even partial soiling as an amend-
ment to the pasture. Whether soiling should be sub-
stituted entirely for grazing is a business matter which
should be decided according to the conditions involved.

373. Conditions favorable to soiling—New England
farmers owning upland rocky pastures in which grow
native grasses of the highest quality for any class of
animals could not widely discard them. Such land gen-
erally absorbs but little capital, and the labor of supply-
ing food by this method is reduced to a minimum. The
case is different with high-priced, easily tilled land located
near good markets. These conditions call for intensive
farming, and grazing animals on permanent pastures is
not a part of intensive practice. Under such circum-
stances the wisdom of a soiling system is clearly indicated.

374. The economy of soiling-crops.—In the first
place, much more food is produced on a unit of area by
soiling than by pasturage. Armsby found that two
soiling-crops in one season, for instance rye followed by
corn, yielded five times as much digestible organic matter
as pasture sod, when the whole growth on the latter was
plucked without waste, the quantities being, respectively,
5,845 and 1,125 pounds. It is variously estimated from
observations in practice that three to five times as many

278 THE FEEDING OF ANIMALS

‘animals can be supported on a given area by soiling as —
by grazing.

Again, grazing is wasteful because of the imperfect
consumption of the growth that is made. Much grass
is tramped down and much is fouled with dung and
urine. These facts are well understood. Other advan-
tages besides economy of land and material pertain to
soiling, such as saving of fences, comfort of the animals
and an increased supply of manure, but these factors do
not require discussion in this connection.

375. Selection of soiling-crops.—Outside of consid-
erations previously noted, productiveness especially, the
‘dairy farmer in selecting soiling-crops must have regard
chiefly to the number of animals to be fed, the time when
the crops will be needed, and the number of days required
for their development. If soiling is adopted in order to
amend the pasture during the late summer and early fall,
a limited number of crops will meet the demand. ‘Three
sowings of peas and oats in late May and early June and
two plantings of corn, one at the usual time and one two
weeks later, would furnish a supply of green food when it
is most likely to be needed. If it is a question of selecting
crops for a system of complete soiling, nothing more
suggestive can be offered as to species and succession
than schemes prepared by Phelps for Connecticut, and
by Voorhees for New Jersey:

_ PRODUCTION OF CATTLE FOODS

TaBLE LX. CONNECTICUT SCHEME

Approximate

Spec‘es of crop Time of seeding time of feeding
Myimeraye . 2. ee Sept. 1 May 10-20
Winter wheat . Sept. 5-10 May 20—June 5
ee July 20-30 June 5-15
Grass (from meadows) June 15-25
Oatsand peas ..... April 10 June 25-July 10
Oats and peas April 20 July 10-20
Oats and peas April 30 July 20—-Aug. 1
Hungarian June 1 Aug. 1-10
Clover, rowen Aug. 10-20
Boyoesns’y. .°. . . came May 25 Aug. 20-Sept. 5
eawpead@ . . . . Jie June 5-10 Sept. 5-20
Rowen grass (meadows) . Sept. 20-30
Barley and peas Aug. 5-10 Oct. 1-30

NEw JERSEY SCHEME
Approximate

Species of crop Time of seeding time of feeding
Winterrye. . Sept. May 1-10
Winter wheat Sept. May 10-20
Crimson clover Sept. May 20-June 1
Oats and peas April 1 June 1-10
Oats and peas April 10 June 10-20
Mixed grasses Sept. June 20-30
Oats and peas May 10 July 1-10
Cowpeas May 20 July 10-20
Corn reat June 1 July 20—-Aug. 1
Japanese Millet June 20 Aug. 1-10
Cowpeas June 10 Aug. 10-20
Corn June 20 ‘Aug. 20-Sept. 1.
Soybeans July 10 Sept. 1-10
Japanese millet July 20 Sept. 10-20
am seh ici oN July 1 Sept. 20-Oct. 10
Barley and peas Aug. 10 Oct. 10-20
Barley and peas Aug. 20 Oct. 20-30

279

The schemes are not practicable for all sections of
the United States. In the southern and western states
more especially, they would need modification to suit
local conditions.

Alfalfa is not included in either of the foregoing lists.

280 THE FEEDING OF ANIMALS

For all sections where this plant can be grown success-
fully it takes first rank as a soiling-crop. In portions of
New York, for instance, in favorable seasons it can be
cut continuously from about the last of May until
October, and no other crop is more thoroughly relished
by horses and cattle. It is valuable for horses, even when
they are doing hard work.

376. Soiling-crop area and rotations.—The area de-
voted to soiling-crops must be determined by the num-
ber of animals and the productiveness of the land which
is to be used. Voorhees states that seven acres, devoted
to the succession of crops which he recommends, will
supply twenty-five cows from May 1 to November 1.
This estimate yeuld hold only when two or three crops
are grown on the same land in a single season, which
requires a generous use of manure or of commercial fer-
tilizers, or of both. The following are suggestions of pos-
sible rotations:

Winter rye, or crimson clover Winter wheat
Oats and peas Cowpeas
Soybeans Japanese millet
Oats and peas Oats and peas
Japanese millet Cowpeas

Barley and peas Barley and peas
Winter rye, or winter wheat Crimson clover
Corn Corn

Some writers estimate the needed area of soiling-
crops on the basis of one-quarter to one-half a square
rod a day for each full-grown animal, the smaller unit
applying to corn and the larger to oats and peas, and
similar crops. All this must be a matter of judgment
based upon the circumstances involved.

“ByeHE JO PPS “ITA Sv

ee ¥

es
bs
eer

es,

CHAPTER XVI _
THE VALUATION OF FEEDING-STUFFS

Ir seems to be very generally supposed that it is
possible to state fixed relative money values for feed-
ing-stuffs, and that by comparing these with market
prices the relation of value to cost may be ascertained.
Such a state of knowledge is certainly much to be de-
sired, for it would be of great practical use to feeders.
For various reasons, however, it is not yet attained,
and there is little present prospect that it will be. The
establishment of such relative values for cattle foods,
as a whole and for general use, is a much more complex
matter than many suppose it to be, for it touches on one
side some of the most profound problems of physiolog-
ical chemistry, concerning which we have only partial
knowledge.

377. Basis of assigning values to feeding-stuffs.—
The problem of assigning values to the classes of nutrients
in feeding-stuffs may be approached from two directions,
viz., from the commercial side and from the physiolog-
ical side. In the first case, the effort would be to calcu-
late on the basis of the prices of standard commercial
feeds what is the actual pound-cost of each of the classes
of nutrients, and thus have a means of ascertaining
whether a particular feed is selling for less or more than
the existing market conditions warrant. In the second
case, the attempt would be to determine the relative
physiological importance of digestible protein, carbo-

(281)

282 THE FEEDING OF ANIMALS

hydrates, and fats, and this being done, the relative
agricultural values of feeding-stuffs would be estab-
lished on the basis of their composition and digestibility,
thus providing purchasers with a guide for selecting the
materials costing the least in proportion to their value.
378. Commercial values of feeding-stuffs.—Experi-
ment stations have for many years published relative
commercial valuations of the various brands of fertilizers
that are in the market. We are not able to establish values
similarly with cattle foods because of existing condi-
tions. The dry matter of cattle foods is made up of
ash, protein, carbohydrates, and fats. We practically
ignore the ash and base the value of a given food upon
the other three classes of compounds, which are the
same in number as the three useful ingredients of
mixed fertilizers. Now if we could find in the market a
cattle food supplying only a single ingredient, as is the
case with fertilizers, we could from its composition and
market price determine the cost of this ingredient. As a
rule, however, these classes of nutrients must be bought
in a mixed condition. All commercial cattle foods, except,
perhaps, one waste product from sugar production, are
mixtures in varying proportions of protein, carbohydrates,
and fats. When we buy one we buy all three. Protein,
starch, sugar, or oils as found in commerce have become,
through the necessary processes of separation, too costly
to be considered for cattle-feeding purposes, and their
prices in these forms are not a proper basis of calculation.
If, therefore, a farmer pays $25 for a ton of wheat bran,
the problem would be what proportion of this sum he
should assign to the 320 pounds of protein, the 1,240
pounds of carbohydrates, or the 84 pounds of fats.
Commercially considered the problem is complex,

or 8S ie ll - * a - F 4 ee Sy A »! ie} ~s 7 7

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oY a < \ “, } ;

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VALUATION OF FEEDING-STUFFS — 283

and no simple process will solve it. If we were to deter-_

mine what is the cost of one pound of dry matter through —
the simple division of the price of a ton of feed by the
pounds of dry matter which it contains, and then declare
that all forms of dry matter have equal cost, we would
get as many prices for protein and starch as there are
commercial feeds, with no distinction as to the money
value of these nutrients. Such a method would be absurd.
It would be a bare assumption to declare that all the
compounds of a food should have equal market cost.

379. Valuation of feeds by method of least squares.—
An attempt was made in Germany, and to some extent

in this country, to calculate by the “method of least

squares” what should be considered the cost of protein,
carbohydrates, and fats as based upon the ton prices of a
variety of feeding-stuffs. Valuations so derived appeared
to find favor for a time, and some of our experiment
stations, following the lead of German chemists, pub-
lished pound prices for the three classes of nutrients,
and calculated what commercial cattle foods should cost
when valued on a common basis. It was soon found, how-
ever, that, mathematically as well as practically, most
absurd results were obtained.

In the first place, it is already demonstrated that
the money valuations are often greatly influenced by
the choice of feeds which shall enter into the calcula-
tion. Penny, in New Jersey, using cottonseed meal,
bran, middlings, cob meal, corn meal, and oats, obtained
certain values for protein, carbohydrates, and fats. Hills
showed that if Penny had left out the cob meal the value
for fat would be only half that found, and the value of
the protein and carbohydrates would be a quarter more.
Woll obtained certain pound prices with a list of common

23. THE FEEDING OF ANIMALS

feeds, but Hills showed again that if Woll had left out
rye bran these prices would be greatly changed. It
appears that varying individual judgments as to the list
of feeds which shall determine values may cause absurd
differences in the calculated market cost of the nutrients,
and introducing into the list or withdrawing from it a
comparatively unimportant feeding-stuff may lower or
raise the price of one nutrient even one-half.

A still more serious difficulty arises from the fact
that often when an apparently typical and proper list
of feeds is used from which to calculate prices, the
use of the method of least squares results in giving a
negative value to one of the nutrients. In several cases
of this kind the fat was shown to be worth less than
nothing, a most absurd conclusion. This mathematical
method is, therefore, not available for the valuation
of feeding-stuffs, and so far no mathematician has offered
one that is.

380. Physiological values.—We are left now to inquire
whether we may not use physiological values, in other
words the work which a nutrient will perform in the ani-
mal body, as a starting-point from which to calculate
relative values. If, for instance, it could be demon-
strated that protein has a fixed physiological value twice,
and fats three times, that of carbohydrates, it would
then be a very simple matter to ascertain what propor-
tion of the cost of a ton of cottonseed meal should be
applied to each class of nutrients. To illustrate, a ton of
high-grade cottonseed meal contains about 590 pounds
of carbohydrates, 860 pounds of protein, and 260 pounds
of fat. If these ingredients are assumed to have a ratio
of value of 1, 2, and 3, then the whole would be equiva-
lent to 3,090 units of carbohydrates, the cost of one unit

VALUATION OF FEEDING-STUFFS 285

of which would be about one cent, when we pay $30 a
ton for the cottonseed meal. On this basis it would be
necessary to assign to the protein a cost of two cents per
pound, and to the fats three cents. If our premise were
correct we could calculate the cost of the nutrients in any
one of the feeding-stuffs, and could either ascertain which
was the cheapest source of each ingredient, or by aver-
aging could establish a basis for a general valuation.
Unfortunately no such a premise can be correctly formu-
lated. We are not yet wise enough to establish fixed
relative physiological values for the three classes of
nutrients.

381. Energy values as a basis of valuation—It may
be stated that the energy values of a unit of each of the
nutrients, protein, starch, and fat have been found with
apparent accuracy. Why, then, may we not establish
the relative value of the nutrients on the basis of their
potential energy, which is measured by the heat they pro-
duce upon combustion? Simply because foods have
another function beside furnishing motive power to the
animal and keeping him warm. They act as building-
material. The protein and fat of milk and of the body
tissues are derived from the food compounds, and the
actual relative money value of these compounds for con-
structive purposes is not yet known. No one has yet suc-
ceeded in actually determining the relative money value
of protein, carbohydrates, and vegetable fats as fat pro-
ducers, and we have no data that allow a definite conclu-
sion concerning the comparative money worth of the
muscle-forming function of protein as against the fat-
forming function or energy function of starch. There is ~
no promising prospect, at present, of being able to com-
pare foods on the basis of their physiological importance

286 THE FEEDING OF ANIMALS

as a means of determining what should be the relative
market cost.

382. Conditions involved in the selection of feeding-
stuffs—Much useful knowledge is available to the
stock-feeder as a means of guiding him to an economical
selection. Some of the important facts to keep in mind
are: Some feeds carry more nitrogenous matter than
others; some feeds are largely carbohydrates; cereal
grains contribute to the ration much the same compounds
in much the same proportions; the variations of composi-
tion among the waste products that are in the market as
commercial feeds; how the coarse foods differ among
themselves and from the grains; some feeds are better
adapted than others to a certain class of animals, even
though of essentially the same composition, and what
practice and science have taught concerning the mixtures
necessary to secure an efficient combination of nutrients
for the work to be done.

383. Digestibility as a basis for selecting feeding-
stuffs.—After all this is understood, there may be several
feeds which are essentially alike in composition and
nutritive function but which have different prices, and
there still remains the problem of selecting the most
economical. It is clear that the best a feeder can do is to
select the feeds that supply the largest quantity of avail-
able nutrients for the least money with due reference to
the class of nutrients desired. If all the feeding-stuffs
were digested in equal proportions, there would be no
need of considering digestibility, but this is not the case.
Large differences in digestibility exist. From 86 to 88
per cent of the dry matter of the cereal grains, oats
excepted, is digested, while the digestibility of wheat
bran, brewers’ grains, and oats is on the average only

VALUATION OF FEEDING-STUFFS 287

about 62 per cent. Oats are nearly one-fourth less digesti-
ble than corn, barley, or rye. The refuse products known
as the oil meals are less digestible than the gluten feeds |
and meals, due, doubtless, to the hulls contained in the
former. These facts are important and affect the nutri-
tive value of commercial feeds very materially.

384. Values based on digestibility—Farmers should
base their judgment of the value of feeding-stuffs pri-
marily upon the proportions of digestible dry matter which
they contain. This method will probably allow as close
an approximation to relative values as any which it is
feasible for the farmers to use now in practice. Doubt-
less “production” values (see Par. 263) will ultimately
offer a closer comparison. It is certainly more accurate
than a comparison of the proportions of total dry matter.
A hundred pounds of corn contains even less dry matter
than the same weight of oats, but the digestible material of
the former is over 20 per cent in excess of that in the latter.
It is to be remembered, however, that comparisons of
this kind can be instituted only between feeding-stuffs of
the same class. The relative values of oil meal and corn
meal cannot be ascertained in this way, neither should
the relative values of coarse feeds and the grains be so
compared. We should not pay for oil meal and corn
meal on the basis of the quantities of digestible nutrients
which they furnish, because the nutrients are not identi-
cal in the two cases. Digestible material which is 40 per
eent protein cannot be measured by digestible material
which is only 10 per cent protein.

385. Digestibility of various feeds.—The following
table shows the digestible material in 100 pounds of
various feeding-stuffs, as calculated from average com-
position and digestibility. In the case of hays, the water-

288 THE FEEDING OF ANIMALS

content is assumed to be uniform, viz., 12.5 per cent,

while the percentages given for the grains are the averages
found by analysis:

TaBLeE LXI
Per cent of | Pounds of Pounds
digestibility |dry matter in Geom
of dry 100 of the a 100 ie

matter feeding-stuff feeding-stuff

Class I—Dried grass plants

Corn fodder, fresh, average. 69 20 13.8
Corn'stoves .:-... » 57 60* 34.2
Huneanamnay ..°.. 2. 65 87.5 56.9
Oat straw ... eres 54 90 48.6
Orchard grass hay :, 56 87.5 49
ete 06): a 60 87.5 52.5
Timo¢y,an. . . . 55 87.5 48.1
Timothy, in bloom or before ; 59 87.5 51.6
Timothy, after bloom .. . «. 52 87.5 45.5
Class II—Dried legumes
Paes ome, :), eran : 62 87.5 54.2
ever, aisike ~~ 2 ee 59 87.5 51.6
Becer ream 2 hh ae 58 87.5 50.7
Clover, white <9... . 66 87.5 57.7
Class II I—Cereal grains
Barley ong cae set 86 89 76.5
Corn'meal,. . . a 88 85 74.8
Corn-and-cob mene 79 85 67.1
aie OOF . . ae ae 70 89 62.3
Oat feed, mainly hulls .. . . 34 92 30.3
Rye meal ees 87 &8 76.5

Class IV—Nitrogenous Seis
16-80 per cent protein.

Brewers’ grain. . 62 92 57
Distillers’ grains (from rye
atemicea . . . ws. ae 87 92 80
Misteproum =... . . as 67 90 60.3
Whesyoranem™ ..: . . a. 62 88 54.5
Wheat middlings ..... ri 88 66
Pea mealies ie. Se 87 90 78.3

*Assumed.

a, i

VALUATION OF FEEDING-STUFFS 289

TaBLE LXI, ContTINUED

Per cent of Pounds of fie ari

digestibility |dry matter in
: ; matter
of dry 100 of the in 100 of

matter feeding-stuff feedine stat

Class V—Nitrogenous feeds
30-45 per cent protein

Distillers’ grains (from corn)—

Paetiammeal . . Jae. 87 92 80

Linseed meal, old process. 79 91 71.9
Linseed meal, new process . 78 90 70.2
Cottonseed meal, high grade 90 92 82.8
Cottonseed meal, low grade 65 92 59.8

It is fully recognized that these figures cannot be
taken as absolute relative values. Feeding-stuffs, bear-
ing the same name, are not always exactly similar in
composition or in equally good condition. Variations
in the moisture-content occur, especially with the coarse
fodders. Even after allowing for all these factors, results
will not follow exactly the quantities of digestible matter
supplied, because there seems to be a greater adapta-
bility of some feeds to the needs of a particular species.
Nevertheless we are forced to conclude that food mate-
rials of the same class must furnish energy and building-
material closely in proportion to what is digested from
them.

386. Valuations based on protein-content.—Certain
writers and speakers base the value of nitrogenous feed-
ing-stuffs, from bran up, entirely on the protein-content,
and they divide the price by the pounds of protein in a
ton in order to determine the relative economy of pur-
chasing this or that material, and the feeding-stuff in
which the protein cost is the least when so reckoned is

S

290 THE FEEDING OF ANIMALS

regarded as the economical one to purchase. This method
seems to be absurd, for it is an assumption that the
nutritive value of the carbohydrates and fat in commer-
cial foods may be ignored. The argument is that the
farm furnishes carbohydrates in abundance, and that
commercial products should merely serve the purpose of
reinforcing the protein-supply. If the carbohydrates of
the farm have no selling value then this argument has
some force, but this is ordinarily not the case. When
starch and similar compounds must be purchased as a
necessary accompaniment of protein, thus causing a sur-
plus of carbohydrate food, certainly hay, oats, corn,
barley, or some other home product may be sold to
relieve this surplus.

387. Feed values based on feeding experiments.—
Many practical feeding experiments have been con-
ducted for the purpose of comparing the different grain
products as foods for the various classes of animals. Useful
facts have been reached in this way, especially as to the
greater adaptability of some materials than others for a
particular species. But experiments of this kind cannot
be relied upon to fix relative values of feeding-stuffs for
milk production, beef production, or for any other pur-
pose. This is so, first of all, because the errors of such
tests are so large that we cannot regard their apparent
outcome as establishing constants. Again, the problems
involved are too complex and the effect of a given ration
too dependent upon variable conditions, to allow logical
conclusions from such experimental data. The difficul-
ties of the situation will be made clear to anyone by a
careful study of the whole mass of data resulting from
feeding tests. Differences appear, some of which are con-
sistently in one direction, especially in comparing nitrog-

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\

VALUATION OF FEEDING-STUFFS © 291

enous with carbohydrate foods, but as between mate-
rials of the same class their comparative values as indicated
by different experiments are greatly variable, even con-
tradictory. Any one who endeavors ‘to reach fixed and
universal valuations on an experimental basis of this
kind will find himself involved in hopeless confusion.

388. The verdict of the cow.—Once in a while some
one talks wildly about leaving food valuation to the —
“old cow.” It is sometimes considered a telling argument
against the chemist’s wisdom to declare that he and the
old cow do not agree. Certainly the cow knows better
than the chemist what she likes to eat, and it is little use
to offer her foods she does not relish. Even a chemist
knows that. If, however, a dozen commercial feeding-
stuffs were spread around on a barn floor it would be
much safer to trust an agricultural chemist, especially
one experienced in stock-feeding, to select a ration than
any cow ever grown—Holstein, Ayrshire, Jersey, long-
horned, dishorned, or what not. The cow would probably
get at the corn meal and stay with it until well on the
way to a fatal case of indigestion. Her juagment is just
about as good as that of a child with a highly cultivated
“sweet tooth,”

CHAPTER XVII

THE SELECTION AND COMPOUNDING OF
RATIONS

THERE are several factors that must be considered
in selecting an efficient and economical ration—factors
which relate to both science and practice. It is gener-
ally desirable that a food mixture shall be “balanced,”
but this gives no assurance that a ration can be fed
under particular conditions with satisfactory results.
Intelligent observation in the barn or stable really takes
the first place in formulating a method of feeding, which
is supplemented to a valuable extent by the scientific
insight of the chemist and physiologist. A ration may be
chemically right and practically wrong, but, at the same
time, it is worth much to the feeder to be assured that the
nutrients which he supplies to his animals will meet their
physiological needs. Moreover, commercial relations
such as the prices of feeds and product must be con-
sidered, and this is a business question and not a scien-
tific matter.

389. Palatableness as a factor in feeding animals.—
A successful ration must be palatable. An agreeable
flavor is not a source of energy or of building-material,
but it tends to stimulate the digestive and assimilative
functions of the animal to their highest efficiency, and is
a requisite for the consumption of the necessary quantity
of food. Common experience teaches that when cows or
animals of any other class do not like their food, they

(292)

i. 2 on
f

SELECTION OF RATIONS 293

“do not do well.”” Persons sometimes claim that they
have contracted dyspepsia by eating food which is not
relished, even food that is nutritious and well cooked,
and which would be entirely satisfactory to other indi-
viduals. The situation is still worse when the food is
undesirable both as to texture and flavor. We have
reason to believe that animals are susceptible to the same
influences as man, though perhaps not to the same
extent. An animal is more than a machine, and is pos-
sessed of a nervous organism, the existence of which
should never be ignored.

One way of stimulating an animal’s appetite is to
feed a variety of materials. Continuous feeding on a
single coarse food and one grain is not conducive to the
best results. The various available fodders and grains
should be so combined as to allow the feeding of all of
them throughout the season, and avoid the exclusive use
of one or two kinds for any extended period of time. The
skilful feeder, then, will not fail to make the ration as
palatable as possible, and will always consider the idiosyn-
crasies of appetite of each animal.

390. Adaptation of rations.—The ration must be
adapted to the species. This is obvious as relates to
quantity, but is equally true of the kinds of materials.
For instance, both poultry and swine generally eat cot-
tonseed meal with reluctance and with danger to health.
Wheat bran is less desirable for swine than for other
species. The horse and the hog are not adapted to rough
fodder as are the ruminants. It is useless, however, to
mention at this point other instances of this character,
or to comment on their importance, further than to
emphasize the foolishness of trying to bring all species of
animals to a common basis in the supply of feeding-stuffs.

} 2 eT

)

294 THE FEEDING OF ANIMALS

391. Physiological requirements.—The physiological
requirements of the animal must be considered. A
ration of maximum physiological efficiency and economy
must contain the several nutrients in such quantities and
proportions as will meet the needs of the particular
animal fed, without waste. This statement is based upon
facts given elsewhere in this volume relative to the
demands of the animal body and the functions of the
nutrients.

It remains now for us to consider how to compound
such rations as are desired, or those that are adapted
in kind and quantity to the requirements which they

are to meet. Obviously, the first essential for doing.

this is the adoption of standards to which rations should
conform, for if we do not have these there is no possi-
bility of concluding whether one food mixture is better
or worse than another for a particular purpose.

392. Feeding standards.—Such standards have been
proposed, which we knew first as German feeding stand-
ards. ‘The standards that are now accepted are the
result of numerous and elaborate studies of the balance
of loss or gain to the animal organism when rations of
various kinds were fed to animals at rest, at work, and
when producing meat, wool, or milk, in desirable quan-
tities. ‘They relate entirely to physiological demands
without reference to the cost of the rations or to the
profits which may result from their use.

The earlier standards were developed chiefly in Ger-
many but those now most in favor are based upon Ameri-
can experimental data.

_ These standards are variable in two main factors:
(1) The quantity of available nutrients, and (2) the
relative proportions of the classes of nutrients. Quan-

PINGS ee ERENT pig El Fee Pat 10) vd

SELECTION OF RATIONS 295

tity is an essential consideration, for it is obvious that
enough energy and building-material must be supplied
to do a given work. It is also obvious that quantity must
be a variable factor according as the animal is large or
small, doing hard or light work, giving much or little
milk, or fattening rapidly or slowly.

Account must be made of the proportions of the
nutrients, because protein, for instance, has peculiar
functions which other nutrients cannot exercise, and
less than a certain minimum of the proteins in any given
case, would limit production by just the amount of the
deficiency. In order for the protein to serve its maxi-
mum usefulness, its energy should not be encroached
upon to fill a place equally well or better taken by carbo-
hydrates; consequently, the proportion of carbohydrates
must also be considered.

393. Nutritive ratio.—The relative proportion of the
nutrients of a ration is known as the nutritive ratio. By
this term is meant the relation in quantity of the digesti-
ble protein to all the other digestible organic matter
reckoned in terms of carbohydrates. If we multiply the
quantity of fat by 2.25 we get its carbohydrate equivalent,
and if we add this product to the quantity of diges-
tible carbohydrates present we have the carbohydrate
value of the digestible matter other than the protein.
This sum divided by the number representing the pro-
tein gives the nutritive ratio. For instance, in a ration
mentioned later there are .94 pound protein, 9.65 pounds
carbohydrates, and .49 pound fat. (.492.25+9.65)+
.94=11.4. 1:11.4 is therefore the nutritive ratio of the
ration.

A nutritive ratio may be designated as “narrow,”
“wide,” or “medium.” These terms do not represent

296 THE FEEDING OF ANIMALS

exact limits to which there is universal agreement. A
narrow ratio is one where the proportion of protein is
relatively large, not less perhaps than 1:5.5. A wide
ratio is one where the carbohydrates are very greatly
predominant, or in larger proportion perhaps than 1:8.
Anything between 1:5.5 and 1:8 may properly be
spoken of as a medium ratio.

Merely for the purpose of illustration, three feeding
standards are given in this connection. These are selected
from standards proposed by Wolff, as modified by Leh-
mann. They refer in all instances to animals weighing
1,000 pounds:

Taste LXII. For 1,000 Pounns Live Wetcut Datty

: Diges- Total
Dry Bee tible | Diges- | diges- | Nutri-
sub- a £ car- tible tible tive
stance ae bohy- fat | organic] ratio
: drates matter

Pounds] Pounds] Pounds} Pounds| Pounds

Cow, yield milk, 22 Ibs..} 29 | 25 | 13 | .5 | 16 |1:5.7
Fattening steer, Ist per. 30 2.5 15 5 18 1:6.5
Horse, medium work. .| 24 a 11 6 13.6 | 1:6.2

These and other standards will be discussed later
when we come to consider the feeding of the various
farm animals. Our present purpose is simply to make
clear the steps necessary to bringing the quantity and
composition of the ration into conformity with the
standard selected.

394. Calculating a ration—As a means of showing
the steps involved in calculating what a ration is, and
how to improve it if necessary, we will assume that it is
desired to learn whether a food mixture which a milch
cow is eating is what it should be, and if it is not, how to

SELECTION OF RATIONS 297

make it so. The standard ration for a 1,000-pound cow,
giving twenty-two pounds of average milk, expressed in

terms of water-free nutrients, has been given in the
preceding table.

The first point which requires our attention is that
this standard is mainly expressed in terms of water-free
digestible nutrients. ‘This means that we must take
into account the composition and digestibility of the
particular feeding-stuffs which enter into a ration, if we
would discover what it really is supplying of available
food compounds. It is evident that usually feeders can-
not have their cattle foods analyzed, and so they must
resort to the tables of composition and digestibility,
which are, or may be, in the hands of every farmer.

395. Calculation of digestible nutrients.—Feeding-
stuffs, especially fodders, differ within quite wide limits
in what they contain and in what the animal will dissolve
from them, according to the species, stage of growth and
conditions of curing, and an average percentage of pro-
tein or an average coefficient of digestibility is likely to
differ widely from the actual facts as pertaining to a
particular material. All that can be done is to select as
nearly as possible the figures which have been found for
feeding-stuffs in the condition of those which are to be
fed. If the hay is from mature grass, use the composi-
tion percentages and digestion coefficients given for
such hay; if the silage is from mature corn, pursue a
similar course in this case, and so on. Difficulty may be
met in finding suitable figures, because tables of com-
position and digestibility are not fully developed and
classified on the basis of the character of the materials.

The assumed ration which we wish to discuss con-
sists of;

298 THE FEEDING OF ANIMALS
‘ Pounds Pounds
Late-cut timothy hay . 10 Hominychops ..... 2
Gorn silage.) ae, 25 Winter-wheat bran ... 3

The averages for composition and digestibility, which
are as likely as any to represent these and other mate-
rials, are the following:

TaBLE LXIII

Composition Digestibility
ad ~~ air
12 1 Oo
a: aE
be a: bot iS bos
o o be ° o be °
> = o 2 = co) no
a = 9 2 | £0 3 2 2° ||) Saeco $
o_ _~
Fla) a | & (2h) & | ele eee

hg
©

bar |

o
ber |

Gr)
ia)

ber |

ry
g

a
5

ry
g
ry
A
ty
ia?)
bn |
GC)
g
hg
ia?)
Le |

Timothy hay, late} cent | cent | cent | cent | cent cent | cent | cent | cent | cent
CUGN CUE 14 3.9 SF | apd hy al Wee Heh > 43 46 59 51
Clover hay .. 15 Paidaow! 24:3 | 37.2.) 2.5 58 54 65 56
Corn silage .. 80 el: 1a 5.4 | 11.1 ay 4 51 65 71 82
Hominy feed . . 11 2.5 | 10.4 4.2 | 63.9 | 8. 65 67 89 92
Wheat bran .. 10 6.2 1Gst) ih, 10; Dao 4.4 CH 39 71 63

Linseed meal, new
process

The first step in the calculation is to find out what
percentages of digestible material the components of our
proposed ration contain, and we shall obtain these by
multiplying the percentages of composition by the co-
efficients of digestibility and dividing the product by
100; that is, if timothy hay contains 5 per cent of pro-
tein, 45 per cent of which is digestible, then .45 of 5 will
be the percentage of: digestible protein in the hay. In
this way the following figures were obtained. The per-
centage of digestible carbohydrates represents the sum
of the quantities digested from both the crude fiber and
the nitrogen-free extract. Tables are now published
which show percentages of digestible ingredients, and
which will render this calculation largely unnecessary:

:
/

SELECTION OF RATIONS 299
TaBLE LXIV
. - Total
Digest- Reet Digest- | digest-
ible rho. ible ible
protein hydrates fats organic

nutrients

_—_—_ eS OO) |

Per cent } Per cent | Per cent | Per cent

mame nay =| wk fee 2.2 40.4 1. 43.6
es... ee tal 37.3 1.4 46.4
rere 8... | ee 9 11.4 ° 6 12.9
mommivaeccd «« - .. Sey 6.8 58.7 7.4 72.9
Mimeno ten . |. |. woe |) 124 41.7 2.8 56.9
Pimeecd meal 8... een al al. 37.1 2.5 70.6

396. Digestible nutrients in a given ration.—The
second step is to calculate the pounds of digestible nu-
trients in the quantities of the several feeding-stuffs to
be used. It is clear, for instance, that 10 pounds of hay
will contain .10 of the amounts in 100 pounds, so we
simply need to multiply the percentage of digestible
protein and so on by 10 and divide by 100 in order to
learn what 10 pounds of hay will furnish to the animal.
If we make this computation for each constituent of each
feeding-stuff, we reach the figures of the following table:

TABLE LXV
‘ ; Total
Digestible Diestible Digestible} digestible] Nutritive
protein |), wdrates fat organic ratio
matter

Pounds | Pounds | Pounds | Pounds

Timothy hay, 10 lbs. . 22 4.04 10 4.36
Corn silage, 25 lbs. . . 22 3.85 12 4.19
Hominy feed, 2 lbs... 14 jE 15 1.46
Wheat bran, 3 lbs. . . BY 1.25 .08 1.70

Several authors have published tables showing the
proportions of digestible nutrients in feeding-stuffs.

300 THE FEEDING OF ANIMALS

397. Correcting an insufficient ration.—When we come
to compare this ration with the standard ration we find
it is seriously defective in two particulars: it contains
far too little digestible organic matter and the nutri-
tive ratio is too wide.

In order to correct these faults, we must add digesti-
ble organic matter which contains a much larger pro-
portion of protein than is found in any of the materials
so far selected, and we must seek such a supply, in part
at least, among the highly nitrogenous feeding-stuffs like
the oil meals and gluten meals. It is easy for one with
experience to see, also, that all the necessary additional
organic matter cannot be secured from a highly nitroge-
nous food without increasing the protein supply unneces-
sarily. In order to avoid this, the amount of silage may
be raised ten pounds and still not feed an excessive quan-
tity. If clover hay is available, it would also be well to
substitute five pounds of it for five pounds of the timo-
thy. If, then, we add to the ration three pounds of lin-
seed meal we shall approximate more nearly to our
standard.

TaBLeE LXVI
| Total |
Car- digest- | Nutri-
Protein | bohy- Fat ible tive
drates organic | ratio

matter

Timothy bay, 5 pounds) «11 | 2:62 | .05 | 2.18

Clover hay, 5 pounds’ “agggee}..of | 1.86 | .07 | 2.30
Corn silage, 35 pounds . . . .| .31 | 3.99} .21 | 4.51
Homimy feed, 2 pounds . .@eead3 | 1:17 | 15 | 1.4
Wheat bran, 3 pounds . . 2jeea/ | 1.25 | 08 | 1
Linseed meal, 3 pounds. . .}| .93 | 1.11} .07 | 2.11

2.22 |11.40| .63 | 14.25] 1:6.8

‘SELECTION OF RATIONS 301

This ration is still below the standard in quantity,
but as the relation of the nutrients is approximately
what is called for, it is only necessary to increase the
quantities of each component about one-fifteenth in
order to furnish the animal sixteen pounds of digestible
organic matter. It is, however, a good ration for cows
of the smaller breeds weighing from 800 to 900 pounds.

398. Relation of ration to size of animal.—There are
several points to be considered in this connection. First
of all, the standard rations are the quantities to be fed
a day and for 1,000 pounds live weight. This is ordi-
narily taken to mean that if a 1,000-pound cow requires
16 pounds of digestible nutrients, an 800-pound cow should
be supplied with only four-fifths as much, or 12.8 pounds,
or that a 1,200-pound horse needs 50 per cent more food
than one weighing 800 pounds. Unfortunately this sim-
ple mathematical way of calculating rations does not meet
the plain requirements of practice. The needs of a pro-
ducing or working animal are not directly proportional
to its size, for the work done or the quantity of pro-
duction is the dominating factor. It is certain that feeding
milch cows or working horses in proportion to weight
alone contravenes known facts.

However, we cannot ignore the size of the Snital
in determining the quantity of the ration. Concerning
this, Armsby says: “The function of the maintenance
ration is essentially to supply heat to the body to replace
the constant loss that takes place. Now, Henneberg
has long ago shown that, in round numbers, over 90 per
cent of this heat is removed by radiation and evapora-
tion. Consequently, we should expect the demands of
the organism for heat (i. e., for maintenance), to be pro-
portional to its surface (including lung surface), rather

302 THE FEEDING OF ANIMALS

than to its weight, and the more recent researches of
Rubner have confirmed this theoretical conclusion.”
For the purposes of calculation, it is assumed that ani-

mals are geometrically similar figures and therefore that.

their surfaces are proportional to the cube root of the
square of their weights. Several steers having weights
from 1,000 up to 1,700 pounds would need, on this basis,
amounts of digestible food for maintenance propor-
tional to figures given in the table below:

Weight of the animal Proportion of food per 1,000
approximately pounds live weighi

GR te Me ae a

EIEN eg AL a! Pa aS 96
IG Le ee ae be. raywe 93
eet 90
RSE ES UR en a a 88
USS cis EAs Sak ORS 2 a A 86
Ben POUNCE Serre ye OC yy as 84
Been) OURS cosh temnnow te Sie ie: Mb daa ti 82

For adjusting a maintenance ration to the weight of a
steer or horse, this method seems to have a plausible
basis, but it is evidently less applicable to dairy cows or
rapidly growing or fattening animals, for in these cases
production and not size must be chiefly considered.

399. The protein-supply.—The matter of the protein-
supply is important. If we are trying to supply the needs
of a cow giving twenty-five pounds of milk, or of a steer
gaining two pounds of body substance daily, there is
without question a minimum quantity of food protein
absolutely necessary in each case. ‘These necessary
quantities are certainly not the same for all individuals,
but they are not likely to differ widely between single
animals of the same class and productive capacity. It is
safe to assert that the earlier protein standards are those
which it is practicable to feed and which unquestionably

~

Df ae A Oe Ae” lee)
ELEN Ey GT Bema,
1 env >.)

SELECTION OF RATIONS 303

generously meet the demands of the class of animals for
which they are designed.

400. Earlier protein standards revised.—Through more
recent investigations, revisions of the earlier protein
standards have been recommended. These are in gen-
eral in the direction of a lower minimum of protein, and
the data secured seem to justify the change. At the same
time, care should be taken in not fixing the protein mini-
mum too low, partly because a generous protein-supply
promotes the general welfare of the animal, and partly
because of the variable efficiency of the single proteins
which are found in the different feeding-stuffs in greatly
unlike proportions. The amount of protein fed in a given
case should be such as to guarantee a sufficient amount
for the actual constructive work demanded. (See Par. 275.)
Probably with certain feeding-stuffs the minimum might
be lower than with others. It is very evident then that
the protein-supply in feeding formulas for production
cannot safely be resolved to the exact limitation of the
nitrogen compounds needed. The standards that have
been suggested will be considered in the following pages.

401. Presence of growth-promoting bodies.—The dis-
covery of growth-promoting bodies attached to cattle
foods (see Par. 278) leads to the conclusion that rations
should be selected under certain conditions with refer-
ence to the presence of these essential compounds. This
is especially true where animals are likely to be fed on a
restricted diet, as, for instance, swine, or where by-
product feeds are used the treatment of which may have
removed part or all of the food accessories. With animals
eating the forage portion of plants in large quantities,
such as. the bovines, there is little danger that there will
be a deficiency in the food of these essential compounds.

304 THE FEEDING OF ANIMALS

As these compounds exist in much smaller proportion in
grain, swine when confined to a restricted grain diet may
suffer from a lack of such accessory bodies. The addition,

therefore, to the grain food of swine of some green food,

such as alfalfa, would appear to insure the animal against
defective growth.

Dairy by-products are carriers of both Fat-soluble A
and Water-soluble B, and the recognized value of these
by-products in pig-feeding is perhaps partly due to the
presence of these substances. As time proceeds, the
knowledge necessary to the compounding of rations with
reference to the growth-promoting value will doubtless
be greatly enlarged.

402. Influence of ration on quality of product—The
rations should be compounded with reference to the
quality of the product. Our knowledge of the influence
of foods upon the quality of meat products is by no means
complete, but that food has an influence upon the flavor
of milk and upon the chemical and physical properties of
butter, seems to be fairly well established.

