illetin Number 472

Dereinher. 1961

1^

The EHecl of Rale of Nitrogen Ferlilizalion

and Dale of Harvest on Yield, Peisislency

and Nnliilive Value of Brome^rass Hay

Yield and Persistency

as Influenced by Nitrogen

Rate and Time of Harvest.

by

Nobel K. Peterson
and Paul T. Blood.
Department of Agronomy

TI. Nutriti\ e Value.

by

Nicholas F. Colovos
and Harry A. Keener.
Department of Dairy Science
and Henry A. Davis.
Department of Biochemistry

New Hampshire

Agricultural Experiment Station

Durham, New Hampshire

ilU'lin iNuniher 472

Deceinher. 1961

1?-

The El'fecl of Rale (if Nitrogen Ferlilizalion

and Dale of Harvest on Yield, Peisislency

and Nnliilive Valne of l^roine^rass Hay

Yield and Persistency

as Influenced by Nitrogen

Rate an<l Time of Harvest.

Nobel K. Peterfion
and Paul T. Bloofl.
Department of Agronomy

.•LA

11. Nutritive Value.

Nicholas F. (lolovos
and Harry A. Keener,
Department of Dairy Science
and Henry A. Davis,
Department of Biochemistry

New Hampshire

Agricultural Experiment Station

Durham, New Hampshire

mK^!^

Bromegrass cut in the boot stage of maturity has
a higher nutritive vahie and a lower yield than
when cut in the soft-dough stage of maturity. A
compromise between the maximum nutritive
value and maximum yield can be obtained by
harvesting the bromegrass in the flowering stage
of maturity.

I. Yield and Persistency of Bromegrass Hay
as Affected by Rate of Nitrogen Fertilization

and Time of Harvest

Introduction

Under New England conditions, grass forages are easier to establish
than legumes and with projjer fertilization will have a comparable pro-
tein content. Bromegrass, rather than timothy, was selected for evalu-
ation of yield and nutritive content as influenced by fertilization and
stage of maturity because it appears to remain palatable for a longer
period, generally yields more dry matter, and has a higher protein con-
tent.

Review of Literature

Considerable research on grassland fertilization has been conducted
by New Hampshire Agricultural Experiment Station personnel (8, 9,
10). Work at Maine (6) and Pennsylvania (12), indicate that while
early-cut hay has a high nutritive value, the yields of dry matter increase
as the date of initial harvest is delayed. In a study of nitrate accumula-
tion in plants, Gilbert et al. (4) found that conditions favoring high ni-
trates were: 1. high nitrogen in the soil, 2. young vegetation, 3. shady
areas, 4. drought or low temperature, 5. form of nitrogen. Raniage et al.
(11) reported that in a three year experiment in New Jersey, applica-
tions of nitrogen increased the crude protein and decreased the nitrogen
free extract and ash of orchardgrass and reed canarygrass.

Experimental Procedure

To provide material for feeding trials by the Department of Dairy Sci-
ence, plots of one hundred feet by seven hundred feet, located at Price
Field, Northwood, New Hampshire were seeded to bromegrass in the
early fall of 1956. All plots received the same rate of phosphorus and
potassium (500 pounds of 0-25-25 per acre per year). There were vari-
ations in the amounts of nitrogen fertilizer and the dates of harvest. The
nitrogen fertilizer used throughout the experiment was urea.

During the first year of the experiment, 1957. material from plots
which had received total nitrogen applications of fifty and one hundred
pounds of nitrogen per acre was available for study. The plots were har-
vested at three stages of maturity, early boot, flowering, and soft dough.
In the suljsequent years ( 1958 and 1959 ) , the plots were fertilized at
rates of 50, 100, 200, and 400 pounds of nitrogen per acre. The three
highest rates of nitrogen were applied in a split application with half
before the first cutting and half afterward. Limit of accuracy of the dis-
tributing equipment, prevented splitting the fifty pound rate of nitro-
gen, all of which was applied prior to the first cutting.

During the first two years of the study, the loose hay was chopped
into a specially built drier. The dried hay was bagged and weighed. In
the third year of the experiment, the hay was baled in the field, then
placed in a commercial drier.

