Group Title: Genetic and environmental factors associated with milk yield in beef cattle /
Title: Genetic and environmental factors associated with milk yield in beef cattle
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Permanent Link: http://ufdc.ufl.edu/UF00097665/00001
 Material Information
Title: Genetic and environmental factors associated with milk yield in beef cattle
Physical Description: 93 leaves : ill. ; 28 cm.
Language: English
Creator: Dickey, James Ronald, 1934-
Publication Date: 1971
Copyright Date: 1971
 Subjects
Subject: Milk   ( lcsh )
Beef cattle   ( lcsh )
Cattle -- Breeding   ( lcsh )
Animal Science thesis Ph. D
Dissertations, Academic -- Animal Science -- UF
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Thesis: Thesis (Ph. D.)--University of Florida, 1971.
Bibliography: Includes bibliographical references (leaves 83-91).
Additional Physical Form: Also available on World Wide Web
General Note: Typescript.
General Note: Vita.
Statement of Responsibility: by James Ronald Dickey.
 Record Information
Bibliographic ID: UF00097665
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000405716
oclc - 37704240
notis - ACF1958

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Ill 1 L E F I .-'.171 LL















Jam:z 1.j:nald Emm-;


I'lall CH.51T OF 1 LORID










.- i.- i'.~ LEDGUNT


The hLuthor .' !E hc5 re cp. 0pess h~h scl:- ~e appFr;-;i iann







toCC Dr.:P .'ari Foger, il; rnr r.. Wind Dr Do l E. T ranke~



co-ch serirn- n. ofD pr. C, e-r-a~, coni-ntcrt -e for -ir Co. neel'








para din of th~is dissertation



r..-r. ered by Dr. .4. C.\.'.1 rsick.n Dr~i J.r C r lennic, Dr. l~rri'. H










san ceui. perso nnel n d fel- r dut s d::-s~ duranc ;ou e ..eh; tl.oni i


ofarl dat .i .. ad-n E --:1 dged ':.it >.: r t a k T e sli











T.-.P.LE OF~ CON;:~TENT


Page


, .C Ni~c''.' LEDG: IE:D.:T5

LIST OF~ T .r.LES

LIST OjF ..FFEN~DI; T.1.LES 1

LIS~ OF~ FIGU RES -5

.-. E 5TR .: T i >

1 1!TRODU CTIONI 1

Li TERA-T URE P~.E11EW 3

E:~lnnviro metal Fjctors jnd Fhi-rot?pic

Geneic~l Studi-s 14





F.1to rialsT 2!
Frocdur. -,23




Mc-ritj blitrr , and Ri p r sbil ity ;7
H..r-it bt~l it -, san r nF tic, 'i-.e not~r ,pl
r,nd E n.lron mer-r ta l '_o rre I;ltic~n s 31


Efecitr 01i Illik Yi eld b,-t~ the




P'E5;UL'TS .-.N~ID DIS i.FSSIO -13

Et.-tr.-1 n--I : or; l Eiifects I M.ilk 'I' l; d11





Pa ge


Genetic, Phe~ncr,typic, and
E nv i ro.nme ntal C orrelation
Coefficients 49
Genrtic Co.Lriince hnd Direct
Effects oi :.111k Yield Estmated~r
by the Indujrect Recaprocal Daughter-
Dajm Corre-lanron 7.1ethod 55
summarv 64

.APPENDIX 69

LITERATURE CITED '83

BIOCRAPH~iCA L SEETCH 92













LIST OF T 8LE~S


T :blt PaPe

1. : s t e d .i n i si s .1 ~ ..*ar rian ce 1'9

1.Sratistical calcul~rtions to obtain jump ofi
squajres foi-rli the nesd anly:ses. of \arxance 30

3. N'~Ested n al.sC i.o i r inc e and c e..ari ence 3



4 Estinates ofa hrrirtbilityr and. repea absht;


I:i-ld wri gr;.;r. Itraits of thej .'"ulgu and



SCoeffici-ntr ofi ien-tic, pheniot-ypii ind

-. er ge miljk .ield ilnd :ral.rh tr.rits
ofi uset .:Agjr ind Herefordd co-..S 50

C' Coefficie ~ns of aireci iProca l d"'u hter-~d.'m
phetnot yp c' urrelat o~in be-:~t ien ti'TT:1rag
mrilk --lerld and ill trsits of the ngue and
Herefcord co...se so

8. C'otifficient ;f stindird Pirtial ilnd partial
rit3r-sioin of dsughrer tr;;te on a.erage
Ilifetun.r e m-i-lk; ?iilld ; the~ ."l:r~u and
He~re ocdJ damj 58



i eral.e~ mili ;cld and gra. rh traits6 of the
xr-nguE an-d Herefo~rd CG'.=.' b3













LIST OF APPENDIX T.;BLE~S


Table pay~

IASubclasi men~sn for rn21k *,iild of AnlEu
cowvs 70

1A -ubelj5 mec~an for milb. ineld of -i Hreford
cowas 7

3A Lasjt-square-s anali-sin of \arrance of
rnilb yield for the Acngu co.v.s 72

4ALctast-squares rtna., conjtants ind
standard trroirs fo~r ma~lk ,-ield of the,
Angus cows 73

5A Least-squares anilysij of --arance for
rnalk ; it d of th~e Hcjre ford cow.rs 7-1

6.-A Le st -sq ae mea;5Ii n, const ant- anld
jtindard trroirs for milb ;irld of th-e
Hererford ~cow.=.' 75

TA ?Jeasn and standard errors for the
contanuous vasriibes Incluided In the
en aronmentalnr j analyses of the Anguss
and He rr fo:-d coo.vs 70

SAi Num~e r ofl lacjtation? by. age of C3r:
an~d breed 77

IGAr~ Nete naly9Se of' -.aranceC for milk
yicld recards of the Angue and Hereford
cows 5.

1A Le j t- s quajres ne sted jrnal , ses of s ire
*.arijracce a.*1thin rig~in o co.i for each
co-=i. t rsit of th,.e l Anus I nd He reiford co.*.'s 79

lA Components of i va r iance and c o.sriance fo~r
ji r ag~e rcilk 1.15ld anC ic..*. gro*...Th tra1 ts of
thei Angus and Helrefo~rd cov~.* 81








Table


Page


12A 1.1eans, standard dev.itnons and coefiielnts
of v.aristion for ave rage minlk~ Iweld and
gro.=.th trrits of 163 A'ngus and 137
He re o rd c ov.s~ 82












LIST OF~ FIGURES



Figulre Pa ge

1. Reclat ionabi~p ~et .e n ioffs pr ing darn
and m rtern l ;randarn 35

2. Effect of cov. age o~n milr y'ield 412





."-.bstract of Dis e1rtati.:.n Pre ented to the G~rJdu ite Counc il of the
University of Florida in Part~ial Fuilfillment of thte Requirementst
for the- Degree' of Doctor of Philosophyv




GEjE TIC AT',D EN'~.'IROlj] 1ENjTAL; F."CTOR5
ASSCSCIATED WIT'H f.11LK HiELD
1IN EE`EF CATTLE








JramelLS Ronild Dulckey)






Chairman Lla~r.in Koir r
Co-cha-irmsrn: Dornald E. Frank-
I.lajor Depairtur~ent- .:4mmal Sc~rerce


Th tia blect~i' I -. of t his s t udyl i.*eri t o et imates en*i. i ro nme ntral


cflects o. milk pe~ld ofi b-ef cov.r, to- eSt~rr.!itv Ijeneitii paramters~

as s-sted ..th milk: yield~ ,andl can, gro-..th trrais and tc et--imate

the direct effecits of average; bletimc: rr!ilk fiel c~r. all trjits




I liik yield d3ta (th. rnclan ofi thr:- .. ithin lactation o.brer-

;.rljn; Oitt ained by the ialf-nurstr m method sftE~r an~ avers: 16-br

-eparatic~n) -.*.*ere~ recorded in 19093 ,and 1970~i for 262? anid 201l lactatio~n ,




b. 3.9 sire-. The~ data **.*erre ar~il!zed b rth least--=quarest n-.ethod

to ce~stir te n.ironrrl~- entalS rieffcs. Oth-in each breed.j Th-r Angus

drats -. re idl iu ted for t he- effeti of co-.\ are (P<.01) ;lnd th-e effect

1%i








of bex of cTall n1urse (P<.01). Hcreford mJlk viold data I..v-er

adjusted for the effe~ct ofi cov. age (P<.05). Thc co.F grow..th

traits, birth *eight, '.Lan ng ceight, '-Leaning grade, ;earling

***eight and 32-month <*.eight -..ere obtaine-d from~ the station

records.

The adjusted milk I,icld data of each bred -nere su~bjtcted

to se parate hnalyou- F of .i j r~ian to obtain heritabilit) and re peatability

es~tlmaters by- the~ int ra clas s -c or r elation meth d. B~r-ritabilrity of

single lacttiron lo-hr msilk yield records overs est;-- mat.-i tob

0. 10-. 15 and 0. 03+. 21, re s peti-.-ely, fir the Angus and He record

So.:os. C or re sondj ngp estl ma~te of r c pe t ability !eri I.2 Z-.10(

aind 0.~40+.00 repectl-.ely..

~11111-.yzeld records (orse or .~.oc In nun-aber) .*;ere averaged

for iachi cov.~ to obtain a-.rige milk yieild Iper iov:. .4.:erage milk

:,icld and the c~o. gro*.Lh traits .'.'er suE~~bjected to analyses of

.rjance andCo.anance t3 obtain comrponec~ts for etcimalting

he ritabi1ity and l-th genetic, p~he notyic and en*:ironrnen al~ Corre lj[ion

coeffic;iensts b the hal-6i b m~ethod. He;rltablitt- esjtimajte for

avera,-c mlk ,ir-ldlbirth -.eightl, .*.*eaning ..-epight, -..caning gradF,

*,earling ..verght jnd 32-mont~h ~.~lh.eght :.re 0.1-1+;. 0,0. 50+. 33,




.ineus co-.:s and 0.13+. J3, O ;Ji .37 0. 04-.32, 0.71-c. ~.7, 1. 46+

3; and 0i.0 SO :, rF speccively, fo~r the Hereford cowrs. C oeffic itnt s

of corre-lation bet-.vee-n mill. !cld jrnd the- iabov gros.th traits,







re-spcccr-.-ely, *.i.ere- :xv follo*. 5 from the .Angus data: 0.8 0. 53,

0. -17+0. TS, ". 394 2. 23, 1. 22+1. On and 1. 98+1. 60 for genetic correlations;

i. I3r0. 09l, 0!. 054. Or, -.01+0.01i, 3. 11 0. 05 and 0.ll1,0.05 fojr pheno-

r)'' pc correlations; and -.10+0. ",, -. 10+0. 5, -. 51+0. 44, -, 26+

0.I .15 an -. 076. 21 for en.i ~ronm~.:nt 5l c oTrreltionsliC. For the


Hei ref- ore corres ~~~ponlri ng c oefficie~ nt s .*.*..r -. 7 il.1I 1, -r,.75+

25. 9 1, -1. 45+1. i0, -. 34+0. 71 anid -. 02,+0. 77 fori s..netic correlation,

-. 07+ 0. OT;, -.05+0!. 03, 1. 05+0. 11, 03. Ot + 0. 6-, an~d 0. 11-0. L1 for


phenotypirc co~rrclstions, jnd 03. 12+'.n0, 0.47+t0. 2.2, i.041+0.80,




.'-n I nd ir iecr reci proca "l daugl 5-t ir da- ;cor relit ion me th jd

*. ar de'. cloped to i imasls. 5cn tic coj.a~-:ar.iar- c b~r et :en res11,i~lkiel




l ifE time mriilk ,iel 1 n sll t r ai t There esjtimae-F .;...r. obtji iedd




g renti~c co. r i nces bet: ... en ascira- m i ilk- ;~i.:1di .in tJhe g r o..Th~

traits, *.1anin; ....ight, ;-..a.n r d ,7w rln g t.n


month ;..ght '.~c-re 0.01,, 0. -5., -. 21 and ?. 12, r.. p ccl.le...l fo~r the


.'.nguf ~Co.s :Ind -. 07, -.olI 0.01 andI -. 47, riespecjit *.el, for the+

Hc-reford con'.. Estima~tes 3f the direcSt effectse of a. rag.:: life~tine




? iarl~in liht and~ ;12l-month: e.~ight, -xpre-ssd as stjndard prrtiil

r.-grssion co.:ffici.n~s nts, *rt 0i. 1, 07.'5, 0).0r., 0.1 5; nd h. 14,







0. 22, resPectr. ly, for the- He ri- ord ior.*.s. Corrisponding partial

regression coefficients .er- 0. 1-1, 7. 99, 0. 05, 19. 00 and 7. 14,

for theF Artgus.and -. 30, :. S9, 0. 25, 11. 98 and 13. 35 for the Hereford.