403. Home supply of feeding-stuffs to be considered.—
Rations should be compounded with reference to the
home supply of feeding-stuffs and to market prices.
Economy often demands that the materials in hand shall
be used even if the ration is not ideal. Again, there
are several protein foods which may be used, and it is
often only a question of price in determining which should
be purchased. Notwithstanding the claims of manu-
facturers, there is no one feeding-stuff essential to the
health of animals or to the highest quality of the pro-
duct, so that the feeder may often consider the matter
of cost and select the cheapest source of protein without
in any way impairing the ration.

CP, ae wee emer : i a
‘ vim . , = 4
- N

SELECTION OF RATIONS 305

404. Selection of a ration largely a business matter.—
Those who have carefully followed the preceding state-
ments must have become convinced that the selection
of a ration which shall be the best possible from a business
standpoint is not a simple matter. We must always dis-
tinguish between the combination that is most efficient
physiologically or productively, and the one that is the
source of largest profit. It is often the case—perhaps
generally—that a food mixture which induces a high rate
of production is the most profitable one to use, but this
occurs only when business conditions make it possible.
Many seem to think that if a ration is “balanced” it
necessarily meets all the requirements for the maximum
profit, but this is an erroneous view.

For instance, a farmer somewhat remote from the
markets may have on hand an abundant supply of hay
and home-raised grains of such a character that it is
impossible to compound them so as to conform to the
accepted feeding standard for milch cows. If the prices
of dairy products are low, and those of purchased feed-
ing-stuffs are high, it is entirely possible for the farmer
to secure more profit from his cows with an “unbalanced”
ration than with one which has a more nearly correct
nutritive ratio.

The western stockman can often afford to waste
corn on fattening steers rather than use it with greater
physiological economy by mixing it with purchased
grains. The cost of the latter would soon offset the
profits otherwise possible. All this is equivalent to say-
ing that practical considerations often justify a wide
departure from the standard rations. Hills states the
case well when he says:

“The study of the requirements of the individual

T

306 THE FEEDING OF ANIMALS

animal and the adapting of food to its needs is to be
preferred to placing the herd, as a whole, upon any
inflexible ration. The capacity of an animal to receive,
its ability to produce, the effects of the sundry feeds upon
the health and condition of the animal, upon its appetite
and taste, upon the quality of the product, the money
values of feed, and the profits to be derived from their
use, are important considerations which do not enter
into the make-up.of the physiological standard, but which
are vital factors in the feeder’s problem. Clearly the
physiological standards may supplement, and in some
measure guide, judgment, but cannot take its place.”

CHAPTER XVIII
MAINTENANCE RATIONS

Ir has already been shown that the demands on the
food vary greatly with different individuals or classes
of animals according to size and the kind and quantity of
production. It is proposed to indicate how rations should
be compounded in order to meet varying conditions and
demands for production of various kinds, but as prelim-
inary to this an understanding should be reached as to

_ what is required to support the producing organism.

405. Definition of maintenance ration—A main-
tenance ration is one supplying the needs of an animal
without production of any kind and with no loss of body
substance. To be more specific, when an ox doing no
work excretes just the quantities of. nitrogen and carbon
that are contained in the food consumed, he is said to be
eating a maintenance ration. The work done by the
animal at rest is largely needed in the following direc-
tions: The chewing of food and its movement along the
intestinal tract; the muscular action of the heart in caus-
ing blood circulation; and the metabolic activity of the
cells in causing the chemical transformation of the nu-
trients. Some work is also done in moving the body and
in the effort of standing. The demands upon the food for

maintenance purposes are therefore largely for the

support of some form of muscular activity.
406. Character of maintenance ration.—Nine-tenths
or more of a maintenance ration may consist of carbo-
(307)

~ 808 THE FEEDING OF ANIMALS

hydrates which, because the income and outgo are bal-
anced, are used solely as fuel. Only a very small amount
of protein is necessarily destroyed by a resting animal,
although a minimum supply is absolutely essential if the
nitrogenous tissues of the body are to be kept from wast-
ing. If an animal is not eating protein, the cleavage of
body protein will go on and urea will continue to appear in
the urine and in time protein starvation will cause death.

407. Uses of production ration.—Any ration, fed for
production, may be looked upon as made up of two parts,
that which is needed to maintain the animal and that
which may be applied to growth or the formation of
milk solids. It is possible, of course, for the produc-
tion of milk or wool to occur when the cow or sheep is
fed what is really only a maintenance ration, but the
materials for production under these circumstances are
furnished at the expense of the body substance. With
what is regarded as liberal feeding, from one-third to
one-half of a production ration is needed for mainte-
nance purposes. It seems fitting, then, to speak of a main-
tenance ration as a fundamental quantity, a knowledge
of which is important to both science and practice. It is
clear that no rational understanding of the uses of food
can be had, unless we know what amount is required
simply for maintenance, and the feeder is certainly helped
to a more intelligent compounding of rations if he has some
means of judging how large an excess he is supplying for
production purposes. Occasionally, too, it is desired to
provide horses and other animals when not at work with
just enough food to keep them in a uniform condition
without gain or loss.

408. Maintenance ration easily provided.—No ration
is more easily provided from the ordinary farm supply

ss ea

MAINTENANCE RATIONS 309

than is that for maintenance, for two reasons: (1) Because
the quantity of available nutrients which must be eaten
is so small that this ration may be wholly or mostly made
up of bulky materials such as corn fodder and hay; (2)
because investigation has demonstrated that mere main-
tenance demands a comparatively small amount of pro-
tein and so this ration may have a wide nutritive ratio
such as pertains to the nutrients of the more common
farm products.

MAINTENANCE RATION FOR BOVINES

409. Various investigations concerning maintenance
needs.—Experiments, having for their object a determina-
tion of the daily quantity of nutrients necessary to simply
maintain animals of this class, were conducted by Henne-
berg and Stohman with oxen as long ago as 1858. A num-
ber of rations were fed and the conclusions which were
reached were based upon the amount of food digested,
the gain or loss of nitrogenous tissue by the animals,
their weights, and general appearance. The average daily
quantities of digestible nutrients which appeared to be
sufficient to maintain a 1,000-pound ox without growth or
loss was approximately 8.2 pounds, of which .53 pound
was protein, the whole having an energy or heat value of
not far from 15,000 calories. Because of the high tem-
perature of the stalls used in the above-named experi-
ments, Wolff estimated later that for winter feeding the
standard should be 8.9 pounds of digestible nutrients, of
which .7 pound should be protein, the energy value being
approximately 16,000 calories, and for a long time
Wolff’s figures were published as the standard main-
tenance ration.

’ } i‘ 4
310 THE FEEDING OF ANIMALS

This standard has been revised. The earlier experi-
ments on which it was based furnished data insufficient
for accurate conclusions, for the only means of judging
whether the animals were gaining or losing body sub-
stance were the changes in live weight, which cannot be
regarded as conclusive evidence. Some of the earlier
feeding experiments conducted in the United States,
especially those of Sanborn and Caldwell, indicated that a
ration based on Wolff’s standard was capable of causing a
material growth of steers, and the accuracy of Wolff’s
figures was called into question. Later observations of a
more exact character have shown quite conclusively that
a 1,000-pound steer may be maintained without loss of
body substances on considerably less than 8.9 pounds, or
even 8 pounds, of digestible nutrients a day.

Elaborate experiments by Kiihn from the years 1882

to 1890, afterwards discussed by Kellner, were regarded
by the latter as justifying the conclusion that the mini-
mum quantity of digestible organic matter which will
maintain a 1,000-pound mature ox at rest is 7.3 pounds,
.7 of a pound of which should be protein. Later Armsby,
in presenting the results of experiments of his own in
connection with a critical review of Kiihn’s work, con-
cludes that “we may place the average maintenance of a
steer weighing 500 kgs. (1,100 pounds) and receiving
only a mainly coarse fodder at 13,000 calories of availa-
ble energy.”” As Armsby has found one gram of digesti-
ble matter from roughage to be equal to 3.5 calories of
available energy, 13,000 calories would equal 7 pounds
of digestible matter from this source. This would be
the same as 6.54 pounds for a 1,000-pound animal.

Still later, Kellner, basing his figures upon extensive
researches by himself and associates, which were the

x _ MAINTENANCE RATIONS 311

most elaborate made up to that time, gave us the
following as the minimum quantities which will satisfy
the maintenance needs of mature animals of different
weights:

Digestible organic

Approximate weight substance from
of anima Energy average meadow hay
Pounds Calories Pounds
0... | ee, _ . 10,740 6.75
B00. A 11,520 7.22
ep)... . eee ak 12,280 7.72
00. | <a 13,010 8.18
OO. - .° ee ee Ts 13,720 8.62
S000. 5 A ee 14,420 9.06

The researches of Armsby and Fries with the respira-
tion calorimeter, in a study of the fasting katabolism of a
steer, furnish us data much more reliable than can be
secured in any other way.

410. Fasting katabolism as a measure of mainte-
nance needs.—The exact maintenance needs of a given
animal are most accurately determined while the animal
is fasting. When an animal is receiving no food there is
no cessation of the vital activities. In the maintenance of
these activities there is necessary a certain amount of
protein cleavage and a sufficient oxidation of organic com-
pounds to meet the energy needs of the animal. The
material that is so used is taken from the body structure,
and by determining the metabolic nitrogen excreted,
and the gaseous products resulting from oxidation, the
exact maintenance needs of the animal are ascertained.
This is a determination of the fasting katabolism of the
animal body. |

The investigation by Armsby and Fries was conducted
with a steer which first was fed daily 3.2 kilograms of
timothy hay, an amount not sufficient to maintain the

sl THE FEEDING OF ANIMALS

animal without loss of body substance. The metaboliza-
ble energy of this insufficient ration was found to be 5.7
therms, and during the time it was fed, the steer lost from
his own tissues an amount of protein and fat equivalent
to 2.4 therms a day. In another period, the steer ate
5.2 kilograms of the same hay, having a metabolizable
energy of 9.26 therms, or 3.58 therms more than was con-
tained in the smaller ration. By feeding the larger ration,
the use of body protein and fat was reduced to .357
therms or 2.02 therms less than was the case with the
smaller ration. It seems, then, that 3.58 therms of
metabolizable energy in the ration replaced 2.02 therms
of energy derived from body substance; or, in other words,
the metabolizable energy in the hay was only 56.5 per
cent as efficient as was the energy derived from the
oxidation of body protein and fat. The other 43.5 per
cent of the hay energy was used, as we have seen, in the
way of mastication, digestion, and other internal func-
tions requiring the use of energy in order to prepare the
food and transmit it to the tissues.

411. Distribution of maintenance energy.—A study
of fasting katabolism has made possible not only the
energy used in maintenance but also the approximate
determination of the distribution of the uses of energy.
Zuntz, on the basis of observations made with a fasting
man, computed that muscular activity, including circu-
lation, respiration, and the voluntary muscles, used about
60 per cent of the metabolism and that the internal
organs, such as the liver, intestines, kidneys, pancreas,
and salivary glands, used about 40 per cent.

412. Use of nutrients in fasting metabolism.—The
studies of fasting metabolism have made it possible to
measure accurately the relative use of the nitrogenous

; Saul
1 )4 i i lie eee

| MAINTENANCE RATIONS ; 313

and the non-nitrogenous tissues. Determinations with
many species of animals, including man, swine, dog,
rabbit, guinea pig, goose, and hen, show that the protein
katabolism in per cent of total katabolism varied from 7.3
to 15.6. In all but two cases the range was from 10.8 to
15.6 per cent. This shows that the energy derived from
the fat and carbohydrates, largely from the fat where
this has been stored, is from six to nine times as great as
from the body protein.

413. Computation of maintenance needs.—The fore-
going data allow a computation of the metabolizable
energy that must be supplied in the ration in order to
meet the maintenance needs of the experimental animal
that was under observation.

The larger ration supplied the need of the animal to
within .357 therm, which was derived from body sub-
stance. ‘This deficit would be equal to .632 therm of
matabolizable energy supplied by the hay. The computa-
tion would be as follows:

Therms

rea ce SOL. | PH CNCTLY 9. kk kw “es a. 3 .632
Sa kilos hay—enerpy .. 2... ke ee 9.262
Rnerey/meeded v2. a0. 0 Oa SO 9.894

9.262 therms : 9.984 therms :: 5.3 kilos hay :2=5.655 kilos.
5.655 kilos=12.44 Ibs. hay, or 6.34 lbs. digestible nutrients.

The animal weighed 822 pounds. If the animal had
weighed 1,000 pounds, using the formula for body sur-
face, the figures for digestible nutrients would be 7.21
pounds. These figures correspond closely to those derived
from previous investigations.

Armsby suggests the following maintenance require-
ments based on production values for cattle, which
include growing animals:

Vey a RU i he
Ka ag

314

THE FEEDING OF ANIMALS
Taste LXVII. Martntenance REQUIREMENTS OF CATTLE
Live Digestible Energy
weight protein value
Pounds Pounds Therms
150 Ss ss eee abo bee
200 Se | eee kN 2 2.4
DO ee aT oO 3.8
(A A 4.95
PO ee a a 6.
oreo... wl, : 6 %
OM .65 7.9

414. Maintenance rations for bovines.—In order to
express a maintenance ration for bovines in terms of hay
and grain, there are given in this connection several mix-
tures, based upon energy values in Table XX XIX, which,
on the basis of average composition and digestibility,
will furnish fairly closely the necessary protein and energy:

To Maintain a 1,000-Pounp ANIMAL

1 a Ibs. average timothy hay. " Ibs. mature corn silage.
3

4 lbs. wheat bran. 4 lbs. timothy hay.

2 lbs. wheat bran.
5 Ibs. timothy hay, ripe.
6 Ibs. clover hay. ifs Ibs. clover hay.
3 lbs. corn-and-cob meal. 4 lbs. corn-and-cob meal.
5. 17 lbs. good mixed hay.

{6 Ibs. corn stover, much water.
2

These combinations are merely illustrative. Many others
furnishing an equivalent quantity of available nutri-
ents may be used. Doubtless these various mixtures
will not show equal efficiency. Ration No. 3 would
probably be more satisfactory than No. 5, because of
greater palatableness. All such factors as the proportion
of grain in the mixture; the stage of growth of the fodder,
whether early or late cut, immature or mature; the
amount of moisture present, as in stover; and the com-
pleteness of preservation, will have an influence upon the

MAINTENANCE RATIONS 315

nutritive effect of a ration, and these factors must be con-
sidered according to the best judgment of the feeder.
It is possible, without question, to maintain an animal
on one fodder alone, such as hay, but for several obvious
reasons it is better to feed some grain. ;

The maintenance rations heretofore stated apply to
a 1,000-pound animal. For animals weighing more or
less the quantity should be increased or diminished, but
not in just the ratio in which the animal varies in weight.

MAINTENANCE FOOD FOR HORSES

The general facts which have been presented in rela-
tion to the function and character of a maintenance
ration are as applicable to horses as to bovines. It is
true, however, that rations simply sufficient for main-
tenance purposes have a very limited application with
horses, because in nearly all cases they are at least used
for occasional driving or light work, and even if merely
“boarded,” regular exercise is necessary to their welfare.

415. Studies of the maintenance needs of the horse.—
Zuntz, who so thoroughly studied the nutrition of the
horse, concluded, after a critical survey of the results of
other men in connection with the elaborate data from his
own extended investigations, that a 1,000-pound horse
can be maintained on 6.4 pounds of nutrients, provided
the total ration contains not more than 3 pounds of crude
fiber. This means that the nutrients should come from a
mixture of hay and grain if this minimum quantity is to
be sufficient. Were only hay to be fed, the necessary
nutrients would probably exceed the amount named.

Grandeau in his experiments found that three horses,
whose mean weight was 852 pounds, were maintained

316 THE FEEDING OF ANIMALS

for fourteen months on 17.6 pounds of hay a day, from
which the three animals digested an average of 6.06 pounds
of organic matter. Using the method of computation
already described, this is equal to 6.75 pounds of digesti-
ble nutrients for a 1,000-pound horse, a result not greatly
different from that of Zuntz.

The latest conclusion of Wolff was that a 1,100-
pound horse should have for maintenance at rest 7.26
pounds of digestible organic matter daily, exclusive of
the digested crude fiber, which would be the same as
6.78 pounds of fiber-free nutrients for a 1,000-pound
horse. As Wolff regarded the fiber as useless to a horse,
either for maintenance or for production of work, the
last figures represent his estimate of the maintenance
needs of a horse at rest.

It is proper to remark that Wolff’s views as to the
nutritive value of crude fiber are not generally accepted.

The following maintenance standards, based on pro-
duction values, are offered by Armsby:

TasLtE LXVIII. Martntrenance REQUIREMENTS OF HORSES

Live Digestible Energy
weight protein value
Pounds Pounds Therms

a). III ek 3 2.

i rr A 2.8

ne: NEE; 6 4.4

ia). ea 8 5.8

1,000 ~~ s 1. rf
fon 1.2 8.15
1500. -; |. oe 1.3 9.2

In calculating rations for horses, the coefficient of
digestibility obtained in experiments with this class of
animals should be used, coarse fodders, as stated pre-
viously, not being so efficiently digested by horses as
by bovines or sheep.

—

MAINTENANCE RATIONS 317

416. Maintenance rations for horses.—Accepting the
standard given on page 316 as the daily requirement of a
resting horse, the followimg rations would maintain a
1,000-pound animal for one day:

- Ibs. medium quality 10 lbs. mixed hay.
mixed hay. 5 4 lbs. bran, or
5 lbs. oats, or
9 10 lbs. timothy hay. 4 lbs. cracked corn.
5 lbs. oats. 10 Ibs. timothy hay.
ef Ibs. carrots.
3 3 Ibs. corn.

4 lbs. cracked corn.

10 lbs. carrots.
4 Ibs. oats.

10 Ibs. medium mixed hay.
414 Ibs. wheat middlings

{3 Ibs. mixed hay.
8

{ro Ibs. mixed hay.
7

iN

HA Ibs. timothy hay.

8 lbs. carrots.
4 lbs. bran.

These rations serve as examples and also indicate
how with ten or twelve pounds of hay the several grains
mentioned may be combined to give a maintenance
ration. It is not wise to feed a horse on hay alone, even
when doing no work. Ten to twelve pounds of hay are
enough coarse fodder, which may be supplemented to
advantage by both roots and grain.

417. Maintenance food for sheep.— Basing his rec-
ommendation of maintenance rations for sheep upon Kell-
ner’s production values, Armsby suggests the following:

Live Digestible Energy
weight protein value
Pounds Pounds Therms

ER 3) SN Re a 3 9 ae oO
a. Or. |. Oo 05 54
Gib’. eee Cees so 07 oY i
Se tee, . . we .09 87

1:1.) ee a 1 1

318 THE FEEDING OF ANIMALS

This means that seven sheep weighing 140 pounds
each, or approximately 1,000 pounds, would require
daily approximately the following quantities of food for
_ Maintenance purposes:

Pounds

DEN DY” i i eee! 20

or
ls So.) Ss 14
2 i ...)) 1
eee, dw we ee 4%

or
Mee). kk. kl 14
RE a J) ee
De TE aa 5

These rations supply protein in excess of the standard
given, but this should not be condemned, as liberal allow-
ance should be made for the growth of wool.

CHAPTER XIX
MILK PRODUCTION

Mix, like all other animal products, is derived from
the food. Its secretion stands almost unrivaled as an
example of the rapid, extensive, and continuous trans-
formation of the food into animal compounds. In no
other instance, except perhaps in the case of the earliest
growth of animals, is so large a proportion of the digested
nutrients utilized in building new material, or is there so
intimate a relation between the extent and kind of the
feeding and the extent and character of the resulting
product. For these and other reasons, the successful
feeding of milch cows requires, perhaps, greater expertness
and a wider knowledge of facts than any other depart-
ment of animal husbandry. This will appear more fully
as we continue to develop this subject.

It is not proposed in this connection to enter into
an elaborate discussion of the chemistry and secretion
of milk, for this is presented elsewhere in the series of
which this volume is a part. It is essential to present
purposes, however, that we call to mind certain facts
which are pertinent to a consideration of the food rela-
tions of milk formation.

418. Composition of cow’s milk.—Milk is a fluid that
is secreted by all mammals in a gland which with the
cow is called the udder. It contains water and solids, the
latter being made up of mineral compounds, proteins,
fats, and sugar. The average composition of normal

(319)

320 THE FEEDING OF ANIMALS

cow’s milk, excluding samples of unusual character,
according to a compilation by Van Slyke of 5,552 Ameri-
can analyses is as follows:

Total solids Ash Proteins Fats Sugar Water
Per cent Per cent Per cent Per cent Per cent Per cent
12.9 v6 3.2 3.9 5.1 87.1

The variations in the composition of cow’s milk are
large, the proportion of water ranging, under perfectly
normal conditions, from 84 to 89 per cent, with occa-
sional analyses entirely outside these limits. The chief
known causes of such variations are breed, individuality,
period of lactation, and nervous disturbances. There
are material daily fluctuations as well, for which no
reasons can now be assigned. These changes are mostly
in the proportions of water and total solids, for the com-
position of the solids, that is, the relative proportion of
proteins, fats, and sugar, is remarkably constant with
the same animal. The effect of breed in cows is illustrated
by averages shown in Par. 362. These variations and
those due to other causes are important in considering
the relation of milk formation to nutrition, because the
food expense of milk is determined, other things being
equal, not by the volume but by the milk solids elabo-
rated, for which reason the draft upon the supply of
nutrients, water excepted, is greater for the secretion of
100 quarts of Jersey milk than for the same quantity
of Holstein milk. In studying the economy of milk pro-
duction, therefore, we should consider the relation of
food to milk solids and not to milk volume.

419. Milk secretion.—There is no milk in an animal’s
food, that is to say, hay and grain contain no casein,
butter-fat, or milk-sugar. They do contain nutrients,
which, when subjected to the vital processes of the animal,

ot te
a hs

MILK PRODUCTION 321

are ultimately transformed into the constituents of milk.
The mammary gland is not a sieve through which cer-
tain compounds in the blood are strained into the udder
cavities, but it is a specialized tissue in which wonderful
and extensive chemical changes occur. Here, for the first
time, we find casein, the mixture of compounds known
as butter-fat, and a sugar unlike any that is found in
plants, or in any other part of the animal organism.
Vegetable fats contain glycerides similar to some of those
found in milk, to be sure, but not in the same number
or proportions. One fact, moreover, which dairymen have
been slow to recognize in all its significance, is that the
udder of each individual cow is a law unto itself in the
characteristics of the milk which it secretes, and is not
subject in any large degree to control through feeding or |
other treatment that is not actual abuse.

The manner of milk secretion is something of which
we know but little, and this is, perhaps, not immediately
important to the dairyman. The food source of the con-
stituents of milk is, on the other hand, a matter of great
practical interest, and here we have information more or
less definite.

420. Food sources of milk proteins——The previous
discussion of the functions of nutrients must have made
it clear that the proteins of the milk can have only one
source, viz., the proteins or closely related compounds in
the food, a unanimous conclusion which rests upon experi-
mental evidence as well as upon the universally accepted
truth that the animal organism does not have the power
to construct proteins from the simpler compounds used
by plants for that purpose.

421. Food sources of milk-fats.—It now seems quite
certain that the proteins are the only constituents of

U

322 THE FEEDING OF ANIMALS

milk which must have their origin exclusively in the
nitrogen compounds of the foods, for we have appar-
ently sound reasons for believing that milk-sugar and
the butter-fats are constructed, in part at least, from

carbohydrates. In an investigation at the New York

Agricultural Experiment Station as to the food sources
of milk-fat, two cows, both of which gained materially
in live weight during experiments continuing two months
or over, produced respectively nineteen pounds and forty
pounds more of butter-fat than could be accounted for
from the food fat and available proteins. The amount
of digestible food fat supplied was relatively insignificant
and the secretion of milk-fat seemed to be related in no
direct way to the protein exchange. These observations
led straight to the conclusion that carbohydrates are milk-
fat formers. The extent to which food fat assists in the
production of milk-fat is not yet determined. While the
ingested fats appear to pass directly into the milk to some
extent, it seems quite evident that the larger part of the
glycerides of milk have their origin in the animal. We
are not sure, either, whether protein is ever a source of
milk-fat, but that it is not a necessary source now seems
to be proved.

422. The rate of formation of milk solids——A cow
yielding 6,000 pounds of average milk a year is not
regarded as an unusual animal. This means, however,
the annual production of not less than 780 pounds of
milk solids, an amount at least double the dry matter in
the body of a cow weighing 900 pounds. When we con-
sider that this manufacture of new material is carried
on not only during a single year, but through the entire
adult life of the animal, we begin to realize how exten-
sive are the demands upon the food-supply. Still more

MILK PRODUCTION 320.7%

striking is the case of high-grade cows yielding annually
over half a ton of milk solids, and when we remember
the performance of Duchess Skylark Ormsby, whose
27,761 pounds of milk produced in one year certainly con-
tained approximately 3,700 pounds of solid matter or
more than twice the weight of the cow, we must regard
the cow as possessing wonderful powers of transmutation.
Her capacity for the rapid and economical production of
human food of the highest quality is not equaled by any —
other animal.

No facts could more forcibly illustrate the necessity
of liberal and proper rations for the milch cow.

423. Uses of nutrients in milk production.—This
ration is used in various directions. It must supply the
raw materials for milk formation, provide for the growth
of the foetus, sustain the effort of milk secretion, and
maintain the usual and necessary functions of the animal
body. The nature and extent of these uses are in part
quite definitely understood. First of all, the kind and
quantity of milk solids may be estimated for any given
case. The daily production of 30 pounds of average milk,
a performance reasonably to be expected in a good herd,
involves the elaboration of 3.87 pounds of milk solids.
Thirty pounds of high-grade milk would contain not less
than 4.6 pounds of solids. For mere maintenance it is
fair to assume that the food requirements of the cow and
steer would not be greatly unlike, disregarding the
demand for energy utilized in milk secretion, and for the
material used in the growth of the young. On this basis
the milk solids and the maintenance needs of a non-pro-
ductive cow call for about 11.2 to 12 pounds of dry matter
daily, a quantity utterly insufficient, as experience teaches,
to maintain a cow giving 30 pounds of any kind of milk.

324 THE FEEDING OF ANIMALS

We are led to the reasonable conclusion that, outside the
building of milk solids, a large expenditure of food energy
is required to sustain the work of additional food con-
sumption, the imcreased metabolic cell activity and —
warming of the extra water and food, which are necessarily
involved in milk secretion. This view is sustained by the
results of investigation. In experiments by the writer
with two cows in full flow of milk, which made only a
slight gain in body weight, the energy of the digestible
part of the rations and of the milk was determined. The
figures reached were approximately as follows:

TaBLE LXIX
Cow 10 Cow 12
wt. 775 lbs. wt. 1,200 lbs.

Calories Calories
Energy of digested nutrients . . . . 27,120 31,300
Energy of milk solids ....... 8,450 10,200
Energy not usedin milk ..... 18,670 21,100

Maintenance needs of non-productive
I 10,100 13,700
Balance of energy not accounted for 8,570 7,400

This energy not accounted for, amounting with the
two cows to more than one-fourth the total energy of
the nutrients digested, may properly be charged to the
work of milk production, including of course, food appro-
priation. Science and practice agree in naming 15.5 to
16.5 pounds of digestible organic matter as approximately
the proper daily amount of digestible nutrients for eco-
nomical milk production with a productive cow of aver-
age size, much less than which is not to be considered as
generous feeding. The necessary supply of nutrients will
vary according to the size and productiveness of the cow.
Productivity independent of size is a controlling factor.

MILK PRODUCTION 325

In general, small cows eat proportionately more food than
larger ones.

424, Protein requirements for milk production——The
question now arises, What proportion of this quantity
should be protein? The actual amount of proteins in 30
pounds of average milk, for instance, is about 1 pound.
If .70 pound is needed daily for mere maintenance then
1.7 pounds of protein must be used for maintenance and
milk formation, a quantity which is now regarded as too
small to sustain such milk production when both food
economy and the efficiency of the ration are considered.
With this amount of protein in 16 pounds of total digesti-
ble matter, the nutritive ratio of the ration would be
about 1:9.5. A ration with as wide a ratio as this would
be regarded by the great majority of careful experiment-
ers, and most intelligent dairymen, as less efficient than
one richer in protein. Few instances are on record where,
in carefully conducted experiment-station work, other
conditions being the same, a moderate ration with a
nutritive ratio of 1:5.5 to 1:6.5 has not proved to be
more efficient than one equivalent in quantity but with a
ratio materially wider. The observations of Atwater
and Woods among the dairy herds of Connecticut, where
the owners were induced to narrow the rations they were
found to be using, gave emphatic testimony as to the
desirability of a larger proportion of protein than is
usually supplied in the ordinary home-grown ration.

There are several possible reasons why the protein
requirement of a non-productive animal plus the protein
found in the milk does not constitute a proper standard
for a milk ration:

1. The stimulating effect of a generous supply of pro-
tein upon metabolic activity.

i] TW eT A ind , Re ay i ee A ae
r ; wt a) hd) re area

3826 THE FEEDING OF ANIMALS

2. The use of food proteins for the synthesis of milk —
proteins over and above in weight the milk proteins —
actually formed.

The partial non-availability of certain food proteins,
because of their constitution, for reconstruction into
milk proteins, must now be conceded. (See Pars. 274,
275.)

According to the greater part of testimony available, a
cow of average size and capacity should receive at least
two pounds of protein daily during the full flow of milk,
the ration to have a nutritive ratio not wider than 1: 6.5.
The nutritive ratio of young pasture grass, perhaps as
efficient a milk-producing food as we have, is even nar-
rower than this, a fact which doubtless explains in part
the large flow of milk from abundant June pasturage, and
which offers a suggestion for the compounding of winter
rations.

425. Relative importance of protein overstated.—
While the importance of nitrogenous feeding-stuffs to
a dairy herd is conceded, there is a tendency with certain
writers to distort the relation of protein to milk produc-
tion. Their utterances give the impression that in feed-
ing milch cows, protein is about the only factor to be
considered. This view is typified by the assertion that
“a cow gives milk only in proportion to the protein that
she receives,” a remark which might be made with equal
accuracy about carbohydrates. It is true that even if
carbohydrates are supplied in abundance, a depression
of the protein below a certain limit in a given case will
diminish the milk flow. It is also true that when sufficient
protein is fed, a reduction of the carbohydrates below the
necessary quantity will cut down the milk yield. An ade-
quate supply of easily digestible carbohydrates is no less

MILK PRODUCTION won) aoe

important physiologically than keeping up the necessary
proportion of protein, though the former may be accom-
plished more easily than the latter because of the usual
character of home-raised crops.

FEEDING STANDARDS FOR DAIRY COWS

The feeding standards for dairy cows, which are
regarded as embodying our most advanced knowledge,
have been reached through several stages of development.
The following are brief descriptions of these stages with —
suggestions as to their imperfections:

426. Thaer’s hay values.—Albrecht Thaer, known as
the father of scientific agriculture, more than a half-cen-
tury ago suggested “hay values” as the basis for express-
ing feeding standards. He calculated the relative values
of feeding-stuffs in terms of good meadow hay, the neces-
sary quantities of rations and substitutions of feeding-
stuffs in them to be based on such values. It is now per-
fectly understood how crude are such standards for they
ignore the varying digestibility of feeding-stuffs and the
necessary relations in the proportion of nutrients. Thaer
seems to have ignored weight and production as factors
in determining what a ration should be.

427. Grouven’s milk-feeding standards. — Grouven
later introduced the factor of weight, and formulated
eight standards for milch cows to be applied to animals
weighing from 772 to 1,543 pounds. The matter of vary-
ing production was ignored. The daily ration suggested
for cows weighing 1,000 pounds was not irrational, this
being: Dry matter 28.7 pounds, crude protein 2.76 pounds,
fat .86 pound, and carbohydrates 14.55 pounds, a ration
adequate to sustain a generous flow of milk.

328 THE FEEDING OF ANIMALS

428. Wolff’s feeding standard.—Emil von Wolff seems
to have been the first one to give a definite recognition

to digestibility as a factor in calculating feeding stan-

dards. The standards he proposed were in terms of digesti-
ble constituents, the quantities fed to be directly propor-
tional to live weight without reference to varying pro-
ductivity. It was the Wolff standards that first became
known, and somewhat widely advocated, in the United
States. Their advocates conceded that they were only
approximations to actual nutritive needs and chiefly
valuable as suggestions in the compounding of rations.

429. Kuhn’s feeding standard.—The fact that Wolff’s
standards made no allowances for varying productivity
caused them to be severely criticised, and properly so.
The most prominent critic was Julius Kiihn, who pro-
posed a basal maintenance ration, additions to be made
to this somewhat in proportion to the demands for pro-
duction. The quantities of digestible nutrients recom-
mended by Kiihn ranged between 20 and 23.5 pounds of
dry matter, 1.5 and 2.4 pounds of digestible protein and
12 to 14 pounds of digestible amides, crude fiber, and
nitrogen-free extract, Kiihn holding to the point of view
of his time that amides function nutritively as do the
carbohydrates.

430. The Wolff-Lehman feeding standards. —'The
first standards to recognize, in an extended way, the
varying nutritive needs of animals according to produc-
tion, are those known as the Wolff-Lehman, which are
an attempt to so modify the original Wolff standards as
to meet the requirements of cows of unlike productivity.
This was certainly a step.in the right direction.

These standards have been widely used in the litera-
ture of animal nutrition in the United States.

rig

a.

MILK PRODUCTION 329

431. American feeding standards.—Beginning with
the feeding standard suggested in 1894 by F. W. Woll
for dairy cows, several standards have been proposed by
American authors and experimenters. ‘These proposals
have been based upon studies of the practice of success-
ful feeders, or upon more or less extended feeding experi-
ments. It cannot be said that with a single exception
these so-called American rations are based upon close
physiological studies. They are, in fact, mostly modi-
fications and extensions of the Wolff or Wolfi-Lehman
standard, arrived at through a critical study of what have
proved in practice to be productive rations.

It is well to submit these various commendable and
useful efforts to arrive at practical feeding standards to a
critical analysis, not only for the purpose of presenting
the conclusions reached, but also in order to set forth the
limitations that accompany experimental work of the
type upon which the conclusions were based.

432. Woll’s standard.—This standard is based upon
the average of about 100 rations in apparently success-
ful use by American and Canadian farmers. From the
average was deduced the following daily ration for milk
production: Dry matter 24.5 pounds, digestible protein
2.15 pounds, digestible carbohydrates and fat 14.5 pounds.
This ration is suggested, apparently, on the assumption
that what is being done by a group of successful feeders
is a safe guide to the practice of others. In a sense this
is true, when conditions are similar. This method of
reaching a conclusion gives no assurance, however, that
the practice observed is the best that could be devised,
even though under given conditions it may be found
profitable. Such a study of existing practice is suggested,
however,

330 THE FEEDING OF ANIMALS

433. Standards for milk production based on
elaborate American feeding experiments.—Three in-
vestigators, Haecker, Savage, and Eckles, carried on
extensive semi-practical experiments for the purpose of
determining the relation between the food of a cow and
her milk production. These several studies were inaugu-
rated for practically the same purposes, viz., to deter-
mine protein demand for milk production and the neces-
sary quantities of total digestible nutrients. More-
over, the data secured have been applied differently
from those derived from previous similar experimental
work. ‘The final measurements have been based, not
wholly upon the weight of the animal or upon total milk
production, but also upon the protein and total nutrients
necessary for the production of one pound of milk with a
given percentage of fat. It is on this basis that these three
pieces of experimental work may be compared.

Haecker began his records in 1892 and carried them
through, during definite periods, until 1901. The experi-
ments upon which his final conclusions are principally
based were carried on in 1894-1895 for a period of 154
days, and in 1900-1901 for a period of 113 days, the num-
ber of cows involved in the first period being 12 and in
the last period 20. The fodders were analyzed only in
part, and the digestibility of the various feeding-stufis
was calculated on the basis of average digestion coefficients,
with due reference to the condition of the coarse fodders.

Savage’s work was done from 1909 to 1911. In both
experiments twelve cows were used in three feeding
periods of six weeks each, production records. being kept
for five weeks in each period. The fodders were analyzed
but their digestibility was calculated from average diges-
tion coefficients,

Cer re dee aif yelp oty Ali. . See bag y Pr
: ‘ aoe

MILK PRODUCTION 331

The experimental feeding by Eckles was in the years
1910-1911, and his observations continued for one year.
The various foods used were analyzed. Digestion experi-
ments were conducted during two periods, one with three
animals while they were on a maintenance ration, and one
with five animals when near the time of maximum milk
production. Eckles, therefore, secured rather more accurate
data than was the case with the other two experimenters.
He was able to calculate more nearly the exact digesti-
bility of the materials involved in the experimental work.

With all three of these experiments the amount of
milk produced was accurately determined and analyses
made to determine the percentage of fat. By ascertain-
ing, therefore, the estimated or the actual amounts of
digestible material fed and the milk production with its
fat-content, it was possible to calculate the relation to the
product of the protein and total nutrients digested. The
following table permits a comparison of the recommenda-
tions of the three experimenters based on the data secured.
A fuller table appears later. (See Appendix.)

TaBLE LXX. StTanparps FoR MitK PrRopUCTION AS DEVELOPED
BY Harcker, SAVAGE, AND EcKLES. PROTEIN AND TOTAL
NUTRIENTS FOR ONE PounpD oF MILK.*

Per Haecker Savage Eckles
@e@mt |] AAA |
paket Protein Total Protein Total Protein Total

nutrients

nutrients nutrients

Pounds Pounds Pounds Pounds Pounds Pounds
3.4 0444 .265 .0599 ol15 .0469 285

3.8 0468 287 0632 .3369 051 .283
3.9 0474 292 064 3428 .056 298
5.3 0558 Ot 0753 4209 048 302
5.5 057 066 077 4311 .0587 396
6.1 .0606 392 .0818 4619 072 505

*In excess of maintenance needs.

332 THE FEEDING OF ANIMALS ~

The figures here given represent the actual use of nutri-
ents by the several animals in Eckles’ experiment, and
not the suggested standards. These follow:

Total Total
Protein nutrients Protein nutrients
Pounds Pounds Pounds Pounds
05 .26 .062 .36
.052 28 .066 A
.055 o 07 45
.058 oo 075 #5)

These figures are calculated on the basis of the nutrients
fed minus the nutrients necessary for the maintenance of
the animal without production. Students of these figures
should bear in mind that in these investigations the only
measures of the efficiency of the rations have been the milk
production and the changes in weight of the animals. It
is evident that it was not possible by the methods used
to determine whether there was, with a given animal, a
gain or loss of body substance other than would be
indicated by a change in weight, which, as is well known,
is often a deceptive standard of measurement. It should
be said, however, that probably no practical feeding
experiments with dairy cows so far conducted give figures
more reliable as a guide to the feeding of dairy animals
than those above cited. It will be noted that the increase
in the protein and total nutrient requirement for each
increase of one-tenth per cent fat in milk is as follows:

Haecker Savage
Pounds Pounds
Average protein increase for .1 per cent of fat

im Wek... I .0006 .0008
Average total nutrient increase for .1 per cent
Ohjapim milk . :- ne... .0048 .0056

434. Requirements of certain feeding standards for ~

dairy cows.—In order to apply the various standards for

MILK PRODUCTION 333

feeding dairy cows that have been set forth, it is neces-
sary first to determine what the standards require. These
requirements for a 1,000-pound cow giving thirty pounds
of 5 per cent milk would be as follows:

TaBLE LXXI

| Maintenance Production Total

Total . Total : Total
Protein nutrients Protein nutrients

Pounds | Pounds | Pounds } Pounds | Pounds | Pounds
Wolff-Lehman§ ig 8.22 2.6 9.88 3.3 18.1
Heaecker?. .. Er 7.92 1.62 11.19 2.02 19.11
Savage... . a 7.92 2.18 | 12.14 | 2.88 |, 20.06

In the next table are given the energy equivalents of
the nutrients required by the several standards:

TasBLteE LXXII

Maintenance Production Total

Protein | Energy* | Protein | Energy* | Protein | Energy*

Pounds | Therms | Pounds | Therms | Pounds | Therms

Wolff-Lehman§ | . 13.05 2.6 15.685 | 3.3 28.735
Haecker ...| . 12.573 | -1.62 | 17.765 |. 2.32 3h320338s
eS oe A 12.573 |. 2.18 | 19.273 | 2.88¢) 31.843
Armsbyll . . .| - 6.7 jes tS es WS LE yp 1.85£9 17.77
*Metabolizable.

