Dairy husbandry. in Canada. Canada C212 P c.3. I a^ Publication 1439/E. Agriculture Canada

Transcription

1 Dairy husbandry in Canada I a^ Agriculture Canada Publicatin 1439/E C212 P c.3 Canada

2 Digitized by the Internet Archive in 2012 with funding frm Agriculture and Agri-Fd Canada - Agriculture et Agralimentaire Canada

3 A FEDERAL/PROVINCIAL PUBLICATION CANADA/ONTARIO DAIRY HUSBANDRY IN CANADA This publicatin was riginally prepared by a cmmittee cnsisting f staff members f the Ontari Agricultural Cllege and the Ontari Veterinary Cllege, University f Guelph, and the Live Stck Branch f the Ontari Ministry f Agriculture and Fd, Trnt, Ontari. Agriculture Canada has agreed t publish this revised editin in accrdance with the terms f reference f the Federal-Prvincial Cperative Cmmittee n Agricultural Cmmunicatins. AGRICULTURE CANADA PUBLICATION 1439

4 PUBLICATION 1439, available frm Cmmunicatins Branch, Agriculture Canada, Ottawa K1 A 0C7 Minister f Supply and Services Canada Cat. N. 1439/1981 E ISBN: Revised 1981 Reprinted M-7:82 Aussi dispnible en francais

5 NTENTS Breeds 5 Dairy Cattle Imprvement. 7 Milk Recrding Systems 7 Canadian Milk Recrding Bard 7 Recrd f Perfrmance 7 Dairy Herd Imprvement Prgrams 8 Artificial Inseminatin 8 Breed Imprvement Prgrams 10 Selectin f Dairy Cattle 11 "Prven Sire Cncept" 16 Nutritin and Feeding 22 Nutrient Requirements f Dairy Cattle 22 Characteristics f Feeds 28 Feeding Dairy Cws 33 Management f the Milking Herd 44 Recrd Keeping 44 Milking Operatin 44 Maintaining Breeding Efficiency 46 Feeding and Management f the Dry Cw 47 Calving 48 Feeding and Care f Calves and Heifers 48 Herd Health 55 Cmmn Diseases and Cnditins 56 Diseases f the Digestive Tract 61 Respiratry Diseases 64 External Parasites 66 Disinfectin 66 Flies 67 Husing the Dairy Herd 68 Management 68 Cnstructin Materials 70 Types f Stall Barns 71 Planning the Stall Barn 72 Planning the Free-Stall Husing System 74 Plans 77 Appendix 78

6

7 dairy husbandry in Canada Because f the cntributin she has made t the health and physical wellbeing f mankind, the dairy cw has frequently been described as the fster mther f the human race. This dcile creature whse cud-chewing habits seem t brand her as a mdel f simplicity is indeed a very cmplex machine, ne that is capable f cnsuming raw material f lw quality and cnverting it int nature's finest and mst nutritius fd. Althugh the dairy cw has cntributed much t the health f mankind, she has als helped t enhance the financial status f thse wh have adpted her as the medium thrugh which their primary farm prducts are marketed. Even s, she des nt respnd equally when subjected t all types f cnditins; rather she prduces mst abundantly when given prper nurishment, adequate husing, reasnable care, and capable attentin when attacked by pests r disease. Such being the case, this bulletin is being published fr the purpse f prviding persns interested in dairy husbandry with infrmatin which shuld, if applied, pint the way t a mre prfitable dairy enterprise. BREEDS Six breeds f dairy cattle Ayrshire, Brwn Swiss, Canadienne, Guernsey, Hlstein and Jersey are in use in Canada. In additin, tw dual-purpse breeds, the Red Pll and the Shrthrn, are used in milk prductin. N figures are available n the actual f purebred animals in f animals f these breeds. numbers f each breed but the registratin Canada prvides an indicatin f the relative number Frm the standpint f breed imprvement, the number f purebred cws n a recgnized prductin-testing prgram is f much mre imprtance than the numbers f animals registered each year, since prductin recrds are essential fr accurate selectin. The last tw clumns in Table 1 shw the number f purebred cws f each breed that were n test in 1980.

8 TABLE 1 Registratin and prductin testing f dairy cattle by breeds in Canada 1980 Number %f N. n % f ttal Breed reg'd ttal R.O.P. tested Ayrshire Brwn Swiss Canadienne Guernsey Hlstein-Friesian Jersey The dual-purpse breeds, as the name implies, pssess sme f the fleshing characteristics f beef breeds and prduce cnsiderable amunts f milk althugh at a smewhat lwer level than the breeds which have been designated as primarily dairy (Table 2). There is a grwing awareness f the ptential fr meat prductin frm the dairy animal, s that the terms "dairy type" and "beef type" are nt as definitive as they nce were. Individuals planning t establish a dairy herd shuld stp t cnsider the breed f cws t be maintained. Factrs f imprtance in this decisin are: Milk market available Persnal preference Market fr surplus breeding stck, bth lcal and exprt Availability f cattle f high genetic merit, bth females and sires TABLE 2 Prductin f cws tested n R.O.P. in Canada N. f Average prductin Breed recrds Milk (kg) Fat (%) Fat (kg) Ayrshire Brwn Swiss Canadienne Guernsey Hlstein-Friesian Jersey Red Pll Dual-purpse Shrthrn Actual prductin in 305 days 2 Purebred and Natinal Identificatin Prgram grades