INTRODUCTIONN


f lilk, ,, .:-ld 1j conlsti..re to bt the~ most imp~;ortjlnt fctor

sffectilng p~re-.in lnin grc-.:.rbi rate ol bIEef Catle. Fe sidual effectf

ofi malkl yleld .jn post~-'.ea.ing~ trrait have' mis bi.-n ric~mon trate].

Ex:p l~. I rmr~tal evienc of1I'~ thi ~e ge n,:tic .-usoc~iation bet*.vicen

mnilkk ne,:id and~ gro-s~.th ti.r-.us In beef~ ca~ttl is5 Ilmit. 3. Cuirrent




arTe riot c~ornsiitent ladd ii n.-,t -uppoirt thr ..xiste-nc.. :1 3 siign~f~icsnn




i ndli a t r, of ,ai j rlcrr:e le ne ric i relrnonhi p bet.=.ee n Ir n Iter n-

xlbilit*, and pri?.'.er~ing Lr,-.*.th In II.:-refocrdi and Drahm~iran *: Shortholrn

esttle hi5 beeni reported. oe:pclfl; genitii stlidy i5 necdedI~




tr i~ts in? b,-ef cattle~. Efici~cnt ectorl-~. .-s of genetic praramecters

x i s iai1ted -i t h milk. toold~ i I i in t i cat tle- onoa help L to~r, .- .aluate

Cljrr..nt selecction; progSr jrre.




the: rrnt;irr e nt al i an it i ons in :sihich b ci i little IP Irform ha ~--

cont ributed to liir it irng .sniirmal numbrst f or ;fficint gcntic

anlyls Uili-atl,io of he~ cilf-njirsl;~inc mthod mslesp pass ble








the rapid collection of malt ,reld data ion large numbers of co-a-s

mamirainedl under pasture conditrions This methoJd .=.as used to

collect data for anal*, ss repoirtedn ~Intis study.

The objecti.es of hi stud: --.cTF to eStimater em..ironrlental

cffects on rr-.l1k yicld of beef co*. j, toa estim!te gcnetjc pariimete rs

assoclhted :*.*ltih mfilk j-ield~ andj CO'. g~ro Th trairs and- to estunatet

the direct I.ffects of a'.'erage l~ietlme mzlk ;-eld ojn all traits

studied.













LITERAiTURE REVIEW


E n: rann-iental F~actors And Phcnot,*p~ic ~s c.: iation





milk ,-jeld of bes~i ca~ttle. Go.i..n (1718s) and Cole and .Johane~son

(1933) repurctd a-.c age no -lk ,aield in .'ngSL coo~.3 :.hlich ranged

from 1,0 <. o 15-1 pou d p r l laton. Since thci e carl, stidies.

much- .; ork: )-. been ..ondu~ctd to define the~ plies-ot, plc rciL~ion-

sh~ip= bcrloc:r :n mili:.;>cid and the factor; .=hich are either affeterd

TM. Or ;1- n l :ild Th c.1-liv imp:-r r r i ce of r;In-~il ic con*~- nIml ior,

and ~t he r 4o r e atl nut: i llr ielnce t p: re-- e.- ni. ..:.::1 gi ;r. thI v s dej mon -

str ated b:. ~ 1j.r~ ind Bl act- ( i4 1) Slrmple cor~r el.- tions be rr. *.en

:7.er agr dail: qrin (.IADG'i s and the thrce rntrati.e comiponcents.,

riilk. c.:.n-umptioi n grain Gunsu mptioi n ,an-d Iia, con Pson-.ption~ **.ere

ii 5.2 0. -l, .ard 0. it, rcjspect1''l.e., Euggesting that milk cojnsum~ption




The~ depcnden,- c of' ilf ro.* ~..th, i., mlilk isldj '.-0 irndicatedc

b." Dre ;.r,, Erj.* r0 and Hunesi (18.9)) ,and b ]"e-.ille (190.2) **.ho




caligai on he ain' mih *, id ;c. 11.: (19t.21 re ort cd tee.'er










oni Lo.-;.r prinns ofi nutrition, Indicatin;* less dependence~ of calf


gain on mnilk supFpl. as oIUt rition iroipro..:es. A positive phenot.,plc

rrelatins hip btcl.e c brii-co-s. mnilk~ :ie~ll- and pre=.*:.--anin- calf


gro~.:tlh has~ been indicated b, thi- jlmlpli correlation5 v. ported

In~ numirous Itudies f"Ifford, 1953 Idens, !o00. Cjld-...ell, 1902';

Ide*.Ille, 1902' Pope et al 196"., Ho. es, 1961, Ch~ristiian Hauser-

ind Chapman,. 1965b kElrtt, Ilaiasn and R~iggs, 1Ci05: Tot~usek and

Arne~tt. 190t5, Schs..ulbt et al.., 1960, W\1striilnd and Piggs, 190.

I.1elton it et 1Jool Gleddici and p,.c-g 1908.Putldge, PEoblnsonn




c or relation estiinm~ate fromn thr si studi as raruLed fromi 0i.0 C.I o

~. 5; ..-ith an on-..erighted mean of I:. -19. Thr mu~tuil depe~nden;e




position of the cattl studied ind fcnotyp ~ ~.. Ithin breed-r :*.ere su4-

gstSe d i factors i n f! unci n g thes i or relatiiion esi ma rte Hlilk




monthsi of lacit:tionl thani- justt prior to *.; ia~l;n.

A por'tion .:.f the .*.eight d-iffe~ren; es presentl 't :-eaningl

trinds to be caried.~ hr~~ough to slauht r thereby aff. i~ :cit~ilg Iionolmic

:'a Iu`. FL de I~ nce~ suget !~; thatli calve rtcor--ul~t thei mosljt m~ ik~ in




a' compa~red. to iil.'ic reici'l~lin [;1 1 milk. TJes*111-- it al. (1902)

reported simpile iorr.:lar-ions b~~..:1- -nmilk ,lwi-d andr i,rige daily







gain c~n Etoickr test~, a.-:erage dsil! :ain on fartenn!g test, .:eight

1-'er cla. of age ait slraughtcr andl sljughtcr grarde to bc 0.12, -17

Oj "). jd 0.5', res ,,pect;. .'l:.. Slrn-l ple~ correlanlone bct .*.veen eali




*.*.ere fund tc. bt 0. 55 and 0i 3-, respecti-.ely, by Cild..*e~ll (1967).

Cook~ :er al ( 1912) repFo rte negate c ~or rellatin c st -imtes ofi -.O, i

-.1 iand -. 70 etC[.'. een. ai~lk *Ij l- d ofi 1.1ilkinrg Short horn ;,clco... andl three







in .-:*,ing digree-, .in~ong those ha*.*2ng been ..*ll docrurnenteeld in~









not bei ng .i gn ificant, re io ;. 3 s ize ea rl S re.*..th r-r of E C oiIi... `.e

ofi ialf ind eshi b~irth ecight.

.1 b~riefT descrript~n ~ rio of oe oi th: mo~re prromrincntt earl,




their resullrs ..hlch supportt thc aboveL-mnnlS l d-c efctir~ s. Clicord

(1i -' : lir ud: ng m~ill- i. 1eld a Ird, a i f;~: Istcd facl t.:rs a n 57 H er r foird,

12 .-r~.ngus nd 12. She..rthornn lactation; estimaatedl 8 -rac~ntl. a ir-.erag






froml1 th~ flirt to th eighth mo~nth ?llkye d .i ssg ifc n




m-ronth. Cor'relat~ion Lc;ifiicints~ =.rer 0. 5?, 0. .-*?, i. 53 sand





0. 55, respectively. Giffo~rd pointed out that other factors such

as "mrotheriing'* and gene~tlC Iinluen1ce mary bre..C beei partly res-

pen sible f or t hIse cor relations. Call capacity wa~s conJidered a

]Irmitine factor on m-ilk yield ofr nigh producing cov.-.s during th~e

first r0 weeks of lactation. Gleddle and BErg (19~65) ilso~ reported

c xl capaceity as a limlit rng fct ro r i n earl l;Iac ta i on. NevIlle1 I (1962)

and Christijn, Hiuser, aind Chapmajn (19t,5b) failed to iind this

limiitation du~e to young jrnjll calves.

O:-.r a 2-s,-r period Dre. .r *,-, Bro*.vn anrd Hone s (1959)

cstimated~."". milk ,iel in : 48 lact;tns of .-ntgue .o--.s. Daily milk


yielId co~llectio:ns ma~dF during ther first, third snd sixthi mon~ith of

lactation averaged 14. 1+".. ", 16.0". 9. and'j 10+. 5 poun~lds, res-

pecti.ely. Co...'s p'ingg th.: mostr rrilk te~ndcd to~ bri. superiorr




call. TIh: effect ofi calf birth- *.v.eight o'n m~lk yield .. as positie

butr signifiic-nt only Io thle thiird n-roonth. Hc:,n (1960) founr d a

;Ig~nii cant correlatrio b-:t.':een birth ...-eght of cal ind milk Syild

ofI 24 .11rlcanlde r c . 5, ~...-e reas no signific~a n lffect as obse~rved~

in Herreford little by Christiian, Hauserr ;rd Chapma-ln (lot5b).

I.hlkl~ pro'dlction in 115 Herefo~rd co.-.j .*..ne lho*:.n by

fle . Ile (1902j) to va ry v.at l c .' l of nu r ition. .19 mea jsure~d b~y

th calf~. Ii- nutr s in n,e tho d t ne .?- month mi lk yi1 ld esi ma tes~ ..*ere

S52.0, 2,504~ and 1,944l po'nd., respe~c;'cti-el for icows on hibh,

me- amandto..' utrtioal e.*ls.CildweC1! ll 162) ElludYingB rrilk









c..n- s :st '0, CO, 90, 130 an~d '50 dajs of lictation L'au.nd highest

*,itlds In rthe ..lr~tus ~co=..s. Fe~ak produ~cts..o .as r.:achedl in rhe

first monj~th of lactitionn follo ved b, a slo-: decliin.: lintil thc: 180th

di;y. -fter which h thc d:Claneu '.*as more raipid. Co*.-. -;ght ihinge







Pope. er il. (lsrl?) reportedj findings fromn milk produiitction

istj oji~ n 7.00 beef c.*:s .:.-r a 3- r period,~ have-.er, n:~rn t of thy

c.:.rrrelatiions~ rep~orterd .*ere bis-d on: datai fromrl -19 -yr-old

ii'Co-.*;s Cilrrelations1 bet:-.eenl 2-1-brh on.1lk ield, obtajined by, th_












as~ c:i i ion? of~ bat h ... eiiht ** irh rnilk .il , asI s rliqhtl;. pos;itl:ve-,

Un osgiiaa.L'.'e1 of i ujpplLn-l.- at ii ~ ;10 .eason ig-















1.ct~e;.Th.c anei groups :-.eraged I. 5, ;.1 I nd; 7. pounds.

r es p.:Ci T ..- l lrl SLP Tt rbe ~l i rote . ihr La repo I rl:~-ted i omi;para ible







1962; Nclso~n, FEurr and? Velaso. 1961,; Furr and r!Flson. 1961;

H~o'..eS. 1961, and Detsct~her, Whitieman and- 1','ebb, 197~0).