Net energy.

True protein.
§For 27.5 pounds of milk daily, per cent fat not given.
| Older production values used.

435. Calculation of rations for dairy cows.—In order
to determine what a ration should be for this particular
animal, use is made of the following figures showing the
digestible protein and total digestible nutrients in the
various feeds entering into the combinations that are
suggested :

we
Nv

334 ‘THE FEEDING OF ANIMALS |

Taste LXXIII. In 100 Pounps

oo ooooooooeoeoea*e*eses~=S eee SS :795°0C0—0—000>05>SS$$_="—a=«xq«*xoOoOwonowon
}

: : Total

protein. | digestible

- Pounds Pounds ©
ears etn Se a. 1.1 BW gh"
ey Oe ee 3. 48.5
Pi eUROEe a we 10.6 51.6
0 a 6.9 83.8
Wheaumalcnimess 13.4 69.3
Ceo. ke ee 21.6 80.7
OE 33.4 fe 7p.5

*Carbohydrates + (Fat x 2.25) +Digestible protein.

The next table shows the rations that would meet
the demands of each of the five standards that have
been suggested, three of these rations corresponding to
the several standards for feeding a 1,000-pound cow giving
thirty pounds of 5 per cent milk:

TaBLE LXXIV
Armsby

: : g lps

3 3 S les

pe ps me |A” a

Lbs. Lbs. Lbs. | Lbs.
Silage, .9 . 0 40 40 | 7.08
Timothy hay ae ee 8 | 3.88
Alfalfa hay 8 8
Corn meah . . : 6 5 6 | 5.03
Wheat middlings 3 1 4 | 2.77
Gluten feed aie 3: 211.61
Cottonseed meal i
Roughage 48 48
Grain 11 12
Protein Res ae ; br. Ad SBe
Digestible nutrients,total 20.37

*True protein.

MILK PRODUCTION 335 —

It is to be noted that these several rations do not
differ essentially in quantity but show some variations in
the proportions of the several ingredients in order to
reach an adjustment with the protein requirement. The
quantities of the several feeds in the Armsby standard

_ are based upon the production values which he has set

forth. (See Par. 263.) The Wolff-Lehman ration is based
upon the standard for a 1,000-pound cow giving 27.5
pounds of milk, the fat content not stated.

It should be remarked that these rations would be
regarded by practical feeders as sufficiently generous. It
is a question whether the amount of protein required by
the Wolff-Lehman and Savage standards are not unneces-
sarily generous, a point to be considered when protein
feeds are more costly than feeds bearing a large propor-
tion of carbohydrates.

436. Suggested practical rations for dairy cows.—
The following are suggested as practical rations for cows
of moderate size and fairly large productive capacity:

10 lbs. clover hay. 10 Ibs. mixed meadow hay.
35 Ibs. corn silage. 40 lbs. corn silage.
1, 2 lbs. hominy chops. 2{ 4 lbs. wheat middlings.
414 lbs. wheat bran. 3 lbs. maltsprouts.

21% lbs. linseed meal, N.P.

1 lb. gluten meal.

6 Ibs. clover hay. 10 lbs. corn stover.
10 lbs. mixed meadow hay. 5 lbs. alfalfa hay.
25 lbs. mangels. 4 25 lbs. sugar-beets.
34 3 lbs. corn meal. 3 lbs. corn-and-cob meal.
2 Ibs. wheat bran. 3 lbs. buckwheat middlings.
2 lbs. brewers’ grains. 11% lbs. cottonseed meal.
2 Ibs. gluten meal.

12 lbs. clover or alfalfa hay.
30 Ibs. corn silage.
5; 4 lbs. ground oats.
3 lbs. ground peas.
2 lbs. brewers’ grains.

336 THE FEEDING OF ANIMALS

These rations may be criticized on the ground that
they are too small to sustain heavy milk production.
This would be a just criticism for cows of large capacity
that are furnishing high-priced milk.

It is the writer’s opinion that a majority of cows not
over 1,000 pounds in weight, maintained under ordin-
ary business conditions, will not render larger profit from
heavier rations. ‘

437. The sources of commercial protein for milk pro-
duction: the home supply.—The dairyman has constantly
to face the fact that from the usual list of home-grown
feeding-stuffs it is difficult to make up a ration through-
out an entire season with a nutritive ratio much narrower
than 1:8, and a proportion of protein even as high as
this requires a generous admixture of clover in the hay,
and the use of more or less oats or peas in the grain ration.
It should not be forgotten that the plants used for for-
age crops are generally not harvested until they are
approaching maturity, and as the later growth of most
plants is largely due to the formation of non-nitrogenous
compounds, the hay and other fodders stored for winter
feeding are comparatively poor in nitrogen compounds.
On those farms where the hay crop comes largely from
the true grasses, like timothy and red-top, and where the
corn crop is a prominent feature, a home-raised winter
milk ration having a maximum efficiency for each unit of
dry matter consumed is not possible. On the other hand,
where alfalfa and clovers constitute a good proportion
of the hay, and where generous areas of peas and oats
are grown, a ration compounded from home resources
may have a high milk-producing efficiency.

438. Commercial protein.—It must be confessed,
however, that most dairy farms are lacking in a proper

MILK PRODUCTION oot

home-raised supply of the more nitrogenous feeding-
stuffs, and as nearly all dairymen depend to come extent
upon purchased grain, it is a quite prevalent custom for
them to seek those by-products that will strengthen the
protein side of the ration. It is unquestionably true that
farmers should be more independent of the markets, and
they certainly may be if an intensive system of cul-
tivating well-selected crops is adopted; but so long as
more or less grain will certainly be purchased, it is wise
to consider the matter of selecting commercial protein
feeds for dairy cows. Those from which it is possible to
choose are the oil meals, distillers’ grains, the gluten
meals and feeds, brewers’ grains, maltsprouts, peas, and
buckwheat middlings. The offals from the milling of
wheat, while somewhat more nitrogenous than the cereal
grains, cannot be considered as an’ abundant source of
protein, although they are excellent components of a
milk ration.

439. No single protein food essential—Notwith-
standing the claims which trade interests may make to
the contrary, no one of the above-mentioned feeding-
stuffs is alone essential to the economical production of
the best of milk. There is no single food or any one com-
bination of foods that is always best for dairy cows.
Apart from certain considerations which will be discussed
later, a selection of the source of commercial protein is a
matter of availability and of relative market cost. For
instance, if gluten meal were to cost $30 a ton, few
buyers could afford to pay $35 for linseed meal to feed in
any considerable quantity. If prices were reversed, oil
meal should be selected. Both oil meals and gluten prod-
ucts may be ignored if buckwheat middlings or the
brewers’ residues are available at more favorable prices.

-

338 THE FEEDING OF ANIMALS

It is simply necessary that the grain ration shall con-
tain protein in sufficient quantity and proportion, and
shall be made up of a variety of materials, better not
less than three kinds, all of which should be palatable
and exert no deleterious influence upon the milk or its
products. There are few grain products that cannot be
used successfully in grain mixtures, even though they
are undesirable when fed alone.

THE RELATION OF FOOD TO THE COMPOSITION AND
QUALITY OF MILK

The character of milk is believed by many to be inti-
mately related to the kind and quantity of food from
which it is produced, i.e., that a dairyman who is pos-
sessed of sufficient knowledge may, by variations in the
rations, cause material changes in the composition of
the milk of his herd. This is equivalent to believing that
thin milk or rich milk, milk rich in fats and poor in casein
or the reverse, may be obtained at the will of the feeder.
Such a view in its extreme form is very far from the
truth. While below a certain limit for each cow the quan-
tity of milk is mostly determined by the ration, other
factors, such as breed, individuality, and period of lac-
tation, are much more potent than the food in fixing
its composition.

In discussing this topic, it must be confessed, first
of all, that the experiments touching its several phases
have not furnished information satisfactorily definite
and conclusive in all respects. The testimony arrived at
is more or less confusing and contradictory. There are
several directions in which it has been necessary to look
for the effect of food upon milk: (1) Effect upon composi-

aes
“3

MILK PRODUCTION 339

tion: (a) in changing the proportion of water and total
solid matter; (b) in changing the relative proportions of
proteins, fat, and sugar, (c) in changing the constituents
of the fat. (2) Effect upon flavor.

440. Effect of food on the proportion of milk solids.
—In discussing the effect of food upon the proportion
of total solids, the question is, Can the richness of milk
be modified by changes in the ration? For instance, is
the milk from a very generous food-supply richer than that
from a moderate or scanty ration, or will a highly nitrog-
enous ration cause a secretion of milk with a higher per-
centage of solids than a ration poor in protein? It would
probably be generally conceded that if variations in milk
are caused in these ways, they are small as compared to
those due to breed characteristics or to individuality.
Can we bring about variations sufficiently large to be
important? This question has been much discussed and
much investigated from the work of Kiihn in 1868 down
to the present day. Many experiments have been con-
ducted for long periods and short periods in which very
moderate rations have been compared with very large
ones, highly nitrogenous foods with those of a low pro-
tein-content, dry with green or succulent materials, and
grains of the same class with one another, and, in a great
majority of cases, the verdict has been that no consist-
ent relation appears to exist between the quantity or
character of the ration and the proportion of solids in
the milk, a conclusion that has run counter to a very per-
sistent popular belief. In some cases, a temporary change
has appeared in the milk immediately after a violent change
in the ration, but in most instances of this kind, there was
very soon a return to the animal’s normal product. In
a small proportion of experiments, the milk appeared to

340 THE FEEDING OF ANIMALS

sustain a permanent, though not extensive, modification.
The weight of testimony bears out the statement that
the content of solids in milk cannot be modified at will
by the farmer, but is largely determined by causes not
under his control, such as breed and _ individuality,
although feeding and treatment, especially the latter,
have more or less influence upon the character of the
milk secreted. It is possible, even probable, that continu-
ous feeding, either very poorly or very highly, may bring
about in time a permanent change in a cow’s milk, but
today no one is wise enough to point out a way of defin-
itely controlling this product through the food.

441. Effect of food upon the constitution of milk
solids.—In the discussions relative to feeding dairy cows,
another point has received much attention, viz., the
effect of foods upon the proportions of the constitu-
ents which make up the dry matter of milk. A popular
notion has prevailed that it is possible to “feed fat into
milk,” having its origin in part, perhaps, in miscon-
ceptions as to the manner of milk formation. If the
mammary gland served simply to capture the unchanged
constituents of the food, then it might be reasonable to
expect the milk to partake of the character of the digested
nutrients and be “fat” or “lean” according to the pro-
portions of proteins and fats supplied to the animal.
When, however, we consider that this gland has the func-
tion of transforming the raw material of the food into a
milk which is characteristic of the breed or of the individual
in accordance with somewhat fixed constitutional limi-
tations, and that from the same food the Jersey cow will
make Jersey milk and the Holstein cow Holstein milk,
that a cow which starts in life giving thin milk is never
transformed into a producer.of rich milk, we can easily

.

~

MILK PRODUCTION 341

understand the general failure to find a recipe for feed-
ing fat into milk. Experimenters who have added large
quantities of fat or oil to a ration have in all but a very
few instances failed to permanently; or even tempora-
rily, increase the percentage of fat in the milk solids;
and, on the other hand, rations rich in protein do not
appear to cause a larger relative amount of proteins in
the milk-dry substance than rations with a wide nutri-
tive ratio. As a matter of fact, after years of investiga-
tion and intelligent observation, we are not able to affirm
that the proportion of fat to other milk solids is in any
way related to the feeding of the cow, and if apparent
exceptions to the general experience have been noticed,
no one has discovered any general method or law whereby
the exception may be made the rule.

Physiological disturbances may result from feeding a
ration so selected or treated that it is greatly deficient
in certain nutrients. In experiments by Jordan, Hart,
and Patten, the deficiency of phosphorus compounds
in the rations of milch cows appeared to cause, among
other effects, a marked diminution of the proportion of
fats in the milk solids. By-product feeding-stuffs simi-
larly deficient might cause a similar result.

442. Influence of food on the milk-fats——It should
not be inferred from the previous statements that none
of the compounds of the food enter the milk as such, or
that the qualities of the milk are in no way influenced
by the character of the ration. Such conclusions would
not be consistent with the outcome of numerous investiga-
tions. While it has become quite evident that the com-
position of butter, and therefore its qualities, such as
hardness and melting-point, are sometimes materially
modified by the cow’s food, it is not now possible to state

342 THE FEEDING OF ANIMALS

with any definiteness just what influence all the various
feeding-stuffs have upon the chemical and _ physical
properties of butter. LExperimenters are fairly unani-
mous, however, in concluding that the liberal feeding
with cottonseed or cottonseed meal has the effect of
raising the melting-point of butter and of diminishing
the percentage of the volatile fatty acids. On the other
hand, when gluten meal rich in oil has been introduced
into the ration in generous proportion, the butter has
been found to melt at a lower point, and appeared softer.
Certain chemical reactions indicate that this decrease in
the melting-point has been accompanied, in some cases at
least, by an increase in the butter of olein, a fat which is
a prominent constituent of olive oil, and is liquid at
ordinary temperatures. One set of experiments, where
gluten meal with different proportions of oil was used,
appears to warrant the conclusion that the softening of
the butter from feeding this material is not marked when
its percentage of fat is small, as is the case with some
brands of gluten meal at the present time. The conclu-
sion which has been reached as a result of some experi-
ments, that gluten meal causes softer butter than corn
meal, the fats and other compounds in the two feeds
being similar in kind, is wholly irrational unless we
conclude that the larger quantity of fat fed in the former
is the cause of its specific influence. In a few cases where
various oils were fed in liberal quantity the butter is
reported to have varied in ways corresponding to the
composition of the oils, a result not at all improbable.

In looking over the record of investigations along
this line it is found that food rich in sugar and other
soluble carbohydrates is credited with producing soft
butter, potatoes are charged with the same effect, and

MILK PRODUCTION 343

even cooked or sour foods are said to have a peculiar
influence. Some writers go so far as to present lists
of feeding-stuffs in the order in which they increase the
volatile fatty acids, but such definite representations must
at present be taken “with a grain of salt.” In most
instances, no relation is established between the effect
observed and the market value of the butter. In fact, it
is distinctly asserted by one or two experimenters that
there is no clear relation between the melting-point and
hardness. It seems quite probable that when the ration
includes a variety of grain foods, practically the entire
list of feeding-stuffs may be utilized under proper con-
ditions without damaging the market value of the butter
for local consumption.

443. Effect of food on the flavors of milk and its
products.—It is not possible with our present knowl-
edge to establish a relation between the flavors of dairy
products and the presence of definite compounds. What-
ever causes flavor in milk or butter is generally present
in such minute quantities that even if the nature of the
substance were known the determination of its amount
would be beyond the skill of the chemist. Milk satis-
factory to the critical taste and smell may be so simply
because bad flavors are absent, or there may be present
the positive influence of some constituent of the ration.
It is probably safe to assert that compounds in the food
pass into the milk as such, and the superiority of June
butter, if such exists, may be due to the almost impon-
derable volatile odors which are derived from the young
grasses. Nothing is more certain than that the dele-
terious odors of certain foods and those that pertain to
the stable are often absorbed by milk, as, for instance,
when cabbage, turnips, and onions are fed.

344 THE FEEDING OF ANIMALS

It is generally believed that odors or flavors from
the foods which affect milk in so marked a manner may
enter it in two ways, by transference through the animal
and by absorption from the air of the stable. Unfortu-
nately, however, the various views which are accepted
regarding this matter are not based upon satisfactory
experimental evidence. Some farmers declare in most
positive terms that they can feed turnips to their cows
with no harm to the quality of the butter, while others
assert that this cannot be done. It is claimed that the
time of feeding, whether just before or just after milk-
ing, has a marked influence upon the extent to which
turnips and similar materials impart a flavor to the milk.
Concerning all these points, we have but little evidence
other than the somewhat loose observations of practice.

The results of certain experiments are worthy of men-
tion in this connection. King and Farrington, of the Wis-
consin Experiment Station, declare that their experi-
ments show beyond question that when silage is fed
before cows are milked a sweetish flavor is imparted to
the milk, and that such a flavor is not detected when the
silage is fed after milking. These experimenters also
placed milk within a silo exposed to the air for an hour,
and silo air was forced through the contents of some cans.
In seven out of twenty tests no silage odor could be
detected, and it was less in any case than when silage was
fed before milking.

Canadian experiments on the effect of feeding tur-
nips seemed to warrant the conclusion that the mere
presence of a strong turnip flavor in the stable did not
affect the milk, and that when the turnips were fed in
small quantity (one peck) daily no flavor was imparted,
but that when one bushel or more was given the flavor

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MILK PRODUCTION 345

appeared whether the turnips were fed before milking
or after. On the other hand, in a Norwegian experi-
ment as high as 2.8 bushels of turnips were fed to cows
daily and no turnip taste could be detected in the milk.
The cows were fed in one place and milked in another,
and so the experimenter concluded that when this taste
is observed it is due to absorption by the milk after it is
drawn. That warm milk may absorb odors is shown by
Russell. These observations illustrate fairly the some-
what inconclusive state of the testimony on the points
in question.

CHAPTER XX
FEEDING GROWING ANIMALS

A piscussIon of rations for growing animals relates in
large part to the uses of food for constructive purposes.
The formation of bone and soft tissue proceeds rapidly
in the young organism, the nutrition of which must be
adapted in kind and quantity to large demands in this
direction. This is true of all young domestic animals.

444. The requirements for growth.—The actual daily
increase in live weight of a well-nourished calf may be as
great as that of a mature steer when liberally fed. It is
not unusual for the former to gain two pounds a day in
weight, and 1.5 pounds is less than would be satisfactory.
It is possible to calculate approximately what this growth
would require of actual dry matter. The only analysis
of a calf’s body which is available is that made by Lawes
and Gilbert, from which it appears that the entire animal
when fat has approximately the following composition:

Water Ash Protein Fat
Per cent Per cent Per cent Per cent
64.6 4.8 16.5 14.1

A gain of 1.5 to 2 pounds live weight means a storage of

not less than .24 to .33 pound of dry protein in the

animal’s body, and the laying on, when the animal is fed

for fattening, of .21 to .28 pound of actual fat. Here,

then, is an actual daily increase of dry body substance

of .45 to .61 pound, which may be equal to one-
(346)

{

FEEDING GROWING ANIMALS SAT

fifth or more of the total dry substance of the ration for
a very young animal.

445. Food freely appropriated by growing animal.—
More definite information is furnished by the somewhat
limited studies which have been made of the metabolism
of the calf. As long ago as 1878 Soxhlet studied the
income and outgo of three young calves fed on whole
milk. One pound of milk solids, practically all digesti-
ble, produced one pound increase of live weight, which
was equivalent to a storage of at least one-third pound
of body dry substance, a food efficiency for growth prac-
tically ten times that exhibited with animals somewhat
mature. Nearly 70 per cent of the protein of the food
was fixed in the bodies of these calves and only a small
proportion was broken down, conditions quite the reverse
of those which pertain to the use of food by well-grown
steers. Seventy-two per cent of the phosphoric acid and
97 per cent of the lime were retained for the purposes of
growth. Later experiments with calves fed on rations in
whole or in part composed of skim-milk, show a deposit
of from 26 to 43 per cent of the protein. These results
ilustrate the vigor with which a young animal assimi-
lates food for growth. The facts show the necessity of
feeding young animals on liberal quantities of constructive
materials, viz., the proteins and ash ingredients.

446. Influence of kind of food on the kind of growth.—
During recent years there has been much discussion
and many experiments touching the influence of food
upon the development of the animal body. Several
experimenters, notably Sanborn and Henry, in this
country, have compared the growth of swine on rations
presenting extreme differences, as, for instance, mid-
dlings and blood against corn meal alone, or shorts and

348 THE FEEDING OF ANIMALS

bran against potatoes, tallow, and corn meal. As would
be expected, the development of the two lots of pigs was
in these cases greatly unlike. Those fed on the nitrog-
enous rations contained more blood than the other;
their organs, such as the kidneys and liver, were much
larger in proportion to the weight of the body, the bones
were stronger, and the proportion of muscle in the car-
cass was much greater. The differences were very marked.
It should not be forgotten, however, that these were
extreme and somewhat unusual rations. It is doubtful
whether there are generally sufficient differences in the
food combinations of ordinary practice to occasion such
marked differences of body structure.

At the Cornell University Experiment Station lambs
fed on oil meal and bran made a much more satisfae-
tory gain than did those the grain ration of which was
corn meal alone, but the photographs of the carcasses do
not show a larger proportionate growth of muscular tissue
from the nitrogenous foods.

An elaborate study of the influence of the ration
upon the composition of the carcass was made at the
Maine Experiment Station, where two lots of steers
were fed from calfhood on rations widely unlike in their
- nutritive ratio. The hay fed was the same for both lots.
The grain food of one lot was oil meal, wheat bran, and
corn meal, and of the other lot corn meal, mixed with a
minimum proportion of wheat bran, the nutritive ratios
being respectively 1: 5.2 and 1: 9.7. One animal from each
lot was killed at the end of seventeen months of feeding
and the others at the end of twenty-seven months, the
entire bodies of the four steers, exclusive of the skins,
being analyzed. It was found that the composition of
the animals did not differ materially. (See Table LX XV.)

FEEDING GROWING ANIMALS 349

TABLE LXXV. PERCENTAGE COMPOSITION OF ToTAL DRESSED
CARCASSES OF THE STEERS

In water-free

: In fresh substance atedetace
f ee | ae
4 ~ o o Oo
; = 5 Ay & | < a & | <
; Per | Per | Per | Per | Per | Per | Per
Protein, rich food— cent | cent | cent | cent | cent | cent | cent
Steer WOsl: . . :. aa 17 | 59.02) 17.89] 18.53] 4.56] 43.66] 45.23] 11.11
MGeNO: 2... . «ee 27 =| 51.91] 16.93} 25.86} 5.30) 35.20) 53.78] 11.02

Protein, poor food—
eer NO:o. «= . oe
peer No. 4... = 2) eee

27 =| 52.16) 17.10] 25.32] 5.42) 35.75) 52.90] 11.35
17 | 56.30] 17.82) 20.27] 5.61] 40.77| 46.39) 12.84

‘The amount of growth was at first more rapid with
the more nitrogenous ration, but the kind of growth
appeared to have been controlled by the somewhat fixed
constitutional habits of the breed. Nevertheless, the
evidence of all well-conducted experiments and of all
experience is unanimous in emphasizing the necessity of
supplying in the food of young animals an abundance of
those nutrients which are needed for the building of
bone and muscle. A satisfactory development of the
organism at maturity is insured only when the early
growth is liberal and uniform, and is such as to produce
strong bone and a vigorous muscular system. More
than this, there is induced by proper nourishment a
lively temperament of energy of body, which chemical
analysis cannot search out or measure, but which gives
the chief value to certain classes of animals and is desira-
ble in all. It is believed that this condition of strong
vitality is promoted by a liberal supply of the proteins
in the food.

447. Estimated energy requirements for one pound
of gain in weight by growing cattle and sheep.—Armsby

350 THE FEEDING OF ANIMALS

has made estimates of the requirements for each pound of
growth of cattle and sheep at different ages, for which he
does not claim any high degree of accuracy.*

TABLE LXXVI
Age Energy value

Months | Therms

SRR 1.5

Ge ie ene nk, 1 Ta
gee ey SENG, oa 2.
Da IE Sah Ne 2.5
eo A Si Zeta
Sato le Wh) ee 3.

_ This would indicate that for an animal of the age of
three months a pound of growth would require an addi-
tion to the ration of two and one-fourth pounds of oats,
and at the age of thirty months four and one-half pounds.

The same author gives estimated requirements a
day and head for growing cattle, these to include the
maintenance requirement :*

TaBLe LXXVII
Li Di ibl E
Age 2
Months Pounds Pounds Therms
St mee). 275 ten 5.
ee 425 1s 6.
TRO ch ewee s 650 1.65 te
Pee ed fc ALN. 850 Le. co
DS) ee ne 1,000 1.75 8.
Se ke RE IG 1,100 1.65 8.

In order to give concrete expression to the standard
that applies to a growing animal one year old, weighing
650 pounds, there has been calculated the necessary ration:

* Based on true protein and production values.

Pounds
ey. eee, ee, se 10
Wee olddlings fare, |. Bee... . 3
Eee Meal. Woe. “ae ww 2

448, Milk for young animals.—In considering the
feeding of very young animals, we recognize the mother’s
milk as in general supplying the necessary nutrients in
the best forms and proportions. It is true in the case of
cows that the very rich milk of the butter breeds, when
generously fed, often causes a serious disturbance of the ©
calf’s digestive organs, but the fact remains that casein,
milk-fat, and milk-sugar are adapted through Nature’s
design to the digestive processes and the nutrition of
young animals. Moreover, milk is rich in the mineral
compounds needed for bone formation. When, there-
fore, it becomes necessary or desirable to substitute other
food for the mother’s milk, it is essential not to act
counter to physiological necessities and conditions.

One fact of importance is that the very young ani-
mal is somewhat undeveloped in its capacity to digest
the starchy grains and similar substances, the secre-
tions necessary for this purpose not yet being abundant.
It follows, then, that the first substitute for whole milk
should not consist largely of the insoluble carbohydrates.
Again, the young animal’s stomach is at first unfitted for
receiving and utilizing bulky, fibrous food. Some time
must elapse before the calf or colt can secure much
nourishment from grass, hay, or like materials.

THE FEEDING OF CALVES

449. Skimmed milk as a substitute for whole milk
in feeding calves.—The most successful way of feeding

352 THE FEEDING OF ANIMALS

calves to secure rapid growth, especially to produce veal
of the highest quality, is to supply them with whole milk
up to the limit of their capacity when this can be done with
safety. Where they are to be raised for stock purposes,
satisfactory growth may be maintained with the use of
substitutes for whole milk, which is fortunate, because
with the exception of the western plains, where cows are
cheaply kept simply for breeding purposes, or where a
breeder is selling his increase at fancy prices, the feeding
of whole milk is not warranted by the value of the result-
ing animal.

For this reason most dairymen, particularly those
who sell milk as such, kill the calves at the age of a few
days, excepting, perhaps, during that portion of the year
when veal sells at a very high price. On the other hand,
many dairymen who have a supply of skimmed milk
successfully feed this to growing calves, when it is desired
to raise heifers or even steers. Experience has shown
that it is entirely practical to do this, and it is certainly
economical, for experiments have demonstrated that, as
prices average, the cost of a pound of growth so produced.
is at least not over one-third what it would be if whole
milk were fed.

As a guide in providing a substitute for whole milk,
it may be stated that a vigorous calf should very early
be made to eat daily not less than three pounds of highly
digestible matter with a nutritive ratio at first not wider
than that of whole milk solids. The exclusive feeding of
skimmed milk for any length of time is not to be recom-
mended. Experience shows that for young calves it
should be so combined with other materials that a mix-
ture is obtained which, so far as possible, resembles
whole milk in its nutritive ratio. After the fat is removed

FEEDING GROWING ANIMALS 353

from the milk, the non-nitrogenous compounds are
probably not present in sufficient proportion to protect
the protein from waste as fuel. No feeding-stuff appears
to be a more efficient amendment of skimmed milk for
the earliest feeding than flaxseed meal cooked into a
porridge. The explanation of this is the high percentage
of oil in this meal, its low content of starch, and its high
rate of digestibility. Besides, it appears to promote a
healthy condition of the organs of digestion. Oil meal
may be used in its stead, but it is less desirable at first.

The calf should be allowed whole milk for a few
days, not necessarily more than a week, when it may
be gradually changed over to skimmed milk and flax-
seed meal. An admirable mixture is prepared by cook-
ing the flaxseed meal in water in the proportion of one
to six by volume, and adding a small amount of this
(the equivalent of three or four tablespoonfuls of the
dry meal at first) to eighteen or twenty pounds of warm
skimmed milk, which may serve as a day’s ration. The
quantity of meal should be gradually increased up to one
pound a day inside of a few weeks. In six or eight weeks
the calf should be allowed access to dry oatmeal, or oat-
meal and wheat middlings, or the oatmeal and middlings
may be boiled with the flaxseed meal and mixed with the
milk. After ninety days the flaxseed meal may be dropped
for the sake of economy. The calf will soon appreciate
a wisp of early cut hay, some coarse food becoming
a necessity before many months pass. This method
of feeding has repeatedly produced rapid growth and
fine animals. For heifers it is probably to be preferred
to whole-milk feeding, as it is fully as conducive to the
vigorous development of the muscular system and is less
likely, perhaps, to promote a tendency to lay on body fat.

Ww

354 THE FEEDING OF ANIMALS

450. Calf rations without milk products.—An exam-
ination of the results of much experimental work shows
very clearly that strong, healthy calves can be raised
without skimmed milk or even milk of any kind after a
brief period, although the rate of gain may not be so
rapid as when whole milk or skimmed milk is available
for at least part of the ration. In these experiments,
where careful records have been made, mixtures of oat-
meal and other cereal products with linseed meal, thor-
oughly cooked, may be used to produce satisfactory
growth, even if growth is not so rapid as with milk prod-
ucts. This appears to be no disadvantage in the subse-
quent development of the animal. Even if skimmed
milk is available, cereal products and the oil-meal prod-
ucts make desirable amendments to the milk.

The Dairy Division of the United States Department
of Agriculture, in experiments with twenty-two animals,
has showed that calves make as rapid gain upon sour
skimmed milk as upon sweet skimmed milk, other experi-
ments indicating that whey may be used as a substitute for
skimmed milk, provided proper foods are combined with it.

Hay tea is sometimes used as a milk substitute, but
it is a poor one. Only a small proportion of the nutrients
of hay is soluble, and the water-extract is a dilute and
comparatively innutritious food for a growing animal,
the use of which can be justified only in the absence of
milk in any form, and which, when used, must be very
liberally fortified by grain feeds.

THE FEEDING OF LAMBS

451. Feeding ewes with lamb.—The first growth of
lambs is chiefly from the mother’s milk and we have little

FEEDING GROWING ANIMALS i 358

occasion to consider substitutes for this food. The fact
first in order and most important in this connection is
that well-fed mothers are absolutely essential to rapid —
growth. A lamb must be fed through its dam. Nothing
is more pitiable than the sight of a pair of hungry twin
lambs making an effort to satisfy their insistent demands
for growth with the milk furnished by a small, lean,
under-fed mother. The treatment of the ewe before
the birth of her young should be such as to prepare her
for the strain of supplying a generous flow of milk.

Ewes that are suckling lambs, while fed from the barn,
should be supplied with good clover or alfalfa hay, or hay
from fine mixed grasses. Pea and bean straws are excel-
lent coarse feeds for sheep. Timothy hay is an abomina-
tion as sheep food, especially under .these conditions.
The grain ration should not be less than three-fourths
of a pound daily, made up in part of one or more of the
highly nitrogenous feeding-stuffs. It is also desirable to
feed a small proportion of some succulent food. What is
needed is a milk-producing ration, and the discussion of
feeding cows for milk production in a preceding chapter
is in part pertinent to ewes. Corn, oats, wheat bran or
middlings, beans, peas, gluten and oil meals are all useful
in making up such a ration. With safe feeding, one pound
daily of a mixture of oil or gluten meal one part, wheat
bran two parts, and corn meal two parts, combined with
two or three pounds of roots or silage and what coarse
feed the appetitite will bear, is a good milk ration, and
will bring the ewes through the strain of suckling lambs
in good condition.

452. Grain foods accessible to lambs.—If it is desired
to produce the most rapid growth of the lambs, they
should also have access from nearly the first to a grain

356 THE FEEDING OF ANIMALS

mixture. Experiments indicate that this mixture is most
economical, especially if the lambs are to be fed later for
the market, when containing a generous proportion of
corn meal, to which may be added, among other mate-
rials, ground oats, wheat bran, gluten feed or meal, or oil
meal, reference being had to the ruling market prices.
In an experiment at the Maine Experiment Station,
lambs suckled by grain-fed mothers and with access to
grain themselves made 75 per cent or more gain in live
weight than those did that received no grain and which
were suckled by mothers that ate a limited grain ration.
Five and three-fourths pounds of grain produced one
pound of growth. At the Wisconsin Experiment Station,
as an average of three trials, lambs fed grain before wean-
Ing gained in ten to twelve weeks seven and a half
pounds more each than those not so fed. Four pounds
of grain produced one pound of live weight.

Liberal feeding means more economical growth, a
higher quality of product, and the earliest possible mar-
ket. The foregoing discussion is applicable to the rais-
ing of early lambs. If, however, they are dropped dur-
ing the grazing season where the ewes have abundant
pasturage, the question of feeding is simplified, for no
ration is more promotive of abundant milk secretion
than young grass; besides, the low price at which late
lambs are usually sold does not encourage extensive grain
feeding. When lambs are grown for breeding stock their
early grain rations should be lighter, and may properly
consist more largely of oats and bran, with a smaller
proportion of corn.

453. Standards for growing sheep.—For growing
sheep beyond the age of six months, Armsby has offered the,
following standards, based on Kellner’s production values:

FEEDING GROWING ANIMALS oor

Taste LXXVIII. EstimaTED REQUIREMENTS PER Day AND
HEAD FOR GROWING SHEEP

se tive ween] Paseo

Months Pounds Pounds Therms
- to ae . ee 70 30 1.30
aoe.” . . . ee 5 he 90 20 1.40
. <i eae 110 20 1.40
aa _. oe 130 ze 1.50
_. re ee so We hk 145 ae 1.60

Expressed in terms of an actual ration a bunch of ten
growing lambs nine months old would require on the
basis of the foregoing standard the following quantities:

RaTION FOR TEN Lamps, 900 Potnps. Ace Ning Montus

Pounds
ree Emer dy gS AT Ah Os See gna 20
TUCUTLE GSES pac Dees toe a hina av re 20
RRM eE At) Bok Rey PIRSA. ore te Ss ge SS 4
aPC RL gyal ce a tare al ts Ee alee a me lie 234

FEEDING COLTS

454. Food as related to quality of the horse.—The
value of a horse for either draft or road purposes is greatly
dependent upon those physical qualities which secure
vigor and endurance. A horse is not regarded as desira-
ble that is devoid of “nerve” and that cannot sustain,
if necessary, the strain of hard, or even severe, work;
and breeders seek to produce animals having these char-
acteristics. wo main factors are involved in the proper
physical development of the colt: food and exercise. The
latter is a part of the general management to which the
horse-breeder must give detailed attention and will not
be discussed in this connection. The technics with which

358 THE FEEDING OF ANIMALS

the horseman should be familiar must be learned through
experience and by consulting special literature.

It is proper to state that our knowledge concerning
the feeding of colts consists largely of the conclusions
derived from experience of practical men. Very little
experimental attention has been given to this subject
by investigators. During the years that experiment
stations have existed in the United States few stations
have reported experiments along this line, and these were
not extensive; but notwithstanding the lack of direct
data from scientific sources there are well-proven and
safe facts to which we can refer.

455. Feeding the colt through the dam.—The proper ~
feeding of the young foal is accomplished first through
the proper feeding of the dam. The mare with a colt at
her side should be regarded as a milch animal, making
demands upon the food for generous milk production
similar to those made by the milch cow. This is equiva-
lent to the statement that when suckling her foal the dam
should be given foods that stimulate milk secretion. If
she is allowed the run of a good pasture, both mother and
colt will usually thrive satisfactorily. Young pasture
grass is as efficient with the mare as with the cow. If, on
the other hand, the feeding is from the stable, either
wholly or to amend an insufficient or inferior food-supply
from grazing, then the grain ration should be made to
include such feeding-stuffs as barley, oats, wheat, wheat
bran, wheat middlings, peas, and even a small propor-
tion of linseed meal. Whenever soiling-crops are grown
these may be fed, especially alfalfa. In case the legume
fodders are available, either green or dried, the necessity
for protein in the grain is not so great and corn may
form a larger proportion of the ration.

FEEDING GROWING ANIMALS 359

A good grain mixture for ordinary conditions would
be cracked corn two parts, wheat bran seven parts, and
linseed meal one part; or ground oats four parts, wheat
middlings five parts, and linseed meal one part.

456. Rations for the colt before weaning.—Before the
colt is weaned, with good management, he will learn to
eat grain which is very likely to be the same mixture as
that eaten by the dam. If desired, an enclosure may be
built, into which the colt and not the mother can pass,
where a special grain food may be provided. This brings
us to the consideration of what shall be the grain ration
of the colt, both before and after weaning.

457. Oats as horse feed.—The opinion is generally
held that oats are superior to all other feeding-stuffs as
horse food, particularly for the development of those
qualities of temperament and muscle which are regarded
as so desirable, especially in a carriage horse. Oats are
usually comparatively costly, but it is claimed that the
superior results, whether in the kind of development of
the colt or in the quality of service of the mature animal,
justify their use. In this particular case, as in others,
certain statements are currently accepted as facts which
have no well-established basis.

Reference is frequently made to the tonic effect of
oats, and there has existed a popular notion that this
grain contains a peculiar compound which acts as a nerve
stimulant and imparts “life” to the horse.

It was announced in 1883 that Sanson had discovered
in oats a characteristic alkaloid having a stimulating
effect upon the motor nerves of the horse, but subse-
quent elaborate investigations by Wrampelmyer failed to
verify Sanson’s conclusions. Notwithstanding the fact
that the oat kernel has been the subject of very care-

360 THE FEEDING OF ANIMALS

ful chemical studies, it is not found that it contains any
compounds so characteristically unlike those of other
grains as to account for an unusual influence upon the
nervous system, or for a superior development of the
muscles.

It may be suggested that the “life,” or nervous con-
dition, of a horse is a resultant of several factors or
influences. These are the quantity of digestible food sup-
plied, the proportion of protein in the ration, the con-
dition of the digestive tract, care, exercise, and all the
many small influences which affect health. In those
instances where feeding oats has seemed to improve the
performance of the horse, even if this has actually
occurred, we have no assurance that in changing the
ration the amount and proportions of the nutrients
digested have remained the same. It seems entirely
probable that if thorough comparison could be made
between oats and the best grain mixtures which could
be suggested in the light of present knowledge, the oats
would not maintain so great a superiority over other
feeds for growing colts as is now generally attributed to
them. Experiments which have been made indicate that
for producing rapid growth oats were inferior to either a
mixture of peas and middlings, or to a mixture of mid-
dlings, gluten meal, and linseed meal; but these obser-
vations were not carried far enough to determine the
relative effect upon the quality of the animal.

458. Rations for growing colts.——Doubtless all neces-
sary conditions for producing growth and quality in colts
can be met by a ration of which oats form a part. The
following grain mixtures are suggested as illustrative of
good ones:

FEEDING GROWING ANIMALS . 361

Mizture 1 Mizxture 2
Parts Parts
a. Se 4 Coma... . Lee a
Bran or middlings 4 Onan... =e 4
a Aes: 2 Braties:,. . .--" ae 3
Oieeel a. .:. . ae Me

These mixtures are generally less expensive than oats
alone, and in kind fully meet the demands for growth
of both bone and muscle.

Henry gives as a fair allowance of grain for a colt,
measured in oats, the following quantities: Up to one
year of age, two to three pounds; from one to two years,
four to five pounds; from two to three years, seven to
eight pounds. In using the other grain feeds suggested,
which mostly have a higher rate of digestibility than oats,
no larger quantities would be necessary. Skim-milk may
be fed to colts in limited amounts with good results, as
experiments show. Feeding it in quantities sufficient to
force very rapid growth is not wise.

It is generally conceded that the colt should be allowed
to eat a reasonable proportion of coarse feed as a means of
properly developing the digestive tract. It is entirely pos-
sible to supply concentrated grains too freely, to the
exclusion of more bulky materials, and in that way fail
to secure a desirable distension of the alimentary canal.
This does not mean that the colt should be allowed to
gorge himself with hay or other coarse material, as an
unfortunate extreme in this direction is easily reached.