9 N cmparisn between breeds has been attempted in this publicatin. Each f the dairy breeds demnstrates by its existence that it can make a cntributin t the Canadian dairy industry. In many classes f stck such as swine, pultry, and sheep, the cmmercial animal is a crss f tw r mre recgnized breeds r strains, yet the vast majrity f dairy cattle n the Nrth American cntinent is purebred animals f a given breed r high-grade animals f a particular breed. Experimental evidence fr distinct superirity f the crssbred dairy cw ver purebreds des nt presently exist and, until it is demnstrated that hybrid vigr des exist fr milk yield and/r ther ecnmic traits, the cmmercial dairy cw will cntinue t be a purebred r high-grade animal f ne r anther f the recgnized dairy breeds. DAIRY CATTLE IMPROVEMENT Milk Recrding Systems Dairy cws vary greatly in their ability t prduce milk and butterfat even n a within-breed basis. Much f this variatin is due t the manner in which cws are fed. Inheritance is a factr as well in determining variatin in milk and butterfat prductin, and lw prductin due t this cause cannt be crrected by feeding. Each dairyman shuld institute sme methd f measuring each cw's perfrmance. If a dairyman is nt cncerned abut the butterfat cntent f milk, he can develp his wn system f evaluating cws by simply weighing the quantity f milk prduced by each cw at each milking and ttaling the individual weighings at the end f each lactatin. Dairymen, hwever, are interested in butterfat test as well as quantity and can enrll their herds n a milk-recrding prgram that will prvide detailed infrmatin. Canadian Milk Recrding Bard The Bard was set up in 1974 t develp and standardize milk recrding prcedures. Membership includes representatives frm each prvincial recrding prgram, the Dairy Farmers f Canada, Jint Dairy Breeds Cmmittee, majr dairy breed rganizatins, the A.I. industry and Agriculture Canada. The Bard has a Technical Cmmittee t prvide scientific guidance. Recrd f Perfrmance Recrd f Perfrmance (R.O.P.) is the plicy spnsred by Agriculture Canada fr the purpse f prviding a service t test milk prductin in dairy herds. At ne time R.O.P. testing was limited t purebred herds, but the plicy has been extended t include grade cws in herds having at least 15 purebreds. Sme 240 inspectrs are invlved in checking the milk prductin and in

10 certifying the recrds f cws in R.O.P. herds. Each herd is visited abut 10 times annually. Official recrds are based n the amunt f milk prduced in 305 days. Breeders wishing further particulars abut the plicy are advised t cntact the Chief R.O.P. Canada. Inspectr, Animal Prductin Divisin, Agriculture In 1979, there were cws enrlled n supervised prgrams and n wner sampler prgrams thrughut Canada. Dairy Herd Imprvement Prgrams Each prvince ffers milk-recrding prgrams that are designed basically fr the cmmercial breeder. They are the "standard" dairy herd imprvement and the "wner sampler" prgrams. The "standard" D.H.I, prgram is quite similar t R.O.P. in that it is guided by the standards set by the Canadian Milk Recrding Bard. Recrds have fficial status and are used fr breed imprvement and sire valuatin. This prgram als includes sme infrmatin n feeding and management. Applicants fr enrllment are gruped int assciatins, each cmprising members. A supervisr assigned t an assciatin visits each member's farm fr ne day each mnth. While n the farm he recrds the prductin f each cw at tw cnsecutive milkings. He takes a sample frm each milking and tests the cmpsite sample f each cw. The test infrmatin is frwarded t the prvincial authrity where the infrmatin n each cw's lactatin is accumulated. All prvinces cnduct unsupervised "wner sampler" prgrams. These recrding plans vary frm prvince t prvince, but essentially they are designed t prvide a culling standard fr each participating herdwner. A small enrllment fee allws participatin. A herdwner simply weighs the milk prductin f each cw nce a mnth and takes a sample f her milk. The prductin figures and milk samples are then sent t a testing center. The prductin data will be accumulated and a statement f prductin issued fr each cmpleted lactatin. Dairymen interested in D.H.I, testing shuld cntact their prvincial agricultural representative. Artificial Inseminatin The artificial inseminatin f dairy cattle has evlved, in the past 35 years, frm a nvel technique t a majr industry which has influenced the curse and rate f dairy cattle imprvement t a prfund degree. ORGANIZATION In Canada, there are eight artificial inseminatin units with a cmplete prgram f semen prductin, inseminatin services and a yung sire prving prgram fr dairymen. Tw f the units are in the Atlantic Prvinces, ne in Quebec, fur in Ontari and ne in British Clumbia. Dairy cattle breeders in

11 the Prairie Prvinces are mainly supplied by semen-prducing businesses in ther prvinces. Tw A.I. units in Alberta and ne in Saskatchewan cllect and distribute semen frm dairy bulls. The A.I. units are prducer wned and managed r wned and perated by prvincial gvernments. SPE OF OPERATIONS The first A.I. unit was established at Waterl, Ontari, in 1941 and 317 services were accmplished during the first year f peratin. In first services were accmplished in Canada. This represents mre than 70% f the ttal dairy cw ppulatin in Canada. It is f interest t nte that abut 85% f the ttal registratins in the pure dairy breeds in 1979 were A.I. prgeny. Apprximately tw thirds f the services were t prven sires. SIGNIFICANCE OF A.I. Artificial inseminatin had its beginnings as a means f prviding wners f cmmercial herds with service t superir bulls which they culd nt affrd t buy and use in natural service. The artificial inseminatin industry has fund, in additin t this basic purpse, a far brader applicatin. Prvided A.I. sires are truly superir and the breeder selects prgeny-prven sires t use in his herd, the ptential fr herd and breed imprvement with A.I. is greater than with natural service. The fllwing pints supprt this statement. A.I. makes pssible the develpment and identificatin f genetically superir sires. These sires are referred t as "Plus Prven Sires". Genetically superir sires in A.I. service have an infinitely wider use than wuld be pssible in natural service. One "Plus Prven" bull may breed many thusands f cws artificially and many such sires have been mated t ver females in a year. Mre will be said abut prven sires in the sectin entitled "Sire Selectin". Other advantages assciated with artificial inseminatin are: Ecnmy The cst f A.I. service is lw cmpared with the cst incurred thrugh wnership f a natural service sire. Disease preventin A.I. prevents the spread f such reprductive diseases as vibrisis, brucellsis and trichmniasis. These diseases may be spread by natural mating.. benefit Artificial inseminatin is an established prcedure in dairy herds thrughut Canada. Under cmpetent herd management, n prblems peculiar t A.I. in respect t reprductin shuld be encuntered. The btained in terms f increased prductin frm the daughters f sires prven t be superir is at nce the purpse and the accmplishment f artificial inseminatin.