Paxton Loarn

V/oodbriwje Loam

Ft'elJ rock

Figure 1. Price Field — Soil Types, Northwood, N. H.
(Area of field — 20 acres)

Soils

The plot area of the experiment is shown in Figure 1. The soils of
the Paxton series are well draincMl and their relief ranges from level to
steep, with mild slopes predominating. They developed on deep, eom-
pact, platy till of Late Wiseonsin age derived mainly from mica schist,
gneiss, and granite. The Paxton soils, classified as Brown Padzolic. he-
long to the same catena as the moderately well-drained ^ oodhridge
soils, the poorly-drained Leicester and Ridgehury soils, and the very
poorly-drained Whitman soils. The Paxton soils range from strongly
acid to medium acid. Surface runoff is generally medium to slow. A com-
pact, platy suhstratum at 18 to 24 inch depth restricts the downward
movement of water. When the vipper layers of the soil are saturated,
water moves laterally ahove the compact layer and seeps out along the
lower slopes. Roots, water, and air penetrate the surface soil and suhsoil
readily. The soil has good tilth and responds to proper management and
fertilization. Because of poorer drainage, production from the Wood-
hridge and Ridgehury loams is lower than from the Paxton.

Yield and Analytical Data

Yield and analytical data are given in Tahles 1 and 2, and Figure 2.
The variation in height and lodging of the third-stage hromegrass dur-
ing the 1959 season is illustrated in Figures 3, 4, 5, 6, and 7. In the later

Table 1. Broinegrass Yields

First Cutting at Three Stages of Maturity

Treatment

lbs. N per Acre

50

100

50
100
200
400

1957

Ist. Stage ^5/30-31/57)
lbs. dry matter 'A

3,388
4,066

2nd. (6/9-10/57)
lbs. dry matter/A

4,898
6,069

3rd. (6/20-21/57)
lbs. dry matter /A

5.576
6,505

1958

1st. Stage (6/4/58)

2ii

id.

(6/13/58)

3rd.

(6 23/58)

lbs. dry matter/A

lbs.

.di

rv matter A

lbs. drv matter /A

50

3,585

4.868

5,907

100

4,703

6,631

6.001

200

5.464

7.225

4,356*

400

4,670

4.860*

1959

1st. Stage (6/3/59)
lbs. dry matter/A

1,787

2,261

4,731

5,190

2nd. (6/11/59)
lbs. dry matter A

2,364
2,971
4,949
5,698

3rd. (6/21/59)
lbs. dry matter/A

2.463
3.210
4,183*
4,109*

* Severe lodging.

stages of maturity, the yields of plots that had received the higher rates
of nitrogen were considcral)ly reduced hy lodging. The extent of lodging
was also influenced hy rainfall. In 1959. lodging occurred in the third
stages of maturity after two and one-half inches of rain fell within a

3.Z

3.0

2.6
2.2

ill

a:

U

2.0

<

tf

18

UJ

Q.

10

Z

16

o

K

z

If

o

^

1 ?

Ui

>-

1.0

0.8

0.6

0.2

1st

2>«1

3>^

1st

2r^

3tTl

1st

2«<)

3>t1

1st

2^

3vxl

50 100 aoo 4-00

POUHDS OF MjTRO&EN Per AcRE PeR YE^R
It severe lo<l(^\n<^

Figure 2.
Broniegrass Yields Averaged for 1957-59 at Three Stages of Maturity.

seven day period (see Table 3). The ainoiint of phosphorus and potas-
sium in the forage generally decreased as maturity increased (see Table
2). Calcium content was more variable and followed no consistent pat-
tern.

T

able 2. Tl

liree

Year

C»>niparis<»n of 1'.

k.

(la (ioiitrni

of IJroniegrass

Forage

1957

1958

1959

Stage of Maturity

and Nitrogen

Percent

Percent

Percent

Rate Per Acre

*

P

K

Ca

P

K

Ca

P

K

Ca

501b.

nitrogen /acre

Stage

of maturity

No.

1

.20

5.00

1.18

.26

4.23

1.18

.23

4.15

1.18

Stage

of maturity

No.

2

.14

3.90

1.19

.23

4.33

1.18

.20

3.98

1.32

Stage

of maturity

No.