CHAPTER XXI

FEEDING ANIMALS FOR THE PRODUCTION OF
MEAT

Tue production of beef was at one time a source
of income to nearly all farms. In earlier days the New
England farmer annually sent to the market a few fat
steers or oxen. The beef consumed in the United States
and that exported now comes very largely from the wide
grazing areas of the West, where the cost of feed and the
necessary amount of labor are at a minimum. The
reasons for this change are not hard to find. The food
cost of beef-making is relatively large as compared with
dairy products, and in the East the growth of home
markets for milk and cream has made it possible for
farmers to turn their high-cost feeding-stuff into prod-
ucts having a higher proportionate market price than
beef. Moreover, certain eastern lands have, with enlarg-
ing markets, been occupied to good advantage with fruit
and vegetables. The time has come, now that the wide
areas of the West are more densely peopled, when beef
production is receiving more attention in the eastern
states. Some eastern farmers appear now to find it profita-
ble. It is certain that it involves good judgment, skill,
and the art of feeding to the highest degree, especially if
fair returns are to be secured. The breeding or selection
of animals of the most profitable type that will supply
the market with a high-grade product, and stable feed-
ing, so as to produce rapid and continuous increase,

(362)

FEEDING FOR MEAT 363

requires experience and an intelligent application of all
the factors involved.

BEEF PRODUCTION

459. Nature of the growth with beef production.—
Feeding steers or oxen for the market may be carried
on with young animals that are still making some growth
of bone and muscle, or with those so mature that addi-
tional weight comes almost wholly from a deposition of
fat in the tissues already formed. This is the difference
between feeding a two-year-old and a five-year-old steer.
In either case the predominating constituent of the
increase is fat. This fact is established by the investi-
gation of Lawes and Gilbert and by one experiment in
this country. Gilbert, in his lectures summarizing the
Rothamsted work, gave the following figures:

TaBLE LXXIX. Composition oF INCREASE WHEN STEERS ARE
FATTENING

Water | Ash /|Protein| Fat

Percent} Percent} Per cent! Percent

Oxen fattened very young ...... 32-37| 2144 | 10 50-55
Matured animals, final period . . . . | 25-30} 114% | 7-8 | 60-65

American results with well-fed steers,
growth from 17 months to 27 months
Ti, TE SSP AINE a ueatieren yet Dis aml Pros vapen se 42.4 | 6. 14.1} 37.5

These figures may be regarded as reliable, and they
show most conclusively that in beef production the
constructive use of the food is largely in the direction
of fat-forming.

460. Rate of increase of fattening animals.—The
extent of the aetual production which occurs can be

-

364 THE FEEDING OF ANIMALS

closely estimated for any given case. It is considered
satisfactory if the rate of increase during a reasonably |
long period of fattening is 2 pounds live weight a day.
This means the actual addition to the dry substance of
the body of from 1.3 to 1.5 pounds. Sometimes during
short periods with excessive feeding the daily gain may
be 3 pounds live weight, and generally after animals are
well fattened, during the finishing period, it may be as
low as 1 pound or less. The actual daily growth of new
material may vary then, aside from the water, from .6 to
2.25 pounds a day. Actual fat formation may thus
range from .4 to 1.8 pounds a day. The protein-con-
-tent of the increase, on the other hand, probably does
not exceed .3 pound daily in any instance, and with
mature animals it is very insignificant.

461. The food needs of the fattening steer—In view
of the foregoing facts and of the conclusion as to the fat-
forming function of carbohydrates, it is clear that the
non-protein part of the ration may be the source of the
chief part of the body substance laid on by a fattening
steer. The amount of protein necessary for constructive
work seems to be very small—with mature animals it is
practically nothing. It would seem, then, looking at the
matter merely from the standpoint of the demands for
growth, that in feeding fairly mature animals for beef
production a ration may be efficient with a wide nutritive
ratio, much wider than was recommended in the Ger-
man standards.

It is recognized, though, that we cannot decide upon
a ration merely upon the basis of the raw materials that
are needed for constructive purposes. The influence of a
particular feed or of a variety of feeds on the appetite
and on what we speak of as general condition, as

FEEDING FOR MEAT 365

well as upon the quality of the product, and the necessity
of avoiding so large a preponderance of carbohydrates
as to cause a possible depression of digestibility, are all
points which must be considered in determining the value
of a ration. We should remember, also, that the stimulat-
ing effect of the food upon the vital functions is a factor
in successful feeding. So, after all, we must appeal tc
experience, scientific and practical, for information as to
what rations are efficient for fattening purposes.

The German standard rations for fattening bovines
which were recommended called for 18 to 18.4 pounds of
digestible organic matter daily for each 1,000 pounds of
live weight, with a ratio of 1: 5.4 to 1: 6.5, requiring from
2.5 to 3 pounds of a digestible protein. In view of more
recent scientific conclusions concerning the functions of
nutrients, it is not easy to understand why a fattening
steer requires more protein than a milch cow or even
as much.

462. Scientific experiments with fattening animals.—
Feeding experiments with fattening oxen, conducted
under the improved methods of research, give results
not inconsistent with the facts to which attention has
been called. Kellner made a large number of experi-
ments with fattening animals by the aid of the respiration
apparatus, and he concluded that the nutritive ratio of
a fattening-ration may vary from 1:4 to 1:10 without
affecting the increase of body substance from a unit of
digestible food material, provided, however, that the
nutrients supplied above maintenance needs shall come
from the more easily digestible feeding-stuffs. He cites,
in the support of his conclusion, the outcome of nineteen
previous experiments by Wolff, in which rations varying
in nutritive ratio from 1:4 to 1:9.5 showed no material

366 THE FEEDING OF ANIMALS

differences in the efficiency of a unit of digestible matter.
It seems to be agreed that a wide nutritive ratio is not
inconsistent with most successful feeding of fattening
steers, especially those that are mature. If the animals
are so young as to be making material growth, there is
more reason for avoiding a very wide ratio.

463. Practical feeding experiments in fattening ani-
mals.—Among the practical feeding experiments con-
ducted in the United States, there are several instances
where the wide-ratio rations have been found equal to
the more nitrogenous. On the other hand, and perhaps
in a majority of experiments, the rations containing the
largest proportion of protein have caused the most rapid
growth. In 1893 the writer made a careful study of many
previous experiments and found that the addition of some
highly nitrogenous feeding-stuff to corn meal, or other
home-raised grain, in most instances increased the pro-
ductive value of the ration. This fact stands in apparent
conflict with the more scientific conclusions to which
reference has been made. The probable explanation of
this discrepancy is that the rations richest in protein
have generally contained the greater variety of feeding-
stuffs, have been more palatable, more stimulating to
the appetite, and, in general, have caused a more vigorous
exercise of the animal’s functions. The proportion of
protein has probably been a minor factor. If as great a
variety of as palatable and as easily digestible materials
can be fed without the use of highly nitrogenous feeding-
stuffs as with them, the result will doubtless be just as
favorable. This means that a mixture of home-raised
grains may form as efficient a ration for fairly mature
fattening steers as when the oil meals or gluten meals
are introduced. Palatableness, variety, and ease of

FEEDING FOR MEAT 367

digestion are the main points to be secured, and these
factors have been somewhat overshadowed by the effort

- to secure merely a definite nutritive ratio.

It need not be feared that when mixed cereal grains
are fed as the major part of the ration, there will be
a materially lower rate of digestibility than when a
protein food is introduced. There is still something to
be said, however, in favor of adding to a fattening-ration
a small proportion of an oil meal, or of some material
of similar character, for palatableness is thus promoted,
and observations show, in many instances, that an
appearance of greater thrift and vigor is thus induced,
which is perhaps due to the stimulating effect of the
greater amount of circulatory protein upon the metabolic
processes of the animal. With young steers making some
growth of bone and muscle, a small quantity of a protein
food is of unquestioned advantage.

464. German fattening for bovines’ ration excessive.—
The German standard for fattening cattle is open to
criticism as to the quantity of nutrients recommended
for 1,000 pounds of live weight. In order to supply 18.4
pounds of digestible organic matter it would be neces-
sary to feed, for instance, 8 pounds of hay and 21.5 pounds
of an ordinary mixture of corn meal, bran, and oil meal.
While it may be possible to induce young steers weigh-
ing from 600 to 800 pounds to eat at this rate for a short
time, so large a ration is seldom, if ever, so profitable as
a smaller one, even if it could be fed with safety. If an
attempt were made, however, to apply this formula to
mature steers weighing from 1,300 to 1,500 pounds the
situation would become absurd, because the ration would
then be from 10.5 to 12 pounds of hay and from 25 to 32
pounds of mixed grains for a single animal. An appeal

368 THE FEEDING OF ANIMALS

to concrete examples of steer-feeding will clearly show
the excessive requirements of the German standard for

-
. f a
Le

fattening cattle. In 1891 to 1893 the Kansas Agricul-

tural Experiment Station conducted feeding experiments
with three-year-old steers, and as these are good exam-
ples of practical management, the data from them will
serve to illustrate the point under discussion. These
data are stated in a tabular form:

TABLE LXXX
First Second
experiment experiment
Number of animals » 3 la 3) 1c joy ee 5
Davyetedeeee ces. :\ {eee Verne ae 182 129
Pounds Pounds
Weight per animal, averagefor period. ....... .. 1,412 1,237
ele SPAT AGES 2 5 ee NL 7.8 6.7
SCAMMER DCHSCI GAY yes he aye ta ticles Gil se es 23.9 Zee
Weanlysostin peranimals, < e005 i 2. RP) ew ks se oy en ena 2.39 2.4
Digestible organic matter daily per animal : cial 19.5 19.
Digestible organic matter per 1,000 pounds live weight . ; 13.8 15.3

In 1895-1896 the Iowa Agricultural College fed steer
calves for fourteen months, during ten of which a record
was kept of all the food consumed. During the second
period the steers were fattened for market. This particu-
lar experiment is cited because the animals were young
and all the conditions were favorable to the maximum
consumption of food in proportion to live weight:

TaBLE LXXXI

First Second

period period
Numberof/animals «> . (eee + alee 5 5
Days feds S50 3h Re... ee 120 181
Age of steers at beginning ee . . 9tol10mos. 16 to 17 mos,

Pounds Pounds

Weight per animal, average for period . ee, 766 1,197
Coarse food eaten daily (partly roots and green fodder ) 11 12.8
Grain eaten daily (partly snapped corn) ..... 9 19.5
Daily cai persanimal . ... .” Skee a 2.04 211
Gain per 1,000 pounds live weight aes = 2.66 1.76
Digestible organic matter daily per animal . 10. 14.1

Digestible organic matter daily per 1,000 pounds live
weight. (me =. . TT te a 13. 11.8

FEEDING FOR MEAT 369

The largest amount of digestible nutrients fed daily
to each animal at any time during this experiment was
about 17.5 pounds, after the animals had reached an
average weight of 1,200 pounds or over. This would be
approximately 14.5 pounds digestible organic matter
for each 1,000 pounds live weight.

These two experiments are instances of successful
feeding where the increase was rapid and very satis-
factory and where the quantity of digestible nutrients
supplied daily was greatly below 18 pounds for each 1,000
pounds live weight.

It is concluded, from observation and a study of the
results of experiments, that under proper conditions 8
to 10 pounds of dry coarse food and 15 to 18 pounds of
grain is all that can generally be fed with greatest profit
to a steer actually weighing 1,000 pounds, and may be
even more than is utilized by the animal to the best
advantage. Such a ration would supply about 16 pounds
of digestible organic matter. If considerably smaller
steers are fed, the ratio of food to weight may be increased,
but if the animals are several hundred pounds heavier
the ratio may be materially diminished. It is safe to
accept as a general principle the rule that the larger the
animal the less the proportion of food to weight. The
fixing of the quantity of a fattening-ration directly in
proportion to the size of the animal is a simple and quite
convenient rule, but is utterly impracticable and is so
recognized at present in the standards for growing ani-
mals, and should be in all estimates and proportions.

465. The selection of a fattening-ration—T'wo con-
ditions already mentioned that are of the highest impor-
tance should not be forgotten, viz., that the ration should
be palatable and be composed of a variety of easily diges-

x

370 THE FEEDING OF ANIMALS

tible materials. Rough fodder in any quantity is not
adapted to fattening bovines. With this exception, the
whole list of high-class cattle foods may be regarded as
available, and the selection will properly depend largely
upon prices and the local supply. In the northern states,
hays from the fine grasses and the legumes, silage, roots,
cereal grain mixtures, and such by-product feeding-stuffs
as offer digestible nutrients at the least cost will all
appeal to the experienced feeder. In the South, cotton-
seed by-products may, with economy, enter largely into
the ration. In the West, the fodders peculiar to that
region will be utilized, corn being the chief, and some-
times the only, grain that can be fed with economy.

466. Suggested rations for fattening steers.—The
following may be regarded as good types of mixtures
for the full feeding of fattening steers weighing approxi-
mately 1,000 pounds each at the beginning of the feed-
ing period. They will supply about 16 pounds of digesti-
ble organic matter if their components are of average
quality and composition:

5 lbs. clover hay. 5 Ibs. clover hay.
1 16 lbs. corn silage. 5 50 lbs. beet pulp.
13 lbs. corn meal. 11 Ibs. corn meal.
3 lbs. wheat bran. 2 Ibs. cottonseed meal.
10 lbs. corn stover. 8 lbs. corn stover.
9 20 lbs. mangels. 04 125 Ibs. corn meal.
14.5 lbs. corn meal. 20 Ibs. brewers’ grains, wet.
2 lbs. cottonseed meal.

2 Ibs. oat straw.
7 75 lbs. beet pulp.
3 lbs. wheat bran. 10 Ibs. beet molasses.
2 lbs. oil meal or gluten feed. 4 lbs. gluten meal.
8 lbs. alfalfa hay. 5 Ibs. alfalfa hay.
44 12 lbs. corn meal. 8 3 lbs. corn stover.

5 lbs. ground oats. 11 lbs. corn meal.

6 lbs. ground barley.

8 lbs. mixed hay.
12.5 lbs. corn meal.

FEEDING FOR MEAT 371

The above rations are well up to the quantity limit
for the profitable feeding of animals weighing approxi-
mately 1,000 pounds. They are simply illustrative, how-
ever, both in kind and in quantity. Many mixtures
equally efficient may be used, and the quantity of the
ration must vary not only with the age and size of the
animal but with individuals, according to appetite
and capacity. Any feeder of experience will understand,
of course, that such rations will be eaten with safety to |
the animal only after a period of preliminary feeding,
during which there has been a gradual increase in the
quantity of food offered.

MUTTON PRODUCTION

_ Attention has been called to the fact that beef pro-
duction in the United States has gravitated to the ex-
treme West. This is also true of the production of mutton
though not to the same extent. Flocks of sheep are still
kept on many farms of the eastern and middle West
states, and the growth of early lambs and the fattening
of maturer animals to supply the demands of the local
markets is found to be most profitable by those farmers
who possess the knowledge and skill requisite for this
branch of stock husbandry.

467. Place of sheep on the farm.—Sheep occupy @
peculiar place on the farm in that they will accommodate
themselves to pasturage that is not adapted to cows and
horses, and will utilize some kinds of rough fodder not
readily eaten by other farm animals without submitting
it to somewhat expensive methods of preparation. If it
were not for the discouragement which sheep husbandry
has received from the depredations of dogs, sometimes

Jie THE FEEDING OF ANIMALS

real and sometimes greatly overestimated or even
imagined, the production of wool and mutton would
greatly increase on the hill farms of this country, with
undoubted profit to eastern agriculture, especially where
soil fertility needs strengthening in every possible
way.

468. The nature and extent of the growth in fatten-
ing sheep.—The character of the animal that is fattened
for mutton varies within wider extremes than in steer-
feeding. This is due chiefly to the greater range In ma-
turity of the former, from the two months’ lamb to the
mature wether. There are corresponding differences in
the nature of the increase while fattening, according as
the animal is young and making growth of all parts of the
body, or is simply storing fat in the mature organism.
The character of the body substance stored, probably, is
also influenced by the stage in the fattening period,
whether at the beginning when the animal is thin or near
the end when a fat sheep is becoming fatter. The only
definite data which can be presented relative to the com-
position of the increase of fattening sheep are based upon
the analyses by Lawes and Gilbert of animals in various
states of fatness. These investigators analyzed a “‘store”’
sheep, a “fat” sheep, and a “‘very fat’? sheep, and from
the figures thus obtained is calculated the increase in two
stages of fattening:

TapBLE LX XXII. Composition oF INCREASE OF FATTENING SHEEP

Dry
substance Ash Protein Fat
Percent Percent Percent Percent

Increase from “store” to “fat”

CONGIRIOM. . sk ee 78. 2.12 7.16 68.8
Increase from “fat” to ‘very fat”

condition=. .. . “Tra 2e Sis 3.12 Tio = TO9

FEEDING FOR MEAT 373

A comparison with the increase of fattening oxen
shows that the sheep stores the larger proportion of fat
in the dry substance laid on.

Sheep liberally fed give a larger increase to the 1,000
pounds live weight than steers. With animals weighing
from 75 to 150 pounds each, the daily gain with good
management may range from .2 to .5 pound a head, or
from 2 to 5 pounds to the 1,000 pounds, live weight, the
increase varying according to age, conditions, and liber-
ality of feeding. Lambs will sometimes greatly exceed
the above maximum. If we base our estimates upon what
will occur with the maturer animals, a number of lambs
or sheep weighing 1,000 pounds, perhaps seven, perhaps
twice as many, will store daily .15 to .40 pound of pro-
tein and from 1.4 to 3.5 pounds of fat.

469. Food needs of fattening sheep.—After long-con-
tinued and careful experiments in feeding a fattening-
ration to mature sheep, whose composition was investi-
gated at various stages of fatness, Henneberg concludes
that the very small amount of protein tissue laid on by
such animals may be ignored. Pfeiffer reached the same
conclusion from experiments with the same class of
animals. This view would not hold with lambs during
their increase from weaning time to one hundred pounds
in weight, for in this period there must be a material and
continuous storage of nitrogenous tissue.

As is, the case with steers, the demand for protein
storage is seen to be small with mature fattening sheep,
the constructive use of the ration being largely directed
to fat formation. The more recent views of the func-
tion of the nutrients allow us to believe that, as with
bovines, carbohydrates and perhaps fats play a leading
part in supplying raw materials for the carcass increase.

374 THE FEEDING OF ANIMALS

There is one point of difference between steers and sheep,
however, viz., the growth of wool with the latter, that
requires the use of more or less food protein.

The German standard for fattening sheep is 18.5 to
18.6 pounds of total digestible organic matter for each
1,000 pounds live weight, 3 to 3.5 pounds of which shall
be protein, thus giving a nutritive ratio ranging from
1:4.5 to 1:5.4. There is little doubt that this standard
calls for an unnecessarily large proportion of protein.
Neither scientific facts nor the observations of practice
justify the conclusion that sheep will fatten faster when
protein is so liberally supplied than when properly com-
pounded rations with a wider nutritive ratio are fed.
Doubtless more regard should be paid to the protein-
supply with sheep than with steers, but it is difficult to
adduce a single argument for insisting upon so narrow a
nutritive ratio with any species of fattening animal,
unless it becomes incidental to an economical purchase
of feeding-stuffs. We may safely conclude that the
resources of the farm are sufficient to supply enough
protein for a ration of an efficient character for the class
of animals under consideration, though we should give
due recognition to the fact that, with fattening lambs
especially, the protein feeding-stuffs may be most effi-
ciently utilized.

470. Quantity of nutrients for fattening sheep.—The
quantity of nutrients prescribed by the published stan-
dard for fattening is practically the same for each unit of
weight as that given for fattening bovines. This runs
contrary to common observation and the results of
experiments. The standard for steers has been charac-
terized as excessive, but this fault cannot be charged to
the one for sheep, for, if anything, it is below the demands

FEEDING FOR MEAT 375

of practice. Even mature sheep about average size will
consume 18.5 pounds of digestible nutrients for 1,000
pounds live weight, but this ratio does not meet the
requirements for the prevalent intensive feeding of lambs
and yearlings weighing from 75 to 125 pounds each. It
is easily demonstrable not only that sheep will utilize a
proportionately larger quantity of food than bovines, but
that they will make a relatively greater increase. The
results of two experiments in fattening wether lambs,
reported from the Iowa Agricultural College in 1896 and
1897, when compared with the outcome of steer-feeding
trials, serve admirably to illustrate the correctness of this
statement. The lambs were divided among seven mutton
breeds. Sixty-nine were fed 90 days and 64 others were
fed 107 days.

The main facts derived from these feeding trials are
as follows:

TES TET TST Tete a A 133.
TE EG GAIN e's | hig OB ea > Sl aa ar Re cs a 98.2
Pounds
Total average weight of animals ........ 16,400
Average weight single animal ......... ; p123
ey Matiee comaumed (‘5/47 2°. 3 2 ee 51,000
Digestible organic matter consumed . ...... 34,500

Dry matter eaten daily per 1,000 pounds live weight 31.8
Digestible organic matter eaten daily per 1,000

pounds live weight: 2’. 0 2, eee cay. 21.5
Daily gain per 1,000 pounds live weight .... . 3.73
Daily gain per animal §:., .... «2. 1 a eee 467

The food consumption in this instance of the suc-
cessful fattening of lambs is considerably in excess of
the German standard, and the amount of food consumed
is not unusual, though it is stated that in the latter
stages of the experiments the animals were crowded to
their full capacity.

376 THE FEEDING OF ANIMALS

If a comparison is made of this experiment with the
steer-feeding experiments previously cited it becomes
clearly evident that the published feeding standards
are not consistent in calling for practically the same
quantity of nutrients for the same live weight of the two
species. Sheep will consume at least one-quarter more
food than steers and lay on flesh proportionately faster.
Moreover, sheep appear to make a larger gain in live
weight than steers for each unit of nutrients consumed.
It may be that the testimony of the experiments cited
relative to the points under discussion is not a correct
expression of average conditions, but the differences shown
are too marked to be accounted for by any unusual con-
ditions pertaining to these feeding trials, and therefore
indicate what may generally be expected in practice.

471. The selection of a ration for sheep.—The range
of feeding-stuffs from which a sheep ration may be
selected is wide and includes practically all home-raised
fodders and grains and the whole list of by-products. It
cannot be said, though, that all materials are equally
desirable as sheep food. Of the fodders, those from the
legumes are especially to be sought, even pea and bean
straws, and among the grains corn stands preéminent
as the basis of a fattening-ration. Probably no feeding-
stuffs are more favored for mixing with corn than oats,
bran, and linseed meal, probably because none are more
successfully used. Barley, peas, beans, gluten feed,
gluten meal, and cottonseed meal have also been success-
fully fed to sheep. A mixed grain ration is unquestion-
ably to be preferred to any single grain or by-product,
because with the mixture greater palatableness is insured,
it is possible to maintain the consumption of a larger
ration, and the danger to health of heavy feeding is less.

FEEDING FOR MEAT 377

The selection of the components of the grain mixture
should be governed somewhat by market prices. A supply
of silage or roots is much to be desired as a part of a sheep-
fattening ration, especially when heavy grain rations are
to be fed during a long period, although successful feeding
during a limited time is entirely possible without these.
A succulent food promotes appetite and health, however,
and is usually economical and sometimes necessary.
Rations made up in definite quantities will not be
_ presented in this connection. The quantity of nutri-
ents which it is desirable to supply is so variable accord-
ing to the age and maturity of the animals to be fat-
tened that a feeding standard is applicable to only one
set of conditions not long maintained and therefore it
must be freely and frequently modified according to the
judgment of the feeder. It is, nevertheless, possible. to
offer practical suggestion as to the proportions of grains
in the mixtures that will be found acceptable, and as to
the kinds and quantities of coarse foods ordinarily utilized.
In the Iowa experiments cited in this connection the
grains used were corn, oats, bran, and linseed meal. In
the last of these trials the grain ration for fifteen days at
first was made up of corn, oats, and bran in the propor-
tions 2, 2, and 1. When the feeding was well established
the grains were oats, corn, bran, and oil meal, the rela-
tion in quantity being 8, 8, 2, and 1 respectively. Each
animal ate about one pound of roots daily and about
two-thirds as much hay as grain. The lambs were fed
up to the full ration very gradually, several weeks being
occupied in doing this. For such preparatory feeding
bran and oats are especially useful. When these tests
began, each animal ate from one and a half to two pounds
of grain daily, which quantity was increased later to

378 THE FEEDING OF ANIMALS

three pounds with the largest eaters, some individuals
not taking over two. The conduct of these feeding trials ©
typifies good practice, both as to materials and manage-
ment, and may serve as a guide in handling other simi-
lar feeding-stuffs. .

It is undoubtedly possible to feed sheep with equal
success without the use of purchased grains, especially
on farms where clover or alfalfa, roots, corn, oats, or
oats and peas, are produced. We are not justified by
experimental results in concluding that bran and oil
meal or any other by-product feeds are essential to the
highest success in fattening sheep, although these feeding-
stuffs are very useful for this purpose. A mixed grain
ration is always better than any single grain fed alone.

Instances are on record of a successful combination
of green forage crops with grain in fattening sheep. The
legume fodders and rape may be fed profitably in the
green state with the usual grain mixtures, care being
taken to avoid indigestion from excessive eating of the
green material. Grain in connection with ordinary pas-
turage is a successful method of fattening sheep or lambs
for the fall market.

PORK PRODUCTION

The feeding of swine is a matter of almost univer-
sal interest to farmers. Even in the older portions of
the East a few animals of this class are kept on nearly
every farm. Swine are well adapted to the disposal of
certain wastes, particularly those from the table and the
dairy. They are especially useful as a means of profitably
converting dairy by-products into a marketable form, and,
moreover, during the past twenty-five years pork produc-

FEEDING FOR MEAT 379

tion has offered more encouraging inducements to the
home consumption of grain than has beef production.

472. Changes in pork production.—Within recent
years there has been a great change in the methods of
pig-feeding and in the character of the animal when
placed upon the market. This is emphatically true of
the eastern and middle states, where pork is grown wholly
for local consumption. Formerly good feeders were not
supposed to slaughter a pig under 300 pounds carcass
weight, and many animals dressed 400 pounds when
taken to the market, this size being secured only after a
feeding period of twelve to eighteen months. Pork of this
character was regarded as well adapted to packing. At
the present time the demand of the local markets is for
small carcasses weighing not over 150 pounds, and sup-
plying the maximum proportion of lean cuts. This change
is in the direction of greater profits for the farmer because
the food expenditure required for the production of small
carcasses is much less a unit of weight than under the old
system, when the feeding was continued during a longer
period. Pigs properly fed are now wisely turned off at
the age of a few months, excepting, perhaps, in those
localities where a slow early growth is cheaply secured on
pasturage.

473. Character of the growth in pork production.—The
modern hog is emphatically a fat-producing organism,
having a capacity in this particular greatly surpassing
any other species of domestic animal. The dry matter
of the carcasses of individual animals has been found to
consist of over 80 per cent of fat, even after the leaf lard
was removed, and the average proportion in the dry sub-
stance of eight dressed pigs, representing six breeds, was
found by Wiley to be 78 per cent.

380 THE FEEDING OF ANIMALS

The statement of the composition of a Berkshire pig
and of a Duroc-Jersey will be found interesting in this
connection:

TaBLE LX XXIV. Composition oF THE ENTIRE DresseD ANIMAL,
Heap, LeEaF-LARD, AND Kipneys Removep. (Wiley.)

: Dry
Weight lWater | sub- Ash |Protein| Fat

carcass stance

Pounds!Percent|Percent|Percent|Percent| Percent

Berkshite see sok 129 | 43.1 | 56.9 | 2.6 | 18. |e
Duroc-Jersey ...... 149 | 30.6 | 69.4 | 1.8 9. 57.7
Fat pig, entire animal

(Lawes & Gilbert) . .}| 200 | 43.9 | 56.1 | 1.9 | 11.9 | 42.38

It appears that there were stored in the part of the
animal analyzed by Wiley only 13 pounds of protein
with the Duroc-Jersey and about 17 pounds with the
Berkshire, the quantities of fat being 52 pounds and 86
pounds, respectively. The figures for the entire animal,
as analyzed by Lawes and Gilbert, are at the rate of
23.8 pounds protein and 84.6 pounds fat, in a pig weigh-
ing 200 pounds.

These proportions bring out sharply the character of
the growth with swine. It is to be noted that in no other
species, very fat sheep possibly excepted, does the body
consist so largely of dry matter, which means that the
increase of a unit of live weight involves the storage of
more food substance than with other domestic animals.
The data at our command warrant the statement, in a
general way, that when a pig gains 1.5 pounds daily in
live weight he stores not less than .84 pound of dry sub-
stance, of which .18 pound is protein and .63 pound is
fat, these figures representing the average growth during
the life of the animal. Lawes and Gilbert estimate that

FEEDING FOR MEAT 381

- the increase of pigs while fattening has the following com-
position: |

Water Dry substance Ash Protein Fat
Per cent Per cent Per cent Per cent Per cent
22 78 10 6.4 71.5

According to these figures the protein storage, with
1.5 pounds daily gain, would be only .10 pound and the
fat 1.07 pounds.

474. Food requirements for pork production.—Under
a system of intensive production pigs go to market so
young that we may properly discuss their feeding from
birth. We deal first with the mother as a milch animal.
According to observations by Henry, in an inquiry as to
the yield and composition of sow’s milk, it seems probable
that in proportion to their weight small sows yield as
large a quantity of milk solids daily as a good cow. The
average daily production of milk solids of one animal
appeared to be about one pound. This would be four
pounds for four sows, which is the equivalent of the solids
in over thirty pounds of cow’s milk of average quality.
It follows, therefore, that the demands upon the food for
milk formation are proportionally as heavy with swine
as with cows, and consequently the ration should be one
that will stimulate and sustain abundant milk secretion.
Such feeding is not only necessary, but economical, for
independent experiments indicate that the food cost of
the growth of pigs before weaning is no greater than it is
after weaning.

Skimmed milk or buttermilk combined with a mixture
of wheat middlings and any of the ground cereal grains,
barley, oats, or corn, cannot be improved upon as food
for milch sows. The supply of protein should be liberal.
The feeding should be quite up to the limits of capacity,

382 THE FEEDING OF ANIMALS

7

and even then the dam suckling a large litter of young
will grow thin.

475. Pigs unwisely fed.—If we merely consider the
nature of the body substance of swine in its relation to
the constructive functions of the nutrients, it would not
be unreasonable to believe that rations with a wide
nutritive ratio are adapted to the needs of this class of
animals for growth. In a certain sense, practice ratifies
this view. Thousands of fat hogs have been the product
of almost exclusive corn-feeding, especially during the
later stages of growth. There is no doubt but that large
size and an excessively fat condition may be secured
through a liberal supply of carbohydrate material, but
such one-sided nutrition is not now regarded as being
adapted to the physiological requirements of the pig or
as producing pork which meets the existing demands
of the market.

It is doubtful whether any other species of domestic
animal has been the subject of so much abuse through
improper feeding, combined with an unhealthful environ-
ment, as has the pig. We now regard the abnormal
masses of porcine fat which have heretofore appeared in
our markets as not only an exhibition of physical mon-
strosities, but as not serving the health interests of the
human family.

476. Point of view in feeding pigs.—The primary
object in feeding pigs should be, as with all domestic
animals, the securing of a normal and vigorous physio-
logical development, i.e., an organism with a strong
bony structure and with such a growth of muscular tissue
as shall insure full exercise of all the vital functions. The
view seems to have prevailed, in a practical way at least,
that pigs can be fed on anything, live and sleep anywhere,

FEEDING FOR MEAT 383

and still not suffer ill effects, as would be the case with the
other farm animals. This has been unfortunate, because
probably no domestic species is more susceptible to
abnormal development through improper feeding than
are swine. It is true, at least, that no other species has
shown so marked a response to changes in the character
of the rations, through modifications of the bony struc-
ture and through variations in the proportions of muscle
and fat tissue.

477. Influence of ration on the development of swine.
—Notable proof of the plasticity of the pig’s organism
was supplied by the experiments of Sanborn and Henry
in comparing rations extremely nitrogenous with those
extremely carbohydrate in character. Pigs fed liberally
on blood, milk, and shorts combined with more or less
corn meal, made growth more rapidly, had stronger bones,
larger organs, and more muscular tissue than those fed
on corn meal or a mixture of corn meal with other highly
non-nitrogenous materials, such as potatoes and tallow.
The latter combination was deficient both in protein and
in bone-forming compounds. Such marked differences
are not usually seen, because rations are not generally so
extremely one-sided. These experiments teach the
lesson, though, that as much care should be exercised in
choosing the pig’s ration as the cow’s.

Experimental observations demonstrate that the pig’s
ration should be selected with reference to supplying an
abundance of bone-making material and a reasonably
large proportion of protein. Evidence is not wanting
that the feeding of wood-ashes and ground bone to grow-
ing pigs promotes both a normal development of the
bony framework and a more liberal consumption of food.
Animals that are grazing may not need to have the ration

384 THE FEEDING OF ANIMALS

so supplemented but it is wise and even necessary with
those confined in pens.

478. Dairy wastes as food for pigs.—In selecting
foods for the production of small pork where the develop-
ment of all forms of tissue is taking place, first rank must
be given to the dairy wastes. As a means of promoting
rapid growth and a condition of health and vigor, and also
as a supplement to cereal-grain products, skim-milk and
buttermilk are not excelled, and perhaps not equaled, by
any other feeding-stuffs. Dairy wastes are more profit-
ably used in pork production than perhaps in any other |
way. (See Pars. 360-363.) In order to secure the maxi-
mum result from a given quantity of dairy wastes, they
should be fed in combination with grain products. When
this is done, and the proportions of skim-milk or butter-
milk and grain are what they should be, it appears to
require less digestible food substance for a pound of
growth than when grain is fed alone or when the liquid
food is largely eaten. In other words, dairy wastes are
not only efficient in themselves in producing growth,
but in proper combination they cause a saving of the
grain products necessary to secure a given ratio of gain.
Henry states, on the basis of eight feeding trials involv-
ing the use of ninety pigs, that 462 pounds of skimmed
milk effected a saving of 100 pounds of corn meal. This
means that 46.2 pounds of digestible milk solids, when
combined with corn meal, saved, approximately, 76 pounds
of digestible corn meal substance.

Henry’s experiments were arranged so as to gain
information as to the most desirable proportion of milk
and meal, and from his data the writer has calculated the
quantity of digestible nutrients required in each com-
bination for one pound of growth:

FEEDING FOR MEAT 385

Piste matter required
for 1 eich of gain

Combination pa
Mixed grams alonemeyye: . «Gsyeee sw. te
1 Ib. corn meal to 1-3 lbs. skim-milk ...., oe
1 lb. corn meal to 3-5 Ibs. skim-milkk .... 3.1
1 lb. corn meal to 5-7 Ibs. skim-milk .... 383
1 lb. corn meal to 7-9 lbs: skim-milkk .... 32

These results show the greatest food efficiency with
the minimum proportion of skim-milk. Other experi-
ments, notably those by Linfield and Robertson, give
similar testimony. With the former, in seven experi-
ments, a milk and grain ration produced 1 pound of
gain for each 2.58 pounds of digestible matter, the re-
quirement with milk alone being 2.85 pounds and with
grain alone 3.19 pounds. When 2 pounds of skim-milk
was fed with 1 pound of grain, 100 pounds of the milk
replaced 31 pounds of grain, but when the milk and grain
were as 4 to 1, 100 pounds of milk replaced only 24
pounds of grain.

Doubtless with pigs in the earliest stages of growth
after weaning, the proportion of milk to grain may well be
larger than in the more mature periods, and in any case
the ratio will naturally depend somewhat on the relative
supply of the milk and grains.

479. Protein foods other than milk products for
swine.—In the absence of dairy wastes, meat meal, dried
blood, and fish scraps may be used to supplement the
grain products or a mixture of the more nitrogenous
feeding-stuffs with corn and barley will be found greatly
superior to the corn or barley alone. Milk is more efficient
with young pigs than the grain feeds rich in protein, but
in the maturer periods the digestible matter of certain
of the latter seems to have a value not greatly, if any,
below that of skim-milk solids.

x

386 THE FEEDING OF ANIMALS

The protein feeds adapted to pigs are gluten meal,
gluten feed, buckwheat middlings, brewers’ wastes, peas,
and middlings. The oil meals, except in small quantities,
affect the health of swine unfavorably and wheat bran
is inferior to middlings.

Of the carbohydrate foods, oats, barley, wheat, rice
products, and especially corn, are all useful. Although
the excessive corn-feeding of swine is to be deplored, this
grain is second in value to no other in the pig’s ration,
and only needs to be reinforced with more nitrogenous
feeds in order to find a safe and profitable use. In the
later stages of growth or fattening it may well form the
major part of the ration. Probably no combination has
been found more satisfactory for all around use than
skim-milk, wheat middlings, and corn meal, the latter
constituting the larger proportion of the grain food.

480. Forage crops for swine.—At the present time
much attention is given to forage crops for swine. Clover,
alfalfa, rape, sorghum, rye, and ordinary pasturage have
all been found to be adapted to hogs. When fed with
grain, economical and satisfactory production is secured.
When fed alone, the growth is so slow as to be unsatis-
factory. In two experiments at the Wisconsin Experi-
ment Station, one acre of rape when combined with grain
proved to be equal to 2,767 pounds of corn and shorts.
Other observations show beyond question that such
feeding is practicable and under some conditions profita-
ble. Better results seem to follow when the pigs are
allowed to graze than when the fodder crop is cut and
fed to animals confined in pens.

CHAPTER XXII
FEEDING WORKING ANIMALS

Workxrne animals are rapidly being displaced by power
vehicles. Those now in use in the United States are chiefly
horses and mules. Oxen were once employed extensively
for farm labor and in lumbering, but these are rarely seen
under the yoke at the present time except in remote rural
districts. It will be proper, therefore, to treat in this con-
nection chiefly of horses that are used for draft and road
purposes.

481. The horse a machine.—In feeding a working
animal, the essential product of the food is energy to be
used in drawing, walking, or trotting. The latent food
energy is made available, as heretofore stated, by the
oxidation of the several nutrients into the ordinary
products of combustion, and the units of heat or work
or other forms of kinetic energy evolved are directly
proportional to the quantity of digested food which suffers
combustion, just as the possible work of a steam engine
under given conditions is proportional to the fuel con-
sumption in the boiler. The establishment of fundamen-
tal relations between food and work requires on the one
hand an understanding of the energy values of food, and
on the other hand at least a general conception of the
amount of work performed. The energy values of food
have been considered and it now remains for us to ascer-
tain what is known concerning energy consumption by a
laboring animal.

(387)

388 THE FEEDING OF: ANIMALS

482. The work performed by a horse.—The labor per-
formed by a draft or road animal, exclusive of the energy
required for maintenance, may be regarded as consist-
ing of two components, viz., the effort of moving the
load and that of moving the animal’s body. If a horse
weighing 1,000 pounds draws 1 mile a wagon which, with
its load, weighs 1,500 pounds, 2,500 pounds of matter
have been moved through the distance traveled. In
other words, a horse moves himself and his load whether
the load is drawn on a wagon or is loaded on his back.

The exact expenditure of energy involved in both of
these components cannot be measured directly. The work
of drawing a load may be determined by the use of a
dynamometer, but it can only be estimated so far as the
body of the horse is concerned. If the latter factor could
be calculated on the basis of simply projecting a mass
of matter through the space traveled, it would be a com-
paratively simple problem. There is a vertical motion
of the horse’s body to be accounted for, as well as a
horizontal, and the reduction of both to units of work is
a difficult matter. If this could be done, our present
knowledge of the food energy necessary for the per-
formance of a unit of mechanical labor would allow
quite definite calculations of the daily food needs of horses
of different classes. As a matter of fact, the actual work
accomplished by laboring animals has been and still is
to quite an extent, a matter of estimation.

Chardin, a French army veterinarian, estimates that
the average daily work performed is about 2,580 foot-
tons. Lavalard calculates that the total ordinary work
of any army horse equals 8,500 foot-tons. As stated by
Armsby, the ordinary day’s work of a horse is estimated
at 1,500,000 kilogram meters, or 5,425 foot-tons, this

FEEDING WORKING ANIMALS 389

evidently meaning the mechanical labor outside the
motion of the body. With the knowledge we now possess
it is possible to estimate approximately the actual work
performed in a given case.