F.lilk yie-ld for 1;5 da;s *.aE i-stima~ted to be- r:L, ;94 and

5;?1 kg~ for 15 .'ngus. 15 Chalrolais aind 15 Hereford cowrs. repetvl




jffected bi both breed jnd 5ag ot" djnm, thereas percent betterfat

ind pecrcentl solida i.ere njt sagnif~icantly affete. 4slgh ml

:yield ad.antage ic~r ~amf nuirrint male cal*.ej -a non--ignificiant.

Millk ,ield deiclinpd in all breeds a- lactation: jd-.sr nced. Thie

est[ima~ted p r ti il regre asoIrn coeffiiiic rntforr dadly Ia-ilk ?ield (kg)

o~n iall atle in d-ays. -tithin each pe-riod s-tudied~ r~nged froim -.0200

(nsF ) toj -. 031 (Pi. 01).

PEreed, sr.e of darn. Inc~nth of rolltion -ind dar of




S Ga.llou.-ayi 5 .iAngus, 5 Chiarjlais : rlogue, S Angus .1 Calla~vjy

irnd E. Hereford~- ca..r --tldlcd b-:. Gledds.: and Belrg (1908). Thie

rv.e~raige mIlk ,ie;ld est~imate .-.ne 7.~'+2.3 k~g. as mea~su~red b*,

thi o:-.lvtocin-roaci inne m~ilki~ne micthoid. Mallk cojn51umptflion




fieldd declined jn s ecap:r oi 0 02 1: : per ds*,- of lactation

Tod~-d, Fltlaul-.ug ind PEiggs (1909) repor''ted e-slljtimate of




method an~ r 55- JU-rcfrd, :5 Erlitrnasn 3' T-erefojrd:-. Brahma~n,

,.5E Brhmn:.a :- -ller.:ferdl andd ---. .140, (Brahm-=n" r 1l-lreford)






co-.~,s during ApFrl and June o.Fr a 3-yr period. Yzeclds for the

breed groups r..ee -.7, 9 -1, 13 9~ I, 15 6 and 15. -1 pounds-, re5-

pect!ily-, in Apil, an~d rJ.8 .?, 12. 6, 1'.5 And 13. 6 poundsls

cc:ip~r-pectl ely in Jun,.; Age- i dar-n had i curvllini-jr eff, et on

mnilk y:ield. Pro~ductioni in~cre-ajed ;rom age : ti~o a remlr..:dF

~con etnt from- 7 to 9. ind decilincd slightly i, dram-s 10 years

31nd lder.

A" stuldy .1 milk: yield estimiated 1-sy the, ialf-nuising

n-.Ethod In ';9 aic~tatlons~ of lj3 Hertford co-:ss J .. se reported lay

Paede 190. ?JeAn m~cntil=:~ '4-hr m~ilk p?eld for the -:.ultrr

cal- ing co-"* '''-.i.js 5. 55. "', 5. j. 5. 1, 1.. 8, .~ 4 nd -1 I: kg~,

rcipectii.el, fo~r Ib.: iier throulgh thi seventh monnth. A.erage






cal bith eiht a 0 1.Yelr of record. -o-~. eighth t aind ese

ofaf sgnficnty afecedmil -iel. get ofi cor had- ;r sig-

nifacant (P-.i'1) cui. zlinear effect ,-n minjlk yield ..ith s nmaximn u m

fieldr at .5. -1 :e rs ..~f a~e Both co~.:- age and ,e~jr f reco~rdI .-.ere-

retp.--rt..d L! Da:..on, Cook-r ilnd1 l-inspp (I' 60) toi havre ign~ilijlnt




Turner. P sg d sle and E~i'ri:-d (1923) repo ited thal;t nI~lkk

*:itld of :air~. co 5 j-air d ~.:th nutrit iona l 1 .:--, butr that it

ijllo-...d i fairl; consi stentr cure ''p..i rd the~ first J fr~inths ,

thezn a de cIline .: ach month;r ~ t o appo.-~: im ratelyc ? I percent of'L" t he

prceriou,- month~r until the ind o:f lactation. Co.~-:s ir, d- .Traceid







stages of geatatiun declined more ripidly in the last 2 mornthsg

of lictation.n Similar declines witjh adr-ancine lacrtation ~...ere

reported by Cannon, Fri-a and Simns (194-2).

A liberil erain Fattenins ration fed to one of eachr of seven

sets of Jersery t'.v.ins from spprej:.2matel ; moIncrths to 21; months of

age~ redued m;!lk yelds In th-e first anid Fecond !ictati~jn as cmpared

to the ir tins ..hrjich .r;J rfed j nor mal ration (S.;an Eon, 1957).

Poor lobule-aleejlar developarlent ..as ojbse.r-.e In the fsttened

group. Pri..i-jning nutrlrtional level, as estlnmted bY ;aning

: ight, .;.as found to b.- nlegati.'ely issoclitared it milk~ !ield of

He-rford co .s 5 tudiecd by C~hristian. Hause a nd Chirpma~n (1?65b).

Utllzing **F.10st Probabtle Producing Abi.r," j. a measure of

m iterrr 1 :bl, ~it ,- of i-'r r frd o :i a'-.i ti air o 7n -= e n ing e-2 At

is a measue i5Cof pre>e.L. ningi nutr tional~ le.*el, Flingus and Erinks;

I1971) found st rong e'. Idence ofi a ne g iti \i as oi-.Iri on. Acci

effect ;s ob3er*.cd fromi S-neratin to gene-ritionn =.ith her.

';'Cjning io'ls projducing~ lo-=.r r.Leining calvecs ..ho in rurni rended

to pir~od uce hi She-r :. c aning; ca l c. H -oltz. Erb and Hodgson (1961.)

. working .. 17b dair, cattl, and- :TiClure ind Meac ham- (1968b) Irking

..ith Angus iind An~gu4 :: Herefiord little. failed to demonstratejr i

relitionship her*.se.. ~n milk; 1yield and .'.DG ojr nultr ii ional le vel in

ther co-.s' carl! life. I.1artin et il. (19t.2) reported i phenrot*pic

cojrrelat~ion of 0. 30 b~et*..eer guni fromi ti rth- to onet ;t i anld iub-








The eairly- esturnates of rnilk yo-ld ini b-ef cows .=.*ere

;btained under dsiry manigement~~ con;djitins (G~o-.-n, 1918 and

Col.. and Jo~har lssoI., 1933). Th..at is. cow~s wcre separatedt~ from~

rhen ialvecs In the first fe -. d:. of Lactstion. then hanld-r ox~lkedd

E *Icedid, 2 th sa e m nne asdaiy c ws. Cil .*.?s v.*e~re

usuall*,-. rsised on nr-lse c=.rs. Thcse- dairy ransagei~:nset condjtions

jre not no~rm~-al for thet typic al rhn g beefi co\ thriif-ore, the-

estuna~~tes5 mlay hi-.-e liml-ited .lue:. The need- of rem:!o.ng the

callr under dair. pconditionss Clini-inates the ujual Cill eff. et on


miilk *,-i.ld iind call' L;row.t-h.

Giff r d (19-5 ?) us eid a n-lrioified ha~ir~d-rnli I lkig m-e thodr~ to

esiaemlkil.C~o "3 ;nd~ c l ie~s we-- c ruln toge.t hei r pas tIie.

* ih 1- iFe ec r o-. o ~ r~ f :l =1:: I'I '' p. r '.I''th c -ing~ th 8~Y-m!i ..aIth 1 -t -t!i on

ron th.: second and third days2 of -separjtion alternite sidie s (t*.*o;

;iu-arter s) v.ert hand~r-rnarlked~ anid thei other side suc.kl.:d b;. thez

cal rri-~irning snd ifte-rnooin.. Ther 4 m~ilk. collection for the 2

days -.*.:rei summelr-, d lj m-ai:. ;n eti mate~i ofi 21-br r.-.ilk Iie~ld.

C lve i wiE re '. ..'vi gh..d and~ r na :- ojred cac h mronth dur iinig thi 3 -da,.







c:..cept folr 1-L.'2 da:.s per me~13.1[ h. Co-3.s and cal*.*es v..=.cro pult in




of ~r~. hndm~kn~s narnn; n aftternool: n of the~ nexit d:,

O... y :ci n 11lject iun ( -10 1. i1.) ;cre a dmi ni *.<~te d beor ea .. C hl m ki n !I~ 1..







Ther oxyto~cii In-mchine milking met~hod his ba~n ujed

by se'.*eral researchers in studier of miilk ,ield iin beei cov.s.

.intrhoiny et il. (1959) and Gleddier and Derg (1968) e:-.plain thajt

the co*=. jnd ca-ll are separated, the co** Iniectesd ..Ith- o:)tocln,,

mnachnlle- jnd..'er land-mlk.ed to e-rnpt. orlider. thein aft~r j 12 -br

period the ~o... is inijectedii~ ll gin **:th oxyto cxn -nd mnilkcd to~ obtain

an estimajte of miilk produ;1d dur Ing the per lod. T hi f is j omcti mes

rcepsted afte r anjt he r l -br period to comI~plete j 'I-1-r r-,-,ill-. veld




YnaFpp andl B~lack- (19411), D~re .*r;. B3rj.-.n and liolne-

(19?}?, ;Je.ille (1062). Pope~c et al1. (L'jtd) -anid Rutledge~ (19,0)

report data here the~ cali-nursing me thol h~as beenl used to




ther techniq~~ue to bte jomeocha~~ t Il:. TheT iJ**,tlrl II-rnlcio1Jni: rrl.ljin g

mneth~odr c:i:cept th-e calf Is used to ex:trac.t the milik. Thep calf iE

..etgheid irmmedi'st--1 before 17nd1 aftir nursing to estimate rndk

yilcld by: taking the differen~ c the r..c ..:.Lights. Thie natural

stimiulu of thei Cal nEBateC [h-- neerd of oxi5toesn InJections;;

the-r~refre a step Is eliimins ted. Po~pe rt .s. Icoint out thati




r~number of cattle .*.*hl..h cin bc jl;-sce In a 'i.-enl perio~cd.

.1 : erae oral' ."I: ,iel d s t; ona~te o .Ibt a i 1ined ll frre one 1 Inortngp

collection by the~- calf-nursing method oJ n : or 3 dalys
by Nec:. i~lle (1902) to be corop:=raj Iblel to:uni fro t...Illci:








pir di; on 4 days~. The phernol,-pic correlstioni bet.t se Ini-lle :,rld

and sall eig1ht ...I-h..n rilk; iteld i.-a lsti-ansatd b:, t.~..* daily col-

letioiins on 4I di iys1 .a 0 8, as corniP~red d to 0.d0 0 77. 0.75

jnd 0.. 69! for o~ni diily collection onl -1, 3, 2 and Ids:,, respecti...'ely.