12 Breed Imprvement Prgrams In additin t the milk recrding plicies prvided by the federal and prvincial gvernments, breed assciatins have prvided awards and plicies t encurage the imprvement f dairy cattle. The awards differ frm breed t breed but, generally, are intended t recgnize members f breed rganizatins wh have made significant achievements in the breeding and develpment f dairy cws. Recgnitin is als made f utstanding brd cws and sires. Canadian breeders f dairy cattle currently have an extensive exprt market. In 1980, exprts f purebred animals amunted t A large number f unregistered cattle f the dairy breeds are exprted annually as well and the demand fr Canadian dairy cattle is keen. Breeders are well aware f the fact that presently, many buyers prefer animals that are attractive in appearance and clsely resemble an ideal in cnfrmatin. As lng as buyers are willing t pay higher prices fr cws f a certain type, the dairyman wh derives a prtin f his incme frm cattle sales will select fr cws f this type as well as fr high prductin. If exprts f Canadian dairy cattle are t be maintained there must be a cntinual imprvement in the prductive capability f ur cattle. Higher levels f prductin will cntinue t becme mre imprtant as wrld ppulatin increases. A discussin f the relatinship between type and prductin will fllw in the next sectin. Breed assciatins have assisted the breeder in selecting fr purebred stck by spnsring type classificatin prgrams fr a number f years. The basic bjective f these prgrams is t encurage breeders t have their animals classified frm the standpint f type in the expectatin that this infrmatin will be used as a basis fr selectin f herd replacements. TYPE AND PRODUCTION Numerus research studies have indicated that verall visual appraisal fr cnfrmatin r type is nt an accurate means f identifying superir-prducing cws especially when cmpared t even ne lactatin recrd n the cw. In fact, verall type and milk prductin are essentially independent traits, genetically. This pint is illustrated by the fact that A.I. sires with high prductin prfs d nt necessarily have high type prfs. It shuld be recgnized by all dairymen, bth with purebred and cmmercial herds, that selectin n the basis f verall type alne will nt necessarily increase milk prductin; nr will selectin slely fr milk yield bring abut any imprvement in bdy cnfrmatin. This is nt t say that the tw traits f gd type and high prductin cannt be cmbined in the same animal. Hwever, if bth are t be imprved, bth must be cnsidered in selecting animals and the rate f imprvement in each characteristic will be slwer than if type r prductin alne is cnsidered. It simply takes lnger t imprve bth traits than ne alne. One cmpnent f type, "dairy character", is a 10

13 useful indicatr f prductin when n prductin recrds are available, since it is psitively assciated genetically with prductin. The utility aspect f type has lng been cnsidered f majr imprtance. It essential that a cw be physically sund if she is t prduce large quantities f milk fr several years. Many cws leave the herd annually because f udder injuries and mastitis. The cw's udder appraches the grund at a rate f 2.5 cm per lactatin and deep udders are mre prne t mastitis and injury. Thus selectin fr udders that are held up abve the hcks may decrease lsses frm these causes. Further research is needed t indicate the type f cw that will stand up under heavy prductin fr a number f lactatins. If research indicates that the present ideal shuld change in sme respects, then breeders and breed assciatins must be willing t make these changes. Otherwise, there is danger f a departure f ideal type frm utility. Certainly, verall breed imprvement requires cntinued emphasis n increasing prductin. Selectin f Dairy Cattle Selectin begins when the new dairyman ges ut t assemble a herd. The beginner is wise t seek the guidance f an extensin specialist r a successful dairyman in making his first purchases. Once the herd is established, selectin is practiced by chsing the sires and females that will be allwed t leave ffspring in the herd. If the dairyman des nt select superir cws and sires cnversely cull as the parents f the next generatin f calves, and r remve inferir cws and avid the use f inferir bulls, his herd will nt imprve genetically. The purpse f this sectin is t deal with sme f the basic principles in establishing a breeding prgram fr dairy cattle, BREEDING GOAL Each dairyman must establish an bjective in his breeding prgram and, having established it, must pursue it with determinatin. A breeding gal is established by examinatin f the dairyman's peratin t determine thse traits f the dairy cw which are f the mst ecnmic imprtance. The relative emphasis t be placed n traits in an ecnmic prgram will vary frm peratin t peratin depending n the milk market, the ptential fr sale f cattle and the kind f cattle making up the dairy herd. The dairyman can hpe t imprve by selectin nly thse traits that are inherited (Table 3). is Traits f imprtance vary in their heritability. The heritability f a trait tells us hw much imprvement we can expect in the next generatin f ffspring when we select in ur herd the superir animals fr that trait as parents. It is generally knwn that the heritability f milk yield is apprximately This tells us that abut 25% f the ttal difference bserved in prductin between tw animals is due t differences in their genetic makeup r breeding 11

14 wrth. If cw A in a given herd prduces 5443 kg f milk as a 2-year-ld while cw B prduces nly 4536 kg as a 2-year-ld in the same herd, nt all f this difference is due t differences in the tw cws' breeding wrth r value. In fact, fr milk yield with a heritability f 0.25, nly 25% f the difference f 907 kg r 227 kg f milk will be due t the genetic superirity f cw A. The heritability f different traits ranges all the way frm t 1. The heritability f mst traits f ecnmic imprtance ranges frm 0.1 t TABLE 3 Traits f imprtance t dairymen Trait Trait effects Lw heritability Days dry Days pen Calving interval Prductive life Reprductive efficiency Milk yield and replacement csts Milk yield and replacement csts Milk yield and replacement csts Replacement csts Milk yield and replacement csts Medium heritability Yield Type scre Mastitis resistance Milking qualities Direct milk sales Breeding sales Milk yield and treatment csts Labr csts High heritability Fat percent SNF percent Prtein percent Mature size Prime differential Nne presently Nne presently Maintenance csts and sales 0.4. If the heritability f a trait is very lw, ranging frm t 0.2, this simply indicates that differences between animals are nt due primarily t differences in their breeding wrth but are due mstly t envirnmental factrs such as feeding and management. In cntrast, fr traits such as fat percentage, which has a relatively high heritability, bserved differences between cws are largely genetic. Traits may be generally gruped int thse with lw, medium r high heritabilities. Traits that are cnsidered lw in heritability cannt be imprved significantly by the selectin f superir animals. These traits respnd readily t imprvement in management r feeding prcedures. The discerning dairyman will nt include in his selectin gal traits with lw heritabilities. It is essential that in shaping a breeding gal the dairyman include nly traits that are inherited t at least a medium extent. 12