It would be a good day’s labor if a 1,000-pound horse
travels 20 miles over a smooth, level, dirt road hauling
a wagon with a load of 2,000 pounds. The draft of the
loaded wagon would be not far from 100 pounds. A sim-
ple calculation shows that the mere moving of such a load
the distance of 1 mile would be equivalent to 264 foot-
tons. The energy expenditure in walking a given distance
has been measured by Zuntz, who ascertained the differ-
ence in oxygen consumption of a horse when at rest and
when traveling at a walk over a level road. According
to these measurements, it appears that a 1,000-pound
horse in walking 1 mile at the rate of 2 to 3 miles an
hour would expend a total energy of 473 foot-tons, 44.4
per cent or 201 foot-tons of which belong to the effort of
walking, over and above the energy needed for mere
maintenance. In the case assumed, a horse would per-
form a total labor, in walking and drawing 20 miles,
equivalent to lifting 9,300 tons through a space of 1 foot.
This estimate is presented merely as an approximation
of the work done under given conditions.

483. Influence of conditions on the food expenditure
for a unit of work.—These figures are, perhaps, less im-
portant to the owner of work or driving horses than is
a knowledge of the influence of speed upon the labor
expended in a unit of time. “According to Marcey, the
work accomplished in a given time is proportionate to the
square of the velocity. His coefficients were 3.42 for
walking or pacing, 16 for trotting, 28.62 for cantering,
and 68.39 for a full gallop.” This general fact would be

390 THE FEEDING OF ANIMALS

applicable to horses under all conditions of labor. More-
over, it is clearly demonstrated by two investigators
that the food energy required for a unit of work increases
with the speed. In other words, a horse that trots 20 —
miles a day must have more food than when he walks the
20 miles. In the same way draft animals require food
somewhat in proportion to the pace with which they
travel over a given distance. Grandeau has shown that a
horse was kept in condition with 19.4 pounds of hay when
he walked 1214 miles, but 24 pounds was insufficient
when he trotted the same distance. Zuntz measured the
oxygen used for each kilogram meter when a loaded horse
traveled at different velocities. When the pace was 3
miles an hour, with a load of 275 pounds, the energy
required was equal to 4,600 calories for each kilogram
meter of horse, which increased to 7,753 calories when the
speed reached 614 to 714 miles an hour. The food needed
for a unit of work increased nearly 70 per cent in increas-
ing the speed from 3 to 7 miles. Zuntz shows that if
a horse exerts himself to the utmost the use of oxygen
rises at a rapid rate, and that the food consumed for a unit
of work is nearly one-half more than with ordinary draft.
It appears to be a rule that as the intensity of exertion
of the horse increases the food cost of a given amount
of labor performed increases. Men of experience recog-
nize this fact in a general way when they insist on favor-
ing their animals to the slowest pace that is consistent
with the conditions involved.

484. The food requirements of a working horse.—
There are two general ways of ascertaining the food needs
of a working horse: by practical experiments in which the
rations are varied until a conclusion is reached as to what
will support an animal under given conditions, and by

al

FEEDING WORKING ANIMALS 391.

determining through scientific investigations the amount
of work performed in various ways and the relation of a
unit of food to a unit of work. It would not be far from
the truth to state, however, that the feeding standards
which are offered to us through investigations made by
Boussingault, Wolff, LeClerc, Grandeau, Hoffmeister,
Lavalard, Zuntz, Kellner, and others, are the outgrowth
of both practical observations and scientific research, a
most desirable combination. In a large number of
instances the kind and quantities of digestible food con-
sumed daily by working horses have been determined,
and in many cases the accompanying wastes and gain
and loss of the animal body have been measured.

The standard rations now found in German tables
are the result of such observations. According to these
standards a 1,000-pound horse requires 11.4 pounds of
digestible food daily when doing moderate work, 13.6
pounds for average work, and 16.6 pounds for heavy
work. With a basal ration of 10 pounds of hay, the grain
needed to furnish these quantities of digestible nutrients,
when consisting of a mixture in equal parts of corn and
oats, would be approximately 11.5 pounds, 15 pounds, and
20 pounds for the three conditions of labor. Lavalard,
who made observations covering a period of a number of
years for 32,000 omnibus, army, and draft horses, has
reached the conclusion that “‘a horse performing ordinary
work requires 115 grams of digestible protein and 1,100
grams of digestible carbohydrates per 100 kilograms
live weight.” This is at the rate of 1.215 pounds of
digestible nutrients for 100 pounds of live weight. This
observer bases the ration upon the weight of the animal,
but practically concedes that “somewhat larger amounts
of protein and carbohydrates are considered necessary

392 THE FEEDING OF ANIMALS

with small horses,” a conclusion which is entirely con-
sistent with observation and related facts. Lavalard’s
formula would furnish a 1,000-pound horse, doing ordi-
nary work, with 12.1 pounds of digestible nutrients daily,
a quantity not inconsistent with the German standard.

Kellner has recommended the following average stan-
dards for working horses to include maintenance:

REQUIREMENTS OF THE WoRKING HoRSE*

Digestible Energy
protein value
F Pounds Therms
Por litpeees . Ss ws ke t: 9.8
Wor medimmmwork ...° =... . 1.4 12.4
Bor heawameerk ek. 2. 16.

Rations corresponding to these standards would be
as follows:

For light work For medium work
10 lbs. mixed ha/y. 10 Ibs. mixed hay.
5 Ibs. cracked corn. 7 lbs. cracked corn,
2 lbs. wheat middlings. 3 Ibs. wheat middlings.
1 Ib. wheat bran. 1 lb. brewers’ grains, dried.

For heavy work

10 lbs. mixed hay.

10 lbs. cracked corn.
4 lbs. wheat middlings.
1 lb. brewers’ grains.

485. Estimate of work ration for the horse based
on energy relations.—The results of the masterly and
extensive metabolism investigations which Zuntz had
carried on with a horse under various conditions may
properly be used for computing a ration. This investiga-
tor determined the oxygen consumption, which is equiva-
lent to ascertaining the food use, by a horse at rest, when

* Based on true protein and productive values.

*smoo ALIep Of PoYs-UOlwoIII JOYUIM “TITA BLVIg

FEEDING WORKING ANIMALS 393

walking on a smooth level without load, and when per-
forming both light and heavy work. First of all, it appears
from his observations that 31.6 per cent, or about one-
third, of the total food energy can be converted into useful
work. This is much less than the coefficient of useful
work found by Wolff, whose conclusions Zuntz regards as
erroneous. But even if Zuntz’s figures are none too low,
it is evident that the animal machine uses fuel with much
greater economy than a steam engine where the coefficient
of usefulness might not be over 10 per cent. The figures
he reached show further that the total expenditure of
energy by a horse weighing 1,000 pounds in walking 1
mile equaled 453 foot-tons, which would be furnished by
.164 pound of digestible food. As 44.4 per cent of this,
or 201 foot-tons, was due to the effort of walking over and
above the needs for maintenance, the extra digestible
food needed per mile of walking was .07216 pound.

Zuntz also found that when a horse increases the
external mechanical labor performed, such increase costs
001155 pound digestible dry matter for each foot-ton of
work. On this basis the 264 foot-tons of energy which is
needed for pulling 1 mile a load with a draft of 100 pounds
would be furnished by .3049 pound of food matter. The
total food expenditure, therefore, for walking and a
draft of 100 pounds over a smooth, level road for 1 mile,
would be .377 pound digestible nutrients, and for 20
miles 7.54 pounds. If we add to this the 6.4 pounds needed
for mere maintenance, we have 13.94 pounds digestible
matter as the proper ration for a horse doing the work
stated for a distance of 20 miles. These figures are cer-
tainly not inconsistent with the standard reached by
other methods for a horse doing average work. Such a
calculation is at least useful in showing the direct rela-

394 THE FEEDING OF ANIMALS

tion of food expenditure to work performed, and the
necessity of feeding a laboring animal somewhat pro-
portionately to what he does. It should be borne in mind
constantly that when the intensity of effort of the horse
increases, even if only the same work is performed in a
shorter time, the food needs for each unit of work are
greater. If a driver in making the regular number of trips
to the railroad station needlessly hurries his horse, or if a
drayman whips his team into a fast walk and then lets it
stand idle, more food must be consumed than if the slowest
possible gait was allowed.

486. Source of the ration for working horses.—In
treating of this matter we must, in the first place, con-
sider the digestive apparatus or storage capacity of the
horse. It is certainly not adapted to the consumption
of large quantities of coarse food, as is the case with
ruminants. If a horse at severe labor needs 17.7 pounds
of digestible dry matter each day, he could get it from hay
only by eating over 40 pounds—a most absurd require-
ment. It is especially necessary, therefore, with hard-
working animals, that the larger part of their nutriment
comes from the concentrated feeding-stuffs. Ten to 12
pounds of hay is all a draft horse should consume in one
day. Working horses on the farm generally eat too
much coarse fodder.

The net values of feeding-stuffs are also important
in this connection. It has been shown that the net energy
value of a unit of dry matter from hay is less than with
that from the grains, and consequently when it is neces-
sary to supply an animal with a large amount of energy
for external mechanical uses, requiring high feeding, we
must resort to the grains in order to construct a ration
of maximum efficiency.

FEEDING WORKING ANIMALS 395

487. Nutritive ratio for working horses.—Concern-
ing the nutritive ratio or proportion of protein in a ration’
designed for working horses, there is a variety of recom-
mendations. The German standards call for ratios from
1:7 to 1:6, according to the severity of labor, the daily
weight of protein for a 1,000-pound horse to be from 1.5
to 2.5 pounds. This is greatly more protein than is
recommended by Lavalard, who, on the basis of exten-
sive experience, declares that 1.15 pounds of protein
daily is sufficient for ordinary work, this to be increased
to 1.35 pounds when the labor becomes more severe.
There is one fundamental fact that is pertinent to a dis-
cussion of this point, which is that the non-nitrogenous
constituents of the ration are largely the source of muscu-
lar energy. As stated before, it was formerly thought
that muscular effort was sustained at the expense of
muscular tissue, but when it was found that no more urea
was excreted by men climbing a mountain than when
they were much less active, this view was abandoned.
Later researches have clearly shown that when work
increases the excretion of carbon dioxid increases in like
proportion without any important rise in the protein
exchange. In other words, the carbohydrates and fats
are largely the fuel that supplies energy for mechanical
purposes. Common experience ratifies this conclusion
of science. Many horses and oxen have successfully
endured severe labor on meadow hay, oats, and corn,
sometimes the grain being largely the latter.

A ration properly compounded from ordinary farm
products, such as silage, roots, meadow hay, legume hays,
and the cereal grains, will generally contain protein in
sufficient proportion, and will seldom need reinforcing
with the nitrogenous feeding-stuffs. It is probably true,

396 THE FEEDING OF ANIMALS

however, that when working animals are called upon to
endure a severe strain material advantage is gained from
introducing into the ration a small quantity of some
nitrogenous feeding-stuff, such as beans or oil meal.

488. Oats for working horses.—One of the opinions
regarding the feeding of horses, which has widely pre-
vailed and which is still held by many, is that oats in
liberal proportions are essential to the successful main-
tenance of road and work horses, especially the former.
It has been believed, as has been stated, that this grain
imparts to the horse greater nervous activity or life than
any other feeding-stuff, and when it was announced that
‘‘avenine,” an alkaloid, had been extracted from oats,
this was quickly accepted as an explanation of their
peculiar effect. We have given up the avenine and seem
likely to modify our views in other ways, for it is becom-
ing increasingly evident that other grains may be sub-
stituted for oats with no detriment to the horse and with
a material saving to his owner. Barley, brewers’ grains,
maize, maize cake, wheat, wheat bran, wheat middlings,
have been extensively and safely fed in the place of
oats, wholly or in part, by experiment stations and in
practice by omnibus and horse-car companies. In this
way the cost of maintaining horse labor is materially
decreased, for usually oats are comparatively much more
expensive than other grains and the by-products in pro-
portion to their feeding value. It is often the case that
a farmer can afford to sell a part of the oats he raises and
buy other grains, and he can do this with confidence that
he will be able to maintain his road and working horses
in proper flesh, good health, and spirit on the cheaper
materials. A great variety of grain mixtures may be used
successfully in feeding horses.

FEEDING WORKING ANIMALS 397

489. Suggested rations for working horses.—As a
suggestion to feeders concerning the ways in which
several feeding-stuffs may be combined so as to furnish
practically the same quantity of digestible organic mat-
ter, the following rations are presented as meeting the
needs of a horse weighing 1,000 pounds and doing mod-
erate work:

10 lbs. timothy or mixed hay. 10 Ibs. hay.
11) lbs. oats. 5 lbs. corn.
414 Ibs. barley.

10 lbs. hay. 10 lbs. hay.
10/4 lbs. oats and corn, equal 5 lbs. corn.

parts by weight. 6% lbs. wheat bran.

10 lbs. hay. 10 lbs. hay.
101% lbs. oats and barley, equal 5 lbs. corn.
parts by weight. 6 Ibs. brewers’ grains.

10 lbs. hay.
41% Ibs. barley.
4 lbs. wheat bran.
3 lbs. brewers’ grains.

10 Ibs. hay. 10 Ibs. hay.
8 lbs. oats. 3% lbs. corn.
4 lbs. wheat bran. 4 lbs. wheat bran.
4 Ibs. brewers’ grains.

0 Ibs. hay.
8 lbs. oats.
4 lbs. brewers’ grains.

Silage, roots, and other green materials may often be
substituted for a minor part of the hay with advantage
to the animal’s appetite and health.

No definite rations are suggested for more severe
labor. The amount of food must simply be increased
with the amount of work performed. Any increase should
apply to the grain and not to the hay, the proportions
of the several feeding-stuffs in the grain ration to remain
the same in the larger quantity. It is well understood, of
course, that a ration should increase proportionately

|
398 THE FEEDING OF ANIMALS

faster than the amount of work done, and that an old >
animal generally demands higher feeding than does a
young one. The condition of the road, the intensity of
the effort, and other circumstances also modify the needs
of the working horse, so that the feeder is always called
upon to exercise the trained judgment which comes from
experience. No working animal can be fed successfully
by mechanical rules.

CHAPTER XXIII
THE FEEDING OF POULTRY

By Witu1aM P. WHEELER

Unpber moderate climatic conditions some profit is
possible with poultry, oftener than with large animals
now, without very critical attention to the food-supply.
This is because much of the food natural to birds, and often
some of the best and cheapest, cannot be utilized except
as selected and found by the fowls themselves. It is
even necessary for the best results with certain species to
provide some approximation to the feeding habits of the
once wild parents. Nevertheless, artificial conditions must
be met for part of the year, and continued success cannot
be assured without full consideration of the essential
food requirements so far as they may be known.

490. Food needs of birds intensive-—One pronounced
characteristic of birds is an intense vitality. Their life
is never sluggish. The growth of the young and the trans-
formation of food into eggs are exceedingly rapid. The
temperature is high, running with certain species from a
little above 100° F. to 112° or more. The energy expended
in this direction is proportionately great and material
for its supply is in urgent demand; for a vigorous animal is
the seat of rapid metabolic change. The large appetite
is an indication of the extensive needs. The very active
digestive apparatus must be in good order and supplied
with efficient food.

The domestic fowls may be classed with the large

(399)

400 THE FEEDING OF ANIMALS

number of birds as omnivorous. While seed-eaters like

the common fowl are able to subsist for long periods on
grain alone, as can also the goose by grazing, the natural
food of most young birds is largely animal. Many wild
birds which feed almost entirely on seeds supply their
rapidly-growing young with an abundance of animal food.

491. Kinds of foods for poultry.—It is a common
experience that better success follows the use of several
foods combined rather than a few and it seems to be a
fact that some variety is essential. While in practice a
combination must be employed for best results which
are partly due to the usually greater palatability and
other indirect effects on the general health, it is not
because of a greater nutritive value of the constituents
from different sources that the different foods are needed.
The important consideration seems to be the proportion
of constituents. In experiments made at the New York
Agricultural Experiment Station, the better results from
rations containing animal food were found to be largely
due to the greater amount of mineral matter, chiefly
phosphate of lime, in the animal food used. When rations
of grains naturally lacking in ash-content were supple-
mented by bone ash, their efficiency was increased with-
out addition of other food. For chicks, during the periods
of most rapid growth, the rations of vegetable origin sup-
plemented by material rich in phosphate of lime were
equal or even superior to rations supplying large quan-
tities of animal protein and fat. For laying hens the
time during which such rations were equally efficient was
limited to a few months. Rations containing animal food
were much superior for ducklings, although the addition
of bone ash to rations of grain and other vegetable food
notably increased their efficiency.

<i ae

FEEDING OF POULTRY 401

Although it is possible, for some purposes, to com-
pound effective rations from grain alone when the defi-
ciency of ash is made good, it is better in practice to use
some animal food. A variety of grain food supplying
enough nitrogenous matter is not always to be found, and
animal foods when rich in protein, as most of them are,
prove of great service; for with them can be freely fed
some of the cheaper, starchy foods, typical among which
is the palatable and remarkably efficient Indian corn. For
fattening mature fowls, animal food is not so important
except when its use improves the palatability of the
ration. This last is a matter always to be considered.

Succulent vegetable foods are eagerly eaten by do-
mestic fowls. Aside from the beneficial effect on the
health of the birds, it is important to use such foods as
far as possible, for the nutriment they supply is cheaply
obtained. With most rations the more nitrogenous
fodders, such as clover, alfalfa, and very immature
grasses, are best. These foods also contain more of the
needed lime than do grains. It must be remembered,
however, that fowls are not fitted to depend largely on
such bulky materials while production is rapid. The
goose is better adapted than most birds to live by grazing,
but the liberal use of the more concentrated grain and
animal foods has been found necessary except during
the idle season.

At the time of greatest egg production the choice of
bulky foods should preferably be confined to those of the
most tender and succulent nature. Certain experiments
also indicate that a ration which contains any considera-
ble proportion of dry or woody coarse fodder, although
finely ground, is not suited to young chicks, and that
only the more succulent kinds of bulky foods, like the

Z

402 THE FEEDING OF ANIMALS

first shoots of grasses and clovers, should be fed in the
fresh condition. After the birds approach maturity and
growth is slower, so that a much larger proportion of the

food is used for maintenance, and during colder weather —

when the heat from the extra energy required for diges-
tion is useful, more of the coarse foods can be fed with-
out apparent disadvantage.

492. Incidental effects of the food with laying hens.—
Another reason, sometimes a very important one, for.
using such foods as young clover, fresh or dried, is the
effect on the color of the egg yolk. Eggs from hens which
are fed only certain grain and animal substances gener-
ally have yolks of a pale yellow color. This is often
objected to by those who have a preference for eggs with
darker orange-colored yolks. The liberal feeding of fresh
or dried young clover, alfalfa, or grass will generally
insure the deeper coloration. The cause for this frequent
lack of what may be considered the normal yellow color
of the egg yolk is not well known, but the occurrence of
the pale color can be generally prevented by attention
to the food.

At the New York Experiment Station, pens of hens
which were fed alike except that no hay or green food
was given to one, while three others had different amounts
apportioned by geometrical ratio, of clover hay alter-
nated with green alfalfa, produced eggs showing marked
differences in color. The orange-yellow shade of the
yolk corresponded directly in intensity with the propor-
tion of hay or green fodder in the ration. The greenish
color of the white also varied but not so regularly. Eggs
from each lot were very uniform in appearance.

The differences in flavor and other qualities which
are probably caused by the food cannot be satisfactorily

FEEDING OF POULTRY 403

explained at present. They are, however, slight with
normal rations. In general the color of the shell is deter-
mined by the breeding or by the individual characteristics
of the fowl.

493. Digestive apparatus of birds (Fig. 17).—The pro-
cess of digestion with birds is essentially similar to that with
mammals although there are important differences in the
apparatus by which it is accomplished. It is necessary
to know something of the general arrangement and
working of the digestive canal when attempting to estab-
lish proper methods of feeding, and for a better selec-
tion and combination of suitable foods.

Although some extinct species of birds were well
supplied with teeth, existing forms have the mouth
armed only with a horny beak. The common fowls
must swallow grains whole but are able to tear some
food into small fragments, which they particularly do
when feeding the young. Ducks, and geese more especi-
ally, have the mouth supplied with laminz which serve
to cut soft herbage.

In birds the salivary glands are small and the lim-
ited amount of saliva probably has little effect on the
food.

The esophagus is of great caliber and very expan-
sible. It is dilated in the cervical portion in ducks and
geese. In gallinaceous birds, instead of this dilatation
there is attached to, and forming practically a part of,
the esophagus, the reservoir called the crop. The food
is temporarily retained in the crop, but is changed very
little other than being softened by the water swallowed
with it, the small amount of mucus, and the inconse-
quential amount of saliva. The high temperature doubt-
less assists this softening effect, and fermentation also

404 | THE FEEDING OF ANIMALS

progresses rapidly when food is retained long in the crop
from injury or by overloading with coarse material.

The divided crop of pigeons secretes, with both sexes
for several days after the young are hatched, a thick
milky fluid which serves to feed the young birds. With
other domestic birds the crop serves for little more than
a temporary retaining reservoir.

The stomach, which is a single organ in some birds,
is represented by two reservoirs in domestic fowls. The
first, through which the food passes after leaving the
crop, is the glandular stomach, the succentric ventricle
or proventriculus, and the second, closely connected, is
the gizzard or muscular stomach. ‘The first, from its
structure, has been considered the true stomach, but it is
now believed that gastric juice is secreted in the gizzard.
The food does not accumulate in the first stomach but
in passing through carries along such juices as are
there secreted.

The gizzard is a powerful grinding apparatus. There
is a strong lining which is capable of resisting great
pressure and the action of the sharp sand and pebbles.
In this organ the grains and seeds, with other materials,
are more finely ground than by the mastication of many
other animals.

The intestines are long in domestic fowls. While
serving the same purpose as in mammals and having
a general resemblance to the mammalian form, they do
not clearly show the same divisions. The diameter is
about the same throughout. The ceca, each of which is
closed at one end and opens into the intestines at the
other, seem to be important and essential modifications
of that canal. Each cecum is from 6 to 7 inches long
in mature fowls. Not far from the openings of the ceca

FEEDING OF POULTRY 405

the intestine ends in a dilatation, the cloaca, into which
the genito-urinary passages also open. It is because of
the mixing here of the undigested residues of the food
with the secretions from the kidneys and with some other

Toncve

EsorHacus SFIRST PORTION
Crop

ESopHagus , SECOND PORTION
Succentrie VENTRICLE
GizzarD

QRicin oF DUODENUM

SECOND BRANCH OF DUODENAL FLEXTURE

OoOPnrt DAA DS © Ww @

ORIGN OF FLOATING PORTION OF SMALL INTESTINE

10.10 SmALL INTESTINE

11-11 CAcA

if é Y 12 INSERTION OF CECA
Mp | ws 1 GE 13° Rectum
TAN =. = G7, yo 14 Cuoaca
i WS = a= j i) / f; i) nl i preg’
= ¢ 3 eit ii ini ase 6 15-15 Pancreas

SA

16 Liver

=).

2 2

, Bs 17 GALL- BLADDER
! Yi 18 SPLEEN

Fic. 17. Digestive apparatus of the common fowl.

406 THE FEEDING OF ANIMALS

products of metabolism, that an accurate estimation of
the digestibility of food by birds is so difficult. No satis-
factorily accurate methods for separating some of the
nitrogenous residues from different organs seem yet to
be perfected.

Into the intestine shortly after it leaves the gizzard
two ducts from the liver and two from the pancreas enter,
discharging the bile and pancreatic juices. The liver, as
usual, is a large organ. The pancreas also is very largely
developed, and extends for several inches along the duo-
denal loop of the intestines, reaching in the common
fowl a length of over 5 inches.

Altogether the structure of the digestive apparatus of
birds indicates extreme efficiency and the capacity for
rapid work. A study of it suggests, also, as does that of
any complicated and delicately adjusted apparatus, that
it should not be overloaded nor violently disturbed when
running at high pressure. It may be said to run at high
pressure while the extremely rapid growth of young
birds occurs and during the extended laying season, for
the resulting products call for an uninterrupted supply
of food and the transformation of all material that is
available. Chickens of two pounds weight at ten weeks
of age show a gain over the weight of the first week of
nearly 1,700 per cent. Ducklings five pounds in weight
at nine weeks show a gain during about eight weeks of
3,900 per cent. Such rates of growth are not very unusual
for young fowls under favorable conditions.

494, Constituents of the body of the hen.—Whether
the production of meat or of eggs is the prime object,
the young fowl must first be grown. It is desirable, then,
to consider what constituents make up the body of the
animal, for all must be derived from the food. Many

—
ie ee
ir ov 7

4

\

FEEDING OF POULTRY 407

slight variations in composition exist, of course, but there
is always a certain approximation to the normal full-
grown animal.

In the whole body of the common fowl, unless especi-
ally fattened, not far from one-half of the dry matter is
protein and about 8 per cent ash. This of itself would
suggest that a slow growth must follow the use of foods
containing small amounts of nitrogenous and mineral
matter.

Analyses made, mostly by Jenter at the New York
Experiment Station, give as the average composition
of the body of a Leghorn hen, typical of the laying breeds,
55.8 per cent of water, 21.6 per cent of protein, 3.8 per
cent of ash, and 17 per cent of fat. This is not the com-
position of the edible portion alone nor of the carcass as
found in the market, but that of the whole body, bones,
blood, feathers, and all the viscera. The different parts
of the body were all separately analyzed. Separate analy-
ses of four individual hens each gave a close approxima-
tion to the average. The composition of the body of a
Leghorn pullet in full laying was little different from the
average for the hens, being 55.4 per cent of water, 21.2
per cent of protein, 3.4 per cent of ash, and 18 per cent
of fat.

The body of a mature capon (Plymouth Rock) con-
tained 41.6 per cent of water, 19.4 per cent of protein,
3.7 per cent of ash, and 33.9 per cent of fat. If the extra
amount of fat were removed, the composition would be
very similar to that of the other fowls. In younger and
immature birds the percentage of fat is very much less
than in older birds.

495. Composition of eggs.—The egg, which aside
from the shell is potentially a chick, shows in the general

408 THE FEEDING OF ANIMALS

proportions of the constituents a striking resemblance to
the body of the grown bird. Of the dry matter of eggs
analyzed, aside from the shell, 49.8 per cent on the aver-
age was protein, 3.5 per cent ash, and 38.6 per cent
fat. Of the dry matter of the bodies of hens 48.9 per
cent was protein, 8.6 per cent ash, and 38.5 per cent fat.

Of the total dry matter in the entire egg, 35.6 per
cent is ash, 25.9 per cent fat, and about 33.3 per cent pro-
tein, or 38.5 per cent if estimated by difference. The
fresh egg with a good firm shell consists of about 11.4 per
cent shell, 65.7 per cent of water, 8.9 per cent of fat, 11.4
per cent of protein by factor, or 13.2 per cent by differ-
ence, and .8 per cent of ash constituents aside from the
shell. Of this ash 53.7 per cent is phosphoric acid. Over
.2 per cent of the edible portion of the egg is phosphorus.
This composition is the average from twenty-four analy-
ses by Thompson, and eighteen by Wheeler, represent-
ing over 400 eggs from hens of several breeds under dif-
ferent rations. None of the analyses differed much from
the average.

496. Necessity for considering the water-supply.—
In the products, which have been mentioned, as in most
animal products sought by feeding, there is always a
large amount of water. In every dozen eggs there is a
pint of water. Aside from that necessary for construc-
tive use there is required for the activities of the living
animal a free supply. Particular mention is made of the
necessity for water, because its great importance is some-
times overlooked, for an especially provided supply is
not necessary under some circumstances. Instances occur
when the lack of water is the cause of ill success.

497. Efficiency of protein from animal sources for
fowl.—Mention of the characteristics and composition

FEEDING OF POULTRY 409

of the different nutrients of the food and a discussion of
their functions will be found elsewhere in this volume.
The facts apply to the feeding of poultry as well as to
that of other animals.

It appears from present knowledge that protein
derived from animal sources is more efficient for certain
uses, particularly the feeding of ducklings, than that
derived from vegetable foods. Previous mention has been
made of experiments at the New York Experiment Sta-
tion, the results of which accord with this assumption.
The rations which contained animal food proved much
more efficient than those of vegetable origin, the latter
having, according to the ordinary methods of estimation,
the same nutritive value as the former.

498. Ash constituents important for egg production.—
It seems probable that the ash constituents have some-
times not been sufficiently considered in feeding. While
the importance of the mineral nutrients can be largely
overlooked without serious practical disadvantage when
feeding some animals for certain purposes, it must be
given consideration when feeding domestic fowls. While
in milk, for instance, about 5 per cent of the dry matter
is ash, in eggs over 35 per cent of the dry matter is repre-
sented by the mineral constituents.

The shell of the egg, which represents about 11 per
cent of the fresh egg, consists almost entirely of carbonate
of lime. Most grain foods, which naturally constitute the
bulk of ordinary rations, contain little mineral matter
and the amuunt of lime is notably low. For simply sup-
plying the deficiency of material for the egg shell, car-
bonate of lime in the form of oyster shell can be used.
This was shown in experiments at the New York Experi-
ment Station made with laying hens after they were

410 THE FEEDING OF ANIMALS

closely confined on a clean floor for over three weeks. It
was then found that about nine-tenths of the lime in the
egg shell was unaccounted for in the food aside from the
oyster shells which were fed.

While less than 10 per cent of the body of a fowl is
mineral matter, it consists largely of phosphate of lime
and exceeds in proportion that of many foods. The bony
framework is also rapidly formed in the growing bird so
that mineral matter is in imperative demand. The
results of many trials made at the New York Experi-
ment Station are clearly in accord with this assumed
need. As has been previously mentioned, the addition
of phosphate of lime from several sources to rations for
young fowls has noticeably increased their efficiency.

499. Common salt a necessity for fowls ——Common
salt in considerable quantity is a necessity to the living
animal. Some foods contain a probably sufficient amount
but in others the proportion is very small. In order to
make sure of an excess, and to avoid any possible defi-
ciency, it is well to add salt regularly to the food, espec-
ially when it also increases the palatability of the ration.
About five ounces in every 100 pounds of food has been
found a safe proportion. Fowls regularly accustomed to
salt are not likely to eat an injurious quantity of very
salty material when it is accidentally within their reach.
Pigeons are very fond of salt and a liberal allowance is
generally considered necessary to insure health in the
loft.

500. Supply of grit for fowls.—Fowls at liberty are
generally able to find grit enough in the form of sharp
pebbles and sand to facilitate the grinding which occurs
in the gizzard. When they are confined or do not have
extended range, sharp and hard grit of some kind should

FEEDING OF POULTRY e ee

always be freely supplied. Clean, sharp sand is useful
for the very young birds and is quite generally considered
an essential part of all mixtures fed to ducklings. Good
results accompany its free use.

501. Feeding standards for fowls.——In studying and
comparing different rations, it is not possible to consider
all the combinations that can be made of the many foods.
It is only practicable to consider foods with reference to
their varying proportions of constituents. The only

portion of these constituents of nutritive value is that
which can be digested. Therefore, in compounding
rations, we are guided primarily by the amount of the
digestible nutrients supplied by the food; and feeding
standards are for convenience limited to a statement of
the assumed requirements in terms of digestible pro-
tein, ash, carbohydrates, and fat. The bulk of the ration
supplying these nutrients must also, of course, fall within
certain limits. In the absence of enough specific data,
calculations must be based on the coefficients of digesti-
bility observed for other animals. ‘These afford safe
enough approximations for present use, for the feeding
standards must be largely provisional.

Growth and egg production can only be sustained by
the food in excess of that required to support life, although
egg production can temporarily occur at the partial
expense of the body. The amount of food, then, required
for simple maintenance puts a limit on one side to an
efficient and profitable ration. In the other direction, it
is only limited by the capabilities of the individual ani-
mal. So the highest. possibilities depend altogether on
the intelligent judgment, and careful, daily attention of
the experienced feeder. In a general way only averages
can be considered.

\

4

412 THE FEEDING OF ANIMALS

502. Maintenance rations for fowls.——A number of
feedings trials made at the New York Experiment Sta-
tion supply information relative to the amount of food
required for simple maintenance. The amount varies,
as might be expected, with the size of the animal. The
larger fowls required more food but much less for each
pound of live weight. These feeding trials did not cover
any molting-period and egg production was, for the time,
suspended. From the data secured maintenance rations
have been deduced which correspond very closely to
those actually fed for quite extended periods during
which practically no change in live weight occurred. The
data were from an aggregate of 52 capons, averaging by
different lots from 9 to 12 pounds in weight, for 158 days’
feeding, and from 60 hens ranging from 3 to 7 pounds in
weight for 150 days’ feeding.

The rations are stated in the following tabulated form:

TaBLE LXXXV. MAINTENANCE RatTions. DIGESTIBLE NvuTRI-
ENTS A» Day FoR Eacu 100 Pounps LivE WEeriIcuaT

Total dry Ach: (Protein Carbohy- Fat Fuel | Nutritive

matter drates value} ratio

Lbs Lbs. | Lbs. Lbs. Lbs. | Cal.
Capons of 9 to 12 lbs.wt} 2.3 .06 3 1.74 -2 | 4,600} 1:7.5
Hens of 5 to 7 lbs. wt. 230 mil 4 2: 2 5,300} 1:6.2
Hens of 3 to 5 lbs. wt. 3.9 Als 5 2.95 3 7,680} 1:7.4

503. Rations for laying hens.—Hens in full laying
seem to require rations which have a larger relative con-
tent of protein and ash, and which show an increase in
fuel value of from 15 to 40 per cent, according to size,
over those required for maintenance. The following
standards approximate the requirements for two general
groups not sharply separated.

FEEDING OF POULTRY 413

Taste LXXXVI. Rations FoR HENS IN Foti Layine. Dr-
GESTIBLE Nutrients A Day For Eacs 100 Pounps Live

WEIGHT.
Total dry -_ | Carbohy- Fuel | Nutritive
matter Ash |Protein drates Fat value| ratio
ie | Lbs.| Lbs Lbs. | Lbs. | Cal.
Hens of 5 to 8 lbs. wt. 3.3 2 -65 2.20 ye 6,240) 1:4.2
Hens of 3 to 5 lbs. wt. 5.5 3 its 3.75 .385 |10,300| 1:4.6

These standards are not absolute and inflexible rules,
for such would not be justified by a thousand times the
number of available data. They supply a definite start-
ing point and are not supposed to obviate the use of judg-
ment. Because it is found convenient, on account of
different requirements and capabilities, to divide hens
into two groups, it should not be presumed that a hen just
under five pounds in weight must always have one ration or
a hen just over five pounds must always have the other.

A ration which corresponds to the standard given for
maintenance for hens of the larger size could be com-
posed of one pound of cracked corn, one pound of corn
meal, one-half pound each of ground oats, wheat mid-
dlings, and clover hay, one-fourth pound of fresh bone
and two ounces of meat scraps.

The following stated ration is given as an illustration
of one which would supply the nutrients called for in the
standard for laying hens of the larger size: One pound
of cracked corn, three-fourths pound of wheat, three-
fourths pound of corn meal, one-half pound each of wheat
middlings, buckwheat middlings, and animal meal, two-
thirds pound of fresh bone, and three-fourths pound of
young green alfalfa.

504. Rations for young birds.—The requirements of
the rapidly-growing young fowl are so constantly chang-

414 THE FEEDING OF ANIMALS

ing that a satisfactory average ration for any extended
period cannot be easily formulated. In the following
statement of rations for chicks, they are averaged for
periods of two weeks at different ages during the time of
most rapid growth. The ration for the last period will
suffice for several weeks longer, although the amount
required to the 100 pounds live weight will gradually
diminish up to maturity. For fattening nearly mature
fowls, a ration with a wider nutritive ratio of about 1:8
can be liberally fed for limited periods.

The duck grows faster than the common fowl and
more food is required during an equal time. Rations for
ducklings differmg somewhat from those for chicks are
given separately.

TaBLe LXXXVII. Rations ror Cuicxs. DIGESTIBLE NUTRIENTS
A Day ror Eacx 100 Pounps Live WErIcHT

Total Nutri-
- | Carbohy- | Fuel F
dr Ash | Protein Fa
pete drates : value vc,

Lbs Lbs Lbs. Lbs Lbs. | Cal.
For the first 2 weeks . 10.1 5 2 fee 4A | 18,800] 1:4.1
From 2 to 4 weeks of age 9.6 2.2 6.2 -) | 17,730:) ses
From 4 to 6 weeks of age 8.6 6 2 5.6 4 | 15,640 | @i:3:3
From 6 to 8 weeks of age 7.4 5 1.6 4.9 4 | 13.780 | 1:3.7
From 8 to 10 weeks of age 6.4 5 1.2 4.4 -o | 11,680) ees
From 10 to 12 weeks of age 5.4 4 a 3.7 -o0 | 10,000] 1:4.4

RaTIONS FOR DvucKLINGS. DIGESTIBLE NUTRIENTS A DAY FOR
Eacu 100 Pounpns Live WEIGHT

Total Nutri-
dry | Ash |Protein Paes ee Lee tive
matter ratio
Lbs. é : d ute Gals
For the first 2 weeks. 17.2 : a u 34,180 | 1:3.7
From 2 to 4 weeks of age| 17. ; ; F : 31,900 | 1:3.2
From 4 to 6 weeks of age} 11.2 : A x ; 21,000 | 1:3.3
From 6 to 8 weeks of age 8. ; E ; 3 14,940 | 1:3.8
From 8 to 10 weeks of age im e : : re 13,030 | 1:4.1
From 10 to 15 weeks of age 4.6 : , P 8,470 | 1:4.1

FEEDING OF POULTRY 415

As an example of a day’s ration which would cor-
respond to the requirements of the standard given for
young chicks during the second week the following is
stated: Four pounds of cracked wheat, two pounds of
granulated oatmeal, three pounds of corn meal, one-half
pound each of wheat middlings, buckwheat middlings,
ground oats, and old process linseed meal, two and one-
fourth pounds of animal meal, and two and three-fourths ~
pounds of young green alfalfa. This would feed from
800 to 1,000 chicks of this age.

Another ration in accord with the standard given
for ducklings about three weeks old might be consti-
tuted as follows: Eight pounds corn meal, three pounds |
wheat middlings, two pounds ground barley, two pounds
of old process linseed meal, six pounds of animal meal,
two pounds of fresh bone, and three pounds of young
green alfalfa. This and other specimen rations are given
under the assumption that free supplies of sharp grit, as
well as water, are also provided.

505. Adaptability of various foods for fowls.—A con-
sideration of the adaptability of the different foods,
aside from their composition, and of the apparent require-
ments of the young at different periods suggests a ration
somewhat wider in nutritive ratio for the first few days
than for some weeks afterward.

In providing a ration, it may be possible to devise
one in accord with the formal standard which will be
decidedly inefficient at times if the chemical composi-
tion and coefficients of digestibility are alone considered.
The adaptability of foods that are palatable must be con-
sidered. The difference in the energy required to digest
various foods which can supply equal proportions of
digestible matter may be important sometimes.

416 THE FEEDING OF ANIMALS

A large number of the ordinary grains seem prac-
tically interchangeable and many grain by-products can
be freely substituted for different whole grains or for
each other and all combined as desired. But some foods,
such as cottonseed meal, do not seem suited to common
fowls, even in very small quantities. Linseed meal can
be fed more freely, but the unground flaxseed is less
satisfactory. It is probable that oats, whole or ground,
which appear so valuable sometimes, should not be freely
used at other times. About 30 per cent of the entire
grain is hull. To obtain the available material from this
requires an expenditure of energy that can be better
applied during periods of rapid transformation, espe-
cially during the first few weeks of the young bird’s growth.
The products of the oat kernel, however, from which
the hull has been separated are in the unquestioned class
of foods. The same observation applies to buckwheat,
some kinds of pea meal, and to certain other foods less
commonly used, containing a large proportion of crude
fiber. Reference to this point has been made before under
the topic of coarse and bulky foods.