L~evi~lle and- Culllough1 (1960) I.ased thc multipllcath':e corrction~j

factor of 1. 35, obtained In a privie-u tudy.a l for oinve'rting~ 1-b--r

milk,!-ld t a 4-brbas R~tledg (197) icound thait m~orniin




ilher iam rneilk~ y.ield:~ ei rnla tes as .=.rr cbtaijne-d c~.1- r ;e:- in collecltions.


H.- reCported correlti.9on3 ofi 0~ : to 0~. 91 b't*...l~.'T total rr.11k ,-lld

o.er so-.i i- ,an rlonthly I:ol; et ions ind .ar iolss prcdict ions of tiotal

rrIsik yzeld bi--ed oni hrl-1ec collections..~

i'hc cmili-niursing methor-~ d has I;-en colrrpired- t .nr -.tions

e.. t h1 o:I:.\ ocin mahi ne mil -ln m r-athed;~r a nd theI 1- and -mIr~1Iilkin m ethodliJ-

in ise**eral frtudi-s (Ch1at*.., 196 1, Taulsck and Arnrtt, 1%65, Schiv.*olst







1970). E ftimres otrintrane b; th-e calf-nuir ing mcthiod i*.*ere usually;

la.-...L than those~j b*, the othe I; methods, h eI.. .. c. rhe **.rariaton .and

aider ofi t~e- obsertatioon bornr Ihe d fiie~rent iirnaleds .-.ere iimlar..

Thei cestimation ofi 305-diy cr tiotil lactation n milk :,ild




ma~n T o 1.mid.,, th i -,, ,.i`..:nse, etc ., ofi 1 :- r do~l, 1 =.*e i inil and

b.-ceause of thie clojse .ireementr of p~r-dlcin r-nritid







meras..rcmentjs nd factual 305-da,. m-ilk yield, ther 12rrite-d 3)stem

ha s been c ommor,1, ? J ed In t he dai r inldus try. Pre~dictiin of 305-

dj. miilk yield fromn bl-rnor.th~ly estilrr~es has bee~n recommen-rdd d

by Cannon, FryeL 91n nSm (19421), '.'n VIleck anld Henrdersojn (1961),

Singh irnd .Achir,a (1969), C~alain~e, GUI snd Achary~a (1970) an~d

Ke~o.*.r. and Va'n Week~ (19;0 jn-i 1971) based on thelaii ghl., significant

;or rel ti on s t hey f oundi~ bet .een p reIdictionls and ac Itul prod uc t ion.


Ge:netic Studiee

The stud, of genctic prarameters associated --.-zth milk~

)ield In bre i cattle has app re ntl?. been 12rnited to twio investigations

-.*. hic h dealt *. ith h; r it bilit ;. Othe rr hoave reported e st~imte ofir

repeat abilit, ..hich c an Le i on ide red thie uppe r limit of heiritabl ity.

G~~ren!etEic~l tdicef duail-p"rpose andl d.nrir, cattle haveF in~dicated




bet.cer. 0. "'0 and 0i. -10, rand thjt genetici correlations,6 be~t-*.*en

miilk yield -and beef traite s ar sligh~tl, positiive, but near zero.

E stimalites ofi he r IItablity for mr-ilk yield obtahine1d by to

d iiel~ rent mehods .*.ere 13 33 allad i.%5 fo~r Aneus, and 0.4 anjsld

07.; 7i fr Herefo~rd (Cald s.ell, 1?07). T~he 3rrt e'tima~te fo~r eaih

breed~ -.-. as 6 lc uljted b., t he int r ii ie co~r rrelat on me~thodj and *=.sr

consid.ered~ the: roi-ost re!iabl' by thu author. Christ~in, Haurer

irnd Chiprnasn (1:05;8) eirimate~d heritabiity cof mi-lkI yield to ber

0?. 50 and 0. jS b) t -., mretholdsi usng identijial ind f~raternal








He-reford twvin j. Estimates fromn t-'.-in sosurce s tend to bc larger

than- Isontv-.= in. orice.. RuitledgeS~ (197;01 Icpo~rted r,-~pcaltablit:.

Stimates~~-; bc U.*iee n Itactations~ of 0. 38+$.0 fori totil n-.ilk rield-

oer i o~.*e-n obse~r.stionj, and 0. 31. 10 :xndd 0. ';+.01l for pred elt;-d

m-ilk yieldd Lased ojn threc obse~rvations. Repe-atibility of r-nilk


yie:1d bi-t..eer. But stions bi-ile w..[i th brd g~roupiF frlrom 0. 0 to

0.;?, ..hereash thI reps~t~'latabd tycts.een oblserri.*ation tken

.. ithin tt la 's, *.* 0. 92 (Cald.= ell, 19--2) Other e:stimaites of


repea" l ablt t*, of dal!.' mnilk -.i.-d ..ithiln Lactation at beef co-~.; jre




L.lctonli at .l. (!'lt6) .and Glrddie jind BErlg (1963).

\'i'o. DrJa.-s.nm!; iid 1.:.ok (195-1) studying 163. ..lilking Short-




;intriaire c orr- Lstio~ metrhod. i.',henr the same I1rmthod ::as usecd on

j r-ducrd numbelit r ofL ilo- 12?. the Cjtin-.atei -.as 0. 1-(+0. 35. Th;-

rededd~ii eistimalte '.*.'asE attributed to rno:~r s: .Iniiforrnli ty amo:n S Cires

of hel? co.sdu toseecio l. 1, the 40I co.; r I-remo~~c

er no cosidreda r~ndn-,samle f te hrd.Usin;g the~


?Inr asiirei r;. g:-essii ino djmag ht~ .=r n dar.1..*.rith the reidu~ce numberl~

at~ ~ ~ ~ ~ ~ ~~~~li co. h eiut *.s0710 0 i~s infaitedetin- ste .''.2


art LItr i t to; mater nll ff iiit (Incil udi ng i .t3pla s In i c Gl. :t s).

..pIsttitc~ effect. Selr-cion Iinfluetnice j.id trrOr. O3the~r et[lir.ites

of hcritabil' ~it- at mik :v.~1d ofi djua- up ose ." r cattleI ''rj .7; b*.




cr Idies- I Is d the'r~l i itr l:2 ,1 iorrl i oi~ n me- tho f;~i or si n ii-, ath anl of~ h;erit bl[ it'







Thiirty estimates- of hieritablity. of m~lk~ yield In dairy

cattle take-n fromi publSi he d reports j-.era ged 0. 3b ..ith; a range

frorr,~ 0.0 toj 0. 71 (Lasleyi, 19C63). Jhnso dRedl(98

revie,. ing- prev\iojus stu~diies of miilk yieild 1.e~ritablit,- li-ted -a


range fromrr 0. 03 to 0.4 l .*.ith r-=ported standard crrorE training

fron-i I. 0-1J to 0. 05. T h: predo~~m inhnie of es t..-rnlates r e- .e.~..e d

*.c.. r bet -.t een 0 0 an1d 0. -1 0.

Re.it--'.eid cjtin-ljts ofi repe~rtablity of rnilk~ yield

brt.=.--en lactatric~ns of dair; co*..'s ranged from? 0. 13 to 0).76




Sailsizr, 1970, and '.'..rd et i1 1970). L~lost eetimates '.i.-ore

be r .\een 0i. !0 .nid 0. 60).




and vriarson be.r 1rajits in ai~r*, and dual-purpose~ ;jttlI ha*.'e

resuiiI~ltd i n inons ign ific jnt j nd in.:0in d ten t iiorr IeI scki ns i :t i s

consluded iin the re.e.:-. articl1s of Johansson (1161~), N1:ichls

and~~~~~~~~ Vire(91,adTlr(90." ligh~tly positiver S1netic

correlationr t~.et*.=ee mlllk '..ield and be--f trjits- ij Indica~ted, btt

beccuse , the- proressc~ limrtsitatio a second triit c::-:.rts ...n thet

firjt, beef tri lns arE usuaIllyl .1:.Clude.d frtral 5, lectioll programs

in dairy carttl. l~-le:.*e-.*r So1ilr, Bar-:iusianJ an aiternaik (10)








Tyleri (19-'O) in his re=.*ie.- of sc.cral Ei~uropea studies

reported .stjimatc; ojif en-e tic crri-lstion~s loate-.eenn mxlk~ yi~ld

jnd beefI traijt of dilry and duail-p~irpose cattl ..-.hich ringed from~-

-.0 to 0. 27. I.La~rtin jid Srarkenburg (19051 repo:rted genette~

co3rr1-l nation ent Irn,: r; 7 he t eat n ranilk~ ;ield jndl tost il ginl j nd fe.=d

efiii i ency;of0i. 1<.and0n.-1, respects'.vt*,, In dual-~lpzrpos ;jtle.






and rr~ilk. ';ollngl iid Cole (1905j) repo:rted genltici or relation

Istrimat-5 bett *. .n rr.lilk; *,.id jndl.sllll :i-~ rLu eftrits In djiry

..atle -.hiih rang~E d~ fromi -.6. tc.[n0. -1. I.oa~t estimaites -..eri not










11-3, F'T;'--- drneth.-d of il estImation,2 .r..:t~ ssll cor tre1 ior-1 b rt.. cd






-id dair traits H*...-*as used 1: inn tl:- nu.-.. ;t r *eseii n jted b.~r HazlEhc





(17~iL~-10 postr~ie genetic or~lrl elatin --. j :r..d usual y ~~ ;:.btiiLned t c -








in the- calculationj, causing a biasj up:=:ard. T'houg~h nOt ignalii-

csntly, diffe-rret from~l zero~, phlen~or:i pic correlatin bet-..*eenr dam'sil

produll~ct i'n and daug~ht<-r'sE sate we.re ;insistl3ntl: l ar e r than thei

rei-c;Pro iCl corr el At i ons btis. t. .r, dar!n 's -:i rc a nd d au ghlt er's pr od!uct Iion~,

thus1~ sulpport'ing'~ the '~"' preenc ;f a mat''rnal Ceff.-t. It '.r is c~onclulded

tha~t Iincluision of g~rc.:th trials in a se~lc.tson program~ \ ould6 retard


,gen,:tji progress'' an mlkr ac1id




estllmalted breeding :'aslue (E ,',' for m~ilk pr~ductionn estim;ate~d from

th..-lr par ent. Indi~cat ed- a negal5ij'. assoc;Iation of 7.5 ( <'. I S b co iet .....e

EB1R' snd ..arcss; =-2Cid *:.hile pos~itl.. ic jCrlatr on- (P<.0j5) oi 0. 11,




dr ade, roarblln~ .core~, snd conformation (Sucss et il., 1903i).

The~ genetic correlt on be~t**:een manternai l ibjibt, -nd




on he~rtitbiljity and gentilc co~rrelstlrn ~Etimi tes *<.:rc .tudjiie in




"1i.3 the maternal i-n*.iron-irnent differi-nc In m-il-ing Lr iilitl 3re




nutrient d-uring the a arl., mrc:,lh I of -r c--=l.th.* Estln:
panmeters~'~ from; pir.:rnl hlfl-sIb corliirelation rr- -h*.i.'n by




pat ceffconts100..fre o mteraleffct. W.eeas e thmt.-













I-ocl: and Clarkk (1r.,-.*) ;I...d:, Indieistd i negan-:l. e :Itiisdcitio







1,r.- H;Il. Legaite. ;nd D'illilrd (I%t. ind Hohelnb-sker, snd Brink (i' 71)

in Hcrefojrdl cattle:; Dee-: ir.d Keeni~c (1907) ;in BRIhmani x Sho~rt-







In th.: tudj. by I'ochl andJ Cl ad: !,1955c L gt (17 fud




ind~ .=eg h~t of r I1lc .















connfir .-r~c in their nigat i*~ e estjlimr711 Ij .-- to theZ ernal Inon~.b .-r o







.5 :In! -.;'' for:1 the1~ genet.~i icar I~re lation~ t1!..e l-, T.c-:. ~rre....







