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widte et’ baie Gen. bio ie 24k Olek Sa tk a a ak ISSUED JULY 31, 1912, é . i Pa Ue Re A CUGTIGAL EXPERIMENT STATION oe _E. V. WILCOX, SPECIAL AGENT IN CHARGE — Uk re Kia sae) as t : 4 a x PRODUCTION AND INSPECTION ee: | OF MILK a + BY ae | wae E. V. WILCOX | | a ; SPECIAL AGENT. IN CHARGE . hah : aN | HONOLULU: nee Sava u x te : z Hoxovunu Stax-Butuerin, Lrp.. 9 |< “s Bai 0 : Cores “A9t2 Dee Po Se Ca a ee HAWAII AGRICULTURAL EXPERIMENT STATION , E. V. WILCOX, SPECIAL AGENT IN CHARGE PRODUCTION AND INSPECTION OF MILK BY E. V. WILCOX SPECIAL AGENT IN CHARGE HONOLULU: HONOLULU STAR-BULLETIN, LTD. 1912 HAWAII AGRICULTURAL EXPERIMENT STATION, HONOLULU. (Under the supervision of A. C. True, Director of the Office of Ex- periment Stations, United States Department of Agriculture.) Walter H. Evans, Chief of Division of Insular Stations, Office of Ex- periment Stations. STATION STAFF. H. V. Witcox, Special Agent in Charge. J. Epgar Hieerns, Horticulturist. W. P. Kettry, Chemist. ©. K. MceCietzanp, Agronomist. D. T. Fottaway, Entomologist. W. T. McGroree, Assistant Chemist. Attce R. Tuompson, Assistant Chemist. ©. J. Hunn, Assistant Hiorticulturist. V.S. Horr, Assistant in Horticulture. ©. A. Sanr, Assistant in Agronomy. HF. A. Crowns, Superintendent Hawaii Substations. W. A. Anprrson, Superintendent Rubber Substation. J. peC. Jurves, Superintendent Homestead Substation. J, K, Crarx, Superintendent Waipio Substation. TABLE OF CONTENTS. Page INO miTalle male, raceme eenaest Geese aie ak ceaarc Levan ere em are aus ae 5-31 BIOlO Mya Ol nailllkeeaeree rere hn ei wis es a cteea tn alae Bee 5 ANATOMY MOLauMemmdGer en oad one. see cae cs 5 Physiology of milk secretion .................. 6 Actes im amiilllkke aera eg ech cee ne ee aS coe ens 8 IDINVAACIVSS su aNes Call Korey Seance dan eee Gel a oor nee 8 eucocytesi anemic neck. wc chasis areieckee sites 9 Germicidal substances in milk ................ 10 Physical propertiessof milk 220.5252... 556..5008- 114 COLOR re eet aoe each een aal he re ene aa tne iil SMe CihlemonavlGyeercs cit se eas Sele citi ee mice ial WAS COSi yar epteaetie sete ic cinie cesarean ls eters, Sela ele ii (OAC Oy Bwes ates Giroliced eter cnc RO Renee oonan ERD eR NE VB an a 12 MICrLOSCOPIC Fappeanrance eee alee eee 12 IDE CLM CMC AG remit sincere choir chat eran cl tas al ee een 12 RCE ZIM DOMME etme es rca aera eae a haya Nene 13 ID XECO ESI Ga MR ae ph Ra 1 Src CRC RY eC PT Ee te Ce aT Ae 13 VEER AGU C INC Oxe arent wis oat iedoreancts cs se reeeere miele 13 CoheSsivier POWeraetie fers: conser eto cron eee ie 13) IDUSCHRICEN! THOIOSIOK) oS uuctountosacuopcoolne soc 13 BASISHOm CGlLeaminesmechods sec ee see eee 13 Chemistry ot smile eee s saree eee ae ee 14 IRCAGCLION hn wikia steak co cos te Hara ee RATS, aes, ee 14 WOTIPOSIELOIN, Ree reece RE ro Meena hee tes 14 | EAE Coat eR peed me aE CP ORES COC EMORY CROCE NSE Bec solar ee teeter eee 14 CASCIO Ney cce er eee it eh ee ee Ie 15 MACtATD UMN: ahh Si aR carne ae ee ees 15 actor] OMUlimMe svete rene aco trace el sea 16 Galacbiniye. Memcisiortoiatene © terete eee oe eI 16. VIA SU aa ewe eaesene eani eres stare oe ae cree ete 16 Wineraliconstituents a. 04ers soe 16 Otherssubstancese sia 65- seco see oe eee ig Factors influencing composition .............. 17 RCC Oe een tr cirn ee io ere Nae © dee ee 7 ANE GH Of COW ia Art ene he ec hoz cueee a ieee 18 Period! of lactation 275. 92.5052 c050.00 56.45 18 iatnya ality: eee er tetsys oc seicee cc che etn earns 18 Manner and time of milking .............. 19 EXErCISey andy wiOGKa sess ee cee se ee 20 SHOE INOW CVE write tetra hee cian cual eae ena A ee eee EE 20 IV Page i=] 4 VG BemPed ee EEG rhe cid nia ceomoe Ow Stor 20 Weather: § ioc) Sanetsre ansretionee tenet etteueorener snatertaaie tele 20 Seasons ley a sds. oh stele Repeater ere cision cy easr sete 21 DISCASC:” is heya ene ec ale renetmeeneletelrar2\ sister sila tens Merenene 21 PXCITEMONE, wn loets fois slepeiel hee eaten cled wer TER 21 HD ss) s oP eh ect een RMP Ac cic aca UTC, Ao & Gabo 6 21 BRCOZINE : Aye iiciaers, «20 sr. shaaeneptae omeetenererss «eaters me eene 23 Sheltermand cane ol) COWS Mane eerie 23 DShHOrMIMS (COWS. cy. ioguseeetaey oka eo ces tee OMe 23 SiZe. OF “COWS! vance svszs cuss aed Sieve eestor i poe 23 Gestation — 2.052 o. o Veco nae eee 23 IMiiscimey (nnd hs. oa chi vabaterereevereme personel ors so ere 23 DRUSSis We Gee Ata ec pbiiaae eeeer aeorer ele cee i: 24 Method of drawing from can .............. 24 LOGO] Stam dans: pvc ooe ae ee eA ee aca eae 24 Market milk, §23. Hee oc een Oh eae Coe 25 Commercialmtormsio tem kage eee eee 27 Sian daira yma ikke | Bese arse set cee ned eke ieee el ote eae eae 27 Standardized, blended milk .................... 27 Modified, humanized milk .................... 28 Certified!) wiillke Says csickact nse ooreuces ahare seiner mncees 28 Guaranteed Vmillkee. aii. anion on are. textoreernoe scree 28 Sanitary mille: 4a Se-s5 2 ccretors acetate ae aah 29 Sterilized: amille (esha dnc g aero eee 29 Clarified ome ee 5.o sey oan eee ieee 29 Carbonated! smile = 5 chad sy ese capes cee Gemtaacke senor 29 Homogenized mille <5. aw os ee on eee nee eee 29 ‘Condensed, evaporated milk ................... 29 Desiccated., milk tc... de co yt wei eer 29 Milk of mammals other than cows (human, ewe, goat, reindeer, hog, mare, ass, mule, camel, In- dian buffalo, zebu, dog, cat, porpoise, rabbit, ele- PHAN. Gti) coches Sek c eee Se ee 30 Il. ADNOrmall milk .. cys. ctehe nom oi weiter cneesieusteaensce are teneeee ote 35-52 Abnormal compositloneeeeee eee ier eer 32 Abnormal TeOlOLSs wees Sek eee ee eens 33 Addedscoloniniesmlattensica. aie leila icine 33 Colorsmdveston bacteriay sae eateriee 33 Blue milk ....... sia waged aA eee ee 33 Red! milk \.csoss = oder Sere ee renee 34 Yellow milks: '.. shee rocco ee locale tee 34 Other, colors eisai ener ekeieh eececns 34 Abnormal tilavers sandeoG OG Smererteeer tiie ni tele 34 Due to eed iners Cutis eee crn et kteteke tetera 34 Page SA DSOLULONBOL OG OFS crm hese eee cu Uae ee 37 Wer torbactenlametss ase ees. 8 same sf ees 37 JBM e ey GaUUiI ke protedcs canals ect ie a a oe 37 S Oa pyaar Ps a elt els Naa eee em ie te hl Oi 38 SOwurpemMl Kegs Maden septa Sica Mat ee See hick is 38 Alcoholiestermentationy §.5 5.5.0. ecesee.e 2. 39 ROD Ors lirnyemraiillikes sis ek Se PANS Ge Mle Se eS 39 Abnormalities due to condition of udder ........... 40 Abnormalities due to ingestion of drugs and harm- Jia ay OESH OWS. aos ORM ei Ne eh cd) aman Re an 43 Pathozenic: bactemaninyemilikcrss -Ssee pleas ee ee. 45 Roxins, antitoxms etes im milk -2 250 seeee sl qs eee. 45 Bacterial changes, milk poisoning .-)..)........... 46 Milk during estrum Boe Ba Be Pe te lool acl ae Se Pe 47 Heuc OcytestinemiilkerAcms samen wre eek Roe a 47 IDG pelt obs TOUS, cea sine Tuan testa Gagan te Ae A CRU Une am 51 ACULET AT ONS Memeo + 58 seas sk cts Meee Welw ms 52 Ill. Hysiene and: diseases of Cows) 94.4.2 50no. oo act enue. 53-98 TEXEL.CISCRe ani wk cents tl samntrec a SiN rma tind Sigel Hee aN | 53 GEOOMIIINE Faseur wei were een ered ACM Bee 1A 8 te ea 54 Re sularityeim Care tar as saat ro Aen oe on ie | 54 Bi Ce CTV meee irat SA) Sm aut, hs Sree ten PR RICE a: 54 Be din cee Pees s Rokiee Chel Ma eaten, Oe ae Le cla AENS 55 AV ZELU Tyo Nahar Sema Pal Bas iro 4 eg PR Te ae 55 ST aes aoa et Comoe WIA. oi: ea 59 DISIMPSCTTO Me ary cars metas SN eR Oe othe Ln 59 IDISCASES LOL COWS. Secs teenie eee de 64-98 AND ON LION? Myeeaee MA Meni n sO NeR ay Fatt ERENCE DY Ca es 64 Actinomycosis Bir Ho uterisren cyan aC MCP CCE CEM EE 65 ANGUINO SACHIORIS, ob Rb ba ocdomodosnaondanaesen vale 65 Lar ON CE hipaa Soo lon, eld Senin Ae anes a 0 a 66 BIBS Se 72 Anas arts eras! Se RUM RS tole Leyes 66 LEUKOC NEN Tee Y Ape ea Batiste Rk tae ate heb | C005 Al eee eee 67 Counstalle disease: i=s2 sacl GSR eee 68 COMO mos Bike aie ances: RCO AN ERM Y NA WE, Oo ya 69 EPO RIG em ater ha 38 ene er ae RRR BRELAIT GEN TG.” 69 TAD UN eS ia ake hae ALD eee, © Renee ean 70 Foot-and=-mouth disease.) /s.se0. see 71 HOO flO tate erye ee ere sie anette ok eh 72 ELE MALU aren ter semce ee ete el Ae 72 Hemorrharic septicemia 4440.02 00 0055.00. 73 LOT Vane it ki eRe seater tu.) ARB eee ve Sy 13 JTC ey ts see ee tel ceo oe Mgt OP pi 74 FOUN UN Cs ae aa ne PS EMA ANNE RE Soe TA vI Page Kieratitismcc ..csr.cie setcieet tot ocr haelo) oi cnet eerie 15 ni ey- Es PO CEE ID OEIC OO Oot LIS too o0 6 75 Malignant catarrhal fever ...:.............--- 76 Malienantnedenmia weirs ee + ctac -titeleie be wit tian tere eau SM ea aa na tl g¥ elas eteedv ates oi.e, oe: old byw tes Se eee ore ene ae 77 INTO ERTS aie nen tetaeeeeic ate aelin, aie Sand eNO owen Rone Reon 79 NTU ReVeT ese weve, s fagh) doe/e so a eee 79 IM Gules FHlel cece et eos com oem. cat o boa c6d0600.0 nC 81 AWW Ini oXe Fast omy plotnco cp eer RCeee Mele can Bisic tole aco piso. 7 0 81 INE Werle Wee aeceareini vo Gipiete ReEeera nC. da oO Clee tb adie Ac 82 IN(SH OPH EL I We eoes cha EO cl ORO Pepe G ol DG/a c1adG, dino mo oredin.0 6 82 IN@YOUEN? GHRGARE ccoacacaanabo0ocs0n0 506 se oists uate 83 Osteomalacia niAc Fees ete scheme oie tele entecelle 83 PeriGarditign. cst tees Cave Sto EEC eco anon 84 PSritOmMitis: > sera cis a tees col aeaeeers eye rs iceeestors Bile ueuens 84 Pleuro-pneum oni.) seis eeieene enn eiens 85 POISONS) 5 ote ats ete sh eke oe tetera crema 85 FRIADIES + acta ots, 5d Seatac oeestrd erence aeonek aon Tone 87 IRS KSIMNONN, Cit EVAMEVOONP. Goa gcoduconooneunesHo5s0 88 RNS UM ACSI Arcs emo ekaeeeaers ee one wee pean opto mee 88 RIMMED ESE wanteec se ccoseyeraiestclens toe escieilesatereeay eo cH 89 Rain WO i sete ea. Mime ats CRE Goa aws eevee eae eM: 89 S Galle sie pee wtsrarene sac iteeere acs ccc) Mee gees A ey ose 90 SCOUPIME ees ceccag taken Raccoon tee e Eee a ene 91 Screwworm fly ........ Ped ee eee, ae ee eg ee ee 91 St@SSers: vssaceinheon weno eapanse varcad yepoeeeren ein ner 92 Stomach: Worms: .5.226keceh nace tenance acuoneege es ere 92 SLOMMAGILIS: ©. 3 ght salecolcis sie nee eran Sore Reratoe No eee nets 92 Meat GiSeases: : Me oeail esas soeasete ceva et eter he uereucton eae oom TEXAS FEVER is cea ea EER mone ce 94 Titherculosis. sigs 2escdecic seer eee : 3 95 TTUIMOTS! oyeSrock tie keds eben are steam ste note ola eeeh eer ty een erent 96 WEPRTUINOUS [ORO MEMS ooossccacnacgeoscacncoeNe 97 War ble: liye sc5 cites emcee enon eRe noted ee eens 97 WOU aside eas etnies one eacteuener 0 omeye eke f etaucue ee enencore 98 IV. Meedine (COW Sic ice Seat eueie ie acs een cas nGT a Cleese yee ner eae eee 99-105 Grains for cows ae eee een eo. nee 99 INNO NY? ElraVol Wyte) TBNMOMNS) CSc aneaavodcaaconcunacce 100 Size of ‘srain wrations) osha ee eee 101 Succulent Weeds. cities % ists Oe ee eee 101 PA SGU) s svosvs /suasc, igs Byawenl ge tenceeton me aerey anemia amet eas 101 SOUMingy jokes ac ve ee Oe Se OO orem OIE 102 SHH. eee een eonchisin IOS OOO OBO OCo nO ao 102 Roots and (rwits: 2c co een eee eee ones 102 VII Diy eROUSHALC! Gisele cords celeste wan seen ests 103 Miscellaneous feeds ........... et oee cnet usec ata ewe ayia 104 SMiNjOUlS WEMNIOINS, co codooncovsvenodgounueecdcuboDoonG 104 We Buildine stand: PREMUSeS) een se once eee lee ele se 106-115 SHB GIER AIReean 55 0:65 Ghagko PACH apIcnO oko ree is Ciena aras paca eaec 106 WAMUIENGOIN cohdoosneooosano an oueouooocDOemooer 106 SCs Heer snc atcs kate cor ofsterePeiaere tial eferaGhe = a+. 