3

.14

3.50

1.13

.25

4.88

1.30

.17

3.57

1.32

100 11]

• . nitrogen acre

Stage

of maturity

No.

1

.22

4.65

1.28

.23

4.73

1.30

.21

4.71

1.33

Stage

of maturity

No.

2

.15

4.20

1.20

.21

4.52

1.20

.18

3.93

1.33

Stage

of maturity

No.

3

.11

3.00

1.20

.16

3.80

1.25

.16

3.49

1.23

200 11]

1. nitrogen/acre

Stage

of maturity

No.

1

.24

4.93

1.40

.19

4.R3

1.26

Stage

of maturity

No.

2

.22

6.00

1.37

.18

4.00

1.32

Stage

of maturity

No.

3

.18

3.90

1.33

.13

3.20

1.14

400 lb. nitrogen/acre
Stage of maturity No. 1

.28 5.90 1.28

.19 4.65 1.48

* Stage of maturity No. 1 cut about June 1.
Stage of maturity No. 2 cut about June 10.
Stage of maturity No. 3 cut about June 20.

-•5

Figure 3. Fifty Pounds of Nitrogen Per .4crc.

5

(>-& -^hJ

Table 3. Weather Data for 1957-1959 Growiiig Seasons at Northwood, N. II.

Month

1957

1958

1959

Rainfall (inches)

April

May

June

July

August

April

May

June

July

August

2.22
2.70
1.95
3.50
1.41

Temperature °F.
Max., Min., Avg.

79:21:48
84:28:57
93:42:68
93:47:69
89:44:66

5.63
2.60
1.78
3.56
1.67

80:29:48
86:30:53
86:37:60
91:50:69
86:45:69

3.32
0.81
4.93

2.47
3.73

74:21:48
90:30:60
94:39:62
91:46:71
94:41:69

Figure 4. One Hundred Pounds of Nitrogen Per Acre.

Figure 5. Two Hundred Pounds of Nitrogen Per Acre.

Figure 6. Four Hundred Pounds of Nitrogen Per Acre. Note Lodging.

Figiirf 7. Fil'tv i'ouiuis of iSitrogen Per Acre on the I^ei't,
One Hundred Pounds of Nitrogen on the Right.

M'

■t •

a^-^-.f^,

Figure 8. Invasion of Ked (Hover in Bromegrass Plots I'ertilized at the Rate
of Fifty Pounds of Nitrogen Per Acre Per Year.

Conclusions

Yield: Broniegrass fertilized with high rates of nitrogen properly bal-
anced with phosphorue and potassium produced the highest dry matter
yield in the third stage of maturity. Nitrogen applied after the first cut-
ting greatly increased the yield of the second cutting.

Fertilization: The best results were obtained where nitrogen was ap-
plied at the rate of seventy-five to one-hundred pounds per acre before
the first cutting. After an early harvest ( middle of June I . fifty to seventy-
five pounds of nitrogen per acre should be applied to encourage rapid
growth of the second crop. Whei*e the nitrogen carrier is acid and ap-
plied at a high rate, additional lime should l)e used. For, where a total
of eight-hundred pounds of urea nitrogen was applied over a two year
period the pH of the plots dropped from 6.2 to 5.5.

Persistency : Without sufficient phosphorus and potassium, high rates
of nitrogen resulted in severe lodging and a reduction in persistency. At
the low rates of nitrogen, the persistency of the stand was lowered by
the invasion of red clover. Figure 8.

Protein: The protein content of broniegrass generally increased as the
rate of nitrogen increased.

II. Effect of Different Levels of Nitrogen
Fertilization and Dates of Harvest on
Nutritive Value of Bromegrass Hay

Introduction

Economical milk production depends on maximum use of home-grown
feeds. The northeast is mainly a forage-growing section and in order for
dairying to remain profital)le in this area it is necessary to continue to
place more emphasis on maximum use of high quality forages grown in
this section. In the last ten years the northeastern agricultural experi-
ment stations have heen concerned with extensive studies related to the
hreeding, persistency and nutritive evaluation of various forage crops
adapted to this region. Because of the difficulty in holding stands of
legumes in this area, the New Hampshire Agricultural Experiment Sta-
tion has centered its attention on certain grasses which appear to have
possihilities of yielding large crops of high quality feed, if fertilized
sufficiently, managed properly and harvested at the right stage of ma-
turity.