Primary consideration has naturally been given to
those domestic fowls upon which we depend for the
great bulk of eggs and meat. Other kinds are of consider-
able importance in certain localities, or often to the
fancier, but concerning them not enough is recorded to
establish separate feeding standards. It is probable that
their requirements will be found to correspond fairly
well with those of either the duck or of the common fowl.
The general food of the turkey is similar to that of the
common fowl but it should be less artificial, and con-
ditions of general feeding, more nearly resembling those
which exist in a wild state, are required.

FEEDING OF POULTRY 417

506. Knowledge of the nutrition of fowls limited.—
Unsatisfactory as is our present knowledge of the funda-
mental laws which underlie the science of nutrition
applied to man and other animals, there are nevertheless
volumes of carefully collected data that make it possible
to ascribe fairly narrow limits to their operations. Com-
pared with mammals, however, the class of birds has
received very little consideration. There have been a
few careful studies made, but for lack of enough informa-
tion our feeding must be guided by the rules applying in
common to all animals. Undoubtedly, the accepted laws
of nutrition observed for other animals are applicable in a
general way to domestic fowls, and it is safe to apply in
the light of the specific data we have any general prin-
ciples of feeding that have already been established. This
has been done in formulating the feeding standards which
are here presented, and all available data of a reliable
character have been considered. There have not been
enough, however, to justify narrow limitations, and the
suggested standards should not be considered final and
unchangeable. They simply represent the averages of
rations which, under careful management and like con-
ditions, have given better results than various other
rations with which they have been contrasted. Slight
modifications were made in accord somewhat with the
habits of the different fowls and with a consideration of
the character of the products desired. It is important
that the feeder, while following such standards in a gen-
eral way, should give enough consideration to the sub-
ject to make modifications suited to the species and breed
and to his particular conditions of market and farm.

CHAPTER XXIV
THE RELATION OF FOOD TO PRODUCTION

One of the questions much discussed by farmers,
and which has an important bearing upon the economics
of animal husbandry, is the food cost of the various
animal products. To illustrate, a herd of cows consumes
a certain quantity of food and produces a certain weight -
of milk, milk solids, cheese, or butter, according to the
terms in which we state the production. If the same
food is fed to a lot of steers a certain increase in their
live weight is secured. There is in each case a relation
of quantity between the food and the product. The food
cost, that is, the food consumption, involved in growing
a pound of beef, is quite unlike the food requirements for
producing a pound of pork, a pound of veal, or a pound
of eggs. If we consider merely food expenditure, that
branch of animal husbandry is most economical of raw
materials in which the largest proportion of the food dry
substance is converted into some new, useful product, or,
differently stated, where the food units bear the lowest
* ratio to a unit of product.

507. Food unit defined.—In presenting the matter it is
necessary to first define our units. Certainly it cannot bea
pound of food as eaten. One farmer feeds his cows silage or
roots, and grain, with but little hay, while another fattens
steers on dry food alone. A comparison of production in
the two instances on the basis of the gross weight of food
consumed would be absurd, because with the cows the

(418)

RELATION OF FOOD TO PRODUCTION 419 .

dry matter is largely diluted with. water. It would be
equally absurd to accept the dry matter in the ration as
a standard. In instituting a comparison between bovines
and swine, we must remember that the former consume
materials much less digestible than do the latter, and so a
unit weight of food does not represent the same weight of
available nutrients with the two classes of animals.

We should, so far as possible, reduce rations to their
units of nutritive value, and so the digestible dry matter
is now the nearest approach we can make to a basis for
comparing rations with each other or with the produc-
tion which they sustain. It follows, then, that if we wish
to show the comparative economy of production in dairy
farming and in beef farming, food alone considered, we
should express this relation on one side in terms of digesti-
ble dry food substance.*

508. The unit of production—What shall we con-
sider as a unit of production? We may answer this
question from two standpoints. We may measure pro-
duction by the quantity of the commercial article which
the farmer places on the market, or by the actual contribu-
tion which any given production makes to the food
resources of the human family. More specifically stated,
we may determine the relation of a unit of digestible
food substance to the live animal, beef, pork, milk, cheese,
butter, or eggs resulting from its use, and calculate the
ratio of any one of these to the actual nutrients con-
sumed, or we may ascertain the ratio of food consump-
tion to the edible dry substance in the various animal

*Since the above was written, we are able to reduce the food unit
for production to what is termed production value. This is more funda-
mental than the digestible matter as a basis for comparison. The com-

parisons hereafter made are, however, with the digestible matter con-
sumed as related to the unit of production.

420 THE FEEDING OF ANIMALS

products. The latter is the important ratio to consider
if we are seeking to learn how we can most efficiently
apply farm crops to the sustenance of the human family.

509. Factors involved in food economics.—This study
of food economics requires a knowledge of several factors.
In the first place, we must have the information coming
from feeding experiments, where a careful record has
been kept of the kind and amount of food consumed and
the weight of the resulting growth, milk, eggs, or what not.
This information must be supplemented by a knowledge
of the digestibility of feeding-stuffs, of the ratio between
the live animal or other gross product and the commer-
cial products, and of the composition and proportion of
edible material supplied by the commercial article. For
instance, we find it takes, on the average, 7.4 pounds
of digestible organic substance in the ration to produce
1 pound of growth in a steer, and we have learned by
slaughter tests that the average per cent of carcass for
97 animals was 61.4, and by the butchers’ and chemists’
analyses, that the carcass contains an average of 33.2
per cent of edible dry matter. From these data it is easy
to calculate that 12 pounds of digestible food are needed
for the growth of 1 pound of carcass or 36.3 pounds for
the growth of 1 pound of edible beef solids.

510. Relation of food to production with various
species.—The following tables give the data upon which is
based the productive power of food when utilized by
the various classes of animals. Data of this kind are
practically our only means of studying the economics
of producing those human foods which are most costly
in proportion to their nutritive value, a study which is
very ‘important wherever it becomes necessary to econo-
mize energy. It shows the coefficients of efficiency of

RELATION OF FOOD TO: PRODUCTION 421

various species of animals in maintaining human life.
The sources of all these figures are not given, for they
are so numerous as to make this difficult.

It is true, in general, that prices are proportional to
the cost of production. If, therefore, natural resources
are to be utilized for human sustenance in the most
efficient way and the cost of living brought to the lowest
possible point, the raw materials of the farm should be
applied to the production of those animal foods that are
most cheaply grown.

The time will probably come when the relation of
population to land areas will be such as to make necessary
an application of food economics along this line.

Taste LXXXVIII. PropucTion spy Farm ANIMALS. PROPORTIONS
oF CARCASS AND EDIBLE SUBSTANCE

Carcass Per cent* | Per cent of
Number in per cent | of edible | edible dry
of live dry matter| matter in
weight in carcass | live animal
Steers, general average
peets, lOWa 2-603 2.
Steers, Kansas. .
Steers, Mainey . .

Eames, lowa .. ..:
Swine, general average

PigsmOWA: ~ ss. 2 56 77.9 62.7 48.8
Calves eee 23 57.2 22:2 127
Fowl, large 12 80.8 27. 21.8
Fowkemall ... <i 78. 27. 21.1
Chickens, broilers 107 82.1 14.7 12.1
Pema 34§ 88.8] 26.3 23.3**

* From Bull. No. 28, Office of Experiment Stations. Revised edition.
+ Grown from calfhood, entire bodies analyzed.

t Not drawn.

§ Number of samples.

| Per cent after removing shells.

**In eggs with shells.

422 THE FEEDING OF ANIMALS

TaBLE LXXXIX. RELATION oF Foop To PRopUCT

Diges- Dizges- Diges-
tible org. | tible org. | tible org.

rs. Number |substance|substance/substance
Benar produ- | produ- {producing
cing 1 Ib.| cing1Ib.| 1 Ib.
ments increase | increase | increase
live wt. | carcass |edible sol.
Pounds
Milk, average. oo Sys 61 5.55
Milk, New York* .... 113f 4.85
Steers, average ...... 32 36.3
Steers, Ia., growth 9 to 24 m. 1 28.1
Steers, Kansas, 3 years old 1 39.6
SteersMainet 4 sou a 1 35.4
Sheep and lambs, average . il 37.9
Lambs, Iowa, growth while
PAGLCTHIME.. : a. joule ss : 2 30.9
Swine,§ average ..... PAS 6.4
ros law. ae bar ae ee 1 6.2
Calves, ayerage ..... 3 1ZS
Fowl, large, to 5 or 6 mos.|| . 6 23.4
Fowl, small, to 5 or 6 mos-|| 6 24.2
Chickens, broilers, 12 wks.| 15 28.8
Lore) i) Pe ae 14 19.6

*Extending over seven years.
+Short periods.
§Deduced from compilation by Dr. Armsby for U. S. Dept. of Agriculture.
{Dry matter, mostly from milk, practically all digestible.
| Unpublished data from experiments at the New York Agric. Exp. Station.
**4.35 lbs. dry matter, assumed to be 80 per cent digestible.
+tEgg product, 100 eggs per year.
§§85.7 lbs. dry matter, assumed to be 80 per cent digestible.

The figures of the foregoing tables can be regarded
as being trustworthy for average conditions. They are
obtained from the recorded data of experiment stations,
and involve a large number of observations with dairy
cows and with growing and fattening animals.

In most cases the amount of digestible matter in the
ration is calculated from the average coefficients of
digestibility.

The facts brought out by this study of the relation
of food to product are emphatic and suggestive. In
order to display them as clearly as possible there are
shown in the next table the quantities of the various

RELATION OF FOOD TO PRODUCTION 423

commercial animal products, and of human food in
animal forms, which can be produced by the use of a
quantity of cattle food containing 100 pounds of digesti-
ble organic matter:

TABLE XC. RELATION OF Foop To PrRopuct

Produced by 100 lbs.
digestible organic
matter in ration

Marketable} Edible

product solids
Pounds Pounds
Milk, general average. S Sees <a, 18.
Milk, New York experiments ot ta oii Rang Ag 20.6
Cheese, ee best ce as NS) 1g Vet eae es 14.8 9.4
Bopter . i. . saa Ne 9)/E hs 6.4 5.44
Steers, general average, live weight bo Cie poeg eo 13.5
pees, lows, live weight ....-......- 16.8
Steers, Waneas; live weight (<0 0.0 fy n>. 12.4
Steers, Maine, live weight ......... 15.
Steers, general average, carcass ..... . 8.3 2.75
Meee laws, carcass: 0. 6 se 10.7 3.56
Mame IGANSAS, CATCASS . <9. 2s Cs ee: 7.6 2.52
Steers, Maine, carcass . . : 8.7 2.84
Sheep and lambs, general aver rage, live weight 13.9
Lambs, Iowa, live WEIGH. hier ee ae 17.8
Sheep and lambs, general average, carcass. as 2.60
Lambs, Iowa, carcass... . Pe ek 8 9.6 3.23
Swine, general average, live weight LP Se Wigan 30.4
Swinesiowa, live weight. . . 3... . 2.847% 33.
Swine, general average, carcass. ...... 25. 15.6
Pr ORNS, CATCASS it's te Ro ee ey, 25.7 16.1
Calveamive weight, 2+. 2.0 eee RE 63.7
eavcemearcdss oe oe RO Oe ame as 36.5 8.1
Powtmrge, live weights. oF). fal oe 19.6
Fowl, small, live weight .. . eee et a 19.6
Fowl, dressed carcass, average . . ee yp 15.6 4.2
prover, live weiglit-2 2°... 78 28.7
Broilers, dressed carcass. . , oo) ee 23.8 3.5

oe ees)! . 19.6 5.1

424 THE FEEDING OF ANIMALS

It may properly be said of the foregoing figures that
they are only averages and that the relation of food to
production varies with different animals of the same class
and with the conditions involved. While this is true, the
relations shown in the preceding calculations represent
differences too wide to be explained on any other ground
than that the various animal products have greatly
unlike food cost.

The most noticeable fact brought out by this com-
parison is the low relative food cost of milk and other
dairy products. The growth of a pound of edible beef
solids requires a food expenditure nearly seven times as
great as is necessary for the elaboration of a pound of
milk solids. On the other hand, swine are fed with nearly
as great economy as are milch cows. In fact, when proper
allowance is made for the period of growth of the cow and
for the annual periods when she is giving no milk, she
seems to have no advantage over the pig except in kind
of product. Next, in the order of economical use of food,
comes the calf when fed largely on milk. Poultry prod-
ucts stand next in line. Sheep and lambs do not differ
materially from steers, meat products of these two
classes requiring the largest proportional food consump-
tion of any form of growth here considered. The order
of food efficiency as related to the several animal prod-
ucts is therefore as follows: milk, pork, veal, poultry
and eggs, mutton, and beef.

It is suggestive, at least, to notice that the food factor
is inversely as the labor factor in these various lines of
production. For instance, labor is a large factor of the
cost of a pound of any dairy product and a small factor
in the cost of beef or mutton, while the reverse is emphati-
cally true of the food cost.

CHAPTER XXV
GENERAL MANAGEMENT

THERE are many considerations pertaining to the
feeding and management of live-stock that have a more
or less common application to all classes of animals and
which may be discussed conveniently under one head.
They are partly of a business character and to quite an
extent lie outside the chemical and physiological princi-
ples of nutrition. Some of those questions are matters
of much importance, but many of them which relate, for
instance, to times and methods of feeding are given a
prominence in current discussions out of proportion to
their real influence in determining success. It should
be understood, too, that many of the details of practice
are not limitable by fixed rules but must be variable
according to the conditions involved. Tact and judgment
are demanded of the farmer who wisely adjusts his
practice to business principles.

511. Factors in general management of animals.—
General management properly includes, among other
considerations, the following topics:

(1) The selection of animals; (2) manipulation of
the ration and manner of feeding; (3) the intensity of
feeding; (4) environment and treatment of the animal.

The object to be sought in feeding animals is the con-
version of a unit of food into the largest possible quan-
tity of the product best adapted to the producer’s com-
mercial opportunities, and here the limitations of the

(425)

,

426 THE FEEDING OF ANIMALS

animal are often the limitation of the farmer’s profits.
Within each species varietal and individual differences
determine the rate of production and also whether the
food shall be transformed into poor milk or rich milk,
inferior beef and mutton or superior meat products, fine
wool or coarse, trotters or draft horses, and small eggs or
large ones. |

The selection of animals should have reference to
three general factors, which largely fix the rate and
character of production, viz., breed, individuality, and
age.
512. The selection of cows.—The breed and indi-
viduality of the cow largely determine the quality of her
product and the quantity of production from a unit of
food. Neither heavy feeding nor skill in compounding
rations can be made the means of causing her to overstep
her constitutional limitations.

The selection of cows simply with reference to breed
is a question of adaptability. If the production of milk
at the minimum food cost for a unit of volume is the
result most desired, the dairy breeds, characterized by
milk with a low proportion of solids should be chosen;
but if the object is merely to secure butter-fat with the
lowest possible food expenditure, the so-called butter
breeds are in general to be preferred.

When the chief consideration is the manufacture of
milk solids most economically, we must deal not so much
with breeds as with individuals. In fact, with all breeds
and with animals of no breed, individual capacity is the
consideration fundamental to profitable feeding. Some
Holsteins will return both more milk and more butter
for a unit of food cost than will some Jerseys, and the
reverse is equally true. There is no magic in heredity

GENERAL MANAGEMENT 427

_which overcomes lack of capacity either for the breeder
or for the dairyman.

513. The general-purpose cow.—The ‘“general-pur-
pose” cow has been much discussed in recent years.
While her specifications have never been fully and clearly
set forth, it is supposed that she is an animal reasonably
- profitable along both beef and milk lines. It is doubtful
whether such a cow, even if she exists, is one adapted to
general utility. There are few localities where milk is
not more profitable than beef or beef more profitable
than milk, and whichever is the more profitable should
be produced by an animal of specialized capacity. Any
extra value which the calf’s or the cow’s carcass may have
when flesh-forming tendencies are prominent, will gen-
erally come far short of compensating for a merely medi-
ocre milk yield in those localities where there is a market
for milk and its products; and the stockman who is
endeavoring to put on the market beef animals of the
highest quality cannot afford to compromise with dairy
qualities. Milk formation and flesh formation are antag-
onistic, and not correlated, functions, both of which do
not operate intensely in the same individual. At present
we have no breed or fixed type of animals that can be
regarded as presenting and perpetuating “general-pur-
pose” qualities. Such a type, if found at all, must be
sought among individuals.

514. The selection of animals for meat production.—
It is generally conceded that the selection of breeds of the
beef and mutton types is essential to the highest success
in the production of meat. This is true with steers, not
because those from the dairy breeds will make very
much slower growth than Shorthorns or Herefords, for
this does not seem to be the fact, but because the quality

428 THE FEEDING OF ANIMALS

of the product is higher with the latter, that is, the pro-
portion of valuable parts is greater and the distribution of -
fat and lean tissue is more desirable, in the distinctly
beef animal.

_A choice from the beef and mutton types and from
the various breeds of swine may safely be left to personal
preference. Many experiments have been conducted
with a view of determining the relative capacity of
growth of the prominent breeds of bovines, sheep,
and swine, and the testimony so far adduced is of a
negative character and does not point to any one
breed of any species as clearly superior to all others.
It is well understood, however, that within every
breed individual variations are important and that
from a “bunch” of steers it is possible to select some
animals superior to the others in their capacity to make
profitable use of food.

515. Relation of age to meat production—A most
important factor in this connection is the relation of age
to the profits of meat production. Nothing has been more
fully established by experimental evidence than that the
younger the animals the larger the ratio of increase to
body weight and the greater the increase for each unit of
food consumed.

Some of the more striking evidence on these points
is presented in the following figures:

TaBLE XCI

Results with steers from five breeds slaughtered at the Smithfield
(England) Fat-Stock Show (from Henry’s compilation)

Age Number animals Daily gain
One year old 77 2,° Ppa
Two years old 89 |S ee

Three years old 54 j Oro ia

GENERAL MANAGEMENT 429

TABLE XCI, CONTINUED
Steers at American Fat-Stock Show (Stewart's compilation)

Age Number animals Daily gain
297 days 30 2.6 Ibs.
Giz." 152 225e
943. “ 145 like
$Ps3 133 Lb 4
American experiments with pigs (Henry’s compilation)
Weight of pigs Number feeding trials Food for 100 Ibs. gain
38 lbs 41 293 lbs
és ied 100 400 <“
ms. “ 119 437. ™
174 “ 107 482 “
at 72 498 ‘
ff aes 46 i) BE
320). “ 19 535
Results of Danish experiments with pigs.
Weight of pigs Number experiments Food for 100 lbs. gain
35 to 75 lbs. 3 376 lbs.
Tato 115 “ 10 435 “
Myto 135 “ 13 466 ‘“
155 to 195 “ 15 513 =
$95 to 235 =“ 14 540 “
to 275 “ 11 614 “
Zia to 315.“ 3 639 *

Testimony of this character is abundant, and the lesson
for practice is that animals should be fed for market at
the earliest age that is consistent with other conditions.

516. Manipulation of the ration—A great deal of
experiment and discussion has been devoted to the
economy of various methods of treating cattle foods,
such as cutting, grinding, wetting, and cooking. The
economy of these operations requires no extended com-
ment. It is a simple and safe rule that any fodder or
grain, that in its natural condition is palatable, is wholly
eaten, and is thoroughly masticated, should be fed with-

430 THE FEEDING OF ANIMALS

out the unnecessary expense which these manipulations
would cause. Grinding any material that is not otherwise
thoroughly masticated doubtless increases the efficiency
of the food, but when the grinding costs as much as 10
per cent of the market price of the grain it is doubtful
if any advantage accrues. Cutting, unless for the pur-
pose of mixing, has the sole advantage of saving the animal
a little work.

Wetting and cooking render certain foods more
tender and more palatable, and when this secures the
consumption of materials otherwise wasted these opera-
tions may become economical. On the contrary, similar
treatment of grain foods already much liked by the
animal is, according to the majority of testimony, an
occasion of loss rather than of gain.

Practice differs as to the number of portions into
which the daily ration shall be divided. Some herds
are fed three times a day and some twice. While it
would be possible to feed too many times or too much
at any one time, it seems more than probable that if
animals are fed regularly the ration may be as efficient
when divided into two portions as when there are three
feeding periods. The adaptation of any system to the
requirements of farm work is a matter of more impor-
tance, probably, than any influences proceeding from the
number of feeding-periods. The warming of the water
consumed has been introduced to some extent with dairy
herds. Certainly it is bad practice to force cows to drink
ice-cold water, but it is also bad practice to warm the
water above the point of palatableness. The likes and
dislikes of animals must be considered, and to ignore them,
even to save the small food expense necessary for warm-
ing the ingested water, is not advisable.

GENERAL MANAGEMENT Aa}

517. Quantity of the ration.—Great stress is usually
laid upon the fact that it is only the food that is supplied
above maintenance needs which is productive. This
truth, indiscriminately accepted, has led to feeding
so excessively as to injure the health of the animals and

diminish profits. The largest production is not always
the most profitable. Abundant testimony can be cited
in support of the statement that very heavy rations
yield smaller returns for each unit of food consumed
than more moderate ones. It is possible, also, to adopt
an unprofitable extreme in the direction of light feeding.
Heavy rations are sometimes warranted by the low
cost of feeds and the high price of the resulting product,
a condition which has not existed for the past ten
years. In the writer’s judgment, milk is more economically
produced by cows not unusual in character or size when
the grain ration, wisely compounded, ranges between
eight and ten pounds daily, according to the weight
and capacity of the animal, than when more is fed, pro-
vided the coarse foods are supplied in the ordinary propor-
tion. It is especially important with breeding animals,
where the physical condition of the dam should be kept
at its best, that the indigestion and high physical tension
induced by extreme rations should be avoided. The wel-
fare of future generations demands this.

518. Environment and treatment of animals.—The
quarters in which animals live should be comfortable,
that is, they should be neither too warm nor too cold and
should be well ventilated. These conditions are essential
to health and the most profitable production. The
stable temperature in winter should be held above 45° F.
as a minimum, and may well be kept below 60°. A con-
stant exchange of air should be secured without creating

432 THE FEEDING OF ANIMALS

cold drafts, and the “King” system of ventilation seems
to be worthy of commendation.

All domestic animals, whether the milch cow or the
fattening steer, should have a reasonable amount of
exercise under comfortable conditions. Little sym-
pathy should be shown toward the modern fad of tying
cows by their heads in one spot for five or six months,
under the plea that exercise is work and work costs food.
The statement had better be in accordance with the
experience of all time, that exercise is health and vigor
and that food is well used in maintaining these. The cow
is more than a machine; she is a sentient being, suscepti-
ble to many of the influences which are essential to the
physical welfare of the human species. Let no one take
this opinion as an excuse for the cruel and wasteful expo-
sure of farm animals to inclement weather, which is so
often observed, for this is simply a violation of the laws
of kindness and economy in the other direction.

A sympathetic relation should be established between
the animal and the herdsman. Close observers declare
that such a relation promotes greater thrift and larger
production, especially with dairy cows. These animals,
possessed of the instincts and affections of motherhood,
respond to fondling through its influence upon their
nervous organization.

Moreover, the economic relation is not the only one
man sustains to the animal world. Farm animals are
man’s companions and friends for which he may enter-
tain even sentiments of affection. The daily life of the
farm-house is full of pleasant experiences that belong to
the care of, and association with, the grateful creatures
whose wants must be supplied—the motherly cow, the
faithful horse, or the noisy,.cackling fowl. No farmer

GENERAL MANAGEMENT 433

has reached his best estate who does not find in the
animal life about him an enjoyable companionship of
which he need not be ashamed, and without a sense of
which he is not prepared to fulfil his obligations to the
creatures dependent upon him.

519. Cruelty to animals.—While it is the purpose of
this volume to deal with the facts and principles of
science and practice, it is not improper briefly to urge
the need of the cultivation of right sentiment concerning
kindness in the care of animals, for we really do not fully
appreciate the unkindness shown by man toward the
inferior species under his control. In no way has he more
clearly demonstrated that he partakes of the brute
nature than in his treatment of the brute. As a master
he has been guilty of cruelty which it is humiliating to
contemplate, a cruelty not so swift in its operation as
that of the beast of prey, but which is greatly more
shocking and is wholly at variance with the exalted
characteristics that we attribute to humanity. The half-
sheltered animals that have endured our cold northern
winters—the spavined, wind-broken wrecks of our livery
stables, whose infirmities secure for them no relief from
hard service—the daily exhibitions on our city streets of
the patient draft horse with raw flesh under the collar
and smarting under blows from unfeeling, cursing drivers
—and especially the deliberately brutal practices of the
race-track, where amid the plaudits of a throng of men
and women who would claim to have kind hearts, noble
animals, by unjustifiable “scoring” and in the subse-
quent race, are often forced to the last limits of endurance
—these are all evidences of an utterly selfish indiffer-
ence to the suffering of living creatures that can neither
utter a complaint nor avenge their wrongs. A certain

BB

-

434 THE FEEDING OF ANIMALS

proportion of humanity appears to regard the animal
as a mere unfeeling machine out of whieh pleasure and
gain are to be forced even to the pound of flesh, and
not as sentient beings capable of the keenest physical
pain and with rights that should be respected. - The
constant occurrence of the ill-treatment of animals is
perhaps the cause of the complaisance with which it is
regarded, but it is no excuse for such thoughtless
indifference. Society notes and punishes flagrant cases
of abuse, but the average human conscience is not yet
sufficiently tender toward man’s treatment of his faith-
ful servants.

“ty

APPENDIX

COMPOSITION, DIGESTION, AND FEEDING
STANDARDS BY TABLES f

. Average composition of American feeding-stuffs, page 435.
. Average coefficients of digestion, page 441.
. Energy-production values of feeding-stuffs, page 448.

. Food standards for milk production as developed by Haecker,
Savage, and Eckles, page 455.

5. Feeding standards, page 457.
6. Fertilizing constituents of American feeding-stuffs, page 460.

m OO bo

1. AVERAGE COMPOSITION OF AMERICAN FEEDING-
STUFFS

The figures in the following table have been taken
from Bulletin No. 11, Office of Experiment Stations;
Farmers’ Bulletin No. 22, United States Department of
Agriculture; Bulletin No. 81, Vermont Agricultural
Experiment Station, and Bulletin No. 166, New York
Agricultural Experiment Station (Geneva). |

The percentages given represent averages from which
there are material variations. These variations are
mostly due to differences in the water-content, the in-
fluence of locality and of the stage of growth and the
changes brought about by the methods and conditions
of curing. They are not so large and important with
the grains as with the fodders.

A more complete table of the composition of feeding-
stuffs is to be found in Henry & Morrison’s “Feeds and
Feedings,” the edition of 1915. The figures given in the

(435)

436 ‘ APPENDIX

following tables, however, are sufficiently full and accu-
rate to illustrate the composition of the various classes

of feeds. . me a, i
‘

me COMPOSITION OF FEEDING-STUFFS
if Nitrogen-

free
Water Ash Protein Fiber extract Fat

Green fodder % % % 70 70 %

Corn fodder—*

Flint varieties....... woe 2.4 6D 43 12.1 7
Flint varieties cut

after kernels had

TVA PU ab Gace ae 21 43 14.6 8
Dent varieties....... 70. By aes Bf 5.6... 12: 5
Dent varieties cut

aiter kernels vhad

REESCL Toke a 43.4 °° 1.6%,-2. Gai 015.6 9
Sweet varieties...... 19 1B S19 44 12.8 5
All varieties......... 49.85 (eS 5 12:2 a
Leaves and_ husks,

Gem ereen.......... 66.2)" SAO Bet of gown Ee 1 |
Stripped stalks, cut

REINS Ao oes, ate 76.1 Br 5 7.3 14.9 &

Sorghum fodder....... 194) SOE ee 6.1 11.6 5
WVCTMEECT. casas cae. £OO > ALS) "2.609 ae 6.8 6
Barley fodder......... 79. LB DH 7.9 8 6
COAtMEPOOT paces te , OA 2b 84 11.2 19.3 1.4
Pasture grass....... RA 1) 2, So 4, 9.7 8
Red-tomf in bloom..... 65.3. 2.3 2.8 11. 17.7 9
Tall oat grass, in

BMMSTYE, 4 vcs sede 69.5 2. 2.4 94 15.8 9

Orchard grass, in
PMT oo phd ohiaver a 73. 2. 2.6 S22 one 9
Meadow fescue, in
RIN... eens ae 69Gmes 2.4 10.8) 948 8
Italian rye grass, com-
ing into bloom..... T3207) 3.1 6.8 13.8 0 Ge
Timothy,§ at different
SES ORL Dials 61.634 s-l 8 86311.8° (e202 ee
Kentucky blue-grass,**
at different stages.... 65.1 2.8 4.1 9.1. 2-G aha
Hungarmen grass....... 71.1. east 9.2 14.2 ow
Japanese millet........ 75: Tay s2.1 7.8 13.1 he

No. of
analy-
ses

40

che He w oe Oe TE

iw)
>

56

18
14
12

*Corn fodder is the entire plant, usually a thickly planted crop. Corn stover

is what is left after the ears are harvested.
{Herd’s grass of Pennsylvania. {Meadow oat grass.
§$Herd’s grass of New England and New York. **June Grass.

-

COMPOSITION. OF FEEDING-STUFFS — 437.

Y : Nitrogen- No. of

analy-

free
Water Ash Protein Fiber extract Fat ses

TO eo :20 pita te Je
Green Fodder—continued : e “ah . a %

fe Red clover, at different

SECS. acc. «eck tre 2.1. 4.4 8.1 13.5 151. Was
Alsike clover,*in bloom. 74.8 2. 3.9 ea AT: 9 4
Crimson clover........ Pea LT x SF Boo 8.4 1 £3
Alfalfa,t at different te

ES Ree ec Ms (2.7. 48. 74 . 123. 1a
Serradella, at different (

BOS oS oe a cheers ct BO lear eo ame 5.4 8.6 7 9
Se ager 83.6 li mee 4.8 7.1 4 © 10
Dee ic Lec. OL C26 CO 6.7, 10.6. 1. °° Be
Pigee bean........:... S42! ES ees 4.9 6.5 4: Mee
Flat pea (Lathyrus ,

TE) 66:7, 2.9 - Sa 7.0 422) 1 2
ee 84.5 2. 2.8 2.6 8.4 5 y

Silage

Coemsilave............ Coe” eae Ie? 6. il. 8 99
Sorghum silage........ (Gil) ok 8 G4" SESS eS. 6
Red-clover silage....... <2: PAY ager: S4°) ThE") Ee 5
Soja-bean silage....... 442) DB AL 9.7 6:05.28 1
Cowpea-vine silage..... 79.3 A! a Ae 6. 7.6 1.4 2
Field-pea-vine silage.... 50.1 3.5 5.9 13. 26. 1.6 1
Silage of mixture of

cowpea vines and

soja-bean vines.... 69.8 4.5 3.8 9.5) 11:1 1.3 1
Millet and soja bean... 79. Don Des 42 Met beam 9
Corn and soja bean.... 76. BA 25 FP A 2 | eae ae:
VEEL cies c acc'e av ee oss 80.8 1G {ic BA 5.8 9.2 3 1
Apple pomace......... 85 0, 12 3.3 8.8 EE 1
Hay and Dry Coarse Fodder

Corn fodder,{ field-cured. 42.2 2.7 45 14.3 34.7 1.6
Corn leaves, field-cured. 30. ae | Gs 21.4) CSE ae 17
Corn husks, field-cured. 50.9 1.8 2.5 15.8 28.3 7
Corn stalks, field-cured. 68.4 1.2 1.9 #11. Wes 5

Corn stover§ field-cured 40.5 34 3.8 19.7 31.5 11 60
Barley hay, cut in milk. 15. 42 88 24.7 449 - 22 1
Oat hay, cut in milk... 15. §.2°% 49.3) > 29-205 735; 2.3 1
Hay from—
Red-top,** cut at dif-
ferent stages...... 8.9. 5.2° C.9r, eee 47.0) ee 9
Red-top, cutinbloom 8.7 4.9 8. 29.9. 464 24 3
Orchard, grass....... 39 6. 8.1. Sao 41, 2.6 10
*Swedish clover. §What is left after the ears are harvested.
tLucerne. **Herd’s grass of Pennsylvania.

{Entire plant.

438 APPENDIX

Nitrogen- No. of
ree analy-
Water Ash Protein Fiber extract Fat ses
Hay and Dry Coarse Fodder % % % 7% % To.
—continued a
Hay from—

Timothy,* all analy’s. 13.2 4.4 59 29. 45. 235 68
Timothy, cut in full

Dloom:.:: : nave a5. a. 6. 29.6:. 41.9>7-3: 12
Timothy, cut soon af-

ter bloom.. Ag me. AA 5.7 28.1 2h6ee 11
Timothy, cut he eS

iearly ripe. ....:. mee OD) COG. 31.1. “Aaya 12

Kentucky blue-grass.. 21.2 63 7.8 23. 31.85. e0 10
Cut when seed was

Lin ate eee 4 | TZ, 6.35 24.5 3420 4
Cut when seed was
MOE ess peo) Gt 5.8 .23.8 33:20 4
Hungarian grass..... Tie abs foe. * AG: 2 413
Meadow fescue...... 20. Tc ee 25.9 38.4. “7am 9
Italian rye grass..... Bea eee ie Oc: - 45. 7 4
Perennial rye grass... 14. Pas Mee cae. 40.5 OLE 4
Nausea grasses....... 153 55°" 7.4 27.2. .42.1 2:5 Gee
Rowen (mixed)}..... 16.6 6.8 11.6 22:0 39.4 3.1 23
Mixed grasses and
Cl Ge) ce ed 12.9.) "Sia SIO SiGe 418) 2.6 17
Swamp hay.......°.. LEG 6.7 = SEG 6 a ee 8
Sak Mare... so. Sk 10.4 (her 5.5 30. 44.1 2.4 10
Redmrover,.”. 3.4... 15.3: - ‘6.2-* 12.3) Y2ESa Yoel eee 38
Red elover in bloom.. 20.8 6.6 124 21.9 . 33.8 4.5 6
Alsike clover........ 07 9 8.3. 12.8. 256 - aa ee 9
White clover........ O77. “Se 015.7: 21> soe rk
Crimson clover...... 8.6-°° 8:6" 15.2 - 22s Veer yee Z
Japan clover:....%.. Li Sp ie.0 | 2ae 39. 3.7 2
VIEean) 5 avs eee sed ete Riese eo 17. 25:4. SG eee 5
permadella., .. 2.45.2; eee. 15.2 21:65 4220 ee 5
FUG Ce Rate Bela. fe weet 14.3 25) 42.7 2S 21
Covapea....5.3..0¢.. Teo 8616.6 204052423 Gee 8
Bojaspean: | 5,555 25. ieee, 15.4 22:3 738/60 oe 6
Flat pea (Lathyrus
syluestris)......... SAvaaiee., 22.9 26:2)° 314253 5
Peanut vines (with-
OuUumtts). 82". 5 ik t.Gaoeee 10.7 3862236. eT ae 6
Péa. wiser 6.08 i. Geis. 24.7 30-00e-om 1
Soja-bean straw....... 10.1 (aie 4.6 8640.4) Bea eee 4
Horse-bean straw...... 9.2 "ae s:S 37.6 “S438 1
Wheatmtraw........... 0.6 “4s 4 38.1 “4345738 7
Rye ite fees... Ls. (Almere Ss 38.9 46.6 1.2 <
Oat straw. . ne 9.2 5.1 4. Si. 42.4 2.3 12
Buckwheat straw. Om OG 5.5.2 43. $5:1..-1.3 3

*Herd’s grass of New England and New York. tSecond cut. tLucerne.

Roots and Tubers

Potatoes. = ........
Sweet potatoes........
ied Gets... Soe
Sugar-beets...........
Mangel-wurzels........
DVM. ccs. A Se
HAMAS... oS ee
(Co) es 0:

Grains and Other Seeds

Corn kernel—
Dent, all analyses....
Flint, all analyses....
Sweet, all analyses...
Pop varieties........
Soft varieties........
All varieties and
BMEVSES:. 0... 5. -
Sorghum seed.........

Spring varieties......
Winter varieties, all
PERULUBES, «oko ol:
All warieties.........
ll See
Pacumneat.........:..
Sunflower seed (whole).
Ss: - 3 nr
Cottonseed (whole,with
it 2) ears eee
Cottonseed kernels
(without hulls)....
Cottonseed whole,
Cl. Of Sn
Peanut kernels (with-
@ue hulls). ...2....
PiGrseeee an... a... 2.5%
Sora Wem... ...... 3%
Cowpea WMA. .....<-2:

\

hs

COMPOSITION OF FEEDING-STUFFS

Water Ash Protein Fiber extract

—%
78.9

fe
88.5

7%

/)

Se el eel cee eee ll dl tS)

10.3
10.5
11.6
11.2
11.4

10.5

91
12.4
11.8
10.6

12.5

11.8
11-3
7.4
10.
16.3
22.6

18.4
31.2
16.8
27.9
26.6

34.
20.8

Ori H ROOM Oe |

Nitrogen-

Tee

% %
ow 47.3
ae.) 24-7

9 8.
9 9.8
9 5.5
1:2 6.2
1.3 a5
1.3 7.6
8 15.9
2.2 70.4
sty" 4051
2.8 66.8
1.8 69.6
2: 70.2
2.1 69.6
2.6 69.8
Ey 69.8
9.5 59.7
ie i220
1.8 7As2

1S eee es
LS 79
2 79.2
8.7 64.5
29.9 21.4
wok 23.2
23.2" een
eb 17.6
20.4 23.5
he 15.6
Y 50.1
4.8 28.8
4.1 55.7

Fat
%

biRbybyy hh iRe

BS ada ca tr Ld

bo ~I OO, ONeH

bo

439

No. of
analy-

ses

WNORPRWDHDO DW

oor N bo

440

Mill Products

Wheat flour, all analyses
Buckwheat flour.......

Soja-bean meal. . ;
Ground corn and Conte
equal parts. .

Waste Products

MerOUS.. Jobe ad ues
Hominy chops......
Glormeran... 2.0.2.0. 5.
(Cirnneerm ...6 35 ......:
Corn-germ meal.......
Gluten meal—

oho) Gers
Gilutenmeeds. 0k:
Buiter Oe A St
Peoria*. .
Disthond,. or Rook:
ford.. ce
Chicago maize Need”:
Glucose feed and glu-
cose refuse. . :
Dried starch feet ‘tie
semrar. LCGGs os 2. 2
Starch feed, wet.......
OPAC MRMEIISY So loos ac ute ee
Oatineee eee ee ey
Barley screenings......
Maltspmants ... 2... 0.
Brewers’ grains, wet ...
Brewers’ grains, dried. .
Grano gluten.........
Rye‘bemi seo.
RYC Snes. Moe k ie es
Wheat bran from spring
wheat... doth ally.

. APPENDIX

ree
Water Ash Protein Fiber extract

%

11.5

5 ee ae a
G0 Wt & OO

Ne

6.7
3.7
3.6
6.4
L:

3.6
2.8
3.6
5.9

5.4

7%

16.1

Nitrogen-

Fat
% % %
1.9°.\' 68:70 Sig
6.6 64.8 3.5
OS RELA. ae
6.5 66.3 22
Ayo gis 8
eh 1.1
3). Faas
7.3. 229 304
14.4 Bie ae
45 9273 16.2
5.7 642° 44
30.1 54.9 5
38. 64.5- "83
i277 62.2 “58
4.1 64. 7.4
Dei ohG2.5 °° (7.1
Ey ins: te ace
14. 458 2.2
12 526 46
5.3 51.2 10.6
6:2). 51D bas
82 51.1, 196
6.6 566 3.5
7.6. 5a) ee
45 56.8 10.4
4.7. §435°V5:
3.888: 3.1
29.7! cB ade ai
6.1 “59.4 >" "ae
7.3. 618° BE
10.9 ATI 73
3.8. 12:52 5 ee
11! 51.7 5.6
12. 33.4 14.9
3.5. - Gg
5.1 °59:9 “ee
8. 54.5 4.5

*Included in above average.

fas . e
BNR woO NRT NP bo w

No. of
analy-
ses

7
7
6
at:
4
0
4
2
2.
1

J

bo

18
12

‘UW

=

_
f=)

COEFFICIENTS OF DIGESTION

Waste Products—continued
Wheat bran from winter

Wheat bran, all analyses
Wheat middlings.......
Wheat ‘shoris.:: 42.
Wheat screenings......
Bapeeeean >... se
Troreeeis.. oe
Ga.) AlCl ie
Buckwheat hulls.......
Buckwheat bran.......
Buckwheat middlings...