109 Bedding a eee ete se et tran cnet Sierra cette auc 110 BamniyaGd se o.-eeseei EAN el sheets FN eC AO) es as etal: Sonee GISOOREI) ccooccacdaosdGanocouedod ood. padeao 111 VIKA OTN cuentas cose esl wetersactet ee atte tes da) src unls 112 Inspection of buildings and premises ............. 114 Wil Milking and handling milk on the farm............... 116-140 Health and habits of attendants ................... 116 Cleanliness in milking, cleaning cows .............. 119 Methods2of snailliicimeerewrteeni 2a cre cise ool cee cieie merece 120 Orainaryemethodts cet cae sete sett cto ls Shoreteveas 120 Free eliamad: mre) sys 3 cysts ses clepel cis) o/s) chataraiie ays) olen = 121 MUlIMe Na CININIe Si yarseacke sos ercilils wae, = siole sas cree 123 REICH NS MONEMMM Kaa. e cuererits enede ere cei oc iS Pitas 127 WSCMOMICOVEREE! sDadlsioi = te we cates srceecnrs eyes os aoetete bam 128 Straining, filtering, purifying, aerating and cooling TOU) Fees ayaa ete Sarat 4c ERR E acecea ere ent CY BUNGE 129 Careronedainy tulemsillge eo jen eg ence nic trenakelsaseelere aceprceets 133 Generalecanevotsmallikes cs chains 2 cee: Ger ae cues 136 VII. Dransportawon and ssaler ot: emilee ease sescierenieeny jnieiciele 141-149 Meansiok transportation anccn assent sme ence: 141 Milk supply of New York City .................... 142 MDI FO OIA WE IBOSMROIN. Good upeousoobucobouodoouseoe 144 Mille smpply,of 2hiladelphiay 5540. 500ee sees. oe: 145 Whe who DIhy Oe @wlaeie CHOWN Socouccccnecsoeuuccnuene 146 Concentration and cooperation in milk business.. 147 VIII. Refrigeration ...... PP gaesisch ag anst me APRN sy edad ae Pappas sors wy tine Brewer on aes 150-161 Effects of freezing and refrigeration on milk...... 150 Method stomnretni serail Oneness nee ween oe eee 151 NG Oipeinrren mee prec aay acters ols ail ebene o mamte oe: tReet oot 152 BYNES: SUC Ietytsc crete pees Cicer 174 Sodium (carbonate ssn ase. - mo eeeiaerekrer aie 174 Ben ZOIG SACI cp asara ees aye ccces Shas cree ee erent 175 Chromates: (s..ccccccasociec tase | ome eee en ae 175 SACCHATIN: s.dstieeiee. ce eroiereeea were Gnateree ee Ree 175 SaliGyWiCsaeide ware 5 eer. outers she, eos 175 WOLIGSy CbC. Gees oe sae aehetetls Ciencia pene aero 175 Proprietary PLESCLVALIVCS mre aire iene 176 Conclusions on use of preservatives ............... 176 XI. Physical and chemical examination of milk ............ 177-197 Testing cows for dairy purposes .................. UTA Hxamimation vot marker miilikeeen cece cei sence 178 Taking, preserving and caring for samples ......... 178 Composite Samiplesr an fs cccsrece cree bie cays cote eee 179 Samplinie. creamer .5 oe eters 273 Bhysiolosy otemothernsemallllkys, vis ceese case see 276 MLO PIE Ts Sr TaN Teese petegetee ete stl (ay Gey ayren os ce aifel teh =) S\Guiverenes aie 277 VVC teTIULITSS © sary ocelot ote Coc ies tenecer eile os here ge mite ecco ocelots 281 Com “seanilkesancomipantSonmursacranis« . sea arises are ae 281 Review, of teedine, methods) |2. 2... .5.2-5- sos. ose: 283 Tne isimples feediNnewEaSe: Be ocscie.c se oy hee casas ese 289 MOLERd ish Ciulii: CASC matress one - oa erate esiekiaoeiy eis 291 Pasteurization, boiling and sterilization .......... 293 Charities and emilnieipalconbroly sesame. crcl. ole 295 XV. Milk products in their relation to health ............. 297-307 Dibalm gd Ar Sip ee es evarseese Mites ccear ee lodeical eveuars hal ane naudin ecevigmees Goo 297 Ay SVE MLC eel ati ONS Pes ore ees oey wo awe Sie Witeeea Stacie albeews 298 CUREE Nod ley erciononnen too 5c Coens Clore Cleo RCRON ara ca Re Roe 298 FS) celina aml eres tetees. as aesccr ae Sco eacl aeecarees nee eres ener Gace 299 UCC oycee yc rorerece aio a oie bs el cosicual eo sue oecanenmtcy sis cp eketomenens 299 WCE SC lrarers Aileen o aeatet cis. cy sane toners suena neuaia: ahausiar eters ates ars 302 es Condensea smile 34. fama ete dale ste see 303 IMGT OWiMGInecryexocreie echere sis & stamens oes i eee ein evs 304 Miscellaneous keprodiuctsmeunnc neice cece: 305 Bwibte rma lle we eye tsiensie Se o eystseiees See Sue eee oe 306 IGS hm CP SE N00 ce etc a heesiean. ata tee eater ERE REL Cree ice ae 306 ET CTI Srey evene siege ores oye ee can O o's Sepa raee Foomatic leg oe 306 SYST tae anes silence Coie enieue: Crore susethes elicwciecensus eseine: Site loka s 307 Carbonated milks o. aeven pis sacs ieee eel elel eras es 307 SOV - LENSIOIAe Or tale WN CUNO Sooaesesnodolousoceneuooud 308-315 MOST SM ACOUMULCSy ere sensiyS cicreitdev Sisk te oe rele isi tO iemetors 308 United States ..... SERRE Ahh Caen SCOR NRE Ree Ameena 3138 NEVE pMoOxraphyeOmillkeinSpeClOny es. ssn. ce aes ok .. 816-343 + ne Ae gd ay ply Ot hee! el tit PREFACE. Milk is unquestionably the most important of all foods. Infants and young children depend upon it almost exclusively for sustenance and growth. Milk enters into the daily ration of nearly every adult person, particularly in the United States. The daily per capita con- sumption of milk ranges from one half pint to one pint in different eilies. Milk is an ideal food, containing in a readily digestible form and in proper proportions all the elements of a complete, balanced vation. It is universally recognized as peculiarly adapted for the nourishment of children, invalids and convalescents. Recent investigations have shown the necessity of Federal, State and municipal control of food products. ‘Such control is particularly important in the case of milk for reasons that nearly all kinds of bac- teria grow and multiply in milk, that in the ordinary method of handling it is exposed repeatedly to contamination, that milk sugar and casein are easily decomposed into disagreeable or dangerous pro- ducts, that milk is consumed in largest quantities by children and invalids who are most susceptible to such products, that milk may carry infections diseases, that milk may be deliberately adulterated or treated with preservatives, and that the consumer can detect none of these abnormal conditions except souring, which is the least harmful of all. Pure milk is obtained by milking healthy well-groomed cows in elean, sanitary surroundings, in thoroughly cleansed pails, and then cooling the milk to 50°F. or lower, and bottling it or pouring it into tightly closed cans without allowing any contamunation to occur from the milkers or other source. Legal phraseology is always ponderous and mystifying and milk inspection regulations may seem unnecessarily complicated. Nevertheless, the only fundamental idea is cleanliness and this idea is easily understood. Healthy cows, healthy attendants, ‘vholesome feeding stuffs, clean water, clean milk utensils, and clean habits are the only requisites. ‘This may be further reduced to two terms, the proper conception of cleanliness and the desire to be cleanly. An ideal system of milk inspection includes a veterinary inspection of cows, stables, water supply and surroundings; a supervision of milk rooms, milk utensils and methods of cleaning them; supervision of methods of cooling milk and their effectiveness; control of the health aud personal habits of the milkers; determination of the temperature at time of delivery, specific gravity, fat, total solids, acidity, presence ot preservatives, and bacterial content. The mere laboratory examina- tion of samples of milk taken from dealers is not sufficient. The cost of milk production has increased in recent years. New equipment to meet the requirements of health officers is an added bur- 2 den to the milk producer, who may reasonably expect more for his milk after the cost of production has increased. At present the con- sumer has too little real interest. in a pure milk supply. We often hear the milk consumer talk glibly about sanitary milk, and at the same time rebel against paying a higher price for such milk. Tow can we expect the milk producer to increase his expenses all along the line from the cow to the consumer, if he is compelled to sell his milk for the same price as milk produced more cheaply and under less san- liary conditions? There have been several discouraging experiences along this line. In one instance a philanthropist established a model dairy where milk was produced under ideal sanitary conditions and with a remarkably low bacterial content. The public manifested no interest in the movement and showed no preference for sanitary milk over ordinary milk at the same price. The project was therefore abandoned. The purpose of the present volume is partly educational and. partly practical. It is hoped that the milk producer may gather from it a conception of what constitutes pure milk and definite suggestions as to how to produce such milk. It is even more earnestly hoped that tlie milk consumer will more clearly realize the value of pure milk and appreciate the extra expense of producing such milk, at least to the extent of being willing to pay more for it than for ordinary milk. More or less effective regulations for milk inspection have been adopted in nearly every city of the United States. The inspector in enforcing these regulations requires veterinary, engineering and chem- ical knowledge and much tact as well as practical experience in dairying. Tn order that the sanitary regulation of milk may be accomplished most fully it is necessary that the milk producer, the milk consumer and the milk inspector should come to a mutual understanding of one another’s problems and difficulties, and cooperate in a cordial and earnest manner. In working to accomplish this purpose the author has reviewed the field of literature on milk and has presented. the es- sential points in the light of personal experience. ‘The dairyman will find a statement of approved methods of feeding and caring for cows, treating their diseases, handling, transportation, sale, refrigeration and pasteurization of milk. The inspector will find a statement of the normal and abnormal properties of milk, the symptoms of bovine diseases, the sanitary requirements of buildings used for dairy pur- poses, methods of testing and analyzing milk, detecting preservatives and adulterants, and the bacteriological study of milk. The milk consumer will obtain information on the dangers from impure milk, on the nature of the work of the milk inspector, and on what it means to produce pure milk. Most of the data recorded in this report are drawn from experience on the mainland, in the old dairy sections. Dairy conditions in Hawaii 3 are different