If a forage makes up a high percentage of the cow's ration, it must
he high in feeding value, acceptahle by the animal, and produce a high
yield per acre.

Work done, at this station and elsewhere, clearly established that the
early cutting of certain species of forage improves their nutritive value.
The stage of growth in a forage greatly influences the acceptability of
the forage bv the animal. Early-cut forage is much more acceptable to
the animal than late-cut. Protein content is also higher per unit weight
when the forage is harvested early. Digestibilities of protein and energ\',
as determined by digestion experiments with dairy cattle, are signifi-
cantly higher in early-cut forages as compared to the same forage when
harvested at a later stage of maturity.

Recent research has also indicated that liberal use of fertilizer in the
soil increases dry matter yield per acre. There is limited information
on the effects of such practices on the nutritive value, yield per acre, and
persistency of the species of forage.

To obtain answers to some of these questions, a cooperative study be-
tween the Dairy Science, Agronomy, and Biochemistry departments was
undertaken. The over-all objectives of this cooperative effort were:

1. To study the effect of different levels of nitrogen fertilization and
date of cutting on the nutritive value of forage.

2. To study the effect of the above conditions on the yield of nutri-
ents per acre and also on the persistency of the species of the forage.

3. To determine the nutritive value of the forage crops on the basis
of digestible dry matter, total digestible nutrients, digestible protein and
digestible energy.

11

Review of Literature

Prince ct al. (8) reported dige*tion experiments conducted in 1931 by
Ritznian and associates to compare the nutritive value of timothy hay
cut June 20 and July 20. The digestihility of j)rotein decreased 15 per
cent, the digestiliilitv of energy decrea'^ed 12 j)er cent and the daily l)al-
ance of energy decreased from 5510 Calories to 1280 Calories in the late
cut hay. Each of the four animals received about 20 pounds of hay daily
as the sole ration. Observations after each feeding revealed that the
animals accepted tlie earlier-cut hay much more readily than they did
the hay that was cut July 20. Hay cut about August 7 from another por-
tion of the same field, showed a digestibility of 32 per cent in the pro-
tein. 49 per cent of energy, and tlie daily ])alance of energy about 1000
Calories which was an additional 17 percent decrease of the digestibility
of the protein and a 6 per cent decrease in the energy lialance.

Colovos et al. (3 I 1949 compared the nutritive value and acceptal)ility
of timothy hay cut at different stages of maturity with clover hay. The
results of this experiment showed a decrease in nutritive value similar
to that in the experiment with timothy hay in 1931 at this Station. (8).

Poulton et al. (7l 1957 reported the effect of nitrogen fertilization at
levels of 100. 200. and 400 11). per acre on the nutritive evaluation of or-
chardgrass hay. The hays thus grown were compared to alfalfa liay. The
conclusion was tliat the total digestilile nutrients of the three orchard-
grass liays were higher tlian the values found for alfalfa.

Nellin et al. (6l 1960 studied the effects of date of harvest on tlie nu-
tritive value of timothy. Climax timothy grown under 100 pounds per
acre of 10-10-10 fertilizer was harvested at eleven stages of maturity be-
ginning May 27 and ending August 5. Delayed harvest decreased the di-
gestible energy and total digestible nutrients of the forage materially
until the first week in July after which the decrease was not as pro-
nounced.

Browning et al. ( 1 ) 1960 reported that liberal nitrogen fertilization of
Coastal Bermuda and Johnsongrass improved the feeding value and yield
of the resulting hays.

Spahr et al. (12) I960, noted that advancing stage of maturity of the
forages tested resulted in lower daily milk production per cow and lower
body weight gains when the forages were fed ad libitum as the only
source of roughage.

Chalupa et al. (2) 1961. studied the nutritive value of reed canary
grass hays grown with 0 lb., 100 lb., and 200 lb. nitrogen per acre and
compared them to alfalfa.

Lloyd et al. (5) 1961. determined the effect of nutrient digestibility
of timothy hay harvested at four stages of maturity and compared the
nutritive value index of the hays. In general there was a decrease in the
apparent digestibility of all fractions of timothy hay with increasing ma-
turity.