15 In summary, each dairyman in shaping a breeding prgram, shuld cnsider his peratin, determine thse traits that are f mst ecnmic imprtance in his herd, and cncentrate n selectin t imprve thse traits which are inherited. At the same time, he must imprve his feeding and management practices t realize imprvement in lw heritability traits which respnd t an imprved envirnment. TRAITS TO EMPHASIZE IN SELECTION All dairymen are frced t remve frm their herds annually a certain percentage f cws that are abnrmal reprductively, have acute mastitis, suffer injuries, r are simply t ld t perfrm. Generally speaking, as many gd cws leave herds fr these reasns as pr cws. It is nly after these cws have been remved frm the herd that the dairyman is free t cull cws n traits that he cnsiders imprtant. Sund management practices will minimize the percentage f cws leaving the herd annually fr disease, injury, and ther reasns f this srt, and maximize the dairyman's pprtunities t select n traits included in the breeding gal. We shuld narrw dwn the list f characters t be cnsidered in the breeding gal by eliminating thse with lw heritabilities. N ecnmic incentive presently exists fr selectin f cws n the basis f the slids-nt-fat r prtein cntent f milk. Recent research indicates that little emphasis shuld be placed n size as a means f increasing milk yield. If the herd is given adequate feeding and management, size prbably shuld receive little attentin unless particular individuals are excessively large r small. The amunt f emphasis t be placed n fat percentage will vary with the market fr milk but, undubtedly, this trait must be cnsidered under mst herd cnditins. One apprach t maintain fat percentage at a desired level is t set a lwer limit fr fat percentage in the herd, and t use bulls whse daughters test high fr fat percentage until this limit has been passed. Fat test can be maintained at the lwer limit by the use f sires whse daughters test at least this high. Only the traits in the medium heritability grup remain. These shuld be given the mst emphasis in a dairy cattle breeding prgram. These are milk yield, type scre, milking qualities, and pssibly resistance t mastitis. A mastitis cntrl prgram shuld eliminate mastitis as a majr prblem in ur dairy herds, allwing us t cncentrate ur selectin n milk yield, fat percentage and t sme extent, n cnfrmatin and milking qualities. The dairyman wh wishes t cull accurately must btain accurate recrds n each cw. Recrds f milk yield and fat percentage can be btained by enrlling in ne f the milk-testing plicies previusly utlined. Careful bservatin f the herd at milking time will prvide infrmatin n milking qualities. With gd recrds, the dairyman is well equipped t cull thse cws which are inferir fr the traits which he cnsiders t be imprtant. The 13

16 average dairyman testing his herd, derives apprximately 80% f his grss incme frm the sale f milk and milk prducts and 20% f his grss incme frm the sale f all livestck. Undubtedly, purebred breeders will derive a larger percentage f their grss incme frm the sale f breeding stck. Hwever, milk yield will be emphasized in all breeding prgrams. The prcedures which may be used in culling cws fr milk yield are generally applicable t culling cws fr fat percentage, type scre and milking qualities. CULLING TO INCREASE PRODUCTION One methd f imprving the prductin f a dairy herd is t cull the lw prducers. There is n prblem in determining what t d with very lw-prducing cws but cws that are clse t the herd average in prductin create a prblem. Is it better t cull an lder cw and give a lwer-prducing, first-lactatin heifer anther chance, r shuld the lder cw be retained? If kept in a herd, very lw-prducing 2-year-lds may d better in succeeding lactatins but their future recrds usually will be belw their herd mates by smething like 50% f the differences between the herd average and their first lactatins. One very practical reasn fr retaining the sund lder cw rather than a 2-year-ld is that the mature cw will prduce abut 25 30% mre than her yunger cmpetitr. We might summarize culling prcedures fr prductin in pint frm as fllws: Enrll in a prductin-testing prgram. Give all females ne recrd befre culling. This prcedure will be pssible in mst herds f cws but it is nt practical in larger herds, since the number f first lactatin females wuld be t great. Owners f large herds shuld retain replacement heifers ut f the highest-prducing dams, and by superir prductin sires. Ail sires have sme gd daughters, but the tp prgeny-tested sires will prduce a much higher percentage f these superir animals. Cmpare all females in the herd n the basis f their milk and fat yield expressed n a Breed Class Average (B.C. A.) basis. The B.C. A. index crrects recrds fr the effects f age and enables us t cmpare the recrds f cws f different ages, thus culling the lwest-prducing animals. Mst severe culling shuld be dne n first and secnd lactatin females. Older cws that are cnsistently belw the average f the herd shuld als be remved when pssible. When decisins are clse between tw females, the dairyman shuld cnsider all differences between the tw animals. Differences in age, fat test, udder sundness, temperament, milking qualities, and perfrmance f ffspring will generally indicate which animal shuld be retained. 14

17 The accuracy f culling is increased by cnsidering all recrds n a cw, each recrd being cmpared t the herd average at the time it was initiated. Prcedures t estimate the breeding value f a cw are utlined in Appendix Table A-9. These prcedures prvide the mst accurate evaluatin f a cw n all f her recrds. The prcedures that have been utlined are mst useful in evaluating cws fr prductin. This is the mst imprtant single trait t the dairyman and must receive tp pririty in cw selectin. When the dairyman is interested in mre traits than prductin, infrmatin must be btained n each f these traits and cws must be ranked n the basis f each f these traits befre they can be accurately culled. There are n simple prcedures t evaluate cws n a large number f traits and rank them accurately, particularly if different emphasis is t be placed n each trait in culling cws. Cws may be ranked n the basis f tw traits, as shwn in Figure 1. Nte that the prductin expressed as B.C. A. fr milk yield is pltted alng the left-hand vertical axis, and the type scre f each cw is pltted alng the hrizntal axis. Each number shwn in Figure 1 represents a given cw, thus cw number 32 had a scre fr type f 80.0 and a B.C.A. f 146 fr milk yield. Nte that n clse assciatin is apparent between high type and high prductin in the herd illustrated. If the cws in this herd were t be selected slely n prductin, cw numbers 9 and 21 wuld be culled first. If the cws in the herd were t be selected slely n type, cw numbers 12 and 7 wuld be culled first. Dairymen wh select with sme emphasis n bth traits wuld cull cws that are inferir fr bth traits. In the illustratin, cw numbers 10, 35, and 36 fall int this categry. Such a chart is ften useful t rank the herd n tw traits such as milk yield and fat percentage, milk yield and type, r fat percentage and type. It des enable the dairyman t identify and weed ut cws that are inferir in a number f traits. Milk yield has been pltted in actual averages f B.C.A. indexes fr milk but culd als be pltted as the average difference f the cw's recrds frm the herd average as cmputed in Appendix Table A-9. The cmparisn f tw cws that are in different herds is accurate nly if each cw's recrd has first been cmpared t the average f the herd in which she made her recrd. As an example, ne might wish t purchase ne f tw cws each having recrds with a B.C.A. index f 120% fr milk. Cw A made her recrd in a herd averaging 100% B.C.A. fr milk while cw B made her recrd in a herd averaging 120% f B.C.A. fr milk. Cw A is 20 B.C.A. pints abve her herd average while cw B is nly a herd average cw. Since mst differences between herds are envirnmental rather than genetic, ne is wiser t buy cw A, ther things being equal. 15