Th Ilarger negative estimate wa55s ttributed to the deflitionary

effect of the2 negativevr m~atErnal environmental (repOrtedl b. Alangus

and~~ Brid:s, 1971) on the o~f~fsring -daml -o.*orianci- estanahte. The y

noted that~ sim~iljr pri.ious studie; (K.*ch- snd Clark. 19I55c; Hill

tt ail., 1906. irnd Deeje nnd 1Koger, 1967) reporrtin r~egatl. eti;tmates

within the sjnme rang.e ha-.e alsoj ued daug~1'htF Tr-dam ce.arian~ce in

th~elr computations. Hohenboken and B~rinls concluded thati the

Isreer negative: estimates~ *..errej rprobably blasedJ jnd that rdy i

i..i-k genetlic antagOlj nim bf'Et*.e-e ofiSpring Ilnd rr~jttrnal effeccts

on -.i ning ".ight 's likely, perhaps In the~ ordi r of their sm-aller


nega"tive estimated, rG= -. 28.











EXiPE E l .1E NiT.:.L PRO3C EDURE~


i.1atcrils

I.lilk ,ielid d~ars i .ere collected frojm Aragu.s ilnd He record







19541, is composedd primrnan1, ofi strson~~ born car.s .i.th i portion

br~. ingS been~ purchased ;in oth,- r easi terl-n itntes as; .=:e,ilingS o~r


yeabugs Dta i.e'rer orbtaind on ll? A~ntus co-..L-< al psi rs ini

1760 nd 45in 97. .".. Lljcal of1 It.2 Angus'~ coi-.=.-s by 46 F!Tres ..-ar

o~b t rl i-ed th~r ough;iat 1.:3- or~ n.- i lacton d uIr jng ~ th r tudy. Inc-ludcd




The; He~r-i:r-for hard !r part' o a enotype- s en-.;;im~rom

!Iintractioni stud , ...hl'ich 'r ocludes i roups ofi cattle~ of tv.j rigi~ne







com Pose'-d ofi I-Pres'im'.:a.-1,- 36 percent E irooks j .1i le lineZ co-.sr

-.hlch, ..c.* e !.rasltly istestion beenl- ,:d 64 eri cent~ Montanj line




..ec.- torn- it E~rIol : ~i h r!-.a l i.: as--a l~ e

in 1952', h;lil. thi .[: 1lnts.,:s l~in ..:as intr~oduced~~ ;n 196' ind 1?6,



fr:. tise .le ~ t tto a d .-h c a.b e l r do.









during l1959 and irirni 4b paira in 100'0. Oine hundred and thirty-

so-c n Hereford co..-:s by 30 sires produlced at leaSt one refco~rd

during the 2 y-ears. F orty--fi .e II u~ht r -d-am pair s **:e-ri inc lud Ld.

The linetbre- d I.lor.ians cattle- =. re- moirC closely r'ellatd

oin the a':e~ragE- than thle Erocls.-.ille cattle. Pah-nishl ct .i1. (191,4)

reported thi I.-cri ge r--ljaionjhipF of thei hlf-Elbs In !1he :.;ontanS

linU toj b= '1. 7 rathlr then thi usual u.'5 for oIutbrr d cattle:. No0

adju--tment r.= as mad for this relajticnship,: therefore thes istimTate s

of herltabl1sty ini the~ H.-riiford catlr msy be slightly Inila-tcd.

Each ofI th- 262."angus .nd 21ij H-rde~rd mlk yilc records

is an a'.'s raget of thr.:-e; collectilons~ to~~r anllo.*ing an 1'.. irage 1-br

repsratio~n Int~r-.-I in c-arly, mid ind late lactation. The obseir-

-ationsj recorded at EiIh --o~lleio incllluded m~lilk y-ield, cailf I.eiGhL,

andsepraionintr lC. C.''.':=-enht and :asl' grade and ultlrasonc~l~

b1.:kfat -core ~..-a re.:0rJ~d. dt ... aning. TIhe pre"~'' rous :.igh't'

andr gradlEs forT ~~._o: :.-.er1 obtained fromn the srrtatin re~cords.~ Earth

.=..: right ; as not a--si labt l e- jion some ci the;. I:ldelr co--= C. T; sr. hI f *.

celln are filled '. irh rh- averl. biirth .eilght to Inlkel posslibl the

est irn ni ~ lof- pai~3ramet. re 4n: o!lving b; rth -.- IFh t. Eqcuipm- e nt uised

fo~r collection oi thc data consisted of I g~ood set of c.:rrlTT1 andl i

sCale 't-hlih II.s con--ideirerd acc ura te to thF nis res t halfi pound..

Thei anal;ses ol diti -:. .:1-e aClita'tedj I~ [lh, p..rannc! ind iquip-

rnent cl the. lin..rsity, of Flo~riada 1-at processing ce-nter.









Proce. dur ;s






Cab-er atio:nj e~r;- made inl miid .1pril, June, an-d Augusta


of 17.'j ind I 0; ro obtanlr er~!imater .s :,1ilk yie-ld ;, nearly, m~iddle-




dtscrbibed b: Dre:.vy;, 13ro -,n and Honesr-- (195T) ....-a us, ~d. Cree-s

andJ ai-F4 .er.- 1.r-aughti to~ thei pen.= and sC-parted- T itbs.-ut noonl on

then di, btfore coll-cr; jln vi dllta. Afterr I1 to 5 hurnsr of separtion,\

o! ba--. en C: andl 1 pn-,i, rhe; .:e-r.= ;irlur; ed v.irh thei o~brjecti-.o of~







:!rlr ojr iij ad ir In p tin.;~? th. C j.- 3 11 large pensli or ?i.-l t.le t ItrapS















o t:y d hit.1, rhe tr e atr -rii may, bi - cauz:ed Ir I-t c.:,slr idi r .1l












o1~11. !Jua~~l;: s!d turnei~d int... I nur;;ing c.n.ld.~e-!dlcn to1 t? io:s









W~hilv a calf *...-as bing ...elcgh..d his darn .*.*as being cut fromr th-e

co-.*. haird into the 93ame ad~Jacent nu~rsing penl. ortsxc .

call pairs- **.*ere pl.=c; d in ..ach of t**.o pe'nj. .ppr o...irna~t elyI ts- c

milnutes : r required tc. -=.igh~ jch~ iall and l located th.. Ja~m,

t he refore. th~ fi rst Pen of cal:,s u suallyll had b-=-n nujrsing~ about

10 minutes ;.he~;n the las~t co=*. .andl calf of the iecolrni p..-n ....re







ofl 10 mnullti s. hej.~c.e~r r somert group~I :.ac .separF~rjtted rerli-r dJue

t o .ji~a pre nt Ilos o suc~I~_kllsag intore st by? most :.jl. s I -:-:rcrtairy




i- 'tand I' at 20 to 2j~5 mIn ult_ F. O~bsr .edi\ Te rtion *..*as recor' lded

and cjlf .-eightt -.-as idJ";ctd up~.*.ard 0. 5 pound. Fe ach! ilbsr-




\*,'hi-n .-ucling inte re st appe ared to, be- lot sr ,nijrima, l

ni jll .. I~ec I.i of a group h..*'v *.*-r.. ,..parit..J as i :ro~up 6nd Iimme-




nursing anid post~nu~rin s .: ight .;.asr rucerdei ai th-e m-IlkF .'i-ld

estim te The lernig).t ;e:airano:n int r ial .j de ter Irnin Jl by

differ'lnce bct -:eenn th-. nurse -ouit tiin.. thc- das btlforr clllction

ind th.. pronIurs;Ing--:v igh~t time.l




a: re ..orkr d. 'The coth-ctioin3 ...c-. usually : cornpluted b=, 3boutl

11 00 .=ln, In tiimu rto pi'par e fojr thc secondl~j hajlf a the cattle to

be measiurud th..r n..xt dj\









Persolnnel nieedrd inlu~lldcd t-..*o rnen to pen, separatee ind

re. conshllil in. io.. TJ nd cajlves f or nu~Jrsn o~~~ n thc- day Lefo~:r c olle ction.




cal.1 to, the rial; one .' 3!rked th- scale gate aInd resad jd-atfitiilC! n







.:ci.-5 to the calves jlnd liter fepiiritd them.

Th.: thrl. e obs- r, tione~ .-ar3 -.-:erlo ed to obit ain on-! ob-;er -


vitionl fo~r -ich 14ct-r:io Thsci nialk yze!ld data are rlhe subjecti~






Anal-li es a nd .I.djustosents for Er.ire.n!-,nlenta Effec-tr:



The Iderntjifict,.~i on ofJ env;ironl-nr nta effects on n-.alk~ yvald

of th-- ce.. i; naportant ...ithiln itl mad, ~..ouldj be~ expe:ctedl to accounting




tis rslld, ; .;i [;Lto lii~ esi ar: ge tic parrmeters, the cllaw-, nation of

ethics c n~. traoree- i nt al i i i f= t to 3 btt in unbli as d L stIn-uat e of ; e~r ne iic


parameters ~~P .=*a ofm1- o c r. P r of th; r cnspo:rar y r iationi

*ould1~ I.< expc to~;r~ i bei rc!rnooed~ h-,: the iimp~le: v.vesilgg of rlh-



thre i th .1 t tonCia r. t n t b iu h n:1.ci i.n




i.- j..d Th mil iei ld .L t r u jct d t e i .-eg a -








.10dcll A\ w~as iise~ to Trlalize the malk ,icld records f.:.r

a ch b~rcd.




b.( J '4~ I o', ( Y, -X )+b


b ( - .. e [




.here


l'ijk = th.: dep' nd ~t '. riab le, rm!! k ii ld for th. ij t cttcn

I = thet c.i.eral l le- st-- require mP ean,

.'.* = he ffctir-: of t~E- it ',.:a;rl o record,



th


:: = thell effeC t ofTC Iithe; ~ T -paci icl C ,wa b, i L-: Conib naiolns

thh
i5 = co tri.6 ipln"ique to lCT th llacai~ O n, ii ]rlln




tth


;iik



















th,~ Ir *;a ri:Jles h... .'r,, !.!jch bla .. a-sumed~~: to be5; un il





Base on th [ut ftu :L s-q a nl*Es







ik



tht



ikl

IkII




b = the.. i.atlil linear c..4:1= no~n .~ceffi ci.:rl-t. deE--r mined for


th.. Con inu s.. - ll'~'', t .*.,- r:li: llnd ~ l i








b'~ I = the iprt .ial qu drai c rege, 1;~ sa~ a rrn co fa i.en d tr enI~: ir~ d









~.L.rthin ojrrgin in order toj r..ano.c t hii \ariatioin ..*ilch may, base


tended to- inflate the~ Ire .arlancei. The origins in the- ."r~g..Is




and 2 for ;o*** bornl lca;lly 1-iclr:-jred ornir in ; a i denti flecd 3- 1


fo~r !.1zl~e Clrt, line io--.r Irroduced-~ to Florbids L for f lilc:- ciltv

lIner -o-o.i IJ...rn lica~ll*, and 3 ifor EFrs!r lli --11 ine co--.s born


lucally.