Experimental

The nutritive evaluation of bromegrass hay grown under different
levels of nitrogen fertilization was carried out over a three-year period.

12

1957 - 1958

The first hays, grown under two levels of nitrogen fertilization. 50 and
200 pounds per acre, were harvested at three stages of maturity during
the Spring of 1957. The digestion balance experiments were run during
the period of October 1957 and May 1958.

The animals used in this experiment were identical twin Holstein
steers. These same animals were used throughout the three years' experi-
mental period.

1958-1959

The hromegrass hays for this year's experiments were grown under
four levels of nitrogen fertilization, 50 lb.. 100 11)., 200 lb., and 400 lb. per
acre, and harvested at three stages of maturity June 4. June 13. and June
23, 1958. Due to severe lodging in the 400 11). N acre, digestion balance
experiments were run only on the June 4 cutting. The nutritive value of
ten hays was determined during this year. Digestion balances were run
fluring the period of September 1958 and June 1959.

A second cutting of the crop on all fertilizations was made on July 20,
1958 on representative })lots to determine the total crop on each treat-
ment but no digestion balances were obtained with the animals.

1959 - 1960

The experiment was repeated with the ten hays grown and harvested
as in the previous years. A second cutting crop estimate was made on all
fertilizations from representative plots harvested on July 20 as in the
previous year. Digestion balances were run during the period of Septem-
ber 1959 and June 1960.

Procedures

The procedure and methods followed in this experiment differed very
little from those used in previous research reported from this laboratory
except in the method of the excreta collection. A brief description of the
procedure and methods is presented below together with the changes
made.

Feed

The hays were chopped and mixed thoroughly before they were trans-
ported into the laboratory in large burlap bags. The hays were fed to the
animals twice a day at which time an aliquot sample was taken to com-
posite it for analysis. A salt block was kept in front of each animal at all
times. A preliminary period of 15-18 days was allowed before each di-
gestion balance collection.

Collection periods were of 8 days duration. During the collection peri-
ods any refuse was carefully recovered, dried and compounded for an-
alysis.

Gross energy determinations of the feed and refuse were made by the
use of an adiabatic bomb calorimeter. Proximate analyses were made on
both feed and refuse. The nitrogen and the energy in the refuse were sub-

13

z

u
oc

a.

72
68
64

60

73

69

65

61
57

53

70
66
62
58 1-
5f

7e

68
64
60
56

Dry /Matter

NITRO&EN PER ACRE
- 50 lb.

Protein

ENERS.Y

Total Di&estible Nutrients

June 1

June 10

June zo

Figure 1.
Effect of Nitrogen Fertilization and Stage of Maturity on Digestibilities.

14

tractcd from the amount fed in order to determine the protein and en-
ergy consumed hy the animal and aL<o oljtain s-ome of the data for the
determination of the total digestible nutrients.

Excreta

Feces and urine from the steers were collected separately by means of
collection devices developed at this laboratory ( 3 » . These consist of
metal containers placed in the opening under the floor and directly in
back of the metabolism stall to receive the feces when the animals defe-
cate. Urine goes into stainless steel funnels which are in the center of
each stall and covered by a grid, and is directed into a bottle in the base-
ment. Both urine and feces are collected in the basement where the temp-
erature is kept much cooler than the rest of the building.

Feces and urine were weighed and sampled daily. Composite samples
of feces were kept at a temperature of approximately — 16° C. while the
composite samples of urine were stored at a temperature slightly above
fxeezing. At these temperatures no preservative is necessary. At the end
of the collection period, the feces samples were thawed, mixed thorough-
ly and an aliquot was taken for moisture, nitrogen and gross energy de-
terminations. The remainder of the sample was spread in a shallow pan
and drie<l in a forced hot air oven at a temperature of 55° C. and then
ground in a Wiley mill. Gross energy was determined on the dry feces as
well to check for anv loss due to volatilization during the process of dry-
ing (8).

Urine samples were allowed to come to a temperature of aliout 20° C,
and their specific gravitv determined; they were analyzed for l)oth nitro-
gen and gross energy. The urine samples used for the gross energy de-
terminations were dried in the combustion capsules under vacuum.