in many respects. The ease with which green fodder can be had the year around is an advantage. In almost every other respect the Hawaiian dairyman is at a disadvantage as compared with the mainland dairyman. Cows give less milk in tropical cli- mates—in Hawaii from four to seven quarts per day. All grains are considerably higher in price. The cultivation of the soil and the rais- ing of green crops are more expensive. The prevalence of the horn tly is a much more serious matter than on the mainland. The most reliable figures on the actual cost of producing milk in Hawaii have been collected by Mr. P. M. Pond, who finds the cost to range between 6 and 9 cents per quart, not including the cost of delivery. Under our present conditions it would seem that the dairyman can not make a reasonable profit on sanitary milk delivered to the consumer at a lower price than 15 cents per quart. The inspection of dairies carried on under the supervision of Dr. V. A. Norgaard, territorial veterinarian, has been a very efficient means of raising the sanitary standard of our dairies, and of safe- guarding the public against the dangers of bacterially infected milk. Dr. Norgaard has brought the intradermal test for tuberculosis to a striking degree of efficiency and reliability. The vital relation which exists between a sanitary milk supply and the health of infants made it seem desirable to include in this report a chapter on dietetics of milk with reference to infant feeding. This chapter has been written by Dr. Louise Tayler-Jones, a specialist in the diseases of children, There is a peculiar need of careful super- vision of the milk supply for children in tropical climates. The recog- nition of this truth is coming to fruition in the work of the Palama Settlement, and other public-spirited men in Honolulu. CHAPTER I. NORMAL MILK. Milk is the secretion of the udder of the female mammal. In a commercial sense milk means cow’s milk unless otherwise specified. The milk of mares, asses, goats and sheep is also used to a limited extent in this country and to a much greater extent in Europe and Asia. Normally milk is secreted only by the female ufter parturition, but occasionally males, castrated males, virgin females and young animals yield more or less milk. Thus quite frequently buck goats, castrated goats and new-born children produce small quantities of inilk. In certain parts of Europe pregnant heifers are regularly milked, but this procedure weakens the heifers and lowers the milk yield after parturition. Virgin female dogs, young colts and mare mules have also been known to give milk. In a few instancese mare iuules have given two or three quarts per day continuously for three or four years. Biotoey or Mix. Anatomy of the cow's udder.—The udder is suspended from the pubic region and consists of two halves. The skin over the udder is rather finer than that of the body as a whole. A considerable por- tion of the skin of the udder is not covered with hair. There is an abundant accumulation of fat in the udder of the heifer and in the connective tissue at either end of the cow’s udder. A two-layered wall of connective tissue separates the right and left halves of the udder. There is no special anatomical structure separating the an- terior and posterior quarters. Nevertheless each quarter is a distinct part of the mammary gland not communicating with any other quarter by blood vessels, lymph vessels or milk ducts. The independence of each quarter is clearly demonstrated in administering infusions through the teats, and also in the course of mammary diseases. In- fusions in one quarter do not penetrate into the other, and disease in one quarter does not affect the milk of any other quarters. The true secretory parenchyma of the udder is arranged in lobes composed of several lobules which in turn are subdivided into numer- ous yellowish or yellowish red alveoli. The various parenchymatous structures are held in place and supported by connective tissue in which are found the blood vessels, lymph vessels, nerves and milk ducts. The connective tissue framework also contains fat tissue. With advancing age the connective tissue increases in amount as the 6 parenchyma decreases. The efferent milk ducts from the individual aiveoli gradually unite into larger ducts, finally emptying into the milk cistern. Each quarter normally has one teat but occasionally there are super- numary non-functional teats. The milk cistern is partly closed toward the teat by a rosette with 5-8 folds. The mucous membrane of the milk cistern bears a large number of folds and ridges connecting with one another like grill work. The true secretory tissue is arranged in the form of glandular tubes enlarged here and there into alveoli. The mammary gland is therefore both tubular and acimous. In the virgin heifer the epithelial cells of the glandular tissue grow out into long processes which fill up the lumen of the alveoli. During the first pregnancy these processes grow still larger, and branch into clavate endings. When the epithelial cells prepare for secretion they become finely granular and sharply delimited toward the lumen. Their form is then cylindrical. Small protoplasmic processes which extend into the lumen show a finely granular structure and contain minute fat globules. At the same time the epithelial cells show mitotic changes and other forms of activity. Leucocytes collect in the connective tissue, some of them penetrating into the alveolar lumen. With the com- mencement of secretion the lumen of the alveoli enlarges and becomes filled with fat globules which later coalesce into larger drops. Por- tions of the cell protoplasm are also discharged into the lumen to- gether with fluid from the cells and blood. In an active stage of lactation the alveolus is darker colored than when at rest. Moreover in a resting condition there is a smaller quantity of secretion, the pro- toplasma is more often striated, more mitotic figures are to be seen and leucocytes are more numerous. In active lactation the lumen of the alveoli is filled with innumerable fat globules, casein, leucocytes in a stage of fatty degeneration, particles of protoplasm and according to Rievel also amylaceous bodies which are very resistant to both acids aud alkalis. The blood vessels of the udder are connected with the external pudic¢ arteries and external pudic veins. A dense capillary network sur- rounds the alveoli and milk ducts. ‘The venous system is so extensively developed in the teats that these organs are to be classed with erectile structures. The connective tissue carries numerous lymph vessels which surround the alveoli and blood vessels or lie free in the inter- lobular tissue, and empty into the supramammary lymph glands. The nerves of the udder arise from the lumbar plexus, and the terminal fibrille form an extensive network but are without end-organs. Physiology of milk secretion—aAs has been abundantly demon- strated milk can not be considered as a simple transudation from the blood. Lactalbumin differs from blood albumin. Casein and milk sugar are not found in the blood. ' The fat globules can not possibly be 7 derived from the blood, and potash salts predominate in the milk as contrasted with soda salts in the blood. Rauber proposed the hypothe- sis that the leucocytes become metamorphosed and disintegrated to form the constituents of milk. The leucocytes, however, are never present in sufficient numbers to account for the quantity of milk se- ereted, and their protoplasm does not contain chemicals which could be modified into the constituents of milk. Milk may properly be consid- ered as the result of liquefaction and fatty degeneration of the mam- mary parenchymatous cells or parts of these cells. As well stated by Rievel, milk secretion is a specific function of the mammary gland. The chemical bodies which are brought to the gland in the blood are here modified into the constituents of milk and discharged into the lumen of the alveoli. With regard to the individual elements of milk the water is derived directly from the blood. In the process of transudation this water carries the traces of urea, creatinin and xanthin which are normally found in the milk.. Casein is found nowhere else in the body, but is formed in the udder from the circulating protein furnished by the blood. The transforma- tion takes place in the gland cells. Von Behring, on the other hand, maintains that under the influence of metabolic products in the gland cells the proteid bodies in the blood are modified into casein. Ac- cording to Basch and others casein is formed by a combination of nucleic acid from the epithelial cell and the blood serum in the glandu- lar alveoli. Milk sugar rarely occurs elsewhere than in milk. The exact steps by which it is formed are not known. That it may be formed from proteid bodies is apparent from the fact that dogs kept on an exclusive ration of meat yield a milk with a relatively high content of sugar. In the case of herbivora like cows the ration contains abundant ma- terial which can readily be transformed into milk sugar. It is well known that the animal body has the power to produce one sugar from another hy transformation. Milk sugar may therefore be derived from grape sugar. A histological examination of the active mammary gland will show that the fat globules of milk come from the gland cells. Milk fat does not arise exclusively from the proteids of the secreting cells. Some of it must be derived from the body fat and also from the food fat. Ex- periments have shown that food fat may pass over into the milk, but in the udder it undergoes a transformation so that its original charac- teristics are lost. The iodine numder of body fat is different from that of milk fat. They are, therefore, distinct kinds of fat. The fat in colostrum, however, and that in the body tissues seem to be identical According to the extensive investigations of Arnold it appears prob- able that the secretion of milk fat depends upon modification of the cytoplasm of the mammary epithelial cells without disintegration of 8 the cells. Fat globules first appear at certain points in the basal por- tion of the cells near the nucleus. Later secretory vacuoles are formed. Arnold argues that milk fat arises as a synthetic product in the secre- tory cells of the udder. The mineral matters which make up the ash of milk are evidently derived partly from the blood and partly from the disintegration of the epithelial cells. The relative proportions in which these minerals exist in the blood are not the same as observed in the milk. The secretion of milk is to a striking degree under the control of the nervous system. The nervous state of the cow has an influence upon both the quantity and quality of the milk. Manipulation of the teats by the hands or by the calves in sucking sets up a nervous reflex which greatly stimulates the flow of milk. Nervous centers of milk secretion have been found in the brain. Bacteria in milk.