Year of j io'..rr birth~ . *as njredl I hin ths; 9: in thie ot h-r


geneti; nal31"-` s. Par t ii l Dnonfe. r,~dang ;. ac of i co.=.- bi irth 1;nd

!r.: of co . ma';: hi s'.'s tendd toj i!;fite thi sire .irian; e; ho-..c.er,

this . is aisumred: toj be nilninul.i


T he ni 3t[d .inay s of !i j.ar~iance us ccd to: dete rr n Ie t-he




Notercd 3 al.-is ...f ..i riince -andl the 1---ir~cite statlsti.:al ca1lculations


(table 2) a.e dze.:..icsed InI 5-mad.:cor (19!5r). E'o~rlniaS~ for cilculat~ing




29



:.5sB A, +~;L k2Vic I and
k3




kl


T.LITLE 1. IJESTED i N- LYI Si O-F V7:~r. RLANC E




S:u~r~ce it 5S 7.1 EIS

Total 11-1

Origi;n O-1 SS1.15V, +, tk 0

Sires Orlgin S-O 5' IS +~ k 1'c + k?'

C7.-,. jS 5rc(ri Orqi C-S 55e_ rli ''+k

.' ithln Co j Pi-C3 SS .1S






N--






I -1






S; 1









k.~ = num"bcr af oricins~

Ni = Iloal nulmber of records




nlj = numberr of re-cords for the ;jh c ow.



OF SQUA..~ F. E5 F OF~ THE ` NEST ED~ ANA.4L'S ES OFT \'AR' lI AI E







Total5 SS L :X-iJ::l CF~




OriginSS=II i L (X..rg..-C
Stresi/rxpnSS (N .inl ..)k.) L I X .in ~...








He-ritab Int a nd v.:pe-atab la-:, c~f mllk ;-ield -- rel e~~~srtimd

L, the- iollo.in- form- ulas, resprc~l ctl, ely


h = c -'





t = ----- ---














5 ;. I c: r ast :.1. (197, 1)-



SE *






,*~~~ 2(1 11 t Iik 11 N -


/I J (Ni C), (C 1)


-iiii. llrn .bt i17nd. Ge .te P ..eis o.Eir r~. ta





C.~-:,cr i.; i tions!-:



S I i t.. teo ~ c ll ;....rg n e e e t t d as r l b e o

(.:. h e. .. .:,.5.: u- r :, I~e 2:.. .-- .: C c t~o I .:1at e re ord


ta,: :h c. .1 re.l- d h r : 2 .n u n -~ f r


-.u i s:1e recsd bl 1 n u n e oo d ,x



t -u~i a~ Ition F..- ac I.i:f ce t e rral y .1. s .. s.1in ti









coarrelition co:e fficients by a mnodi icati o n ofi t h~e orm~ub~ b. 5-.eiger

et al. (190-1). A~pre.:-.imate c~tand-irli errors fr~r Iphernot~,-p;c nd

e~;.invironmr ntal cojrrel nation CCIedici entt~ -..re calcuIlatd .l. i th


.30 k calilcubstor uslng the mcthorts pi~ire--enz. by Sube~inblere (!?i,6).




;s presF l!ente by; I:l.len lr;en (1953) ire2 -hosvn In t able 3 along -1ith

the formu~l a b., 3.v~ig r t jl. (!190-1 tar calcu~i l-etan the- k: -.;rlu for





EAOLE7 3. NESTEFD .'lN;. 'i SES O7F ;'-.Pl-JCE \ND~ COlARXI.P IANE




rSirice dl .3X ICP :J(s 15 El~i7 C




Orion O-!

5ses O ign -0 ~ 1..5 .iCP 113 '. C E' Cray +



i''ahr. ir 1 N- 15 LiiCP 1.;5 VCo.




. 1. .


thi
a = ~umb r o oo.5 11 th 1 ile.











Th:c can-~ i- :Ile,1 hnIl pu;- pr g a u:tl i zed Ir rh intr -.r i or r -?l u t ion i t


rnt; e c a d 5 i u- s n .91 ,I 60 r ei ae u ia ii*















Co. Cov

r~zC G G ,


Finen- til "~\'-1 *.m c t l a c l to : il:e~ =a s
c.-C .' tr l ib t .or..e o; u n -2 o . a 1


co re"to --a e alu .Ied b l: d F lo.n r 9 1)d c


apparently ~ ~ ~ ~ 1 aron--u comte re iI -e :-o inllatedl hei-









i : i i t it*,' Ctin l. .1,, I aiae i T11 i alre ~3l c i ince -C1 -. Il .:2use 11; reduci !l-Jon








Cenetic Covar lnce ind Direcit Effects ,;f Milk Yieldl
by thec Ind ir ecit Rlc i prTocal i- Dughlt e- n am C:,orrI-ela in 1 Alet .:Ihod



T h ; avcnvnt ional da ughrt er- dam Ir onv9 iance mecthod pr ciecnted




-:h:--In mte r njl i fce ts r re pres~ent. Koc~h anid Cr~lj < (19 -Bb, i)




thrt only th-= pattern il hafi- dib correlat;ion mie thl .: free o ,jern-

fou~~n..ling .v;r~ith mat rnal effects -+.e~r, .*orking:*.Iit~ mnaternil lly !inluern cedd

trjits.


.in jalnternath Ienethlod. patte~rn:d iiter th-e rnetho.1~ re~sented

by~ Koch snd C~lrk (195C.),;=.as d:.er~loped rio til;_, j 3::silble Joughtecr-

damlT re1latson-hIps to: IeSllan~t. qun-:ts. : prs nmeters ar~d thi- directr




















.li.*hi lh- , re~lr ut eil-ed. for : de-carnat ion r of cdii .- glll.;.r ic ~ io*.ariance









I -1


rigore 1.~ ~~~ R .:t n hi p .e ..-.IIr r; -.e n ra~r a

:Lljlnd arn. 11I '.:he e tra its I~ ll -roup t Iar : irth = c;.* i r. .r n t








r-no;r tionr. and t-.=.0 primres = gIrandain 6Fneration. T he 5

rupres cnts th rclatijn;- hip betw~.een ge-nrjtions. Trhe c-.. t r its

referred to in th-e path di sgrsm and othe rs inciludtd in; subsequent




cea~ning 'ovezgtht IS), mi'lk yzelld (4), wea~ ning gr jde (5), yearling

..-eight (6) snd 32----n10nt -.ight (;).

Tubsequenn t calculat~ions :~.cr2 madej wth the follo.rjng

assu~rnpticons: th- direct effet: oi iall birth \-.-eight on mIrlk yield

ofi the dami i.ne n.;gligible. prcntat~l snd peastnatal matsernil enviro~n-

inent, other than effectss of miilk yieldl,hid negligible. effets-i c~n

thet traits jtu~died, epiisttic effects :rere neifjligible and other

entironinenital and gen-tic effec-is \ere rando~ly Jstributed.

.i. Tp.er ageilk ..ield fo.r the 2-: r stuid., .-.va used asc an indication

of ee age li tme il *;el. ince; esti mated I lif t ime yield .;.i

utili zed in plrace of ;r~ lctioni :.iild c or respondingg to thi igrs.-.vth

trjj!, the- sLbo---c dire-~ct ffect of milk ,ield (In.) is iqusl toj the- prodluct

ofI repeatibilit*, (t) and dlirc~t effect of the Iactitlon~ yield ("rn.").l

Tha i, I =t "rn. The equat one ind procedure~ aused to
11i

obtar in c-E tnimate ofjiS gnet I:i 0. co-rianc bjet .veen n-slklll yIeld ani rIhe

gro*>th tF raits, iind th- cirec- Tt effets ~ I.il~k ;ield by, th~e indlirect

d:=ughte r-da~rrn~ me~hod, azei ;Iubsequentlr,. presentedr. Dairt h ...e i ght

..*-t not includedj ;1n rhese Ic 11,il -s dul~e toJ miss Ing data orrn r omie d-on s.

Rc~i iprocljiI~ du hi ,;r -d ar phiileno, pic c or relati on ;oeffii ci nt

:;rima~r t es **r e calculted b.t .e m l i-d :n ac r *t









triit. Theo.:rrtical ciusal com~ponents o the phenot ~pic correln tion

coeffiicji n e.Stimat--s ---oreIc dcicrrnirned by followin g all p;~ath o-









correlat en i bc;t .ee.,I mIlk~1. yi- l d (4) ind th.-- growth trails (1).



r =. h hrG4 + .5 ri5 FI n~hqirG [1)

r I = 5~ c h b1 rG- C .25"t +mb r


I qualti o~n j I lnd r ..are the~n r:du~ced b, their list compoF~n cnt

.251- a bbr and r:, h br1 r'spective-1- .~ Thesei








corii m nt II, .- la h rit *:-ic -a 1 1rom 'h be i eti i r st l u:*a i lei ii :-:i::t e of i ~



rnalk .i~e l e n gr o--,itij ..th tirai her it i it C e g eneih t rsicth co r lt ion I i








from~i the .eightedd averi cc. --tirnatesI r 1--orted by' len.11<. (190,3)

or P tt.'sad Cart--r zM (o,-,-,) and dir ct d rn ik 1.:1 tiffet


o J u htr_ m l ed(n )- -for l n iec a g trd








m = (rp 5 h ) / (1 + 5 h ) [3]


.* he-re


P PS 4 4 4 41


h; = herrstabirlt of milk vt.cl-id .stimated fromn rlhese dit-
L.,; thi intrasir, icorrcel ation mctho3 (frt.. of maitir nal


Subtirracing the c estimated last coml-pojnent froml- eachI 1ppr'o-

pri-rt c: Crr.:.-lj io n coe fficiint, cequjtio:ns i and 2 bet -sm. reducedd

eq7uaric:'n 4 anJ 5.

"r" = .5 h rGgi + m







I[5I









"rP,12i = .5 h rCCG E rl [0]

"r" =. b r. + 25m h ~ (5]


"r" "r"l 0 + (m. 5 mn l )
pil P, 1 1

= rn t (1 -] 2 ". h








Thu~s, equation to is:








b = heritabilit;, of m ll-~: -,;e L e-t~mated from t hes e data
b, thi intrJ.-.r: icorrelat~~n ion methocd.

Th. iddltr-.*e 6'1netic ceai':. nce:"' btjto.eei n mlk ;i.:1dJ and

e clh -ro~.*.h tra-it .as mri., d~ bi qujtlon ; *.**hich was.~ derl'vedC





"r" = c + rn." I4]
P' Pi


"r" i~- mi 5 1' C b. [. tu;


G4Oi 1 .Gze














P.ESUILT .--U DIS~CUSSION1


ofT ls:actaione per subelas arc-E g i e in tiible= 1:-. irnd 2.-., re -pecti-.-el,,

fori the, Angus~ 'Lnd' ITTlr ord~ ii....e Th -o elfrlat- 1-r












bl. of cirr- geo f J.alf. ifr i rsct-t lle c itionad tl c rage sep rationi

inter~~ alf .-b ~i ihe~tl. Ir: and quadIratic:ln c-it ts a..er neluded.



S.: irfi till and ciic e or 9f co.-, bothj! ~ J lie r 1Ind u drtliC ,y fe:gr iic r.t









5.1 anuid 0...) .- mor co -,le rn de rn ld n Llre r I..



sinc i herei 3! l t r ir part of tim rerl"de Ir. the pr s ntmo









AnLus cows. nulrslng bull calveIs produced i. 06 poun1Tdf m.Ore

( P <.01j) mnilk. t han t hose n ur i. ng h~e i r calv~e sr. M-_1~ton e~ al. (19!67)

ru perted ai ;1on i Ini ica ntr Inc rI iced ,21--ld in co~an nu rsing bull cal ve .

cOlford (1',5?).) 7.1elton et sl. (13r;7) an- rGleddie .and BErgy (196.9)

asso~cii ated hlgh..r mrilk; yield .; ith ti-.0 greater caPi.cu; ofi bull

ca=..sineallataio.This ;ould1 not~r br;c- evalr.luae *=.ith these,1

d als.