Results and Discussion

The composition of the broniegrass hays grown under the levels of ni-
trogen fertilization of the experiment and harvested at the three stages
of maturity are shown in Table 1. The letters E, M. and L before the
numJjers under the forage column denote early, medium, and late cut-
tings, or about June 1, 10, and 20 respectively. The number after each
letter denotes the weight in nounds of nitrogen fertilization per acre.

The proximate analyses of the three years' crops differed little when
compared on the basis of date of harvest. The protein, ether extract, and
ash percentage composition decreased while the crude fiber and nitrogen-
free extract increased as the harvest was delayed.

The protein content in the early-cut hays of the two higher fertiliza-
tions. 400 lb. and 200 lb. nitrogen per acre, ranged between 16 and 23 per
cent. This is in agreement with other investigators (2j who found protein
values in grasses as high as in legumes.

Digestibilities of drv matter, protein and energy, as well as the total
digestible nutrients for the three years are shown in Table 2 and for
comparison in Figure 1. Digestibilities decreased as the date of cutting
was delayed. The decrease in the digestibilities of dry matter, protein,
energy, and total digestible nutrients averaged about one half of one
per cent per day of delay after the first of June.

15

The effect of nitrogen fertilization and date of cutting on the yiekl of
digestilile nutrients of hroniegrass liay per acre is shown in Tahle 3.
l^iekls of digestible protein and digestible energy per acre were liigher
in the early-cut hays when the comparison is made on the total yield, ex-
cept in the case of digestible energy in the 1959-1960 hays. The reason for
this is obviously the sevei-e drought experienced during the growing sea-
son in 1959 that reduced the yield considerably.

Table 1. Effect of Nilrogoii Fertilization and Stage of Maturity
on the Chemical (lonijiosition of the IJroniegrass Hays'''

Stage of Maturity

and Nitrogen

Rate Per Acre

Ash

Protein

Ether
Extract

Crude
Fiber

Nitrogen-
Free
Extract

50 lb. nitrogen/acre
Stage of maturity No
Stage of maturity No. 2
Stage of maturity No

100 lb. nitrogen/acre
Stage of maturity No. 1
Stage of maturity No
Stage of maturity No

200 lb. nitrogen/acre
Stage of maturity No
Stage of maturity No
Stage of maturity No

400 lb. nitrogen/acre
Stage of maturity No. 1

Percent Percent

7.02

Percent Percent

21.12

3.37

30.25

Percent

1

6.73

11.58

2.67

33.75

42.53

2

5.69

8.49

2.30

35.01

45.34

3

5.08

6.95

1.98

36.34

46.44

1

6.05

11.71

2.95

34.38

44.36

2

6.39

9.28

2.47

37.49

43.97

3

4.81

7.49

2.02

36.86

49.38

1

6.97

16.89

2.94

32.44

38.04

2

5.67

11.86

2.45

34.46

42.02

3

5.55

10.00

2.30

36.60

41.41

37.51

* Percentages are expressed on dry basis.

Table 2. Effect of Nitrogen Fertilization and Stage of Maturity
on the Digestibilities and Total Digestible Nutrients

Stage of Maturity

and Nitrogen

Rate Per Acre

Dry
Matter

Protein

Energy

Total
Digestible
Nutrients

50 lb. nitrogen/acre

Stage of maturity No. 1

Stage of maturity No. 2

Stage of maturity No. 3

100 lb. nitrogen/acre

Stage of maturity No. 1

Stage of maturity No. 2

Stage of maturity No. 3

200 11). nitrogen/acre

Stage of maturity No. 1

Stage of maturity No. 2

Stage of maturity No. 3

400 lb. nitrogen/acre

Stage of maturity No. 1

Percent

70.73
66.34
60.61

72.60
68.23
64.63

70.34
64.98
59.80

71.67

Percent

66.99
58.81
53.39

69.05
61.93
55.55

73.67
68.91
60.81

76.78

Percent

65.98
61.45
56.20

69.55
64.04
60.30

65.40
60.75
54.74

68.83

Percent

66.18
60.84
57.30

69.58
65.84
62.60

67.42
61.75
56.48

69.24

16

Summary and Conclusions

Nutritive values of Ijromegrass hays grown undei four levels of nitro-
gen fertilization and harvested at three stages of maturity were deter-
mined with identical twin steers.