Cottonseed meal.......

Cottonseed hulls.......

Lins’d meal, old proc’s.

Lins’d meal, new proc’s
Peanm, meal..........
Pemen nulls.......)..

Miscellaneous

a).
Apple pomace.........
oe re
Beet molasses.........
ol.
Prickly comfrey.......
Pumpkin (field)........
Sugar-beet leaves......

ree
Water Ash Protein Fiber extract Fat
J.

%

J

Nitrogen-
% % %
8.1 53.0, 1a
9. 53.9 4,
5.2 58. 5.6
TA 56.8 4.5
4.9 65.1 3.
9.5 49.9 8.8
35.7 38.6 ok
6.3 58. res:
43.5 35.3 LF
31.9 38.8 3.3
4.1 41.9 Lig
5.4 25.2 10.8
46.3 33.4 2.2
ha. = 1 OO. 1.2
8.4 36.7 3.6
5.1 23.0 8.
64.3 15.1 1.6
44 348 19
1.2 16.6 A
3.9 16.2 1.3
2.4 6.3 oti
oes 59.5
1.5 3.9
1.6 5.1
ibys 5.2
2.2 4.4

2. AVERAGE COEFFICIENTS OF DIGESTION

i i Go.

441

No. of
analy-
ses

- Ba

<7
ee

WNHNRWOO Wl

35
41

The coefficients of digestion which follow are mostly
taken from the compilation by Jordan and Hall as pub-
lished in Bulletin No. 77, Office of Experiment Stations.
Others, marked G, are from the compilation of Dietrich
and Kénig (“Composition and Digestibility of Cattle
Foods,” Vol. II). Later figures are found in Report of
Hatch Experiment Station, Massachusetts, 1905, and in
Henry & Morrison’s “Feeds and Feeding,” 1915.

442

No. ex- Kind and condi-
perim’ts tion of food _

—
Ne WO Pk OD Ot Be ee Pw

Hee oO

ee

APPENDIX

DrGEsTION BY RUMINANTS
———— Digestion coeficients ———_—>7.

j %
GREEN FopDERS
M eadow Grasses
Aungarian:.....22..%. 67.2
. Barnyard millet....... 66.6
mimothy.. cs. ona 63.5
. Timothy rowen....... 64.8
Ser OStUTe: SASSER, 22S 68.7
: Mixed-grass rowen..... 65.6
Cereal Plants
POE su seit dees ae 8 65.9
. Dent corn, immature... 68.8
. Dent corn, mature..... 66.6
. Dent ccern, ali samples.. 67.8
MECeD COIM.!.:)..s : > 2 + 71.1
. Oats meat ns, be ac Syed eo ciegaks 59.5
MEIER oie ts 28a orcas oot’ 73.4
P@rehum). 2.2.6... 67.3
Clovers and Legumes
beycit: CC: er wo
. Crimson clover........- 67.9
sien ‘clover: 2. 2<5 42s 66.1
.Red clover, before
Bloom (GY..o 5.22 e6e8
. Red clover, beginning
bloom (G). J...) eee
. Red clover, bloom to
Bnd VG) Anemone aun
. Red-clover rowen...... 59.3
. Canada. pessoas > oom 68.4
GROW DOE 2 ss Goes. he kee 68.3
Soxbean. ..: 2.4.4). .5)
. Common vetch........ 61.8
~eisery vetch:. 2.622452 70.3
Mizxed
. Barley and peas....... 53.4
(Ones ARG PEAS. 5... 24: 65.4

. Vetch and oats........ 67.

Dry Organic
' matter matter Ash

Jo

68.6
67.
65.6
66.4
70.
67.4

67.5
70.7
68.5
69.8
72.2
60.9

69.1
68.1

%

52.2
59.5
32.2
45.2
49.7
46.2

54.4
45.4
19.4
35.6
595.3
53.4
55.8
42.4

56.1
5D.

43.4
42.3
22.8
18.9
17.3
45.1

46.2
45.4
52.7

7

64.3
61.5
48.1
Te
65.5
67.4

71.8
65.2
52.3
59.7
64.

71.8
79.4
46.8

81.
CU ok
67.

74.
74.

64.

61.9
82.

75.6
75.1
71.4
82.8

tiem
76.1
74.8

Pro-
tein Fiber

%

71.2
66.5
55.6
63.8
74.3
62.6

60.8
66.6
51.6
60.2
62.9
52.8
79.2
59.

41.
56.1
52.6

60.
Af.

44.

52.5
62.4
59.6
47.

44.2
61.1

43.5
59.7
68.3

itrogen-
free ex-
tract Fat

Fores 7e

67.9 65.7
68.3 64.3
65.7 53.1
67.8 52.9
72.5 54.7
71.6 55.2

71.2 59.9.
73. #2.

74.7 tite

73.0 @laee
76.6 75.6
62.6 69.2
70.1 74.5
74.6 74.2

72, 465.
74.5 66.5
77.6 64.5

83. 65.
rey See?

(O38;

65.3 60.8
71. 52.4
80.6 59.4
73.2 54.1
76.1 58.6
76.3 71.6

61.4 59.7
OY.%.. ‘GFF
67.9 47.2

COEFFICIENTS OF DIGESTION 443

Digestion coefficients

: Nitrogen-
No.ex- Kind and condi- Dry Organic Pro- free ex-
perim’ts tion of food matter matter Ash tein Fiber tract Fat
u 2% Se % Tr 7% %
SILAGE Su” —"y
Maize :
S-. Deatcorm. .... “Sarees 65.1 67.1 32.2 49.3 66.7 68.6 80.
©. aes COM. «.<. anes 73.1 76:1 329° 62.8 75.1 76.9 Le
13 . Dent corn, immature... 65.6 67.4 34.3 51.3 70.6 67.4 02
10. Dent and flint corn,
Mitthre:.. <, Ameer 70.5 {6:0)24007-56..:70. 76k (92.4
GaemESt com. . 2... 681 701 31.9 54 711 718 (83.5
Miscellaneous i
Meetwpen.......:...... 59.6 63.4 30.3 57.5 52. 72.5 62.6
1 . Soybean (steers)....... 49.8 53.8 28. 55.3 42.9 61.2% 48.9
1. Soybean (goats)....... 59. 59.3 56.7 75.7 54:8 . 525719
1. Corn and soybean..... GO; ~ #0. 2. 65. °64.8 743i
1. Millet and soybean.... 58.8 59.9 .. 58.4 69.4 59.2 72.2
1. Corn, horse beans, and
sunflower heads..... 65.6 67.8 41.1 62.7 60.1 72.4% 76.7
1. Corn, horse beans, and
sunflower plants.... 65.5 69.3 25.6 58. 65.3 73.7 74.1
Drizp FoppERS
Meadow Grasses
1.Black grass (Juncus
SPUDOSUS) 22... sc. BoB > ea Si Gat 60.5 57% 41.5
1.Black grass (Juncus
reraran). iss... y - 53.4 52.1 69. 54.3 57.4. 49: Sean7
IMG FOI) oc... Sse} 54.3 55.8 29.4 63.4 .54.5 55:7
1.Branch grass (Spar-
tina stricta glabra)... 56. ae -. °62.5 52. 54. Has2.
1. Branch grass (Distichlis )
TST. i ar 49.7 48.9 58.1 51.7 56.4 45.7 36.6
ices or cheat........ 45... A7.3 23. 42.-° 46. 40) Meee:
2. Cra grass.:.......... 53.6 56. 37.6 .. 69.1 S25Raee
1.¥Fox grass (Spartina
PiMms).....2.6:%... 48 54.5 $8.2 59.3 574 ‘53 Tees
1.Fox grass (Spartina
Tappan, etc. ).. . <.< S 53. p .. Of:°° SD Sauer
BO Wstteeere o . . s a dc o Se 56.1. 57.3 62. °51.8 °60.4 (Saas
1. Hungarian grass...... 65. 66.3 47.4 60. 67.6 67.1 63.9
2. Johnson grass......... 56.5 58.3 30.5 41.4 65.7 5@0@ [384
1. Bareyard millet ....... 57.4 56.8 63.1 63.7 61.6 568463
A Cat—eall millet: 2. 202. 62.3 61.6 68.4 62.6 66.5 59.0 46:1
2 .. Orchard. grass>.. 55.6.2 56.6 57.8 .. 89:5 60.4 S552
2 -Red-toum... .. «sees ct 59.7 61.2 29. 613 61.3 612s
1 . Red-top and sedges.... 46. 48.5 ..101. 37.2 55.7 45.6 49.
17.-Timothy . . .: .. "ee 56 "SL.9eS2.S- 46.9 52.5 62.3 > 522

444 APPENDIX
= T)igestion Buetivieuts :
\ Nitrogen-
No. ex- Kind and condi- Dry Organic Pro- free ex-
perim’ts tion of food matter matter Ash tein Fiber tract Fat

% yo an % Vas? Ao

Meadow Grasses—continued

3. Timothy, before or in

e . bloom ae 60.7 61.5 44.2 56.8 58.8 64.3 58.4
4. Timothy, past bloom. 53.4 54.5 30.3 45.1 47.1 GORE
1. Timothy rowen....... 62.2 64.4 564 68. 66.5 63.4 49.5
2 SWild-oat grass........ 64. 65.2 34.7 58.3 67.9 Gbiauouee
2. Witch grass. 61.2 62.3 40.9 58.6 62.8 65.6 57.2
1. Black grass and: red

top (cove mixture)... 54.6 54.3 57.5 47.9 59.7 53.2 40.3

5. Mixed grasses......... 57.1 58.8... 58.5 59:7 SSaieeeue
Meadow hay—
Best WG ae nore hes ms LOT. .. 65 63 GSS
Medium (G)........ we Ol. .. 8%.. 60. (G4 See
POT te Ss ke ake 2) OO. -.-- 50. 56..9°59s eee
Semeasttire TASS... ... . .. 72.6 73.2. 518 73.4 76.1 T4235
Migeevale DAY. 22. 0. cls. 39. a -. 34 £33. 46...3eee
1. High-grown salt hay... 53. Bok ~. 63. 50. “53.4
1. Salt-hay mixture...... 56.4 54.9 69.8 42.6 60.7 54.7 29.7
2 watowen hay........-7. 64.4 65.8 46.6 69.1 66.6 66.2 47.4
Cereal Plants
fanmeariey: hay... js ks: 61.2, 62.38: 44.8” 65.2°> 61.7. 463 40.
17 . Dent corn fodder...... 64.3 - 66.1... 30.7. 50.4 ~.62:2 73.6
7. Flint corn fodder...... 68.6 71.7 42.6 60. , 749° 7eea 714

13. Dent and flint corn
fodders (immature).. 63.9 65.7 37.2 51.7 66. 66.2 72.2
10.Dent and flint corn

fodders (mature).... 68.2 70.7 30.6 56.1 65.8 72.2 73.9
3. Sweet corn fodder..... 67.2 69.8 35.6 64.1 73.8 68.2 73.6
5 morn ‘Stover, ... so stenee 57.2 59:1. 32.6 35.9 64.2 59702
3. New corn product..... 98.1. 59.2 38.7 46.7. 57. | GQ eee
2. Topped corn fodder.... 57.4 62.3 3.8 38.7 71. 587.9 674
1. Corn blades and husks. 63.8 67.1 22.6 47.7 72.9 66.4 58.1
2.Corn leaves (pulled
fodder) 2g: 645... ae 59.8 63.6 26.8 48.4 67.5 63. 59.9
EP tieeprn HuUsks.-.. 66:35 hee a2. 44.2 16. 29.5 79:5 Baie
Peon BUGS. os ck eee 06:5 69.4 11.5 2). - 73.5569 sere
1 /-Qat hay......0. 2...) 7° 50.1 34.6 54:2 43.5 Bee
Ls Qametraw.s o.oo. 50.3 52. an oo) OT6 Basa
Bean straw. . ve ARCO. .. 495°. 48... ile eee
Wheat straw (G). Ase ; 46. .. 20035 ee eee
Rye straw (G).. RG .. 255. Gd. sepo. eee
Barley straw (G). bole nae 2 (gullies | ee 54... 42.
Rice straw (G)........ 47. .. Sears $220 ana:

1 . Sorghum fodder (pulled) 63.1 64.8 29.5 60.8 70.4 64.5 46.7
1 . Sorghum bagasse...... 60.6. 62.2 13.4 13.7 63.8 64.8 46.4

COEFFICIENTS OF DIGESTION -

No. ex- Kind and condi- Dry Organic
perim’ts tion of food matter matter Ash
% % %
Clovers
2. Alsike clover. .....5... f2.3 63.2 °°52.2
4 . Crimson clover........ eo. 69.1, "51D
G . Ate@ clover... ....25 ett 59,7 29/1
2. Red-clover rowen...... 58 5911 45:8
1 . White clover.......... 66. 66.6 58.5
Legumes Other Than Clovers
oo. 1 a 58.9 60.7 39.5
1 ieewpes vine........:. 59.2 60. 49.5
Seeeeeanut yine..:.s..... 59.9 63.1 20.4
Mey ean. .2....c.70.2. 624. 63.9.’ ..
Peery vetch..........; 69.4 71.8 42.2
Bean straw (G)....... Nee. aaEee ie
Pea straw, good (G)... 59.
Miscellaneous and Mixed
1 . Buttercup hay........ 56.1 56.6 .48.1
1. Whiteweed hay....... SUS > BS.0~- 02.
2. Cloyer and timothy.... 54.6 53.2.
1. Vetch and oats........ 58.1 58.7
Grains and Seeds
Peele (Cais is... 86.
MS Cox ic dose 5 vs orks sues Betty ig
he ern meal.........4.. 894 89.6
2.Corn-and-cob meal.... 78.7 79.8
UMMA wl, es ns) (Bhd SBT os
Poeremmenl........:.... 86.8 ‘87.9 ‘43.7
Hrem) beans.......... x. 3.4. $9, Ae.
Ps Soymean meal ........ 81.9 84. C4
i . Cottonseed, raw....... 66.1 65.8 43.3
1 . Cottonseed, roasted.... 55.9 56.8 ..
ERRROMEAED cos 24 yr sprees ati %e a eee
Acorns 88.
By-Propucts
Cereals
VV, Atleeemeal.. . vn. 2 oe 79.6 83.4
1 . Cerealine feed........ . 90.4 92.7
OB. cOOMmMEODS.. 2 ost oan. 1S i: ae
1 . Dried brewers’ grains.. 61.6 65.4
Bi, Gluten teed... 002.2. 86.3 87.3
4. Gluten meal...... .. 89.7 90.4
1 . H.-O.. dairy feed: 2 ay 65.3 68.

Pro-

Jo

66.1
68.7
58.

64.8
73.2

72.
64.8
63.3
71
82.3
49.
60.

56.3
58.4
42.3
59.7

70.
78.
67.9
55.6
84.4
83.2
88.
91.1
67.8
46.9
oF.
83.

——— Digestion coefficients

%

53.5
46.7
54.2
47.4
60.6

46.
42.
51.9
60.8
61.1
43.
52.

41.1
45.5
49.6
66.

26.

45.7
25.7
72.

71.2
75.5
65.9

60.
62.

72.8 105.7

76.6
19.3
79.3
85.6
88.2
77.8

82.2
57.5
52.6
78.

40.8

445

Nitrogen-

free ex-

- tein Fiber tract Fat _

Foyle Seo

70.7 50.2
64.6 43.4
64.4 55.2
62.8 59.8
69.5 50.6

69.2 51.
70.6. 51.8
69.5 _ 65.9
68.3 29.2
72.9 70.3
67. Sead:
64. 46.

66.9 69.7
66.7, 62.
57.5 54.
54.2 18.6

92. 89.
77. ube.
94.6 92.1
87.6 84.1
91.9 64.2
93.6 54.5
92. { 81.
76.3. 85.7
49.6 87.1
51.4 71.7
55. | 86.
91. £87.

84.5 91.2
95.3 80.6
48.4. aie

57. Soe
89.2 84.4
89.8 94.4
69.9 85.5

446

No. ex-
perim’ts

1

Kind and condi-
tion of food

~ Cereals—continued

. H. O. horse feed.......

™ Maize feed. 7.-..~-..

1
E
1

wea

ao

fat bet et et et et

. Maltsprouts...........

. Quaker oat feed.......

i Victor corn-and-oat
S. feed S325 Se soe
@ Wheat. bran. 220. as
. Wheat bran and shorts.
- Wheat middlings......

Oil-bearing Seeds

. Cottonseed hulls......
. Cottonseed meal......
. Linseed meal, old pro-
NS a eee
. Linseed meal, new pro-
BPO: oe ois santa eco a

| Miscellaneous

eeenut feed... =) .25 5<
SRige meal... .22-~--

Roots

Maneolds 94.2.2 32>

. Potatoes, raw......-..-

. Potatoes, boiled.......
anita bagas. tos34. 2 ee
. Sugar-beets...........
BEBUEDIDS: .. 2S us ee

ANIMAL PRODUCTS

2

2

Cow’s milk (G).......
Meat meal (G)........
Dried blood (G).......
Dried fish, ground (G).

DIGESTION BY HORSES

Dried Fodders

. Timothy. hay in full

bloom, well cured.. ..
. New corn product.....

APPENDIX

Dry Organic

matter matter Ash ~

1)

70.1
87.1
67.1
62.

To

72.6
87.1
67.2
65.3

%

74.7
62.3
60.2
75.

77.4
65.7
60.7
78.5

7.5

23.2
23.7

16.4
31.2
31.9
58.6

93.

43 MAD: 34,
49.9 51721.7

70.6

<

Digestion coefficients ——————$—>

Nitrogen-
rae. free ex-
tein Fiber tract Fat
7%

7 % 7

74.4 35.2 78.7
85.5 82.5 87.9
80.2 32.9 68.1
81.1 42.6 67.4

70.8
77.8
75.8
79.8

48.3
28.6
18.3
33.1

83.

69.4
64.3
81.3

88.4
88.8
85.2

61.9

74.7
44.7
45.45 87 ee
80.3 74.2
91.3 100.7
89.7 103.

42.8

94.
96.
62.
90.

21.2 42.6 47.3 47.3
67.5 54.6 46.9 59.8

No. ex- Kind and condi-
perim’ts tion of food

bo ww bo bh

at et

1.

1

eas
2.

Dried Fodders—continued
Meadow hay—

Red-clover bay a (G)..
Alfalfa hay (G).......
Wheat straw (G)......

Roots

Potatoes (G)..........
Prarroia (G)i .2.2,).. . <>.

ls) 3)
ete) a: ke
Corn (G)..
Field beans (iG.

2 3 re

. Dent corn, unground...
. Corn meal, same ma-

terial, ground.......

. White oats, first qual-
ity, unground....... ;
. Oats, same material,

BeOUME 2 ki ea aed

Grains and Seeds

. Barley, whole kernel. .
. Flint corn, unground .
. Corn meal, same mate-

rial, finely ground..

. Corn-and-cob meal,

whole ear ground .

. Wheat, unground.....
. Wheat, cracked.......

Pes, ground.........

By-products

Wet bran. 2) 223...

Rye @ran (Gong) eee.
Wheat shorts.........

COEFFICIENTS OF DIGESTION 447
———— Digestion coefficients
Nitrogen-
Dry Organic Pro- free ex-
matter nee Ash tein Fiber tract Fat
Gy pn he Bh
58. 63. 48: 65. \22:
50. 57. 39. 58. 18
46. 55. 38. 52, 494
51. 56. 37. 63. 329)
58. 73. 40. 70.°me
21. 28. 18. 28. ‘ 66.
'
93. 8s. 99. /
87. 99. 94.6
69. 79. . 29. - 75 eae
87. 80. +. STs
89. 76. 40. 922 Ge
87. 86. 65. 94) 13.
i, 6 80. 83. 8. 89, 7.
74.4 75.3 26.3 57.8 (7) 88. 47-7
88.4 75.6 (@) Gigouges
79:4. 74.1°<33.1. 86.1 31.1 Teens
75.7 77.7 29.2 82.4 144 S864 79.9
DIGESTION BY SWINE j
80.1. 803° 65.4 814 48.7 Saupe
89.7 913 .. 89.9 48.7 9319 77.6
89.5 91.2 . 86.1 29.4 942 81.7
75.6 76.7 .. 75.7 28.5 See ee
72. -. 44... 70: ~ 30: 4a
82. .. . 60. 80: 60. —seeewe
89.8 91.5 40.3 88.6 77.9 95.1 50.
65.8 “<4 75.1 33. 65.5 71.8
2 See 66. 9°. eweas
76.5 5.4 73.5 36.5 86.8
Tid OPO S6. ~ 12. Pass ap:

Linseed meal’. . Daa... .

448 - APPENDIX

Digestion coefficients

it: #
, No. ex- Kind and condi- Dry Organic Pro- fies ox.
perim’ts tion of food matter matter Ash tein Fiber tract Fat
% % % % % % %
Roots
2 . Potatoes, raw ae... 97. .. 446 84.57. 7 Soe
2. Potatoes, cooked...... 95. 2! 40. *) ae 7 See
B Animal Products
milcat meal (Ginaiee. 2) 3 92. oie MS «|. eee
Dried blood (G).. See e ee ae | .. ) 92.gae
Sour nnlk (Gyre stat OB. P+ .. O8iaae

A

3. COMPUTATION OF ENERGY-PRODUCTION VALUES
(TO THE 100 POUNDS)

The following remarks and tables are by Armsby and
Putney (Pennsylvania Experiment Station, Bulletin No.
142), who write: “It is obviously impracticable to apply
the laborious methods of respiration and calorimeter
experiments to all the great variety of feeding-stuffs now
in use. It does appear possible, however, to select a few
typical representatives of the different classes and to apply
the results obtained upon them to other similar materials,
much as is even yet done to a considerable extent with the
results of digestion experiments. The somewhat compli-
cated method used by Kellner for this purpose has
already been described in Bulletin No. 71 of this Station
as well as in Kellner’s smaller textbook, of which an
English translation entitled “The Scientific Feeding of
Farm Animals’ has lately been published. (Kellner
expresses the results in terms of so-called ‘starch values,’ —
which are really energy values and can equally well be
expressed in Therms.) A simpler method, however, can
be used. Extensive tables are available which show with
more or less accuracy for a large number of feeding-stuffs
_ the digestible nutrients, the sum of which, of course, makes
up the total digestible organic matter.”’

ENERGY-PRODUCTION VALUES 449

As an illustration of the method of computation we
may take average timothy hay, containing the following
amounts of digestible matter:

In 100 Pounps or Timotuy Hay

Pounds
ME SULAL LCE «7 SEG os Ee es 3 Se ve eee ye ow eo 88.4
Digestible
TSE ot rena 3.
SER GRE: ne eae Sa 42.8
OE SSCS. . SES et oe ooo ean 1.2
Total digestible organic matter ................... 47.

According to previous figures, each pound of digestible
organic matter in roughage contains approximately 1.588
Therms of metabolizable energy, while Table 1 shows
that each pound of dry matter of timothy hay causes a
heat expenditure of 0.3547 Therms. The net energy value,
therefore, of the 88.4 pounds of dry matter contained in
100 pounds of the hay would be:

Metabolizable energy . .1.588 Therms x 47.0=74.64 Therms
Heat expenditure. ...0.3547 Therms x 88.4=31.36 Therms

MEET OTIEL IY VAINO os Dilod anaes coe ede 43.28 Therms

Continuing, Armsby and Putney discuss the net energy
values of American feeding-stuffs as follows:

“Henry and Morrison (‘Feeds and Feeding,’ 15th
edition, pages 633-66) have recently published a very
valuable compilation of American analyses of feeding-
stuffs and of the results of American digestion experi-
ments, and on this basis have calculated the content of
digestible nutrients (for ruminants) in a great variety of
feeding-stuffs. |

“With the permission of these authors, we have under-
taken to compute from their tables the net energy values
of the more important feeding-stuffs in the manner illus-

cc

450 APPENDIX

trated in the last paragraph of the foregoing paper and ~
with the results contained in the following table, which
includes also the digestible (true) protein and the non-
protein. In regard to this table it is to be remarked:

“First, both the digestion coefficients used by Henry
and Morrison and the data for the expenditure of energy
due to feed consumption are derived exclusively from
experiments on ruminants (in the latter case, on cattle).
Consequently, the net energy values here computed are ap-
plicable to ruminants only and not to horses nor to swine.

“Second, the table shows primarily the net energy
values for maintenance or fattening. There seems good
reasons for believing, however, that they may be taken
without serious error to represent also the net energy
values for growth and at least the relative values for
milk production.

“Third, in comparing the figures for the various feed-
ing-stuffs, account should be taken of the differences in
moisture-content. Many of Henry and Morrison’s
averages for dry feeds show a remarkably low moisture-
content, tending to raise the suspicion that some of the .
analyses averaged were made on partially dried samples,
although the authors state that every precaution was
taken to exclude such cases from the compilation. It is
evident at least that more study of the actual percentage
of moisture in feeding-stuffs as they are used in practice
is much to be desired.

“Fourth, Henry and Morrison’s tables include only the
crude protein (N X 6.25). The amount of non-protein
has been estimated from the crude protein by the writers
on the basis of Kellner’s averages.”

In accordance with the method and data mentioned
the following table was calculated :

ENERGY-PRODUCTION VALUES _—— 45 1

ave AvERAGE Dry Marter, DicEesTIBLE CRUDE PrRoterIn, DIGESTIBLE
True Prorein, anpD Net EnercGy VALUES To THE 100 Pounps
FOR RUMINANTS: oe
) —Digestible— Net
Dry Crude True energy
matter protein protein value
Pounds Pounds Pounds The

Driep RoUGHAGE

Hay and Fodder from Cereals .
Bromewracs, smooth: .-5....:........ 91.5 5 3.5 40838
Corn fodder (ears included, medium dry) 81.7 oe 2.3 ,
Corn stover (ears removed, medium dry) 81. 2.1 1.6
Remmeungarian..§.2............0/.. 85.7 5 3.9
Mixed timothy and clover............ 87.8 5.3 3.2
IRAE SE 2 eee ee ee 88 4.5 3.9
EE ee 88.4 4.7 3.3
sn css aot Fes bo wah os 90.2 4.6 3.9
fener all analyses..........-. 25... 88.4 a: 2:2
Timothy, before bloom............... 92.8 4.7 2.9
Timothy, early to full bloom.......... 87.2 3.6 2.5
Timothy, late bloom to early seed...... 85.1 2.4 1.8
fummmeny, NeCArly TiPe.......5.0..4.0-.% 87.5 2.2 1.8

Hay and Fodder from Legumes
Petal) ANAlYSES.......25...6..-4- 91.4 10.6 7.1 #23
mirairampetore blogm..:............... 93.8 15.4 10.3 $386.23
NETRA PHROOMIS.”. 250.06 e- cin. 2 a, arte. 92.5 10.5 6.7 32.33
wurraemerann SECO. ke. 89.6 8.5 6.2 gape
EPI SECG. ee te er 87.7 7.9 5.3 S42
A EERETC ES’ 6 1 RS RS a 89.4 9.7 6.9 36.21
@lovermmed, all analyses....:..:.:.... 87.1 7.6 4.9 38.68
Clover, red, before bloom............. 89.6 11.6 5.4 42.17
isisveemeed, in bloom:..............3. 86.1 8.1 5.3 Game
Clover,red, after bloom.............. 77.9 6.8 4.5 64.51
Sclomeremeveet, White... .. 0.2.02. ies 91.4 10.9 6.7 38.98
Cowpeas, all analyses.......:......... 90.3 - 13.1. 9.2 . dae
Cowpeas, before bloom............... 92.2 17.8 12.8 aie
Cowpeas, in bloom to early ped Vi BO AL”: ASG 9.5 11
SSS ie, hore ue om ead a, feb aien O14. EL 8.8 44.03
Straws

a cs) 2 3 Ree Sacp in cate 85.8 9 6 36.61
nen...” . ghoweestc es 8. a ae 90.1 4.2 3.2 4.55
lee EE. 2's DRE a sso wate ee 88.5 1 8 34.81
SE RR Oooo as an 92.9 < 5 17.59
OEE a 2 Se oe St aa a 91.6 ud 3 f.22

452 APPENDIX

—Digestible—-_ Net
Dry Crude True_ energy
matter protein protein value
Pounds Pounds Pounds Therms
FresH GREEN RovuGHAGE

Green Cereals, Ete.

Bamey fodder.4 Ges oc cess 23.2 2.3 2. 14.08 ~
Blue-grass, Kentucky, before heading... 23.8 an 2.8 14.82
Blue-grass, Kentucky, headed out..... . 36.4 2.8 2.2 Vite
Blue-grass, Kentucky, after bloom..... 43.6 1.9 1.6 22hGF
Buekwheat; Japanese................. 36.6 2.2 1.5 # ieee
Mgt grace Oe he ie 8.9 1.9 1.3 8.87 ©
Cabbage, waste outer leaves........... 14.1 12 14 7.05
Corn fodder, dent, all analyses......... 23.1 i 8 14.6
Corn fodder, dent, in tassel........... 14.9 1 8 9.52
Com. fodder, dent,.in mvk ss... 19.9 1. 8 18.64
Corn fodder, dent, dough to glazing.... 25.1 ie 1. 17.35
Corn fodder, dent, kernels glazed...... 26.2 1.1 8 16.74
Corn fodder, dent, kernels ripe....... 34.8 1.5 1.1: 2e4s
Corn fodder, flint, all Pea ara eh iP 8 . 13.58
Corn fodder, flint, in tassel.. Naot catia) ch SEG 9 PY | 6.89
Corn fodder, flint, in milk.. Be eed Fs 9 . . foe
Corn fodder, flint, kernels glazed. ren ae D4: ie 8 13.49
Corn fodder, flint, kernels ripe......... 27.9 1.2 9 17.84
Corn fodder, sweet, before milk stage... 10. 8 6 7.82
Corn fodder, sweet, roasting-ears or later 20.3 1.2 9 13.38
Corn fodder, sweet, ears removed...... 21.5 ils 8 14.26
WiilcGetuNn arian. <5. fetal s ame 27.6 1.9 1.1. .©17:24
CA HMIGEIC. choc Aue t hoe eee 26.1 2.3 2. 14.06
Orch PEASE: oye Peace eae 29.2 1.7 1.1: . 5-88
TRA oho Sono ae, See whe Pee nye ork hag 16.7 2.6 1.7 >on
AVC FMAUers Act a Sit iti ote ands ee dhe oie 21.3 2.1 1.4 . 15.99
Sweet/sorghum fodder.......:......... 24.9 i Af 15:37
‘Timely; ‘before blognie!s ces 6 abe als 24.2 1.8 1.1 > 18:36
‘Timouy, in. blooms = “Spee ese be aoot 1:3 8 18.89
‘Dimeiiy, In seeds... ets 46.4 1.5 i 26.36
Whea fodder... 2) .%'s. ae es « 27.4 2.8 1.9 § 18:75
Green Legumes

Alfialf., before bloom.’. :..4/¢2eweee =: - 19.9 3.0 1.9 9.2
Alfalfa, in bloom... | .). - Sees 25.9 3.3 18° 111.5
Alfalid, after bloom:..-)/. -.=eueEee-.- 29.8 2.1 Li Te
Clovérhalsike:.. . 50)... 4) =e 24.3 2.4 1.53. 14.56
Clover, @rimson........... >. See 17.4 25 1.6 10.83
Clover, red, all.analyses. .. .}. (ogame. - 26.2 wok 1.76 15:88
Cloveggred,/in:bloom.. .. ..; 2 eee 27.5 28 1.8 16.74
Clovergredrowen.... .. . :. ee 34.4 ne 2.260 “ise
CowD@ns.icge wets... ea ee 16.3 pS: 7 ~=—s«:10.42
Peas, @Ganada field........... 1.035 16.6 2.9 2:1 9.78
Soybeans, alleanalyses................. 23.6 3.2 2:4 ~~ tas
Soybeans, 2 bloom..... ™%..).. 4m Pa29.8 3 2:3°:) 1044

ENERGY-PRODUCTION VALUES 453

-——Digestible— Net
Dry Crude True energy
matter protein protein value

Green Legumes—continued Pounds. Pounds Pounds Therms
Soybeans, in seed.........- [—...... 24.2 3.1 2 SOF
Vetch. iaeyt...... canes =~ - 181° 5.5 “eet

SILAGE ;
Corn, well-matured, recent analyses.... 26.3 j he | 6 159
Carmmemnmature...¢ sete. Sse 242 ip A 1133
Corn, from frosted ears............--- 25.3 1.2 6 1427
Corn, from field-cured stover.......... 19.6 5 3 8.98
RR a>) 27.8 1.3 8 7.26
SS > EM hse 22. 1.8 11 10
= 0 27.1 2.6 1.5 11/59
Gamebect pulp... ......-.........-.- 10. 8 5 9.32

Roots, TUBERS AND FRUITS é,

ee os gs em ete a ws de oe 18.2 4 ol Wso2
RIE RESHIEEIAINS: Son, ts ww st, Ve ji 9 OL 7.84
SMPEHIPT= 2... Be kes See 16.4 12 A 2
EE io.) ov ce eee eee ae ee i's BF 8 5 9.21
Et oe 2 eos eae 9.4 8 a 5.68
ER ee ie ee ba a aes 21.2 LY 1 ©6227
TAS TUE Fs ae 8.3 5 a | 6 6.05
IER ns oa che tna he Gis Loe 10.9 i, a5 8.46
Mn es nee ee Otte ate oe ahs 9.5 i A 6.16

GRAINS

Cereal Grains
Sli ae aye heme ae ah 90.7 9 8.3 89.94
SSE TEL o> 8 ~ 5h Shc Ne Sein, Wea Ae 87.9 8.1 7.2 (59.73
ol. SS ee ee eee area 89.5 top Py 89.16
EEN p25 Sa foew, rei oi obs aa taper te 87.8 ok 7.2. 5S
aorteeei-cob meal...... 2. .....0 5) «,. 89.6 6.1 5.7 fi5s
ere EL 425,” Sod Gi Sn aie ate a eae eae 88.7 6.9 6.4 88.75
os... SRS a ee oo ee oe 90.8 9.7 8.7 ‘$7.56
RRERTSTEML <0. ons ssh ns 0 el ee 92.1 12:8 JStpeanee
MUEMINM , 50, ootl hee ic Syn Fo esate Se echmaniene 90.6 9.9 9. 93.71
Wiel See anal yReS = :*. 4. sto Me ete 89.8 9.2 8.1 #eSs2
rire WebCT: ws 2 en ss ee eR 89.1 8.7 7.7 91.66
NES ry 9 Sera oe ae MeL ga 89.9 9.2 8.1 91.41
Leguminous Seeds

PREYS =. 5. Saleen ne Cs oem 86.6 188 16.4 = 73.29
[op = Re So OP Sarees tes 88.4 19.4 16.9 79.46
ene... He RW 2 ss.) egies 90.8 19. 16.6 _ 78.72
esc ae 5 SS eae re ee 89.1 19.8 17.2 B7e62
RGCTINEL VRE LURE LE Peet ls. al. eo 93.5 .19.4 16.9 TeReae
Peanut kernéh., si -.........- .. 94, DAA, 22.2 109.04

Soybean......-- 0 geet i. - Be og = (30.7 2a ee

454 _ APPENDIX
—Digestible— Net
Dry Crude True_ energy
matter protein protein value
Pounds Pounds Pounds Therms
Oil Seeds
Coigan’ sced..J Dae So ee e's e's 90.6 138° TOR. fae
Ties seed.. . cee seo... 90.8 20.6 19.2 8347
Sumtlower SCGdsssereee Ve woe... 95.5 23.6 ~20.205s9ne
Sunflower seed with hulls............. 93.1 13:5 TL7 Sgeeo
Dairy Propucts
Water Miilig ey ae ees. ke 9.4 3.4 3.4 8 di3ise
ae S aM Leas 13.6 are 3.3 —2o.0F
Skim-milk—centrifugal............... 9.9 3.6 3.6 4.33
Skim-milk—gravity.................. 9.6 3.1 3.1°" S548
Slamo-milk—dried.. Sos... eee 91.7 34.4 344. T0881
kts WE a Oy I Os ea a 6.6 es) & 139
By-Propucts
Fermentation Industries
Pemers prains, Gried.. 0... Ue hd 92.5 21. 20.2 Gia
Brewers’ grains, dried, below 25 per
Rt PTGGE Uae 6 si so chs Oe oooh, bie bee 91:8 18.7.1 17:5 g50:93
Brewers’ grains, wet....2......000-.0. 24.1 4.6 4.4 £14.53
Distillers’ grains, dried, from corn...... 93.4 22.4 18.3 85.08
Distillers’ grains, dried, from rye....... O28 13:6" sk 4 56.01
Distilars’ grains, wets. ..2. 5 3.3.0.7... 22.6 a0 2.8. ¥-22.05
LIEW het: staat esas 5 ASE oe har ott Nea dC aS anata a 94.2 15.8 11.8 87.82
Ml alieprOUtS i. ck cael eS nee 92.4 20.3. 12.5) %R272
Milling ,
Buciawheat rahe. sails Mov ewtelnd bow oF 88.8 10.5 9.1 Ae0isae
Buaeewheat. bullseye... 0is-aoet ewes. 89.7 4 ? -7.69
Buckwheat middlings................. 88. 24.6 20.8 @iv2te
Hommy feed. (256) pee ee ae ee 89.9 te 6.5) “Hye lea
Ryerpran:.) os 0 Dee. 88.6 .12.2 °10.5 #e7oas
Werest bream: hoo ieee os. 89.9 12.5) °10.8 Sa
Wheat middlings, flour..: 23o252. .)... 89.3 “Seba 75.02
Wheat middlings, standard............ 89.6. 1g tee 59.1
Oil Extraction
Coconttt meal, low in fat.. . 2. gage + - 90.4 188 183 £83.49
Coconut'meal, high in fat... .2:ya.%--. 92.3 18:4.°°35. 30g
Cottonseed hulls: .:...,. .... 32s 90.3 fe ? 9.92
Cottonseed meal, choice.............. 92.5. “aie 35.4 93.46
Cottonseed meal, prime............... 92.2 334 32. 90.
Germimil meal,corn....-.....:. . ee 91.1 1635 £14) eae
Linseed meal, new process..........-. 90.4 31.7 30.9 85.12
Linseed meal, old process............. 90.9 .30.2 28.5 88.91
Palmnut cake. ..:...~... owes im 89:6 124 12: 94.18

nk: < gine ek fri ‘

i}
-

MILK PRODUCTION 455.