(P<.05~l) ind -. 01374.+. 01706 (P<.0j51, rr Rpecti*.ely, for the




.i r real l el at '. I of I : ;e ior the .*ngue ice~.*.s indi .. I: :.r ofI age

fori the Herefiord ;uve~. The.i: ei-timte .vere- obtajined b, setting

thi fic.- t dece I.lri-.e of rk.te Cur,.11inar iqusation equ il to ze ro, t hen

joloin i I io ile lt m lllml :ihilj. t igur ll ustate t 1Ui T( he

inicra,; in n-~iilk *, 1ld obser-:ed.. f~rorn ag~e 3 :r toj the mair:-:imum~

Inrjr i r, th:nr tie dc~r~ree .s; ig ad* anced. the range of co~.v

age *=.si :. to. 14~ r and .j tor 12 .r, r pF;ii cti--a-.* for th: An guei jnd




tjblat.'.1. These~ r.:rulr ir.;i in cloe agr..ern..~nt n.ith ...irk r~portedj




Cooki jnd E-~n~pp (196) snd f ciil n at il. (1C'b7) ev a lu iting ef fect





















SoJ



o/








I -i

00


\ 0
O
'J
OT


'~ ""T


Q C`


spu-c.1 ppH- im'J










of ag- as a dl.i lcret e: . Iriab h- reportedc ma..n.r ,- ld t ?to









Ci ark;, 195 i ) -.-. hich~ IugII ti hlt .-- : ii ng .;.aght .i lri.tIon art ribted~c

tor - co ag i, prol..abl; :- fun~.rl:M n .:1 the~ ic...-:1 of nalk~ irroductionn

as ha s nen r 1ll: be c ri ass..uu i nt .:)1;j.ithoug t hI- _ .'s p. g netic ~r i p it. L n al







The~ leasrt--qu re-r~ s m~-~l n rlk:?r L 01 is 5.: a+.09j pound~--




.~i Th-:5. ~icl.i s *.i : re: I;-oj. eteel incjrl: [(as ag th._ p-astial




c.= iorted b.l Dick*-~ :t -al. (1970)] tor .. Stimit 2 ~-l-lar -, l ds o 8-,i d.












that~ limi~:t- i :to.it er*. tios :sr. suall*. .,m~d ildica tors of L~otal


pr..elucti'':..n '. mj't o he ple. e: ..arc a i ,~ l









(1962), NeI~rlle (1907.') PopIe et .al. (19!63), Furr jnd Nels~on (19b1),

Ho!1..es2 (1904), ChriStiin, Hauser and Chspm;an (19b~bl, I.:eIt on

tr 3l. (lobl) Lnti To~dd, Fitnringh anrd PEiggs. (!99). Mlost other

e-,tin-iat in Eriti 3h i stlee dliif re.j --w ry little from th~is 3 =.Edy.

Hotever.~;r su~bstantial\li- ight r estrimaiite. hiave been ob,~t sned in

studlice of dual-purpose,~ dair,-befc icrssbred and Brahmasn

de ri.:?ti.e breeid;.



C~eneicr EfeCits



Hecritablht;; and RcP, istbl~ity



I.lilk !ild records ~..=.re adijus1ted for sIlnificant (P<.05)




bireed onstasnts prescnted In~ table.; -lAi jnd 6A. 'Th1 Angue~l dsta

--.re dinedfo th efec-.of se::~ f alf a~1 nd age ofi co-J., i.lile~

rth Heclii..rd iita 3 .C re on~l. adju ted lor the effect of <.0-..v i,<.-

'The s-:erjg -a .jlue s orf thei. continoulS effect a re preie nted in table

'Afo ac redThe~ data ire idiusteid to thei :I;.rige c.e. jjT

fojr ic~a<. brccd.




*. Ith-in .ir: ir i~ ree...i~rd ith~lin co.*:s irG LI:id t*.* Obttai lli the m -


pon~UItIE of *:.m~Lijnlce for ..tunatsing buith heritsbility .aid r.:--pealab!lity

of nulk ,-el fr eacrhbr-.d L0,- the intraclass ,corr.!iaton meth~od.

Thei i31- Tllred 5L unlgue of~ .riline, Tare pr3s .ented in t ible 9A~ for the









..ngllj and Herefoard co-.... Co-.-: effect ..aj sig~ifiri n t (P<. 05)




idereford jnil*,'sis. T ee fc f-r s-=a o i~ii a t









(table~~~ ~~~ -1. .-to ,hte ee tnae re no:t st all tii ll~, different

from cor ale:- l'.e ofh-:rtablit; i In icaed. Pre i-.u i tudiesa


hav.e usuarll. r-portl. ~ higher l e;.cl: of he-ritaility, both fori beef

cattle (Cild*.*ell, 1902~ ind Ch!ristian, Hrlause-r and cha~pma-ln, 1905a)

ind for Juall-purpera~ cttle !Iiae, Dr.'.=ci .and Cook., L**54; Masoin,

1Sc0l. ind I.lroin ind Start-e'~nburg,~ 1965). The esanaesofti3




In daiir*, atlte as ilrn~r!-lrned b:y both Li-ley (01913) sind TlobarnFon









!i..otentiia for nIlk prj:il] lizon. ."- ii indlliCated by theC 10.. hertitabilityi



eai n te oft t l. n. raena a t r p a e t r








TABL.E -I. E STII?.1.'TE S O F HE RI TA'RILITY AND RE PE.-kT.iBILITY'
OF l.11LI:'E YILD OF TH~E: ANGUS .iND HERFEF~ORD COV.'S




Breeid He rr;tabiliIity. + SE R epea ~ tabiIity + SE


.-ngus 0, 10 v. 18 0. 22-r. 10

Heefrd0. 03+. '1 0. 19r+.09




Re;peatabilt~~.it ofll milk ild .-i; estima~td to be 01.2 '1.10

nnd 0. -19. .09, respctritely,, for th-e Aingus andj the H'reford co.~ s.

asjed or, the ftanld4T d trrors of thre s estimnates, they are bothh


significantly different from zeroro and diffe~r signifirantl:- hor.in each

other~, being moire th~n 2 standard .-!e.zations separaited.

The- .;rnguj eJI1Timat lr in th1 l;a.eci orange of th1 re~pestabl ty

estimatesrc revic..ed ind~ igrees- ckafuly .:-ith hjthos rcported b;y

Melltoni ct al. (1900), maohrking .ith bree cattlee in T.-
(1970) .and',j '.re t il. (1970) reported firnil,-,r est~mimate for dairy

record- In Columnbia and venezue~ln. DueCf tore rn-iny; -stre s c

cattle Are -sub~icted to ii, the mor- trop:ical areas, especilally under

ranse condition tempo~rary cn:ro~nmecn tal *.*ariince is pjrobablyl

sulbstintiall expasnded. The~refore, lo-.. repar~atbility esitimates

rni.; be nojrm~l for thes e condulansl~h.

The repentabili j cti es~tmat obltained fo~r the Her-fordl dati

wai necar the iverage; of the pu'blished i-stimates rev~ie-.redd and com~-

pasribl to the eltlstimt sf 0. 3- .09 r-ported for Hel~reford cirtle









(Rutle~dge7, 1"07. Repea~tabilxty is the p~ercentageg of tot il vb~aliaCe

rwhich can bec accoonted for by: genetic and perm~ane~ t n-.ironmental

fators. Since herirrabllty wais Ic~.v. forr Herefrdij milk yzeild, the

gtnetic portion of .a-inrr aneight be similary (cav. Th-erefore,

pcrmnane nt e-.irornme~i ntal tsourice af variat ijn wo.uld be exipected

to be lagEZ tj account for thej high-er repeatablity. Evidenc. e has

beecn found in this stuid:- jnd c rlie r jrtudic s by' Totu~se (1?968i and

i.Tangus and BErinks~ (19-1L) Irhich sugge~rsts that pre~.csnanin nut ritionail

sthtusj mayh Influeni c subsequlent mllk yield or mitrnrral ability. This

may tend toi;ncrcease the FPrmane--n env.irronrmii ntl .ariance, thus

increasing rupeatabillty ah'E t hat -,bserl'.*d fo~r the .nFgus daa.

Results of this irtudy, slbsequ.--ently, discujssed, juggest that this

prt'E --eaning infilue iiCnise ma b st r .ngs-r In the He~ref o~rd thain the-

Acnguj cjttle at the Broo~s.;lle Statio~n.

He-r Iiablit5 of a.er age~ m~lk lield and .-f th Sra:.~th trait s

-tudried in associanior. .=xth m~ilk !ield <*a- estimated b: the~ half-

sib method.j The analy-es of .*arianrce are 6iven in tible 10A.

V'riaance cjmponents for aire~ effects (rable 11..) ...ere used to

crlilsclt rhe hslritlbiiies jhok''nn irltible 5. .kn,-adr

dev,~iations and c oeffiicients o *j .asr ijion ior thes t ~ raits are prr~esnted

in table 1'A.

The estimates of b.-ritabiit5 for av.--rage milk~ ;ieldl of

0. 14+. 30 and 0. 13+. ?3, rr jpec-ti*.ly f !ur the Angus bnd He;;re fords

::-erei sli;htl; hlghe-r than thec coGr rre poi-dingt ~s timate s for single








lactation reords as would be e:
eTrrors hir...ever, these difference v.-re not jj;ignificant. II. Avering

more than one reco~-rd, nevertheless, tends to remote. a portion

of the tenlporiry en-.irornmentall va;riance-, t~us rcducing total

.ariance~. Geneirc variance *.i.*ooild not be e.pe~cted to be affected

b; av.erag!ng the before, the ge netic portion wiould tend to constitute

a larger percentage of the total iriation.

:.10st of the heritability estimiares for the :Tro..thh traits (table 5)

~..*ere lightly higher than tht *.*.eighted ravrage Festim-ates prFesented by

Temple (1963) and Pertty and Ca rtw.rright (17r.0). The estnimtes for

herr itbilit; of Itjrllng *.=.*ight for both brccd e:.ct:eded jny of the

estimates rtVeunewd by thee auth-ors. Considering the large standard

errors~,,-.hich ..-ere e:xpe~cte ..:rth theF rFe-~laxl~ elysmll number of

cattle ituldred, estimates in th-is studj.' do. not d~iffer tatistically

from thi. publ i he d u.eighted ave~rsagF he rita bil ity' estimate s. Partial

confou~ndang of year of co-.=. bic:h and ;ire of ~co*.= probably tended

to inflate fire~ \iriince estimjtes for gro*~.*.th trjits. Thes trraits

~. oul.d be e::pected to be influenced more tby ye ar of ce*= bit t

would subsjequent milk yield.