—The bacteriology of milk is discussed in chapter XII. In this connection we may, however, refer to the bacterial con- tent of normal milk. When first secreted in the udder of the healthy cow milk is free from bacteria. In the milk ducts or milk cisterns the milk becomes contaminated with the bacteria which have penetrated trom the outside. The nature and extent of this contamination de- pends upon the circumstances of each case. Most bacteria find in milk ideal conditions for their growth. They multiply rapidly and soon produce souring or other changes after which the milk must be con- sidered abnormal for consumption in a fresh state. Since it is impos- sible to obtain commercial milk free from bacteria it becomes necessary to set up legal standards for the bacterial content of milk. These standards vary in different States and are discussed below in this chapter. In respect of bacterial content the distinction between normal and abnormal milk is somewhat arbitrary, but for practical and sani- tary purposes the distinction has to be drawn. For a discussion of the kinds of bacteria in milk and of their action on milk consult Chapter XII, Enzymes in milk.—A number of enzymes or unorganized fer- ments have been found in milk. Stoklasa isolated an enzyme which ferments lactose, decomposing it into carbon dioxide, lactic acid, alcohol and acetic acid. Both aerobic and anaerobic oxydases occur in milk serum without being: associated with any of the essential ele- ments. Spolverini found that when an oxydizing ferment was added to the ration the amount of the oxydase was increased in the milk. Experiments with amylase and certain other oxydizing ferments indicate that they do not pass over into the milk. Gillet found a lipase in milk which caused the decomposition of monobutyrin. The action of the lipase was not increased by the presence of bacteria in milk, but was destroyed by a high degree of acidity. The addition of sodium fluoride or chloroform diminished but did not prevent the 9 action of the ferment. Since this lipase has no action on other giveerids than monobutyrin it was called monobutyrinase. It resists temperatures of 60°-65°C. Lesperance reports the presence of peptic, tryptic, lipasic and glyco- lytic ferments in milk. According to Seligmann there are at least three oxydizing ferments in milk. Superoxydase, corresponding to the catalase of Loew, decomposes hydrogen peroxide and may be pre- cipitated with casein by means of an acid. A direct oxydase is also found not requiring the presence of hydrogen peroxide to produce a reaction. Finally milk contains indirect oxydases which are active only in the presence of hydrogen peroxide. The power of milk to de- compose hydrogen peroxide is increased by the additions of formalin, as is also the power to give color reactions for enzymes. Raw milk loses its power of reaction by heating, while the milk treated with formalin is only slightly changed in this respect. Boiled milk showing no reaction is again rendered active by treatment with formalin. Var- ious tests used for distinguishing raw and boiled milk lose their value since formalin can restore the reaction lost by heating. By means of hydrogen peroxide milk may be sterilized without destroying the enzymes present in it. In this way a proteolytic enzyme has been discovered, its action being increased by adding alkali and raising the temperature. The proteolytic action of hydro- gen peroxide may easily be distinguished from that of the enzyme According to some investigators amylolytic enzymes are much more frequently found in milk than are proteolytic enzymes. Galactase, a proteolytic enzyme of milk has been studied by Bab- cock, Russell and others. This enzyme is more active in colostrum than in normal milk. The progressive formation of soluble nitrogen- ous compounds is very striking as milk increases in age. Galactase attaches itself to finely divided particles in suspension. It therefore occurs in larger proportions in cream and separator slime than in milk. Concentrated extracts of galactase prepared from separator slime rapidly oxidize hydrogen peroxide. Galactase is destroyed by heating for 10 minutes at 76°C., or by mercuric chloride, formalin, phenol or carbon bisulphide. The decomposition products formed by galactase are very similar to those of tryptic digestion. Galactase added to milk first coagulates the casein and afterwards redissolves the curd. Babeock and Russell have shown that the main proteolytic changes which take place in the ripening of certain cheeses are due to the action of galactase. The presence of lactic acid diminishes the action of ga- lactase. Leucocytes in milk.—Leucocytes collect. in the connective tissue of the active mammary gland and find their way into the milk. They are always to be found but their numbers vary greatly. Some confusion has been caused by attempts to distinguish arbitrarily between leuco- 10 cytes and pus cells. Stokes, Bergey and others have been inclined to set ‘up the arbitrary standard for normal milk of 10 leucocytes for one field of a 1-12 immersion lens. More than this number are considered as constituting pus. A number less than ten per field of the microscope is held to be the normal leucocyte count. On the basis of numerous tests Barthel came to the conclusion that milk normally contains great numbers of leucocytes. The reaction with peroxide of hydrogen is attributed to their presence. Cream and separator slime are richer in leucocytes than skim milk, on account of the fact that the leucocytes adhere to the fat globules or other finely divided particles. Barthel considers the leucocytes or an enzyme secreted by them as the cause of the phenomenon observed by Babcock and Russell and by them at- tributed to galactase. According to the method of Stewart a diseased condition of the udder is to be suspected if the milk contains more than 100,000 leu- cocytes per cc. The Doane-Buckley method, however, gives much higher counts than the Stewart method. Ward in testing these methods came to the conclusion that the Doane-Buckley method is the more reliable, and that it is not possible to detect udder disease in cows by the examination of mixed milk for number of leucocytes alone. Ward also insists that the presence of streptococci in milk can not be con- sidered as proof of mammitis, and that the microscopic examination of milk for staphylococci is of doubtful value. An average count of 49,000 leucocytes per cc. was obtained from healthy cows; in one dairy the count was 191,000 per ce. In another dairy one cow showed a count of 4,800,000 per ec. Russell and Hoffman found wide vari- ation in the leucocyte count of cows showing no disease of the udder. These investigators believe that not enough data have been accumulated to formulate a scientific standard for judging milk for the presence of pus. In healthy cows the number of leucocytes ranged between 50,000 and 1,000,000 per cc.. At present it seems impossible to distinguish hetween pus cells and leucocytes, and the role and significance of leu- cocytes in milk need further study. Germicidal substances im milk.—Several investigators, notably Koning, Hunziker and Meyer, maintain that milk possesses certain bactericidal properties. It has frequently been observed that for some time after being drawn milk shows a diminution in the number of bacteria which it contains. This apparent bactericidal power of milk is more pronounced at relatively high than at low temperatures. IXoning claims that he has observed a difference in the bactericidal power of the milk of different cows. Colostrom in some instances seems to exercise a strong bactericidal influence. The supposed germicidal action of milk affects both milk bacteria and also various pathogenic bacteria. The soluble proteids of milk such as lactalbumin and lacto- globulin possess no bactericidal action toward coli or typhoid bacilli. Conn and Stocking do not believe that the decrease frequently ob- af served in the total number of bacteria in milk during the first few hours after milking is due to a germicidal action possessed by the milk, but believe that certain species i bacteria finding milk an smanriienl é medium for growth, disappear more or less id and that when such species are more numerous than those finding milk a suitable medium a decrease in the total number of bacteria may result. Lactic acid bacteria multiply continuously from the outset. Their growth produces an acid reaction in the milk in the presence of which many other species of bacteria can not grow. The possible passage of specific antitoxic and immunizing bodies from the cow into the milk has been actively discussed in recent years. Opinions are still far apart on this problem. Some investigators like von Behring have argued that the milk of cows affected with disease carries the specific antibodies of the disease and therefore has the effect of immunizing calves or human beings which may drink the milk. The extent to which milk may carry immunizing properties is still an open question. Puysicat Proprertizs oF MILK. Color.—Milk is nearly white. In different animals it varies from semitransparent to completely opaque, especially in thick layers. When viewed in thin layers it has a bluish tint. Neither the white nor the blue color is due to a pigment. The blue color is a sort of fluorescence, while the white color is caused by the fact that milk is not a homogeneous fluid but is composed of substances of different re- fractive indices. The small innumerable fat globules reflect the rays ot light in various directions, and few if any of the rays of light pene- trate through the milk. The smaller the number of fat globules in the milk the less opaque the sample. The yellowish tint frequently observed in milk is apparently derived from the feed stuffs. Specific gravity.—tIn order to detect the possible dilution of milk the specific gravity is determined. In normal milk the average spe- cific gravity is 1.030 at 60°F. and 1.029 at 70°F. If the lactometer spindle floats above 33 it may be assumed that the milk has been skimmed, and if it floats below 29 that it has probably been watered. The specifie gravity of normal milk may vafy from 1.028 to 1.035; in individual cows it may occasionally sink as low as 1.026, or rise as high as 1.038. In mixed or herd milk the variation is much less. ‘The usual variation in herd milk is from 1.030 to 1.033. The lacto- meter indicates the specific gravity of milk at a temperature of 60°F. Uorrections must be made for other temperatures. Viscosity.