——Digestible— Net
Dry Crude True_ energy
matter protein protein value
Pounds Pounds Pounds Therms
Oil Extraction—continued we

ys Peanut cake from hulled nuts........., 89.3 42.8 414 93.55
Peanut cake, hulls included........-.. 944 202 19.5 42057
Os Soybean meal, fat extracted........... 88.2 38.1 37.3 99.5
Sunflower seed cake.............-+055 90. a2 29.1 88.87
Starch Manufacture a
SR 5 a 91.3 21.6 20.1 sf
Pa 2 ae css oN. as 90.9 30.2 28.1 8415
Siemieed, dry... 2.94... ..2-.... 90.7 -11.2 ‘ 9.2) 77
EES (GS ey aR 0) - la 33.4 4,1 3.4 30. 5
Sugar Manufacture J
EE EES. ale sy wt 2 ne Se we 74.7 Le -. se
Molasses, cane or black strap............ 74.2 x on) ies
MEEEICEL DUIP..).. 22-63... ie ood 92.4 5.9 3.5 és
Sugar-beet pulp, dried................ 91.8 4.6 leer
Sugar-beet pulp, ensiled.............. 10. 8 a) 9.32
Sugar-beet pulp, wet...............-5- 9.3 it 5 8.99
Packing-House .
ISON 9 0 ache Lie a aes pias ied 90.3 69.1 68.6 68.12
Tankage
Over 60 per cent protein.......... 92.6. 58.7 55.6 393.04
55-60 per cent protein...............92.5 54. 51.1: Wasbe
45-55 per cent protein............. 92.5 48.1 45.5 @2.96

Below 45 per cent protein.......... 93.5 37.6 35.6 @esi6

4. STANDARDS FOR MILK PRODUCTION AS DEVELOPED
BY HAECKER, SAVAGE, AND ECKLES 7

PROTEIN AND ToTAL NUTRIENTS FOR ONE Pounp oF MILK

——Haecker—— ———Savage———— — Eckles——,
Per cent Total Total Total
fat in Protein nutrients Protein nutrients Protein nutrients
milk* Pounds Pounds Pounds Pounds Pounds Pounds
.O7 78 .07 -7925
Za .039 .219 0527 .2574
2.6 .0396 .224 .0535 .2629
204 .0402 .229 .0543 .2685
2.8 .0408 .233 0551 2743 y
2.9 .0414 .209 .0559 .2812
Ay .042 .244 .0567 .287
ouL .0426 -249 .0575 .2928

*For maintenance, per 100 pounds

456 APPENDIX

Per cent ——Haecker—— — See —Eckles—-—,
fat in Total , Total Total
i Protein nutrients Protein nutrients Protein nutrients

Pounds Pounds Pounds Pounds =‘ Pounds Pounds

3.2 0432. .254 .0583 .2987

3.3 .0438 26 .0591 3055

3.4 0444 265 .0599 3115 .0469 = .285
3.5 .045 271 .0608 3185

3.6 0456 276 .0616 3243

3.7 0462 282 .0624 3312

3.8 .0468 287 .0632 3369 051 283
3.9 0474 292 .064 3428 .056 .298
4, .048 297 .0648 3497

4.1 0486 302 .0656 3555

4.2 0492 307 .0664 3612

4.3 .0498 312 .0672 3671

44% .0504 SF .068 3729

4.5 ; 051 322 .0689 3787

4.6 .0516 327 .0697 3842

4.7) 0522 331 .0705 389

4.8. .0528 335 .0713 3945

4.9. 0534 .339 0721 3992

5. J 054 344 .0729 4048

5.1 0546 .349 .0737 4105

5.2 § 0552 353 0745 A15

5.3 0558 357 .0753 .4209 .048 332
5.4 0564 361 0761 4253

5.5 057 366 O77 A311 .0587 .396
5.6 .0576 37 .0778 A355

5.7 0582 375 0786 A413

5.8 0588 38 0794 4469

5.9 .0594 384 0802 A517

6. .06 388 081 A572

6.1 .0606 392 .0818 4619 .072 505
6.2 .0612 397 .0826 4676

6.3 .0618 AOL .0834 A721

6.4 0624 A07 .0842 A791

6.5 .063 Al 0851 4835

6.6 .0636 A15 .0859 A882

6.7 .0642 A19 .0867 4926

6.8 3 .0648 423 0875 A984

6.9 0654 428 0883 504

iq .066 431 .0891 5075

*For maintenance, per 100 pounds.

aay aa

FEEDING STANDARDS 457

5. FEEDING STANDARDS

The feeding standards for the various classes of farm
animals are taken from Mentzel & Lengerke’s Landw.
Kalender for 1899. They are intended to apply to ani-
mals of average size fed under normal conditions. They
are not to be regarded as feeding recipes, but are to be
varied according to circumstances. Small animals should
receive proportionately more food than large ones; milch
cows in proportion to the quantity and richness of the
milk; growing and fattening animals according to the
rapidity of increase desired; work animals according to
the severity of labor, and individual animals according
to their peculiar needs.

The quantity of “dry substance” will vary according
to the digestibility of the ration, with no harm. It is
important to maintain the necessary quantity of diges-
tible dry substance. This should be somewhat more if
the ration has a larger proportion of coarse materials
than when it is mostly grain. The nutritive ratio may
widely vary according to the availability and price of
feeding-stufis. The method of calculating a standard
ration is explained in Chapter XIX.

Per 1,000 Las. Live WeicuT, DairLy

Dry —Digestible organicsubstances— Nutri-
sub- Pro- Carbo- g tive.
Kind of animal stance tein hydrates Fat Total ratiol:

Lbs. Lbs. Lbs. Lbs. Lbs.

1. Oxen—
ReLeSG #. C--s TUBE. 18 7 8. 1 88 118
feet work. ..go027.... Bot TA AE o.. aa (fy é
Moderate work........ Die Vanes Tis > 6.5
Eeavere WOFrkGw" 7f5.... 28: - 23 Bee 8 16.8 5.3
2. Fattening bovines—
Firsmsperiod 92.2....... 30 ..- 2:5 eee ‘oR 6.5
Secondsperiodw,....... 30 3. 14.5 - 86.138 5.4
Third period =423at™.. 2 26 2iie@ID, 7 184 6,2

458 ~ APPENDIX }

Perr 1,000 Lss. Live Wercut, Darty

; Dry Dicetih Nutri-
' sub- Pro- tive
Kind of animal stance tein hydra Fat Total ratio oP

Lbs. Lbs. Lbs. “Libs: Lbs.
3 . Milch cows—

Daily milk yield 11 ery
11.9 6.7

poundages wee. . « Zp. 1.6 .- 108 oO
Daily milk yield 16% :
POWMNCS sete «i. er 2s Te As ts Ee 6.
Daily milk yield 22
poundsied eck 20 2.5, 13. of Ga 5.7
Daily milk yield “OT
POUNGS fats sikea es a is ie Bese emda yj | 4.5
4 . Sheep—
Coarse wool’ ea Dc... ss Paw ae ., 10.5 2 Tes 9.1
Tianies WOOL tee ew Seed hs? 2. oO hiss 8.5
5 . Ewes, sucking lambs..... 25 2.9 165. > eee 5.6
6 . Fattening sheep—
est CCN uw). hase oh ks 30. = 3. a5. 0) Wa 5.4
Second period ......... 28 3.5 14.5 6: 8&6 4.5
7 . Horses—
TSENG WG os le 2 ahs 20. 1.5 9.5 ee © oe: en
Moderate work........ DO Dee Py £6) 2.438 6.2
BEVere WOrK vcs. es DG) se, AS S22 16.6 6.
BST BOWS s5e8- 1 8 dade els 22°. ib ae 4 18.4 6.6
9 . Fattening swine—
at ETION oo. ois b auk aerate 36: 4.5 § 25. a BG 5.9
Second period......... 32 «Oz 24. 6 28.5 6.3
Third, period 2502 s.. « 25° 27 2 1S AS Sit Weer
10 GrRowiIne CATTLE
Dairy Breeds
Live weight
Age in per head
months Lbs.
ee ics Vs teh oa ueaie 150..2. 323). 4 Be 2. pA 4.5
SE. Sos acts Ota oie 300....24 3. 12.8) fee 16.8 Dad
=> |b. ee ect e eee 500s) eeu. 2. 12.5 o 1@ 6.8
iGAa.:, eae rete aoe TOO. eee tS = 12.5 A 14.7 ao
BSA OR ees ae ie ae 500... seem 12, 2 13.4 8.5
Beef Breeds
ph: iy 6 a 165: 2a «=<. 2: 19.2 4.2
SA SEE BRE els 0 sae 330...) 2” =. «12.8 1b aie 4.7
Ga Lee Bee hee ah ete 550... . 25a. 13:2 t =6416.4 6.
121s ee 2 750... .. 24 0 12.5 se 6.8
18-24. |, TP ahi... oes 985 am, 24 Ls 12, 4A 14,2 7.2

FEEDING STANDARDS 459

Per 1,000 Las. Live Wereut, Darty

‘ ; Dry —Digestible organicsubstances— Nutri-
Hb, = sub- Pro- Carbo- tive
oy Kind of animal stance tein hydrates Fat Total ratiol:
Lbs. Lhs. Lbs. Lbs. “Lbs

| GROWING SHEEP

Wool Breeds
' Live weight f
Age in ’ per head \
months Lbs.
Be oie ec wn ee Epes? = 25. sae. da 7 195 7
eee ae 2 D2. eee as ba G. es (54
eM ou ss es be ee be ae Pao cook 11:5 Lega Pee ) 6.
_. ieee eye: Oe coe. ANSE Ll A TiS a.
Es Ky RI 10000522. eat 1038 S126 vA
Mutton Breeds ,
o> ae 65.3... 26,7 5464 “15.5 9 20.8 4.
_- 2 ORS 85 ic). 20 & tele eho c° -393 4.8
Ere LOO. ic eee irae 14.3 &S vs a2
Lin | ae 120. SS 22s 2A Bol eae 6.3
=. “SS ee LOOye nee oS: 12 4 12.4 6.5
GROWING SWINE
Breeding Stock
oe Os ae 45s). 4a STIG. 28: Is 35.7 4
ES eee FOO. F8 SH. s 5, pat | 8 28.9 a
MM ithe en eo eR BQO Seo Od ec elae A “254 6.
CaS ee ieee tS. 28 2.8 18.7 S 21.8 t.
Eg a ear Fs 0, | Rag eee =e NE 8h tte ARLE ios > 7.5
Growing Fattening Animals
| SS ASS. 446-76. 2S io 35.7 4
2 hl ee a ee LITO}. coors 23:1 8 28.9 ef:
Eo oc 1a0) eoo4 NAS, Bae G = ZEZ 5.5
MR doe Soo ee ace 20032 s500 3.6 20.5 4 24.5 6.
SA. Serene eee 2Ovanedee te 18.3 a ies 6.4

SEMEN ARB we CY
460 APPENDIX
6. FERTILIZING CONSTITUENTS OF AMERICAN

FEEDING-STUFFS

This table is the one prepared by the Office of Ex-
periment Stations, United States Department of Agricul-
ture, and published in the Handbook of Experiment
Station Work, Bulletin No. 15. pape

\ phoric sium

Moisture Ash Nitrogen acid oxide

% % % % %
Green Fodders
Cee fodiens: in sie .)4 ahem ee s+ 78.61 4.84 41 15 ae
Bareiium. 1oddery Wianee es seks es 82.19 ste 20 .09 .23
UV GMMROLEEE SS ches dddiste Fohs ne 3 se © 62.11 ds 33 15 73
ar CH ONe see's. 5 Gace So Seales 83.36 1.31 AQ 13 .38
Common millet................ 62.58 ae 61 19 Al
dipemese millet: } ic. kt ee ee 71.05 oe 53 2 34

Hungarian grass (German millet) 74.31 ice -39 16 55
Orchard grass (Dactylis glomer-

SE eee She Oc a ie 73.14 2.09 43 16 .76
Timothy grass (Phleum pratense)* 66.9 2.15 AS -26 .76
Perennial rye grass (Lolium

212 CY RO eel Ne 75.2 2.6 AT > eh al
Italian rye grass (Loliwm itali-

EURMMRE te tae oe OSs ele hat 74.85 2.84 54 29 861.14
Mixed pasture grasses........... 63.12 3.27 91 .23 75
Red clover (Trifolium pratense).. 80. ate 53 13 46
White clover (Trifolium repens).. 81. Ate 56 2 24
Alsike clover (Trifolium hybri-

Qa). 2. ND. Se I ee 81.8 1.47 44 sil 2
Scarlet clover (Trifolium tincar-

ROTM so. oe oe 82.5 a 43 13 49
Alfalfa (Medicago sativa)........ 75.3 2.25 By 13 .56
Cownaa. 0 65 iiss ee 78.81 1.47 20 di re
Serradella (Ornithopis sativus).... 82.59 1.82 Al 14 42
Soja bean (Glycine soja)......... 13.2 oa 29 £5 .53
Horse bean (Vicia faba) ........ 74.71 fae .68 45 bs A li:
White lupine (Lupinus albus).... 85.35 “ties 44 320 .- L733
Yellow lupine (Lupinus luteus)*.. 83.15 .96 25. nue «hd
Flat pea (Lathyrus sylvestris)*.... 71.6 1.93 Ss 18 58

Common vetch (Vicia sativa)*... 84.5 1.94 59. WS a!
Prickly comfrey (Symphytum as-

DETHUIEIML oerivia sis «ss s sins ate 84.36 2.45 42 11 75
Corniniece eee... oc eo am ome 77.95 a2 28 4 aot
Corn and soja-bean silage....... 71.03 Lye -79 42 A4
Apple pomace silage*........... 15, 1.05 38 15 4

*Dietrich and Kénig: Zusamensetzung und Verdaulichkeit der Futtermittei.

- FERTILIZING CONSTITUENTS 461

Phos- Potas-
F phoric sium
Moisture Ash Nitrogen acid oxide

ge % % % Jo

Hay and Dry Coarse Fodders —
Corn fodder (with ears)......... 7.85 4:91 1:76 54 S739
Corn stover (without ears)...... 9.12 3.74 1.04 .29 14
Teosinte (Euchlena luxurians)... 6.06 6.53 1.46 55 i §
Commngpmillet......a2:8%.-.-:- 9.75 ae 1.28 A9 .69
dapanede millet.........28----- 10.45 5.8 1. A 1.22
Hungariag ‘prass...0..0.).--..- 7.69 male 1.2 205 io
Hay of mixed grasses..........- 11.99 6.34. 141 Bf | .55
Rowen of mixed grasses......... 18.52 W5t>: 1.61 43 A9
Red-top (Agrostis vulgaris)...... Cee 42580 115 36 02 -
Ep aR op ree tbe 4.93 1.26 53 9
Meme erase... cs. se 8.84 642... 5.31 41 £1.88
Kentucky blue-grass (Poa pra- f

MR os sc aw cs cue wees ss 10.35 4.16 1.19 4% 1.57
Meadow fescue (Festuca pratensis) 8.89 8.08 -99 4 W221
Tall meadow oat grass (Arrhena- J

thrum avenaceum)............ 15.35 4.92 1.16 o2 % 1.72
Meadow foxtail (Alopecurus pra- f

ee ae 15.35 5.24 1.54 44 # 1.99
Perennialuye prass............. 9.13 679° +4223 567 1.55
Peat PTASS...0.. 0.2... 8.71 ic 1.19 .56€, 1.27
eeltdiameh hay..(..........-.. 5.36 mae 1.18 25 By
Japanese buckwheat............ 5.72 “pe 1.63 met RE
REET. ew ets SENS 11.33 6.93 2.07 38 2.2
Mammoth red clover (Trifolium

SMELT 1s Scat Chirag Se 11.41 Sil eee 55 Bp 1.22
MUILGMMOVET. osc c 2 coed ees bos oe Pa werr a 2:15 .52/ 1.81
PrP VE! «ck os se ee 18.3 Wad 2.05 A Sissi
1S 7 re 0:94 >) eT 1T |) 3234 67 32.23
PEIERUEIOMEID os. sone ce ee ce ee we 6.55 CAM hon aoe 51/ 1.68

Blue melilot (Melilotus czruleus) . 8.22 13.65 =" 1.92 5A 2.8
Bokhara clover (Melilotus alba).. 7.43 eed 1.98 56 1.83

Sainfoin (Onobrychis sativa)..... . PZ Ag, 7.55: 2.63 16 @ 202
Sulla (Hedysarum coronarium).. . 9.39 a 2.46 A5 2.09
RHE DIMMRULB =. Sis oo). oes hs woe 152 $.23 , 2.1 09, 1.81
Soja bean (whole plant)......... 6.3 6.47.» 2:32 67, 1.08
poly pean Gtraw)......°......: 13: AK 1.75 Ag 1.32
Cowpea (whole plant).......... 10.95 8.4 1.95 oF 147
Si cl NR oS eee 7.39 10.6 Per § .78 -65
PRONURIEREEES O2.> sD ea ic kes 'os 15.8 ca 2.96 BSD!) eke
Ox-eye daisy (Chrysanthemum leu-

OS ee ee 9.65 6.37 .28 48. 3.25
MOTY-EarrOUOPS....>.2c- s,s... 9.76: .. 12253. 3:13 61 4.88
LS yo See: a 11.44 5.3 1.31 Be 2.09
Barley chafi./. >), 0e.:....... 13.08 =i 1.01 wat .99

*Dietrich and K6nig.

462 . APPENDIX
Moisture
Hay and Dry Coarse Fodders— i
continued ,
Wireat Straw. .o arti ce ee 12.56
Weeat ebafly eee ee kd 8.05
Ee StLAW.. Ny pee ys)? 7.61
Game. stiaw o . Gute eee aes 9.09
Backwheat Bulls. si-2 cee. . 11.9
Roots, Bulbs, Tubers, etc.
eeetOCH ac 2 Soke enon tapers bier ok’. 79.75
US TMM tee © a ile ate a Sa 87.73
Yellow fodder beets............ 90.6
Pile =DEC ta ksets fete eee sts kes 86.95
Manpel-wurzels.............. . 87.29
IN SONS aS) 2a ca 89.49
n> oie ct a 89.13
AA Gt ae oe A 89.79
Grains and Other Seeds
Mommricernels 2)... ep ao vie ee 10.88
Boremim seed...) 0062 So see ke 14.
MM AS 5) ORNS toc eee nae 14.3
“is Sly CPS anita enc REL os 1BALT
Wheastspring)= oe... i. ee eas 14.35
Wiha A wariber) cde Sek he 14.75
PAVERS Potis toe ce er hut Pia te de 14.9
Connon millet cS A oP 3 Se 12.68
Japamese millet. st 4 lacijas ol. se 13.68
PCE OS, Sues oe os 12.6
eee wheats st. oo Cece eee 14.1
SoPameeans oo. cso in eee aed 18.33
Mill Products
Cormemeal . 0063.8 Vee 12.95
Corn-and-cob meal...:......... 8.96
Grownd oats 0.6. ek ee tt217
Grogud barley... ee fect o.AS
Ryempur 00. eb oe.05.000 i 14.2
Wheamflour... 62... 020 0.4.7 ogee 9.83
Pea thee ays 2 05. 6 one 8.85
By-products and Waste Materials
CSOUTLAMMDH EAN’. .0'cs ss oe 12.09
Homey feedien:s... ore 8.93
litem meses. +. sc a ee 8.59
Starch feed (glucose refuse) ..... 8.1

*Dietrich and Koénig.

%

mab A ae
aT Ask aa
' er Potas-
S \

Ash’ ‘Nitroment sides tet
% % %
59° aaa
79, aug 42
46 | 28) ae
62 “Bie
AQ: Of aaa
21 Wz aa
2 «(OB a
19. 096° 46
og en ae 48
19 098 pas
18° 39
19 Ae as
15 .09 oun
182 @ A
148 @ol° .
1.51.79 .48

2.06 .82 .62
2.36 39
2.36 89. 61
1.76 eA
2.04 86 .86
1.73.
1.08 > aS "ge
1.44, #44’) ee
5.3. ae ones
1.58 - #8 Sa
1.41 eect. Aen
186 Uzr... 59
1.55.66 134
1.68. £85. GE
2.21? WaT eee
3.08 “82. a8
5 06 6

1:63 gth98 gas
5.03 & 33 28.05
2.020 Ban”

/

FERTILIZING CONSTITUENTS | 463

Phos- Potas-
f _ phoric sium
Moisture Ash Nitrogen acid oxide

SF By-products and Waste Materials— ta ae 7 %

; cont:nu
Maltaprouagey......... ivecd es 10.38 /; 12.48 3.55 1.43 3
Brewers’ grains (dry)........... 6.98 6.15 3.05 1:26)> #65
Brewers’ grains (wet)........... 75.01 en .89 ol 05
vere... st hee. 4 12.5 4.6 2.32 2.25 9 “ae
Rye middlings*................ 12.54 > 3.52 1.84 126 aE
ition meme. Ae eee 11.74 6.25. 2.67 2.89 > ae
Wheat middlings .............. 9.18 2.3 2.63 95 ° .63
Te Se ge os oye 10.2 12.94 and 29 8.24
SE ie pe 2! 10.3 9. 1.97 . 2.67 Sig
Buckwheat middlings*.......... 14.7 1.4 1.38 68 /§ .34
Cottonseed meal............... 9.9 6.82 6.64 2.68 ‘1.79
Govmmmeced hulls,......0..5.... 10.63 2.61 By fs 18 1.08
Linseed meal (old process) ...... 8.88 6.08 5.43 ~1.66: £37
Linseed meal (new process) ..... Watt 5.37 5.78 1.83 Qiao
mp pomace.............. Rarer ss" BL Lo .02 s13

*Dietrich and Konig.

INDEX

Abomasum, the, 103.
Absorption of food, 116.
Accessories, food, 193.
Acids, the, 80.
fatty, 84.
amino, 66.
limiting factor, 191.
Age, influence of, 133.
relation to meat production, 428.
Air, carbon in, 13.
Albuminoids, 57.
Alimentary canal, parts of, 94.
Alfalfa, 227.
Amides, 66.
Amylopsin, 109.
Animal, ash elements, 23.
bodies, mineral compounds of,
44,
fats, food sources, 208.
foods, origin of, 9, 266.
growth, chemical elements in,
72.
heat, a waste product, 184.
regulation of, 183.
source of, 10.
organism, work performed by,

162.
production, adaptability of
crops to, 273.

refuses, 270.

size of in relation to ration, 301.

substance, source of, 10.

Animals, cruelty to, 433.

elements in, 21.

environment and _ treatment,
431.

factors in management of, 425.

fattening, experiments with,
365.

feeding experiments in, 366.
- food needs of, 364.

DD

Animals, fattening, rate of increase,
363.
selection for meat production,
427.
young, milk for, 351.
Anti-bodies, 85.
Argon, 17.
Ash compounds, distribution in
the animal body, 45.
distribution in parts of plants,
42.
in plants, 39.
constituents, influence of manu-
facturing processes, 43.
for egg production, 409.
elements in, 21.
after ignition, 39.
in blood, 46.
elements in soft tissues, 46.
of plants, mineral compounds
in, 38.
variation in plants, 40.
variations due to species, 40.
Assimilation, 87.

Bacteria, 89.
intestinal, 110.
in digestive tract, 92.
Barley feed, 250.
Beef, growth in production of, 363.
Beet, sugar-, molasses, 256.
residues from, 255.
Beri-beri, 193.
Bile, the, 106.
function of, 107.
Birds, digestive apparatus of, 403.
food needs of, 399.
young, rations for, 413.
Blood, the, 138.
ash elements in, 46.
circulation of, 142.

(465)

466

Blood corpuscles, 139.

the plasma, 140.

vessels, in absorption, 115.
Bovines, maintenance | rations for,

314.
Breakfast foods, residues from,
. 248.

Breed, influence of, 133.
Brewers’ grains, 251.
Buttermilk, 268.

Cupinm, 19.
Calorie, definition of, 165.
Calorimeter, respiration, 214.
Carbohydrates, the, 69.
as.a source of fats, 161.
oiakctheation of, 70.
digestibility of, 120.
functions of, 160.
physiologically economical, 186.
regulation of use, 149.
source of energy, 160.
Carbon, 13.
dioxide, elimination of, 147.
Cattle foods, classification of, 219.
distinctions in, 263.
- energy values of, 166.
Cellulose, 78.
and gums, digestibility of, 121.
Chlorine, 18.
Coarse foods vs. grains, 263.
Collagen, 57.
Colts, feeding, 358.
rations for, 359.
Cooking foods, 128.
Combination of nutrients, influ-
ence of, 131.
Compounds, classes of, 26.
classification of, 27.
Combustible and incombustible
matter, 24.
Combustion, 24.
Corn, as silo crop, 231.
Cottonseed by-products, composi-
tion of, 259.
hulls, 257.
kernels, 258.
meal, 257.
Cow, the general purpose, 427.

—

INDEX

\ rf y Syoste
\ pe id

Cows, dairy, calculation of rations.
33a.
feeding standards for, 327.
practical rations for, 335.
requirements of, 331. _
selection of, 426.
Crops, adaptability to environ-
ment, 272.
to kind of production, 273.
drying of, 220.
ensiling vs. field curing, 233.
forage, classes of, 220.
harvesting of, 222.
influence of maturity, 223.
for swine, 386.
high productivity, 275.
methods of preserving, 233.
productive capacity of, 274.

soiling, 276.
value not proportional to yield,
224.
Curing fodders, losses through,
221.

Dairy by-products, 268.
wastes, as food for pigs, 384.
Dextrin, 78.
Dextrose, 71.
Digestible nutrients, in the ration,
299.
Digestibility, as basis of values,
286.
determination of, 135.
influence of age, 225.
meaning of, 122.
Digestion, 87.
artificial, 103.
as a whole, 112.
changes in food, 88.
changes in stomach, 104.
coefficients, inaccuracies of, 136.
factors influencing, 122.
in intestines, 113.
stimuli to, 111.
stomach, 112.
summary of changes, 114.
work of, 176.
Digestive fluids, 113.
Di-saccharides, 72.

INDEX

Drying crops, conditions of, 220.
Drying fodders, effect of, 125, 221.

Eggs, composition of, 407.
Egg production, ash constituents
for, 409.
Elements, distribution of, 27.
Energy, chief source of, 183.
determination of 165.
metabolizable, 168.
distribution of losses of, 169.
expended in feed consumption,
het
how originated, 163.
in cattle foods, 166.
loss from food, 167.
loss in gases, 168.
maintenance, distribution of,
alZ.
measurement of, 165.
metabolizable, 167.
estimates of, 171.
in feeding-stuffs, 172.
in fodders and grains, 173.
nature of, 163.
net, 174.
calculation of, 178.
necessary to work, 163.
uses of, 151.
requirements by growing ani-
mals, 349.
stored by plants, 10.
transformation of, 164.
values, as basis of valuation, 285.
calculation of, 212.
net, computation of, 179.
determination of, 211.
with different rations, 175.
Enzymas, 85.
action of, 92.
in pancreatic juice, 108.
Ether-extracts, 84.
Esophageal groove, 99.
Ewes, feeding of, 354.
Extractives, 67.

Fat, milk-, 83.
Fats and oils, 80.
functions of, 161.

467

Fats, digestibility of, 121.
from carbohydrates, 161.
in grains and seeds, 81.
milk-, food sources of, 321.
nature and kinds of, 82.
Fat soluble A, 194. ;
Fattening animals, rate of inc rease,
363.
Fatty acids, 84.
Feces, constituents of, 118.

Feeding and watering, influence of
frequency, 130.
experiments as basis of feed

value, 290.
conclusions from, 203.
with fattening animals, 366.
practical, 203.
practice, conclusions from, 202.
standards, 294.
American, 329.
Grouven’s, 327.
Kuhn’s, 328.
the Wolff-Lehmann, 328.
Wolff’s, 328.
Woll’s, 329.
stuffs, classification of, 265.
commercial by-product, 242.
commercial values of, 282.
home supply of, 304.
misleading terms for, 264.
physiological values of, 284.
selection of, 286.
valuation of, 281.
valuation by method of least
squares, 283.
Feeds, classification of, 264.
digestibility of various, 287.
Fermentation, intestinal, 110.
results of, 91.
Ferments, 88.
action of, 91.
conditions of growth, 80.
definition of,,89.
organized, 89.
structure and distribution of, 89
unorganized, 92.
Fertility and legumes, 276.

- Fibrinogen, 55.
| Fibroin, 57.

468 :

Fodders, effect of drying, 221.
losses through curing, 221.
preserving of, 126.

Food, absorption of, 114, 116.
appropriation by growing ani-

- mals, 347.
as a source of energy, 162.
combustion, measurement of,
Sake
compounds,
185.
relation to the digestive pro-
cesses, 119.
economics, factors involved in,
420.
effect on constitution of milk
solids, 340.
effect on the flavors of milk,
343.
effect on the proportion of milk
solids, 339.
general uses of, 151.
influence on kind of growth,
347.
maximum absorption of, 117.
needs of fattening sheep, 373.
relation to quality of the horse,
357.
relation to production, 420.
requirements for pork produc-
tion, 381.
unit, the, 418.
use of, 145.
wetting, 128.

Foods, animal, origin of, 266.
cooking, 128.
influence of grinding, 129.
influence on milk-fats, 341.
kinds for poultry, 400.

Forage crops, classes of, 220.

harvesting of, 222.
yield at maturity, 223.
Fowls, adaptability of various
foods to, 415.
feeding standards for, 411.
maintenance ration for, 412.
salt a necessity for, 410.
supply of grit, 410.

inter-relation of,

INDEX

Galactose, 71.
Gastric juice, the, 103. .
Gelatin, 57.
Gelatinoids, nutritive value of,
192.
Gliadin, 56
Globulins, 53.
animal, 55.
plant, 54.
serum, 56.
Glucose, 93.
Glutenins, 56.
Gluten products, 252.
Glycogen, 77.
Glyco-proteins, 59.
Grain, storage of, 241.
Grains and seeds, 240.
coarse food, 263.
Green versus dried fodders, 220.
Grinding foods, influence of, 129.
Grit, supply for fowls, 410.
Growing animals, energy require-
ments of, 349.
Growth, effect on water-content,
32.
in beef production, 363.
in fattening sheep, 372.
influence of food upon, 347:
requirements for, 346.
Growth-promoting bodies, 303.
Gums, the, nutritive value of, 188.

Hay values, Thaer’s, 327.
Heart, the, 140.
Hematin, 60. 4
Hemi-celluloses, 77.
Hemoglobin, 60.

Hen, constituents of the body, 406. —

Hens, laying, effects of food upon,
402.
rations for, 412.

Histones, 58.

Hominy feed, 251.

Hordein, 56.

Hormones, 85.

Horse, the, a machine, 164, 387.
estimate of work ration, 392.
food requirements, 390.
maintenance needs of, 315.

INDEX

Horse, relation of food to quality,

the stomach of, 104. ,
work performed by, 388.
Horses, digestibility of coarse
foods by, 134.
maintenance food for, 315.
rations for, 317.
oats as food, 396.
working, nutritive ratio for, 395.
rations for, 397.
source of the ration, 394.
Hydrochloric acid in stomach
digestion, 104.
Hydrogen, 15.
Hydrolysis, 72, 93.

Individuality, influence of, 133.

influence on energy losses, 171.
Intestinal juices, 109.

action of, 113.
tract, changes in the walls of,
116.

Intestines, the, 105.

form and length of, 105.
Invertase, 93.
Iodine, 19.
Iron, 19.

Katabolism, fasting, 311.
Keratins, 57.
Knowledge, sources of, 201
\
Lactase, 93.
Lactose, 73.
Lacteals, function of, 115.
Lambs, feeding of, 354.
grain food for, 355.
Lecithins, 85.
Lecitho-proteins, 60.
Legumes and fertility, 276.
Levulose, 71.
Linseed meal, 259.
oil, extraction of, 260.
Liver, the, 149.
Lungs, the, 143.
Lymphatic system, 115,

469

Maintenance food for horses, 315.
for sheep, 317.
measured by fasting katabolism,
311.
needs, computation of, 313.
investigations concerning, 309.
of the horse, 315.
rations for bovines, 314.
for fowls, 412.
Maize, 226. ;
kernel, the, structure of, 252.
Maltsprouts, 251.
Maltase, 93.
Maltose, 73.
Manufacturing processes,
ence on ash, 43.
Man’s relation to animal life, 3.
Mastication, 94.
work of, 174.
Matter, classes of, 23.
Meat production, relation of age
to, 428.
selection of animals for, 427.
Metabolism, fasting, use of nu-
trients in, 312.
Meta-proteins, 61.
Methane, losses through, 171.
Milk, 266.
cows’, composition of, 319.
effect of food upon flavors, 343.
fats, food sources of, 321.
fats in, 83.
influence of food upon, 341.
for young animals, 351.
of several breeds, 268.
production, protein
ments for, 325.
production, use of nutrients in,
RES
proteins, food sources of, 321.
relation to food, 338.
secretion of, 320.
solids, effect of food upon con-
stitution of, 340.
effect of food upon propor-
tions, 339.
rate of formation of, 322.
substitutes for calves, 354.
substitutes for swine, 385.

influ-

require-

470 INDEX

Milling processes, 247.
Mineral compounds, in animal
bodies, 44
in ash of plants, 38.
elements, distribution of in ani-
_mal body, 154.
‘ quilibrium of in animal body,
154.
functions of, 152.
relation to animal structure,
1153.
relation to tissue develop-
» ment, 155.
relation to elimination of
waste products, 154.
relation to muscular control,
“55.
relation to osmosis, 155.
relation to vital processes,
152.
supply of, 156.
Mono-saccharides, 70.
Motive power, source of, 11.
Mouth, the, 94.
Muscular activity, relation to pro-
tein, 183.
control, relation to mineral ele-
ments, 155.
Mutton production, 371.
Myosin, 55.
Myosinogen, 55.

New process linseed meal, 260.
Nitrogen, 16.

compounds, relative impor-
tance of, 189.
supply of, 16.
uses of, 17.
Non-nitrogenous compounds,

classification of, 69.
composition of, 68.
Non-proteins, 66.
Nucleo-proteins, 58.
Nutrients, digestible,
of, 297.
energy value of, 212.
energy values, 166.
functions of, 151.
how oxidized, 145.

calculation

Nutrients, quantity for fattening
sheep, 374.
rate of oxidation, 146.
use in fasting metabolism, 312.
uses in milk production, 323.
Nutrition, laws of, 197.
Nutritive ratio, 295.

Oat clippings, 250.
grain, the, 249.
hulls, 248.
Oats, as horse feed, 359.
for working horses, 396.
Oil meal, 259.
meals, the, 256.
Oils, methods of extracting, 257.
Old process linseed meal, 260.
Omasum, the, 102.
Organic and inorganic matter, 25.
Osmosis, relation to mineral ele-
ments, 155.
Oxidases, 146.
Oxygen, 14.
uses of, 15.
Oxy-hzemoglobin, 60.

Palatableness, 292.
Pancreatic juice, the, 123, 108.
enzyms of, 108.
Pectin bodies, the, 78.
Pellagra, 195.
Pentosans, the, 77.
Pentoses, the, 72.
Peptones, the, 62.
Pepsin, 104.
in gastric juice, 104.
Phospho-proteins, 59.
Phosphorus, 18.
compounds,
of, 15a
Physiological requirements, 294.
Pig, stomach of, 104.
Pigs, dairy wastes for, 384.
unwise feeding, 382.
Plant ash, elements in, 21.
Plans, elements in, 20.
new versus old species, 273.
Plasma, of blood, 140.
Poly-saccharides, 74.

relative efficiency

, : ~~
dads See
yor ‘ iA
, Lie > 6
Se ee

INDEX 471

Pork production, 378.
food requirements for, 381.
Potassium, 19.
Poultry, kinds of food for, 400.
Preparation of food, influence of
methods, 127.
Preserving fodders, influence of
conditions and methods,
126.
Problems in feeding animals, 5.
Production, relation to food, 420.
the unit of, 419.
values, estimation of, 181.
relation to profit, 195.
Proteans, 61.
Protein as a source of energy, 159.
of fats, 159.
coagulated, 61.
commercial, 336.
content as basis of valuation,
289.
derivatives, 60.
efficiency from animal sources,
408.
foods, no single one essential,
-; Sap.
functions of, 158.
home supply of, 276, 336.
how determined, 48.
importance of, 47.
physiologically necessary, 186.
relation to muscular activity,
183.
relative importance overstated,
326.
requirements for milk-produc-
tion, 325.
sparers, 187.
standards, revision of, 303.
supply of, 302.
Proteins, alcohol soluble, 56.
as tissue formers, 158.
classification: of, 49.
cleavage products of, 63.
digestibility of, 119.
efficiency of, 215.
familiar examples of, 52.
greatly unlike, 49.
glyco-, 59.

Proteins, lecitho-, 60.
milk, food sources of, 321.
not wholly oxidized, 146.
nucleo-, 58.
phospho-, 59.
phosphorus-bearing evathaee
of, 192.
properties of, 62.
simple, 52.
the true, 50.
relative efficiency of, 1
ultimate composition of, 51.
unlike constitution of, 63.
Proteoses, 62.
Psychic factor, the, 111. ‘
Ptyalin, 98. :

Ration, calculating of, 296.
influence on development of
swine, 383.
and quantity of, 124.
of size of, 171.
on quality of product, 304.
insufficient, correcting of, 300.
maintenance, 307.
character of, 307.
for bovines, 309.
for horses, 317.
how provided, 308.
proportion used as fuel, 160.
the manipulation of, 429.
the quantity of, 431.
relation to size of animal, 301.
selection of, 305.
uses of production, 308. —
Rations, adaptation of, 293.
calculations for dairy cows, 333.
fattening, selection of, 369.
for laying hens, 412.
for young birds, 413.
practical, for dairy cows, 335.
selection of, for sheep, 376.
Rennin, in stomach, 104.
Respiration, 143.
apparatus, 209.
calorimeter, 214.
object of, 144.
Reticulum, the, 101.
Rigor mortis, 55.

472

Roots and tubers, 239.
Rumen, the, 100.
Rumination, 102.

Saccharose, 72.
Saliva, the, 97.
rigin of, 97.
operties and office of, 97.
quantity excreted, 98.
Salt, effect of, 129.
a necessity for fowls, 410.
Sap, al:
Season and storage, influence of,
131.
Screenings, 247.
Secretins, 85, 111.
Sheep, fattening, food needs of,
I oie.
quantity of nutrients for,
«374.
nature of growth, 372.
growing, standards for, 356.
maintenance food for, 317.
place on the farm, 371.
selection of rations for, 376.
Silage, acidity of, 230.
cutting and shredding, 237.
crops for, 234.
growth of corn for, 236.
Silo, changes in, 228.
cleavage of proteins in, 230.
extent of loss in, 231.
filling the, 236.
importance of losses in, 233.
losses in, 229.
necessary loss in, 232.
rate of filling, 237.
Silos, construction of, 235.
Skimmed milk, 268.
for calves, 351.
Sodium, 19.
Soft tissues, ash elements in, 46.
Soiling, conditions favorable to,
277.
crops a necessity, 276.
area and rotation, 280.
selection of, 278.
the economy of, 277.
Soil moisture, influence of, 33.

INDEX

Species, influence of, 133.

Spongin, 57.

Stage of growth,
127.

Standards, German, for fattening
animals, 367. ;

influence of.

for milk production, 330. 4
Starch, manufacture of, 253. A

Starches, the, 75.
rate of digestibility, 120.
Steapsin, 108.
Steers, fattening,
370.
Stomach, the, 99.
Straws, the, 239.
Sugar-beet pulp, 255.
Sugars, the, 74.
simple, 70.
Swine, changes
379.
character of the growth, 379.
feeding of, 378.
forage crops for, 386.
influence of ration on develop-
ment, 383.

rations for,

in production,

Teeth, the, 95.

Temperature, the critical, 185.
regulation of, 183.

Therm, definition of, 165.

Urea, elimination of, 147.

Vitamines, 85, 193.
Vitellin, 56.

Wastes, elimination of, 146.
Water, 28.
content, conditions affecting, 34.
measurement of, 29.
variation in animal bodies,
Sri
elimination of, 147.
functions of, 152.
hygroscopic, 29.
in feeding-stuffs, 34.
in living plants, 30.
in the animal, 36.
physiological, 30.

INDEX

Water, proportion in plants, 31.
relation to preservation of foods,
35.

Water soluble B, 194.
Water-supply, for fowls,
sity of, 408.

to plants, 33.
Wheat, composition of milling
products, 246.

neces-

473

Wheat, grain, structure of, 243.
offals, 243.
the milling of, 245.

Whey, 268.

Work, food expenditure for, 389.
influence of, 133.
of animal organism, 162.

Zein, 56.

The following pages contain advertisements of a

few of the Macmillan books on kindred subjects

\

“The Breeds of Live Stock

By Live Stock Breeders. Revised and arranged by CARL
W. GAY, Professor of Animal Husbandry in the University

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THE MACMILLAN COMPANY
PUBLISHERS 64-66 Fifth Avenue NEW YORK

Prune geet

The Principles and Practice of
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“By CARL WARREN GAY
Professor of Animal Industry in the
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Rural Textbook Series. Cloth, 12mo, illustrated, $1.50

This book has been prepared to meet the demand incident to the
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THE MACMILLAN COMPANY
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~

THE SCIENTIFIC FEEDING
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By Professor O. KELLNER

Authorized Translation by WILLIAM GOODWIN, B.Sc
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THE MACMILLAN COMPANY
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~ By MERRITT W. HARPER

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Manual of Farm Aniwele

A Practical Guide to the Choosing, Breeding, and Keep of
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