18 FIGURE 1 Methd f ranking cws n tw traits (each number represents a cw) 190- Q> <2> <a> <S) i < u c u 3 O <S> ^ ^ <3> <3> < <S <S <a) Type Scre "Prven Sire Cncept" The selectin f a sire t be used in a herd is the mst imprtant decisin in the imprvement f dairy cattle. Prgressive dairymen recgnize this fact and, after cnsideratin f the infrmatin n a number f bulls, make a careful decisin in favr f ne r tw bulls fr extensive use in their herds. The mst reliable indicatr f the breeding wrth f a dairy bull is infrmatin n the perfrmance f a large number f daughters scattered at randm thrugh a large number f herds. Befre the initiatin f artificial inseminatin (A.I.) few bulls sired daughters in mre than ne herd. The perfrmance f the prgeny f a bull in a single herd is nt an accurate indicatr f his breeding wrth. At best the perfrmance f up t 40 16

19 daughters in a single herd is nly 50% as accurate as an A.I. prgeny test n a reasnable number f daughters. Tday, as a result f prgeny testing thrugh A. I., we knw with a high degree f accuracy the breeding wrth f a large number f sires and their services may be btained thrugh A.I. studs. Sme breeders will cntinue t select yung bulls n pedigree and use them extensively in their herds. A percentage f the bulls s chsen will be gd but sme will be inferir and nly a prgeny test will separate the inferir frm the superir with accuracy. It is almst inevitable that in the future, the majrity f breeders will use A.I. prgeny-tested superir sires extensively in their herds, sampling yung, unprven bulls n the heifers and yunger cws in their herds. Thse breeders wh will cntinue t use their wn sires will undubtedly arrange t sell enugh semen t ther breeders s that a reliable prgeny test is btained n these bulls. In cncluding, we may simply state that it is well established that the best indicatr f a sire's breeding value is a prgeny test based n a large number f daughters in a large number f herds. The dairyman wh cntinually uses superir prgeny-tested sires n his main cw herd will insure steady genetic imprvement f his cattle. This, in a nutshell, is the "prven sire cncept". SIRE SELECTION A sire whse daughters are superir t the daughters f ther sires fr a given trait is a breed imprver fr that trait. This des nt indicate anything abut his breeding wrth fr ther traits. A truly great sire will leave daughters that are superir t the prgeny f ther sires fr all traits f ecnmic imprtance. Let us briefly utline prcedures fr identifying the breed imprvers fr traits that may be f ecnmic imprtance t Canadian dairymen. Milk Yield All first-lactatin milk recrds are used t evaluate dairy sires. These recrds are analyzed t btain a cmparisn fr milk prductin fr each sire with a sizable number f daughters. The results f these cmparisns are published in a semiannual reprt n sire appraisal by the Animal Prductin Divisin f Agriculture Canada. All breeders may btain these reprts. The same infrmatin is released t dairymen by means f A.I. Stud newsletters s that each dairyman has at his dispsal the infrmatin n a large number f bulls that have been prgeny-tested in a number f herds. Hw d we decide if the bull is a breed imprver n the basis f his prgeny test? Let us cnsider milk yield. Table 4 shws the sire appraisal infrmatin n a number f plus-rated bulls as it is reprted semiannually by the Animal Prductin Divisin. The bulls listed have a sufficient number f daughters in a large enugh grup f herds t cmpute a reliable prf. Their 2-year-ld daughters are cmpared 17

20 t 2-year-ld daughters f ther sires in the same herd. Bulls with ratings abve the average fr the breed grup are breed imprvers fr milk and butterfat yield. Bulls belw the breed grup average will, n the average, decrease milk yield. Sire selectins shuld be made frm breed imprvers (i.e., bulls with plus milk ratings). The higher the plus rating f a sire the better chance the breeder has f btaining a high percentage f superirprducing cws. The pint is illustrated in Figure 2. Bull A with a rating f +5.3 has a much higher percentage f daughters that are superir t their cntempraries in milk yield. Althugh bull B has sme superir daughters, many mre f them are lw in prductin. Imprvement f the milk-prducing capability f ur dairy cattle depends in large measure n all plus fr milk. cws in the dairy herd being mated t sires that are rated There is ne exceptin t this rule. Occasinally a dairyman has a herd that prduces milk with a lw percentage f butterfat. If n prven sire is available with a plus rating fr milk, which will als imprve fat percentage, the dairyman may be justified in using a sire with a slight minus rating fr milk and a high average fr fat percentage. In Table 4, the first tw digits in the semen cde clumn indicate the A.I. unit in which the bull is maintained. Semen may be btained frm living A.I. sires thrugh the lcal A.I. Stud. Infrmatin n privately wned bulls must be btained thrugh the breed assciatin and, in general, prfs based n a grup f daughters in a single herd are nt gd indicatrs f a sire's breeding wrth. Fat Percentage Sires that will imprve fat percentage may be selected by cmparing the average fat percentage f their daughters t the average fr the apprpriate breed. Breed averages fr fat percentage fr the year 1976 are shwn in Table 5. Feeding and ther management cnditins have little effect n fat test and thus a cntemprary cmparisn is nt necessary fr this trait. A.I. Stud newsletters and sire appraisal reprts always shw average fat percentage f the daughters f each bull. Breed imprvers fr fat percentage are sires whse daughters test abve the breed average. Once the herd is testing at a sufficiently high level, hwever, the dairyman is wise t cncentrate selectin n sires that are breed average r better fr fat percentage and abve breed average fr ther traits. Type A sire which is superir fr cnfrmatin will have daughters that exceed the breed average fr type scre r exceed the breed average fr the percentage f 18