—V iscosity is a term used to denote cohesion or friction hetween the particles of a fluid. It is determined by noting the time required for a given quantity of the fluid to flow through a tube of known size. ‘The viscosity of milk or cream is greater than that of a 12 iwomogeneous liquid of the same specific gravity. The larger the fat giobules in a sample the greater the viscosity. The viscosity decreases as the temperature of the milk increases. Thus at the freezing point Ube viscosity of milk is two times greater than water, while at 30°C. it is only 1.7 times greater. A number of viscometers have been devised which are well adapted to determining the viscosity of milk and cream. Odor.—The odor of milk often resembles that of the cow’s skin, but such is not the case if proper cleanliness has been observed in milking. Milk has a characteristic, indefinable odor apparently depending upon an odiferous body of unknown composition. Aromatic substances sprayed on the cows to keep off flies may lend an odor to the milk. Various drugs and medicines have the same effect. The specific odor of the feeding stuffs used in any particular case is very apparent. Some ot these odors are objectionable, while others are barely perceptible and not disgusting. Distillery byproducts, rape, onions, cabbage, \unips and silage may be mentioned among such substances. Microscopic appearance.—Under the microscope the fat globules are tne most conspicuous elements of milk. They vary in size from almost tne limit of visibility to .0809 mm. The largest fat globules have peen observed in sheep milk. In cows a variation in size is to be noted in different breeds. The fat globules are small in Holsteins, medium- sized in Brown Swiss and large in Shorthorn and Jersey. At the beginning of lactation the globules are largest and gradually become smaller toward the close of the period. Well in comparing these con- ditions at the beginning and end of lactation found the ratio of fat globules per emm. to be 103:213, and the ratio of size 458:170. The morning milk has larger fat globules than the evening milk, and in the first streams both the number and size of the fat globules are smaller. In an ordinary sample of milk the largest fat globules are about six times the size of the smallest. There seems to be some relation be- tween the globules of different size. Aikman suggests that the weight of the small globules probably equals that of the large ones. If leucocytes are present in milk they appear as relatively large cells with nucleus. Several kinds of leucocytes may be recognized. Lymphocytes are small cells with a deeply staining nucleus. Large uninuclear leucocytes are larger with a larger, less deeply staining nucleus and a larger mass of protoplasm. Multinuclear cells show an irregular nucleus or several nuclei or nuclear granules. Specific heat of malk.—Since milk varies in composition its specific heat varies accordingly. According to Fleischmann’s determinations the specific heat of milk averages .874 and of cream .78. Guerin found the specific heat to be .98, and Schnorf found it to range from 1.004 to 1.085 with an average of 1.042. If the last determination be correct it is apparent that more refrigeration is required in freezing milk than in freezing water. 13 Freezing point of milk.—lt has been found that the freezing point of milk lies .54°-.58°C. under that of water. If water is added the freezing point approaches that of water. The eryoscopic test may therefore be used in detecting dilution with water. In tuberculosis, mammitis and various other diseases the freezing point of milk is lowered. - Density of malk.—The maximum density of milk appears at a tem- perature of —.3°C as compared with 4°C. in the case of water. The expansion coefficient of milk increases with the temperature and also with the increase in solid contents. = Refractive index of milk.—The refractive power of milk varies ereatly according to the composition. In normal milk the refractive index ranges from 1.3470 to 1.8515. A minimum of 1.3435 is very rarely observed. Cohesive power of milk.—At a temperature of 5°C. the cohesion of milk is 100.15 with water at 100. At higher temperatures, however, the cohesive power of milk is less than that of water. Electrical resistance and conductivity.—The electrical conductivity of milk depends upon the degree of dissociation of the salts which it carries in solution. The resisting power of milk ranges between 180 and 210 ohms. If water is added to milk its resistance is increased. An accurate determination of the amount of dilution can not be made by an electrical test for the reason that the resisting power of water varies with its salt content. Basis of the methods of creaming milk.—The fat globules are lighter than the milk serum. Consequently the fat is separated by the force of gravity or centrifugal motion. Several methods of separation are in common use. In the shallow pan system the milk is poured into pans to a depth of 2-4 inches and kept at a temperature of 40°- GO F. for 36 hours at the end of which time the cream is as nearly separated as may be by this system. From .5 to 1 per cent of the cream remains in the milk serum. This is due to the fact that some of the fat globules are caught and held by the curdling casein, fibrin or other constituents of the milk. Obviously any fat which is caught in the curd can not rise to the surface. Deep setting consists in placing the milk in Cooley or shotgun cans about 8 inches in diameter and 20 inches deep. If the milk is kept at a temperature of 40°F. it does not curdle so rapidly and the cream rises somewhat more quickly, the piocess being completed at the end of about 24 hours. When properly operated only about .2 per cent of the cream is lost by this system. The physical basis of the dilution method is the fact that the whole nuxture possesses a lower viscosity than undiluted milk and that therefore less resistance will be offered to the rising fat globules. Tf milk is diluted with an equal quantity of pure cold water the fat will 14 rise in a few hours after which the water and milk serum may be drawn off from below, leaving the cream. The centrifugal separator depends for its efficiency upon the same fact as that utilized in separation of cream by gravity, viz. that fat globules are lighter than milk serum. When milk is revolved at high velocity in the bowl of a separator the fat globules remain near the zenter of the column while the serum and other constituents of the milk are thrown to the outside. The cream and skim milk may there- fore be removed by separate tubes in continuous streams. The various makes of separators differ chiefly in the diameter of the bowl, rate of revolution and the fixtures in the bowl. The essential principle, how- ever, 1s the same in all. CHEMISTRY oF Mitx. Reaction.—The milk of carnivorous animals has an acid reaction. In herbivora the reaction varies being sometimes neutral, sometimes alkaline, sometimes slightly acid and usually amphoteric. Milk with an amphoteric reaction turns blue litmus paper red and red. paper blue. According to Soxhlet the amphoteric reaction is due to the presence of two sodium salts of phosphoric acid, one of which is acid and the other alkaline. The exact nature of the amphoteric reaction is not well understood and it has little significance. With some testing papers and coloring matters milk always shows an acid reactien while with other tests the reaction is uniformly alkaline. In most cases the apparent reaction is as much a function of the testing substance as of the milk. The reaction of normal milk, however, is always nearly neutral, being only slightly acid or alkaline. Fresh milk tastes sweet on account of its content of lactose. The lactose is soon broken up into lactic acid and other compounds by the action of lactie acid bac- teria after which the reaction is decidedly acid. Composition—Milk has a very complex composition. The chief constituents of milk are water, fat, milk sugar, casein, lactalbumin, lecithin, cholesterin, citric acid, extractives, salts and gases. Of these water, fat, proteids, milk sugar and salts are most important. Analyses have been compiled showing the content of these substances in milk from mixed and pure herds in various countries. These analyses vary in certain details as is to be expected in a fluid, subject to such variations as milk. In general it may be said that milk con- tains 87 per cent water and 13 per cent solids. An average deduced from 200,000 analyses indicates water 87.10 per cent, fat 4 per cent, milk sugar 4.75 per cent, casein 3 per cent, albumin .4 per cent and ash .75 per cent. The fat may vary from 1 per cent to 12.5 per cent, and the solids not fat from 5 per cent to 10.6 per cenit. Fat.—Milk fat is in a finely divided state and of better flavor than other fats. Like all fats it is made of glycerids composed of glycerine 15 and a fatty acid. The most important glycerids in milk fat are stearin, palmitin and olein, but there are several others such as butin, butyrin, caproin, caprylin, caprin, laurin and myristin. Stearin melts at 55°C., palmitin at 62.8°C., and myristin at 31°C. Most of the other fats are liquid at ordinary temperatures. The aver- age composition of milk fat is butyrin 3.85 per cent, caproin 3.6, caprylin .55, caprin 1.9, laurin 7.4, myristin 20.2, palmitin 27.7, stearim 1.8, and olein 35 per cent. The proportions of these glycerids vary considerably and the melting point _of milk fat is therefore variable, ranging from 29.5° to 33°C. Milk fai is soluble in water and also non-volatile. The density of milk fat ranges from .9307 at 15°C. to .8667 at 100°C., and the specific grav- ity ranges from .9300 at 15°C. to .8637 at 100°C. The average index of refraction is 1.4566. According to Richmond milk fat mixes with esters, 1s dissolved by glycerol, all hydrocarbons which are liquid at ordinary temperatures, ether, carbon bisulphide, nitro-benzene, and acetone. Butter fat becomes rancid as a result of hydrolysis, split- ting up into fatty acids and glycerol. The latter is oxydized, yielding aldehydes and soluble acids. The fact that the globules of milk fat do not coalesce but remain separate has caused much speculation. Storch has proposed the theory that each globule is surrounded by a mem- brane of casein or mucoid material. The chemical study of milk has furnished little evidence in favor of this theory and it seems unneces- sarv to explain the emulsified condition of milk. Casein.—Casein, or as some writers prefer to call it caseinogen, is the chief albuminoid of milk. Other albuminoids described as oceur- ing in milk are lactalbumin, lactoglobulin, galactin, galactozymase, syntonin, albumoses, fibrin, nuclein, galactase, ete. Casein is found in milk in a fluid condition but is not soluble in water. Sulphur is in- corporated in the molecules of casein which, therefore, belongs with the nucleins. According to Kirchner the percentage composition of casein is carbon 53, hydrogen 7.12, nitrogen 15.65, oxygen 22.6, sulphur .78, phosphorus .85. Pure casein is a white, amorphous, tasteless, odorless body, practically insoluble in water, completely in- soluble in alcohol or ether, slightly soluble in acids and readily soluble im alkaline solutions. Tf casein comes in contact with lime it takes up some of it and therefore often contains lime to the extent of 1 per eent. In fresh milk casein is in a colloidal or semidissolved state and is somewhat opaque. If milk is allowed to stand a small‘ portion of the casein is changed into soluble peptones. The curd of milk is com- posed chiefly of casein which may be coagulated by acids (such as lactic in souring milk), rennet enzyme, trypsine and certain other fer- ments. Lactalbumin.