Nutritive evaluation was made on the hasis of digestil)le dry matter,
digesti])le protein, total digestihle nutrients, and digestihle energy.

The experiment was repeated for three years to study the uniformity
and persistency of the crop on the hasis of nutrient yield per acre.

The level of nitrogen fertilization did not affect the digestihilities of
the dry matter, the carhohydrate portion, nor the energy of the forage to
a great extent. The digestihility of the protein, however, increased with
the level of nitrogen fertilization. There was no appreciahle effect on the
total digestihle nutrient content of the hays due to the level of nitrogen
fertilization.

Advancing stage of maturity decreased the digestihilities of all the in-
gredients of the hromegrass hays, confirming previous results at this Sta-
tion wHh timothy hay.

The results showed that early-cut hromegrass hay grown under a 200
pound nitrogen fertilization per acre was as good a protein source as le-
gume hay.

The results further showed that while the late-cut hromegrass hay in-
creased the yield of dry matter per acre, and consequently the digestihle
energy by ahout 10 per cent, the digestihle protein content decreased by
more than 30 per cent.

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References Cited

1. Browning, C. B., Lusk, J. W., and Miles. J. T. High Fertility Improves Hay
Quality. Miss. Agr. Expt. Sta. Farm Research, Vol. 23, No. 6. 1960.

2. Chalupa, W. v., Cason, J. L., and Baumcardt, B. R. Nutritive Value of Reed
Canarvgrass When Grown With Various Nitrogen Levels. J. Dairy Sci. 44:
874-878. 1961.

3. CoLOvos, N. F., Keener, H. A., Prescott, J. R., and Teeri, A. E. The Nutritive
Value of Timothy Hay at Different Stages of Maturity as Compared W ith Second
Cutting Clover Hay. j. Dairy Sci. 32: 659-664. 1949.

4. Gilbert. C. S., Eppson. H. F., Bradley, W. V., and Beath, O. A. Nitrate Accumu-
lation in Cultivated Plants and W eeds. Wy. Agr. Expt. Sta. Bui. 277. 1946.

5. Lloyd, L. E., Jeffers, H. R. M., Donefer, E., and Crampton, E. W. Effect of
Four Maturity Stages of Timothy Hay on its Chemical Composition, Nutrient Di-
gestibility and Nutritive Value Index. J. Anim. Sci. 20: 468-473. 1961.

6. Nellin. T. N., Poulton, B. R., and Anderson, M. J. A Study of the Effects of
Date of Harvest on the Nutritive Value of Timothy Forage. Paper presented at
the annual meeting of the Eastern Division of the American Dairy Science Associ-
ation. University of New Hampshire, Durham, N. H. 1960. University of Maine
Mimeo. Aug. 1960.

7. Poulton, B. R., Macdonald, G. J., and Vandernoot, G. W. The Effect of Nitro-
gen Fertilization on the Nutritive Value of Orchardgrass Hay. J. Anim. Sci. 16:

462-466. 1957.

8. Prince, Ford S., Blood, Paul T., and Percival, G. P. Studies of Feed Value of
Early Hay. N. H. Agr. Expt. Sta. Cir. 41. 1933.

9. Prince, Ford S., Blood, Paul T., Phillips, T. G., and Percival, G. P. Fertilizer
Experiments on '"Run-Out" Hay Land. N. H. Agr. Expt. Sta. Bui. 271. 1933.

10. Prince, Ford S., Phillips. T. G., Blood. P. T., and Percival, G. P. Experiments
with Grass Hay. N. H. Agr. Expt. Sta. Bui. 306. 1938.

11. Ramage, Carroll H., Eby% Claude, Mather, Robert E., and Purvis, Earnest R.
Yield and Chemical Composition of Grasses Fertilized Heavily with Nitrogen.
Agron. Jour. 50: 59-62. 1958.

12. Spahr, Sidney L., Kesler, E. M., Washko, J. B., and Bratzler, J. W. Effect of
Stage of Maturity at First Cutting on Yield and Nutritive Value of Forages. Depts.
of Dairy Science, Agronomy, and Anim. Hush, and Nutrition, Pennsylvania State
University, University Park. Pennsylvania State University Mimeo. Aug. 1960.

19