21 I I I I I I I 00 t- LO ^ 00 t (*) (N r- CN O) (D O) O M LO LO CN t- *tf ^ LO rf CN ^ CN O) CN CN CM t- i- -C O) TO Q O'J r(d «- LO OLO W (O «- <fr C5 LO O 00C0OL000 LO t- O) CN CM 00 O) LO ^fr O 00 t t «- ^ CN a -* DC E <?f rr O) i^ l Oi in O) in O O) N O) 1^ CN IN O) CN ^t in a r^ in LO O 0> O) IN TO Li. r- NOO LO r- CM O O O *- O «- t- r- CM (O ^ r- ^ d d ci II II ^ LO O CN t- r- O I I I I I ^c O O d d c> I t r^ c rs ^f c c t- cm in r- t- CN ^- ^tlooo LO r O) O) N, CM (O LO LO LO Tf ^T'd"'?f c "3 +j +-> U c i_ ^ 05 Qi i_ l cd jz > +> E M Qi O c 00 c <s> LU 'c c q > Cc c a > Qi E LU (J > c O E c O c Q. O > O Qi T5 Qi «- > LU c LU.*: '*-> C 'v. JO 'a.c _c c.q > 3 TJ C Qi C7 ^ a O _J O 00 DC < ^ > r i_ T5 C g s O r c a> il > r uj c H m c C c > «u -J LU c - 2 cc c > - a Q- E c ^ -c M O ^>»_ O -Q ^3 "D C > O r r ^ a> n E 05 CM IN Oi IN O 00 5f O 00 rn O IN 05 G5 r~ ^- t ^ IN 00 LO LO LO 00 T CM ^ CM CM CN t- ^r t- CM 00 t- t- LO CM LO CM O) t- C0 O) CN CN f CN O) LO fn ^t O LO ^r r- re a E ^ ( 29 0) "0 u c O) E aj «fr a> <3) LO CM t <fr O *t IN <tf 'i^- <fr LO rn IN CM C35 CM <* CN <fr O) ^ CN LO LO CN <tf- ^ r ^- CN CN CM O ^ CM r N, O O O O O O O X X X X X X X X X X X X X X X X X X O) ^f T 05 Oi 00 O) fn IN IN fn O) IN IN r*. 00 IN CN fn IN LU -J < < c +- c a> E a 0) -> TO 19

22 I I I I 0) c r* CN t- "fr ^ (D IO CM CM CN «- CM O O O) cm r^ c ^r c 1- c 00 r^ cm -3- l r^ *t «- CM.c Q c 00 l c <* cm ccc c r* n-ccmcmt- t-i^r^r^c CM <st c ^ 1- CN CM CM 00 ^t t- CM CM a a) j*: LL b CM 00 O) ) cm c O) r^ r^ If) r». r- CJ) 00 O) 00 O) re LL If) r»* ID <*- *- r- O <fr - 1- N q f III I O O «- d O O d CM t r» p^ ^t 10 *- c en l c r* 00 c cm CM CM CM CN CM CM CM CM CN c '3 4-» X a._ -a E I c CJ *t LU -I O) g - c C * as c 09 E Z n E z a; O c a> E a> E r a> > c n> 0J E k. a 8 c T «Q i_ 03 CL -E a -C > 00 If) 00 r- O) r>» If) -3" CM 2 c E.2 1- < M 2. "<5 CJ Q) ^ CC _^ QJ? c E. -m C -O -m U_ QC LL <2 c 1* Si* (J Q) 1- Q. E -55 a CJ O ^ O) l c ) r^. t- 1"^. CM r- ^> h* O) I s * O) ««E "c -C O SI c r b > -= > O z c > O CC " X u.q _cd O >.h O QC Q X a> E r- N CM CM O) LO LO LO <tf t- r^ r- ^t c c t- cm c ^r CC > c -a > c c O a> LL > c Si I > 25 if. c x = c >. O E c -* QC t E lu E Q" > O a> 7 T3 - +^ "^ c "S > := O = c c h- t- C3) LO C0 00 O cd r- r^ c a) CM CM LO LO r^ LO r*«^f CM CM If) CM LO <tf ^* O LO p^ CM CM r r CM ^ CM ^ CM r*» CN CM r r- O O O O O O O X X X X X X X X X X X X X X X X X CN ^~ ^> O) CM r<. r^ r*. r*. r*. r-h r» r«. r^ r>» C3) rv CM P>. r^ r-. r-*- fnj,-,-,--^ ^cvj,-^,- ^^^.^(M 20

23 daughters scred "Gd Plus" r better. All sires f each dairy breed with 10 r mre classified daughters are summarized n type peridically by the Department f Animal Science, Ontari Agricultural Cllege, University f Guelph. These summaries are available frm the Department f Animal Science, as well as frm Breed Assciatins and A.I. Studs. In each f these sire summaries, the infrmatin n individual sires is listed acrss the table and at the tp f each table is shwn the breed average fr verall classificatin and each screcard cmpnent. If the average f the sire's daughters is abve the breed average fr verall classificatin, as well as fr any particular screcard cmpnent, the sire may be cnsidered a breed imprver fr either verall classificatin r the particular screcard cmpnent. In general, if a dairyman shuld find that his herd is weak in a FIGURE 2 Distributin f daughters f tw sires based n cntemprary cmparisn Bull A (+5.3) Bull B (-5.1) VI w 0) *- -c D> 3 O Q > E D Z I I r r- +50 Difference f Daughters frm Cntempries (B.C. A. Mi Ik) 21