—In normal milk lactalbumin differs from blood al- bumin but in colostrum it is nearly identical with the latter. The average amount of lactalbumin in normal milk is .6 per cent but in 16 colostrum it is much more abundant. Lactalbumin is soluble in water and is not coagulated by rennet or dilute acids. It is coagulated, how- ever, by a temperature of 70-75°C. Moreover, it is precipitated by alcohol, phosphotungstic acid or tannin. Its composition is not changed by coagulation. Lactalbumin contains no phosphorus but contains more sulphur than does casein. Lactoglobulin.—This albuminoid is readily soluble in sodium chlo- ride solutions, is coagulated by heat and precipitated by tannin or neutral sulphates. In colostrum it may be present to the amount of 8 per cent but in normal milk there is merely a trace. It appears to be identical with serum globulin. Galactin or lactoprotein.—This peptone is present in fresh milk to the extent of .13 per cent. According to Richmond galactin is com- posed of portions of the casein and lactalbumin and their decomposi- tion products. Other albuminoids.—Galactalzymase, syntonin, albumoses and pep- tones exist in milk at most in mere traces, and are perhaps not normal constituents but rather decomposition products. Babcock claims to have demonstrated fibrin in milk with a coagulation power one two thousandth part that of blood fibrin. Milk is said to give the guaiac and H,O, test for fibrin. True peptones are apparently not present in normal milk. Nucleon or sarcophosphorie acid was found in milk oy Siegfried in the proportion of .09 gm. per liter. The mucoid pro- eid described by Storch is probably a modified portion of the casein. Milk sugar.—Milk sugar or lactose is found only in milk. Its composition is 0,,H5s0,,-H,O. Under the influence of lactic acid bacteria each molecule of milk sugar breaks up into four molecules of lactic acid. It contains one part of water of crystallization which is not driven off by drying the sugar at a temperature of 100°C. It does not readily dissolve in water or alcohol and is therefore not very sweet. Ata temperature of 15°C. about 7.5 em. is dissolved in 100 ee. ot water. Milk sugar dissolves the oxides of lime, lead, copper and mercury. It is not fermented by trypsin, pepsin, rennet, yeast, inver- ase, or diasase. It is hydrolized into glucose and galactose, however, bv lactase which is found in kephir grains. Jn commercial practice milk sugar is obtained by crystallization after the fat and albuminoids have been removed. The preparation of milk sugar is therefore most profitably combined with the cheese industry. Mineral constituents.—The ash obtained by burning milk does not truly represent the mineral elements in milk, some of them being thereby changed. While present in small proportion the mineral constituents of milk are very important. They vary in amount less than the other constituents of milk. On an average the ash constitutes avout .75 per cent of the milk, varying from .5 to .9 per cent. Soldner gives the following composition of the ash of milk: Saainiaaec Milonic e qe i eterno ee PL ek 10.62 Potassium chloride ...... RD Maia ead SS PSE 9.16 Monopotassmm phosphates. ..234 o..o2 ete Sa TG Dipetassimumemphosphateswsee oh 2le Geek 9.22 if OPAC SIUUTINRCHEG ALC: on ne eyed See aias Sloss teeth. aie eae vad 5.47 iDimacnesinm, phosphate pee... teas tite dees stil MMciertesnmnmacitratiey aspera et cates BARS SS Ok - 4,05 Wicalenums phosphate seereese.2 2 She. ee RG we 7.42 acaleiumagohosphate rapes. sisi eoks Sk Neha lS 8.90 Calcimmeeitrate nso se aMeectsimecioe. ds saa BAe 23.55 ime: combined ‘wath, proterdso.ii.. sess .5 20 Sen. aes While, however, the total amount of mineral matter in milk varies within very narrow limits the individual mineral constituents vary greatly in amount. Citric acid and lime may be considered as normal constituents of milk. In some samples of milk sulphur has been found to the extent of .048 per cent. Occasionally iron is found in the milk of cows, goats and women. It is commonly believed that a portion of the phosphorus in milk is in organic union with nuclein and lecithin. Other substances sometimes found in normal milk include acetates, silica, iodine, fluorine, thio-eyanates, amyloid, urea, alcohol, lactic acid, acetic acid, leucin, cholesterin, creatin, xanthin, tyrosin, a color- ing matter, an odoriferous substance, oxygen, nitrogen, carbon dioxide and other gases. Recently Biscaro isolated potassium orotate from milk sugar. The enzymes commonly found in milk have been men- tioned in discussing its biology. Factors InrLuencine THE ComPosITION oF MILK. Breed.—The influence of the breed of cow upon the composition of the milk has received a great deal of attention. The results obtained in this study are by no means uniform. There is the greatest varia- tion in respect of composition of milk within the same breed. In general, however, the Guernseys and Jerseys give milk relatively rich in fat, and the Holsteins and Dutch Belted a milk relatively low in fat content. The other breeds stand somewhat intermediate in this respect. In milk tests of breeds attention is chiefly directed to the fat content of the milk. The total solids vary less than the fat. In a test. by Lloyd the fat content of the milk was 3.74 per cent in Short- horns, 5.38 in Jerseys, 5.01 in Guernseys, 3.65 in Red Polls, 4.33 in Kerries and 3.97 in crosses. In the same test the total solids were highest in Jerseys and lowest in Shorthorns. In a test in Wisconsin the milk yield was highest in Holsteins followed by Brown Swiss, Shorthorn, Guernsey, Ayrshire, Dutch Belted, French Canadian, Red Polled, Jersey, Polled Jersey and Devon. In a test of fat percentage the Jersey stood at the head followed by Guernsey, Polled Jersey, Devon, French Canadian, Ayrshire, Red Polled and Shorthorn. A comparative test in Toronto placed the 18 breeds in the order Aberdeen Angus, Hereford, Shorthorn, Ayrshire. In a test in New York the Guernsey stood at the head followed by Jersey, Ayrshire, Shorthorn and Holstein. It is apparent from these few figures that the breed is not as important as the individual merit of the cow. Age of cow.—In Algau it has been found that the yield and fat content of ‘milk increase up to the fifth calving after which both de- erease. The results of extended observations in Scotland covering 1,340 cows indicate that in mixed herds cows 15 years old give milk with a fat content of 3.74 per cent, and cows two years old 3.83 per cent. This difference is not striking. No regular increase or decrease was found in cows of ages intermediate between two and 15 years. A series of milk records kept for five years shows that young cows give milk richer in fat, while older cows give more milk. It may be safely asserted that any individual cow yields as rich milk as a heifer as she will as a mature cow. Period of lactation.—At the beginning of lactation the amount of milk is high and the fat content low. During the first few days the milk is known as colostrum and has a very different composition from normal milk. The composition of colostrum is about as follows: albumen 6.77 per cent, fat 3.57, sugar 4.68, mineral salts .82 and water 84.16 per cent. The solids of colostrum may be as high as 20 per cent. In the course of the period of lactation the yield gradually diminishes while the fat content rises. After a few weeks the fat content may fall slowly till near the end of the period of lactation when the fat content becomes abnormally high and the yield very low. Just before the cow is dried off the fat percentage may be so nigh as to render the milk almost abnormal. The percentage of the other solids is not affected. The ash content of the milk remains practically constant during the whole period of lactation. Variation is greatest in the fat and less in the milk sugar and proteids. An in- crease or decrease in the fat content is usually accompanied by an opposite change in the content of protein and milk sugar. Dividing the period of lactation into three equal parts the sugar is 10-12 per cent greater during the first months of the second period than in the first. period, but later it slowly diminishes. The total amount of fat and casein of the second period follows closely the milk yield. Van Slyke found the per cent of fat highest during the first month of lacta- tion. In the second month it dropped considerably in the richest milk. The total yield of milk increases, however, so that the greatest fat. yield is obtained during the second and third months. As the period of lactation progresses there is more and more fat lost in the skim milk. In some cases this loss of fat is not observed. Individuality.—The greatest differences are observed in the fat content of the milk of individual cows of the same breed. Thus Uleischmann in a continued study of this point in 18 cows of the same n9 breeding and subjected to the same conditions found that the fat con- tent of the milk varied from 2.66 per cent to 3.88 per cent. Wherever this matter has been investigated it has been found that the individual peculiarities of the cow are of the highest importance in determining the fat content of the milk. The fat in the milk of one cow may be very high while in another it may be low with no assignable reason except the individual nature of the cows concerned. The tendency to produce milk of a high fat content is in a pronounced degree heredi- tary. The tendency is not always inherited from the mother but a bull with an excellent milking ancestry is of great influence in in- creasing the fat content of the milk of his offspring as compared with the grade cows to which he is bred. Manner and time of milking.—During the course of each milking there is an increase in the fat content. By separating one milking into 17 portions Shov found that the fat content increased from .7 to 8.9 per cent, or in one case to 9.6 per cent. Four characteristic periods were observed in the same milking. In the first the milk con- tained less than 1 per cent of fat, in the second period there is a sudden rise of fat content, in the third period the fat remains at the high point, while in the last sample there is a great increase in the fat. In certain cows extremes of .8 and 13 per cent were observed. Differences have been observed in the fat content of morning’s and evening’s milk. Fleischmann in a long series of tests found a fat con- tent of 3.26 per cent in morning’s milk and 3.18 in evening’s milk as compared with 3.22 for the day. In other investigations, however, the content of fat, protein and ash has been higher in the evening and the content of milk sugar lower. Gilchrist found the morning’s milk sometimes below the market standard in fat and recommends three milkings per day to prevent this occurrence. Beach found that by milking three times a day the total yield of fat was increased 14 per cent. Slight inequalities in the intervals between milking cause no ser- ious effeft upon the quality of the milk so long as the changes are not sudden. Great inequalities in the intervals may reduce the fat per- centage. A change from a narrow to a wide ration is likely to diminish the fat content of the morning’s milk more than that of the evening. If all the grain is fed in the evening the fat content of the morning’s milk is increased in most but not all cases. If the intervals between milkings are very unequal the larger milk yield and lower fat percentage follow the longer interval. Stokes believes that cows reassimilate some of the fat for their own uses if the milk is allowed to remain too long in the udder. In one test of three milkings per day the fat percentage was highest at noon and lowest in the morning. An experiment in milk- ing cows four times per day showed that the yield of fat is thereby inereased but the percentage diminished. The advantages of milking more than two times per day are not sufficient to justify the procedure. The foremilk is not rich in fat and has a high bacterial content. 20 From 4 to 10 streams should therefore be discarded. The strippings contain the highest fat percentage. Much fat is therefore lost if the cows are not thoroughly stripped. The efficiency of milkers differs greatly in this respect. The Hegelund method of milking, described in Chapter VI, has been highly recommended by Woll for increasing the amount of fat obtained. The composition of the aftermilk ob- tained by the Hegelund method is essentially the same as that of the ordinary strippings. Lepoutre found that when each quarter of the udder was milked separately the fat percentage was highest in the first quarter milked, and lowest in the last quarter. If two quarters were milked simul- taneously the fat content of this milk was higher than that of the milk from the other two quarters. Ingle found appreciable but not constant differences in the composition of the milk from different quarters of the udder. Carlyle reports that a constant change of milkers so long as none of them is a stranger to the cows results in a slightly increased fat percentage. So far as milking machines have been tested they seem to have little or no effect upon the composition of the milk. Exercise, work, and fatigue.—In experiments carried out by Hills cows driven and transported by rail gave milk with a low fat content on the next day but for the following few days the fat content was above normal. The percentage of solids not fat was not affected. Morgan tried the experiment of working cows one or two hours daily. The percentage of fat was thereby increased while the content of milk sugar decreased greatly. A reasonable amount of exercise for the cows has little effect on the composition of the milk. Spaying.—If cows are spayed during a period of lactation this period may be extended for a year or two beyond the usual term. The milk yield gradually diminishes and its composition varies. As a rule the percentage of fat, milk sugar and casein is increased. Spaying may cause great temporary fluctuations in the composition of the milk after which it returns to its normal character. ‘strum.—Milk may or may not show alterations in composition during estrum. Malpeaux noted a slight diminution in fat. Snorf found that estrum had no effect on the electrical conductivity of milk but lowered the freezing point. The percentage of fat may be tem- porarily increased but soon falls to normal Doane made determina- tions of the total solids, fat, protein, casein and sugar in the milk of 5 cows before, during and after the periods of heat. In no case was the percentage of fat lower than normal during the period of heat, and in only two instances was there any increase. No variations were observed in the other constituents nor in the temperature of the cows. Weather.—Sudden climatic changes and unpleasant weather are more likely to affect the amount than the composition of the milk. The Essex County council of England found no evidence that exces- 21 sively dry or wet seasons had any influence on the quality of milk. Stokes, however, traced some abnormal milk in London to farms where the cows were subjected to drouth and excessive heat. The total solids in the milk amounted to 12.6 per cent. Crowther found that extremes of temperature tend to cause a decrease in the fat content of milk. Atter studying this matter Dymond states: “Throughout this exper- iment the considerable variations in fat and solids have not been to any great extent due to alterations in food or weather or to any ex- ternal conditions under which the cows were kept and which the dairy farmer could control. The important point is to recognize that these changes are continually taking place but since they are not usually dependent on external conditions but on the idiosyncrasies of each cow, almost complete uniformity can be obtained by mixing the milk of a sufficient number of cows.” Seasons.—There is little or no difference in seasons as to the qual- ity of the milk. Richmond found the lowest fat content in May and June and the highest in October and November. These differences may have been due to other factors and are not uniformly observed. Other things being equal there is little difference in the average qual- ity of the Safle during a whole period of peeation whether the cow calves in the spring or fall. Disease.—In case of any serious disease the milk should be con- sidered unfit for food. The changes produced in milk by the various diseases are discussed in Chapters III and XII. Excitement.—Under the influence of worry, excitement or fright cows may give milk of a fluctuating quality. At times the fat con- tent is as low as 1.8 per cent, at other times as high as 7 per cent. The other solid constituents are less affected than the fat. Feed.—lIt has long been the dream of dairymen to devise a ration by means of which the fat content of the milk could be greatly in- ereased. This achievement seems to be quite impossible. The results ot hundreds of experiments along this line indicate that it is impossible to increase materially or permanently the fat yield of a cow by changes in the amount or character of the ration, except in so far as the increase in the total yield of milk increases simultaneously the total fat yleid. The percentage of fat is not thereby affected. Woll found ‘nat “the food of the dairy cow influences the quality of the milk pro- duced to this extent that the cow will yield a maximum flow of milk of the highest fat content which she is capable of producing on rations rela- tively rich in nitrogenous substances.” Wing and Foord experimented with a herd of cows which had been previously poorly fed and cared for. By feeding them an abundant ration easily digestible and rather nitrogenous in character and continued through two years an aver- age increase of .25 per cent of fat was obtained. This was accom- panied by an increase of about 50 per cent in the total amount of milk fat produced. With cows which have been well fed, however, a 22 change works no permanent effect on the quality of the milk. While it is impossible to increase the fat or other constituents of milk mdefi- nitely or permanently, the ration nevertheless exercises appreciable effects upon the composition of the milk. Morgan demonstrated that to a certain extent food fat exerts an invariably favorable influence upon the production of milk fat, and that fat should not be omitted trom the ration of dairy cows. A few instances of specific effects of rations upon the composition of the milk may be mentioned. In gen- eral the cows which consume the most food produce the most fat. In one case the discontinuance of silage caused a slight increase in the acidity of the milk. If calcium phosphate is added to a ration which already contains sufficient mineral matter for the ask of milk, an increase in the phosphate content of the ash is noted. Mayer found that. butter made from cows which were fed 4 pounds of sugar per day had a low melting and solidifying point and the volatile fatty acids were increased. In many cases great changes in the mineral elements of the ration have caused no corresponding changes in the composition of the milk. Milk fat is derived from carbohydrates, fat and protein in the food and from body fat. The addition of large quantities of fat to the ration may cause a marked increase in the fat content of the milk for a time or to a certain degree. Beyond this point it may produce the . opposite effect. The use of the oils obtained from cottonseed, linseed, corn and various other feeds may have a temporarily good effect upon the fat content of the milk. At the same time the sugar and proteids as a tule remain without change. If a raticn containing much oil is used the milk at first shows an increase in fat but soon returns to a normal condition. In rare cases the peculiar properties of the food fats can be recognized in the milk fat when the former were fed to excess. For the most part, however, the food fat loses its individuality in the mammary gland. stat. tl. ate ~...2 parts Solution of milk sugar .......... 