24 TABLE 5 Average fat percentage f diary breeds n R.O.P Breed % Fat Ayrshire 4.07 Guernsey 4.83 Hlstein-Friesian 3.76 Jersey 5.10 certain aspect f cnfrmatin as, fr example, a high percentage f faulty r lw udders, he may wish t chse a bull whse daughters scre well abve breed average in the screcard sectin fr udders. The practice f using a sire wh is strng in the characteristics fr which a weakness exists in a herd is knwn as crrective mating. Certainly, mst emphasis shuld be given t dairy character, a gd predictr f milk yield, as well as t udder shape and attachment and t feet and legs, if type is t be included in the breeding gal. If the dairyman wishes t select fr type, he will be mst wise t select first thse sires that have a plus rating fr B.C.A. milk and are breed average r better fr fat test. Frm this list f superir bulls, thse which will imprve the weaknesses in cnfrmatin in the cw herd shuld be selected. Such a prcedure insures nt nly imprvement in cnfrmatin but cntinued imprvement f milk yield and fat test. NUTRITION AND FEEDING Nutrient Requirements f Dairy Cattle Feedstuffs must supply energy, prtein, fat, minerals, and certain vitamins t the dairy animal. The quantity f each nutrient required is sex, age, grwth rate and milk prductin f the animal t be fed. dependent upn Energy, which is btainable frm the carbhydrates, prteins and fats in feedstuffs, is required in large amunts fr grwth, lactatin, and reprductin, as well as the bvius requirements fr physical activity and fr keeping the bdy warm. In yung animals, insufficient energy supplies will result in pr and unecnmical weight gains. Fr satisfactry reprductin there must be adequate energy intake, and heavy lactatin demands an even greater intake. ENERGY The mst plentiful and ecnmical surce f energy fr cattle is the carbhydrate prtin f the feed, including bth the nitrgen-free extract (starches, sugars) and the fiber (cellulse) fractins. The actin f the micrrganisms in the rumen enables cattle and ther cud-chewing animals t 22

25 digest much f the fiber cnsumed. The feeds high in fiber are knwn as "rughages", and this class includes pastures, hays and silages, as well as crn fdder, stver, crncbs, and hulls f grains and ther seeds. Feeds such as grains, which are high in sugars and starches but lw in fiber, are knwn as energy "cncentrates". The term Ttal Digestible Nutrients (T D.N.), used t express the energy value f a feed, includes all the digestible carbhydrates, prtein and fat (the last being multiplied by 2 1/4 since it has a higher energy value than the thers). The higher the T.D N PROTEINS value, the higher the energy cntent f a feed. Prteins are cmplex nutrients cntaining nitrgen in a special cmbinatin. They are abslutely essential t life in all animals, fr the frmatin f muscles, rgans, bnes, milk, and certain ther bdy cmpunds. The requirement is greater during perids f rapid grwth, reprductin, and lactatin. If the grwing animal is nt prvided with enugh prtein t meet the heavy demands f new tissue, grwth will be slwed dwn. Early and rapid gains are usually the mst ecnmical, and sufficient prtein t permit this type f grwth shuld be made available. It is well t bear in mind, hwever, that prtein is usually the mst expensive nutrient item, and the feeding f mre than is required is rarely ecnmical. In pregnancy, the cw requires additinal prtein t build the bdy f her calf, and in lactatin the requirement is even greater t prvide the large amunt f prtein in the milk. Sme animal species (e.g., pultry and swine) are very exacting in their requirement fr specific "high-quality" prteins. The bacteria in the cw's rumen are able t manufacture gd-quality prtein frm pr-quality prtein in the feed and, t sme extent, frm certain ther nitrgen-cntaining substances which are nt prteins. Fr example, the chemical substance urea can be used t replace a limited prtin f the prtein in cattle ratins. Practically the nly cnsideratin in prtein-carrying feeds fr cattle is the digestibility f the prtein cntained, the prprtin f the prtein which is digestible varying frm ne feed t anther. FAT Nt all the fat in milk cmes frm fat in the feed, much f it being made frm the carbhydrate prtin. Nevertheless, the amunt f fat in the ratin des have an influence upn health and prductin. The cncentrate prtin f the ratin shuld cntain a minimum f 3.0% fat. While nt a cmmn prblem, excessive amunts f fat (ver 6%) in the ratin may cause digestive upsets and scurs. 23

26 VITAMINS Vitamins are a special class f nutrients required by animals in amunts which are very small in cmparisn with carbhydrates and prteins. Nevertheless, their presence is essential fr gd health and prductin. The many vitamins required have individual functins t perfrm but, in general, they can be described as regulatrs f bdy prcesses. Only tw vitamins, A and D, require special attentin in cattle feeding. The rumen bacteria manufacture vitamin K and all the vitamins f the B grup, and thus an utside surce f these is nt required after the first 2 mnths f life. Prir t this, the calf btains these vitamins frm milk. There is n evidence that supplements f vitamin E are required by dairy cattle n usual ratins. Vitamin A Vitamin A is btained frm the feed in the frm f cartene, a yellw-clred material which the animal changes int clrless vitamin A within its bdy. Sme f the vitamin A, the surplus ver the cw's requirement fr its wn bdy activities, is stred in the liver and the bdy fat and secreted in the milk. Variable amunts f unchanged cartene als ccur in these places, giving the yellw clr t bdy fat and milk fat. This vitamin is required fr grwth, fr visin, fr the maintenance f healthy cnditins in the tissues f the digestive tract, the respiratry rgans and the eyes, and fr successful reprductin and lactatin. Shrtages f vitamin A will cause pr grwth, and extreme deficiencies will lead t night blindness, sre eyes, staggering, pr muscular cntrl, and reprductive trubles. Mre cmmn than marked shrtages are slight r brderline deficiencies causing lwered perfrmance in grwth, lactatin, and reprductin. The cmmn surce f cartene fr cattle is green plant material. It is fund abundantly in fresh pasture, and the yunger and leafier the grwth, the higher the cartene cntent. Under similar cnditins clvers and alfalfa better surces than grasses. Dried-up pasture grwth is very lw in cartene and sun-cured hay cntains less than the freshly cut crp since expsure f the drying plant material t sunshine and air readily destrys cartene. The newer methds fr the barn-drying f hay usually yield hay much higher in cartene than field-curing, since lng expsure t sunlight is avided. A gradual destructin f cartene ccurs in hay during strage in the mw. When carefully dne, the making f silage frm pasture and hay crps will f the cartene in as a are preserve gd amunts the crps. The green clr f hays and silages can be used rugh guide t their value as cartene surces, althugh the green clr itself is nt cartene. Cartene is fund als in yellw crn, and the feeding f crn grain r crn and cb meal will, therefre, make a cntributin t ttal vitamin A intake. 24

27 The ability f cattle t stre sme f the vitamin A surplus during perids f excess intake frm excellent pasture is very valuable in assisting them thrugh perids f lw cartene intake, such as drught perids r late winter. Supplementary vitamin A may be supplied t calves by dry r ily preparatins. Fish liver ils, especially thse f lw ptency, shuld nt be used as supplements fr milking cws but dry preparatins are satisfactry when a supplement is required by lder cattle. Vitamin D Grwing animals require vitamin D fr the frmatin f strng bnes and teeth and adult animals require it fr maintaining these structures. The minerals calcium and phsphrus, which frm the majr prtin f hard bne structure, are nt used and depsited prperly in the absence f adequate vitamin D. A deficiency f vitamin D results in the cnditin f rickets in calves, the symptms f which include swllen jints, lameness, and, in later stages, decreased grwth, dragging f hind feet, and bending r even fractures in bnes. Vitamin D is btained rdinarily by cattle in tw ways: thrugh expsure t sunlight, which frms the vitamin in the bdy, and thrugh feed. Sun-cured plant material cntains vitamin D prduced thrugh the actin f the sun's rays. It shuld be nted that methds f hay-drying which avid expsure t sunlight result in higher cartene retentin but, at the same time, prevent the frmatin f vitamin D in the hay. Similarly, frage preserved as silage cntains little r n vitamin D. Calves, especialy thse kept indrs, require a vitamin D additin in the frm f a dry D supplement mixed with the cncentrate. MINERALS Of the numerus minerals knwn t be essential fr dairy cattle, many are present in the usual feeds in ample amunts, and usually nly calcium, phsphrus, salt (sdium chlride), idine, and cbalt require special attentin. The use f supplements t supply minerals ther than these cannt be recmmended at present fr general use in Canada despite the pssibility that deficiencies in sme ther trace minerals may ccur in certain regins. Calcium and phsphrus Calcium and phsphrus are discussed tgether since their utilizatin in the bdy is related, and in sme f the supplementary surces they ccur tgether. They are the main mineral cnstituents f bnes and teeth, and the demand fr them is very great during grwth and pregnancy t permit the manufacture f new bny structures. Since milk is very rich in bth calcium and phsphrus, cnsiderable additinal supplies are required during lactatin. 25

28 Insufficient supplies f either r bth f these minerals will cause defects in bnes resembling thse described fr vitamin D deficiency. Serius phsphrus shrtages in ratins give rise t sme ther symptms such as a decrease in appetite and, as the deficiency prgresses, a "depraved" appetite shwn by a desire t chew bnes, wd, dirt, etc. Phsphrus is als an essential mineral fr nrmal reprductive perfrmance in the female. Many sils are deficient in phsphrus, and feeds grwn theren are crrespndingly lw in this mineral. Cattle ratins, therefre, mst frequently shw greater deficiency in phsphrus than in calcium. Frages are pr surces f phsphrus, grains and seeds being better. The latter are lw in calcium, whereas frages are better but variable, legumes being much richer in calcium than are grasses. Yung calves receive adequate amunts f calcium and phsphrus frm milk. Deficiencies f calcium and phsphrus are vercme by supplemental feeding f such prducts as bne meal, dicalcium phsphate, mncalcium phsphate and deflurinated rck phsphates. Disdium phsphate supplies phsphrus nly, whereas limestne prvides calcium nly. Varius trade names are applied t these prducts by manufacturers. The amunts and prprtins f the supplements t be fed depend smewhat upn the ther ratin ingredients, especially the nature and amunt f the rughage. The best prcedure is t include 1% salt and 1 2% f mineral supplement in the grain mixture and in additin allw the animals free access t a mineral-salt mixture in a separate bx. Mst cmmercial mixed cncentrates cntain supplementary minerals and it is nt necessary t mix in any additinal mineral. When feeding these cncentrates, hwever, it is still wise t allw the animals free access t a mineral mixture. Salt, idine and cbalt Cmmn salt (sdium chlride) serves many functins. It aids in milk prductin and serves t imprve the palatability f the ratin and t stimulate the appetite. Idine, althugh required in very small amunts, is a very vital mineral, essential fr the activity f the thyrid gland which is the master cntrl fr all bdy prcesses. Deficiency f idine is indicated when calves are brn with giter r "thick neck" A supplement is recmmended fr many regins, and the mst cnvenient and satisfactry supplement is idized salt. Crps in sme areas f Canada are lw in cbalt, and cattle feeding n them may nt receive enugh f this mineral unless a supplement is fed. A deficiency leads t unthrifty, listless animals which shw gradual lss f appetite, weight lss, rugh cats, and anemia. A depraved appetite similar t that f phsphrus deficiency may develp and reprductive trubles may be encuntered. 26

29 FIGURE 3 A simply cnstructed, weather-prtected salt and mineral bx (see Plan 2163, Canada Plan Service) 100 cm The small amunt f supplementary cbalt required can be supplied best in the frm f cbaltized salt. Its use is recmmended fr all dairy cattle. The cbalt-idized salt may be mixed with cncentrates at the 1% level and/r placed in a cvered bx in the yard r pasture field with the ther minerals. It shuld be brne in mind that the clr f salt blcks cntaining idine (red-brwn) and cbalt (blue r purple) is due t added clring substances and nt t the trace minerals themselves. The fact that idized and cbaltized lse salt may nt be clred des nt make it Mineral supplements and mixtures inferir nutritinally. Varius cmbinatins f the suggested calcium and phsphrus supplements and salt may be used t meet particular needs. Sme suggested mixtures are given belw: A. 67 kg dicalcium phsphate, 33 kg cbalt-idized salt. B. 50 kg dicalcium phsphate, 25 kg mncalcium phsphate, 25 kg cbalt-idized salt. 27