3 parts 2 to 3 oz. q.2h. As cream was usually old, he advised in 1889, when discussing the subject, that top milk be obtained by letting it rise in tall pitchers. The solution of milk sugar was made by adding 1734 drams to a pint of water. In this same paper he says that sterilization of milk is not necessary in all cases, but is most necessary among the poor. Booker, in the discussion, advised sterilizing in summer. Holt called attention, in the light of our present knowledge, to an interesting condition. He said that frequently the mistake has been made of giving too much and too frequently of artificial food, and that he had been examining the size of stomachs, with a view to finding out the proper amount of a feeding. It was soon apparent that the one formula was not. practicable because of the different weights and conditions of children, and that the same food for a child of eight days and one of eight months was quite impossible. A more flexible system, adapted to the ability of the child, was worked out. This came to be known as the percentage method of feeding, or, on the other side of the water, as the American method. To no one so much as to Dr. T. M. Rotch, of Boston, is the world indebted, for the development of this method and the work- ing out of the principles involved. The difhiculties were innumerable, and at times seemed insurmountable, but the results will remain as a monument to the father of percentage feeding. His idea very early came to be that, as skilled pharmacists prepared drugs, so should milk laboratories be established where educated clerks, under medical supervision, should fill prescriptions for milk modified to exact per- centages. This must have seemed impossible to nearly every physician at that time, yet in 1891 the first. Walker-Gordon laboratory, under the care of Mr. G. E. Gordon, was established in Boston. One year later a second was established in New York City, and today there are 21 laboratories* in as many different cities (Rotch, Morse). At these laboratories all cases for modified milk have to be on the pre- scription of a physician. The advantages of this method were imun- erable, both to the mother and the physician. It also placed infant feeding where it. should be,—under the physician’s care. The two objections to it were expense, costing about 40 cents a day, and the * The laboratories have distributing stations at all the principal resorts from Bar Harbor to Norfolk. On their 69 different farms there are more than 4,000 cows, all tuberculin tested. 285 manipulation necessary. But if manipulation had to be, it was better done with the best of facilities for cleanliness and exactness than in untrained hands. In difficult feeding cases the results were found to be much more satisfactory than in any other way, for variations from the formula called for were at a minimum and ehomee: of such a small percentage as would be impossible in home modification could be made. . Tf expense made the laboratory milk impossible to consider, milk could be modified at home less accurately but, in most cases, quite satisfactorily. There were many questions which arose regarding the creams, sugars, et cetera, to be used. Cream, as is well known, may be obtained either by gravity or by centrifugalization. Certain objections had been raised against centrifugal cream, but of the two it seemed much preferable because freshness was considered a very important quality and gravity cream was 24 hours older. As top milk has been coming into use more and more for home modification, this agitation over centrifugalized versus gravity cream will drop into the background to some extent. Milk sugar and cane sugar each had its advoeates. Holt, Rotech and Morse believed in the former as more rational, because the sugar in woman’s and cow’s milk was milk sugar, and because cane sugar fermented sooner. Jacobi was one who for years advocated cane sugar instead of milk sugar, because milk sugar hastened lactic acid fermentation and so caused quicker coagulation with larger curds. In addition it changed into oxalic acid, (Baldwin) by fermentation in the intestinal canal. 345 INDEX. abnormal milk, 32-52 abortion, 64 acidity, determination of, 188 actinobacillosis, 65 actinomycosis, 65 actinomycosis in milk, 261 Adams method for fat, 184 adulteration of milk, 52 aerating milk, 129 afterbirth, retention of, 8&8 age of cow ana milk fat, 18 air, examination of, 249 albumin, determination of 186 alcoholic fermentation in milk, 39 alkalinity of human milk, 286 ammoniai for cooling milk, 154 anthrax, 66 anthrax, carried by milk, 259 antitoxing in milk, 45 areometer test, 183 ash, determination of, 187 ash of milk, 16 Babcock asbestos method, 184 Babcock test, 182 bacteria, affected by temperature, 239 antagonism among, 241 classifica*?on of, 198, 211 extent of milk contamination, 237 growth in milk, 242, 245 in milk, 8 in milk, sources of, 205 list of in milk, 213-237. pathogenic in milk, 213 rate of multiplication, 240 reducing number in milk, 241 reproduction of, 202 bacteriological examination, 246 bacteriology of milk, 198-250 barley for cows, 99 barley water for infants, 287 barnyards, 111 barnyards, bacteria from, 209 bedd ng, bacteria in, 209 bedding for cows, 55, 110 benzoic acid in milk, 175 bibliography of milk, 316-343 bitter milk, 38 blackles 66 blendea milk, 27 bloating, 67 bloody milk, 42 blue milk, 33 borax in milk, 171 boric acid in milk, 171 Boston, milk supply of 144 bran for cows, 99 breed of cow and milk fat, 17 brewers’ grains for cows, 100 brine for cooling milk, 153 buckwheat for cows, 100 buildings, 106-115 butter, 299 cold storage of, 159 standard, 298 buttermilk for infants, 289 standard, 297, 306 carbonated milk, 29, 307 care of cows, 54 casein, 7, 15 determination of, 185 certified milk, 25, 28 charities and milk for infants, 295 cheese, 302 cold storage of, 159 chemical examination of milk, 177-197 chemistry of milk, 14 cholera from milk, 270 chromates in milk, 175 cities, milk supply of, 141-149 clarified milk, 29 cleanliness in milking, 119 cohesive power of milk, 13 cola storage, 159 color, detection of, 191 of milk, 11, 33 colostrum, 18 composition of milk, 14 condensed milk, 29, 303 by freezing, 160 standard, 297 cooling milk, 129, 137 cooperation in milk business, 147 corn for cows, 100 cornstalk disease, 68 cost of producing milk, 3 cotton seed for cows, 100 covered pails, 128 cowpox, 69 carried by milk, 260 cream, 298 sampling, 180 creaming of milk, 13 culture media for bacteria, 248 dehorning, effect on milk, 23 densimetric method, 184 density of milk, 13 desiccated milk, 29 dextrinized gruel for infants, 288 diarrhea from milk, 271 diluents of milk for infants, 287 diphtheria from milk, 269 dirt in milk, 51 dirt test, 194 diseases, carried by milk, 251-272 of cows, 53-98 disinfection of stables, 59 drugs, effect on milk, 43 electrical pasteurization of milk, 204 resistance of milk, 13, 203 enteritis, 69 enzymes in milk, 8 estrum, effect on milk, 20, 47 evaporated milk, 29 excitement, effect on milk, 21 exercise, effect on milk, 20 for cows, 53 fat, determination of, 182 testing for, 194 feed, effect on milk, 21, 35 feeding cows, 54, 99-105 fermentations, abnormal in milk, 244 filtering milk, 129 flavors in milk, 34, 37 fluke worms, 70 fluorids in milk, 175 foot-ana-mouth disease, 71 earried by milk, 257 foot rot, 72 foremilk, 127 formaldehyde in milk, 169 freezing point of milk, 13, 150 frozen milk, 157 fruits for cows, 102 346 galactase, 9 galactin, 16 garget, 77 gelatine, detection of, 194 Gerber’s acidobutyrometer, 183 fermentation test, 193 germicidal property of milk, 10, 210 gestation effect on milk, 23 erains for cows, 99 grooming cows, 54, 119 guaranteed milk, 28 heated milk, detection of, 192 Hegelund method of milking, 121 hematuria, 72 hemorrhagic enteritis and milk, 263 septicemia, 73 history of milk inspection, 308-315 homogenized milk, 29 horn fly, 73 human milk, 276 humanized milk, 28 hydrogen peroxid in milk, 173 hygiene of cows, 53-98 ice cream, 306 ice for cooling milk, 152 individuality of cows, 18 infants, feeding, difficult case, 291 methods, 283 simple case, 289 with milk, 273-296 motality of, 273 inspected milk, 26 inspection of buildings, 114 of milk, history of, 308-315 jaundice, 74 joint ill, 74 kafir corn for cows, 100 kephir, 305 Keratiti 75 koumiss, 305 lactalbumin, 15 lactoglobulin 16 lactometer 181 leben, 306 leucocytes in milk, 9, 47 lice, 75 linseed meal for cows, 100 liquefying bacteria, 212 literature on milk, 316-343 347 malignant catarrhal fever, 76 - edema, 77 mammitis, 77 ana milk, 262 mange, 90 market milk. 25 examinaition, 178 matzoon, 305 metritis, 79 milk, abnormal, 32-52 and infants, 273-296 bacteria in, 8 biology of, 5 care of, 136 cars, 141-149 comparison of human and bovine, 281 contaminated in handling, 209 definition, 5 elie ls A: fever, 79 and milk, 263 inspection, history, 308-315 normal, 5-31 of various animals, 30, 31 pails, 128 poisoning, 46 powder, 304 products and health, 297-307 rooms, 112 secretion, 6 milk sickness, 81 ‘in milk, 261 sugar, 7 by freezing, 160 determination of, 186 utensils, care of, 133 milk-borne diseases, 265 milkers, health of, 116 milking and handling milk, 116-140 milking machines, 123 methods, 120 mixing milk, 23 modified milk, 28 mother’s milk, 276-281 municipal control of milk, 295 mycosis, 81 nagana, 82 nephritis, 82 New York, milk supply of, 142 nodular disease, 83 nutrose, 305 oatmeal water for infants, 288 odor of milk, 12 odors in milk, 34, 37 osteomalcia, 83 paper coil method, 184 parturient apoplexy, 79 pasteurization, effect on milk, 164 of milk, 162-168 of milk for infants, 293 pasteurized milk, 26, 29 pathogenic bacteria in milk, 213 peptonized milk for infants, 287 pericarditis, 84 peritonitis, 84 Philadelphia, milk supply of, 145 plasmon, 305 pleuro-pneumonia, 85 in milk, 261 poisonous plants, effect on milk, 44 poisons, 85 : preservatives, detection of, 189 in milk, 169-176 proprietary feeds, 104 ptomains in milk, 46 purifying milk, 129 pycnometer, 182 rabies, 87 in milk, 260 rations for different climates, 104 narrow and wide, 100 size of, 101 reaction of milk, 14 | red milk, 34 refractive index of milk, 13 refractometer, 185 refrigeration of milk, 150-161 rheumatism, 88 rice water for infants, 287 rinderpest, 89 ringworm, 89 roots for cows, 102 ropy milk 39 roughage for cows, 103 saccharine in milk, 175 sale of milk, 141-149 salicylic acia in milk, 175 salt for cows, 59 samples, taking of, 178 sanitary milk, 29 sanose, 305 scabies, 90 scarlet fever from milk, 268 scouring, 91 screw-worm fly, 91 seasons, effect on milk, 21 septic diseases and milk, 264 sewage, disposal of, 111 shelter, effect on milk, 23 silage, 102 . skim milk, 299 standard, 297 slimy milk, 39 soapy milk, 38 sodium carbonate in milk, 174 solids, determination of, 185 soiling, 102 sore throat from milk, 263 souring of milk, 242 spaying, effect on milk, 20 specific gravity of milk, 11, 181 heat of milk 12, 150 stables, 106 staggers, 92 _ standard milk, 27 standards, legal for milk, 24 of milk products, 297 starch, detection of, 194 sterilization of milk, 162-168 sterilized milk, 29 stomach worms, 92 stomatitis, 92 straining milk, 129 streptococci in milk, 245 succulent feeds, 101 sunlight, effect on bacteria, 203 PntQueites alee 348 teat diseases, 93 : temperature, effect on bacteria, 239 testing cows, 177 tetanus in milk, 261 Texas fever, 94 thrush from milk, 271 time of milking and milk fat, 19 toxins in milk, 45 transmission of disease in milk, 251-272 transportation of milk, 141-149 tuberculosis, 95 earried by milk, 251, 271 tumors, 96 typhoid fever from milk, 266 tyrotoxicon, 46 udder diseases, effect on milk, 40 udder of cow, 5 ventilation of stables, 108 verminous bronchitis, 97 viscosity of milk, 11 warble fly, 97 water, bacteria in, 209 examination of, 249 for cooling milk, 151 for cows, 55 in milk, 192 weather, effect on milk, 20 weighing milk, 177 wet nurse, requirements, 281 whey mixtures for infants, 286 wounds, 98 yellow milk, 34 yoghurt, 307 ok ni OO00895aéaélb