TABiLE 5. ESTII.1.;T ES OF HER~.ITABILITY' OF Al~'ERAE. E.1lK
YTE LD ANlD GROW'rTH TRAIiTS OF THE ANGUS AND
HEREFOP.D COW~S




.-:gus Hereford
Traits 1.2 + SC b"- + SE




y1eld" (-1)b 0.1I-1+. 30) 0. 13+. 33

Birth- rc I.eigt (1) 0. Sc.+. 33 0. 73+. 37

V,'e rising -.i lE ht ( 3) 0. 7i 1 3-1 0. 0-1~+. 32

i'.'eaning grade ( 1 0. 0+32 07+3

Yearling ..~ ig fht (O) 1. 5-l. 3-i 1. -lt~. 37

3 2 m ont h .r i 'ht (7) 0.91. 50+. 37


" ':iragec 10-br mlil: \i-ld examated from~ ojne or t a l ac~tt~atio

Angu~s jnd Hlcrefordr

Strait iode ium-rber in pire~nthesesi-



e~netic, Phenrotypleic a En.>irolnrnent 1t; Correlationn
icC I ffilC nts;



E r tima jte <.1 4 gene .t ic, phtnoty pic and i-n*. ironmenrt il Gcr relit icn

coeffiiciients t~at:.eenc a.-erige milk Iyield and gro--.th treats are~ listed

in rtble- a. for the .;ngus Ind He~rcifrd cattle. Thicser estimates :=:etre

icomputed irom thc iomponentsti af .ariance hnd courjr~iace obtained

fr;om th ei~i hl-s ib an il;s-i a. T he i ppFr>.:'irnajI:te ltada rd r ror s - .ere

large for all iarrtltion estimaltes as v.ould be cxpected \th thusi

small ...ljllnlume of djta. Sma ll numbe ~~r~r s Incre iiis t h,. p. e i ility ro









TABLE: 6. COEFFICIENTS OF GEN~ETIC, PHENdOTYPIC .\-ND
ENVIR' FON MENTA ~L COC6RRE L ATIC.N BE T i?' ENE
A~VERAGE MILY.YIE~LD AN~D CROW.~TH TRAITS OF
THIE .ANGjUS ANrD HE~REFORD COWrS






Gro.vh raxs 5E r +E r +El5E
Crorh rsvs G i-- rPlPi--,


.ANGIUS

O~j0. 0+. 3


Birth .\eight (1)


0. 13+0. 09 10i0. 39


Weansing weig1ht (3)

WYeirning grhde (5)

Yea ruling ..ei ght (0)

31---'-roonth veight (7)







Wea~nlng: .-.*eight (3)

Wealning grjd (5)

YeasrllnS .e ight (0)

32-rnontnh .; eight (7)


0. 47+.~ To

2. 3C0+.73

1.'2+1.0 a

195+1 00

HEP E F OR.D

-.3+1. 14




-1. 45+1 b0


0.05+0.Do

-.01+0.01

0 11+0.05







-.07+0.07

-.05+0.03

0.08+0 11

0. 00+0. 3

J 12+0) 21


-.20v0. 46




-.0+0.15







0. 320. 6

0. 4:+0. 32

1.04+0 ii




0. 34+0. 641


tra.it 2od; nuLmber in parenrthese

reca~l culated sol..stititi ing the .-.elghted '"erage he ritability of
yeairling..h eight 0.- (Pett~y ind Crt:*rgight, 1906) ior the estimated



(~ P<. 05) (pC 051)









sjlmplin ng error ~.*:hich csn lead to erroneousj an~d possibly~ infllated

re ultls. Thils mIg- ~ht pa r i ally ex plain t he cor r ela ti n e stlm te s

. hich e:;;eeded the po~ssble range o f 1. The bet=>.eenn irnd .ithin

sire c~m ponr:nt s oi .jr i nce i nd c o.ar rance frromn ~ **.ich the e stim -tes

.*.ere cal2ulated are lIsted jn table llA iior both breeds.

The co-etricielnts of Benetic car rcltioln bet:..ee-n milk :ield

and th-e reT'.th traits ..'.cre all pofitive for the .ba.,us and all negative

for ther Herefo~rds. Thi upggst~s apo~ssible breed3 diifferece"c.

Wiithi the large jstndard errors, ho~-..*eer, the co~rresponddi in sstimaltes

for the tw.o bjreed- . ere notr statistically d~iffre-n fromir ech other

cr fromn I. ro. TheC rathcr erjrtic results iind Large fstndard errors

obtajined in this study; are t,p~icl of the no~n--onclusi. e pre,iOusj

genctic correlatio~n studies In dairy and- duail-psl.rpose cattle, as

summairized by JohanssonDI (196-1), I~ichojls and 14'hite !196-1) snd

Tyler (1070). The lack, of cons-iistency In the result of these I stltdjes

mright 51uggen thaT enetlic iiorre~llanon: my not be the fime for

all bjreeds nar the samie ithin breeds un~der dlifferent en*.ironments.s

Thle treire re.iew'.s agreei that I I.netlc cojTrrlations bet-.een m-ilk

yield and . irious measuri-s of gro*;.th o~r size ir- proabab~l po~siti.*

but near ,-ero.

L~isairngfulJ corparzsonsI might~ be mide :-;.ith beef cattle

?tudi1. ..'hich ha.- e stimated the genetii c association bet--een

ma-Iternil abilit;- (iassumed to be rrrimatrl l ani e..presslan of milk








yield) and gro.=.-h traits (Koach and Clirk, 1955c; Hill, Legates and

Dllard, 1966, Deese2 and Kogerr 1967, Hohe nboken an~d Br ink,

1971, and 1.'esely and Robinson, 197;1). Hereford cattle v.e~re studied

by I.och aind Clark. Hill et al., Hohecnboken and Brlnks and \'.esely

and Robinjon, the refore, their results ma~y be more relative to

the Hereford estimiates of our stud;. Koch and Clirk (1955c)

reported negatie coefciientsit of genetic correljtnon b~l~etwee

majternjl ability~ and pre*..*ening ai~n -..ach~l ran-ged from~ -. 65 to

0. 68, and between maternjl jbility jnd oveannmg scored :-.hich ranged

iromn -. 32 to -. 39. Th~e ringe in thiese ertiatjres -..-as due to~ different

values assured for heritabiilty and the direct effect of maiternal

en.ironmennt, -..hliiic -.ere necessary to comrplete the esti~rnatlon

e qu at ion. Pos it i:e c oc ific int s of cir rela t i n ber .,i c n m te rnal

ability and thep post..waning trjir i, yea ruling g3in 3Ind yearjling

Bcorei 'e.re found. These pree.~ea~nlrng e~i-stimte jgree in rign \.tith

lth esiitimae brn~r ri the Hreord d~ata In th-i.; tudy~. Thle posAtv.eaning~

escrmatejs did not agree, but those~ of the percent itud v.eree neair

zer0.

Hojhenbojken and Brinkr (1971) estllmajted cenctic correltions

ofr -.'8 and -.;'~ be-.;.een miternal abily and pre vea ning gro\.h.

The best estimate .as 9 ad to t~e -.25. These autho~rs jugge sted

thjt their large negative- esimrate as we;ll jr the netgat.e estia~jrat

reported b: Koch jnd Clirk~ (10j5501, Hill, Lcgates jnd Dillird (1966)









and Deese and Koger (1967) -.*.'re bluecd In a negati~.e direction by

a common factor. Thisj reasoning mIighrt also be appilicd to the

negitl.c genetic co.-arisne recentl*,' reported by 1'esely and

Robinson (1971I) bct**.een maite rnl abil~ty and gror..th potential in

Hereford cattle. The c~rrnomo elernent suggejted ..as th-at of the

offspring-dam couriarnce uSed to estinmate Stenetic correlation

btr.~.een rn-aternal aIbilty and growth, b ein~g blssed do~.'..*nmard b~y a

negjti.t~;e enirojnmental effct of prev.*.aning gro.*:th rate or, subscquent

majternal performance as reported b', ~s- Maus and Brinks (1971).

Offsprir~g-ssr co.ariance .L.*~ich i free ofi the negatite bias '.<'as

ured to obtjim teilr best estimatiie. Deese and Kogerr (1967)

repojrted a neg.-ati. e comasr~ riece bet.'.een the additive comnponents

for miaternal abjlit~- alnd pre .ear~lr~g gro*.*.th an a Brahmran x Short-

horn herd, iile~l~ the cos.airiance ..'e etimrated to be zero in the~

Brjhman herd studied. They~ pointed ou~t that other artiiact Iin

Estllrrltes, suchi as bn ov~er-E timatc~e oi jire i-iect~s, could result

ir, a nrgati e prtimate~ for the relanlonShip. The.' questioned .-:lihethr

rhe relatrionship could ber ge neral!: ne Saive: in iiview of t he c harjic-

terjsticr of Se'.*eraTl bree~ds.

Gernetiic fudies o ti hi t, p. on other bt.~i bree~ds ha-.e not

be cn foun ii n ther lite rat Ir e. ievr.trheles s, th~e de'. iation ;f thP

Brahm-an estirr~ates from? the consijtent nesjti-:e ~stim-ateis frrn;

the HE record and c ros sbred~ data r u~pprl't I thi pos siilrrt*, ihat the

genetic assocria~tlion mal~y d~iffr btt~..'.en~ brcteds. ComparisonJ T of








the .ingus and Hereford ocoeficient from~ this: study give~ further

evidence of this possibility. WVhile the m-agnitude of hth standard

e rrors do not SUbstantiafte a real differences between -coefic~ients

for the tas.*.o breeds, theser tim-ates along with other reports

suggest thle need for fu~rthtr stud\ to better define specific breed

p"arameters. Conclu~s ons rel~latx. to the geeetic aissociation bet.=.een

b~eef cattle gro.th- 4nd milk yieFld should be reserved pendlng further

research.

..lost of the phe not) pi~c or rel ition coeffic ients ..e re non-

significant (~talc 6), but usually, larger than thioze repprt-d 2n

previous studiEs -:.*ith diiry and dual-purpose cartltl. The anal1:..iS

of ths .Angus data gav'e siymfic-ant positi.'e phenotypFic correlation

estimates b t .:-cen m-ilk yield and1 the~ gra..-t h traitj, !ea di ng ~e ight

(p< 05) anid 32-r-.10nti ...cight (P<.01). N~o nignificant phenot*,pic

corre-l t ions wecre found tor the H etre ford data.

Environrlnent.11 correlation (the correlation cf thr en\iro~n-

rnentjl deVlstionss plu the non-a~dditis.e genatic dei-\itions) between

milk- *,ield and each- gro.th trjit is showvn also in table t. These

estimates diffe-r in sign *~ith thi iorresp onding genetcic oceffsicint

indicating one of t..=.0 po ssble co'nditions. First, if the- est1imtes~

are acculrate, the differences in signi showMs that ginetric and en'.'iron-

mecntal SOUrECe of vriati;f on iffect thel traitS through different

ph-,iolgicl mchaism. (alcner 191).For exarap;ile, i high









level of nutrition directly ailects both gro .th and milk productionl

favorably, 'ihile there is e.-idence that high nutr tional levels during

the~ rerly- gro*.t-T period Are antagonistii cr toubsequent mrilk prro-

duction (5 .snson, 1'957). '.r nsnj fo~ru nd that hifeiir r gr o.~..n cn a

fattening ration drposited fat In thre uldder :..hic~h :Ipparently. limited

mnilk production. Other F"pers (T~homa~s. S-,ke and r.10art. 1959;

Crichron, Aijtlrn and Bo,ne, 1900O, and S-:..anson, 1967~) h-ave reported

that ubsequent milk yield v.as not iffectid b,- rate ofi gain .ith-in

the Inormanl ringe for: dev-oping dairyl; healers.g The~ c[Jher posibilit:,

is that of er:..r in estirnatlc0n. Thie la rge r an.da I~~rd erro esi~mates

mal-eI the latter a more like~l; expljlnation for the~se dats. Re plicate

studio s, preferrabl,- s.-.th lirger numbers of uniiorm~~ cltltl, should

b? conrdu~cted before confi~dnt conclusionn s icoud be made concerning

the e nvi ronmernt al c r~r ela Cntin.



Genetric Co~varian~c jnd Direct Elec~ts of Mlilk YIield
Estim sited b, thF Indirectr R~ciprocal Dsuglter -Dsm
Co~rrelation Fhlethcd



Etimar~tes of c;reciprca daugiter-dam phencotypic: correltion

cEfficiient' bet-.een a.er gEc mil: I,il.5 ind co.*, traine (exclujding

birth ieigh~t ..hIicht ...s not reicorded f~r F ome dmslr) tire li;Fted In

table ;. Onif. t he i or re lat ions bt~t.*e n thei damn's tr, i k , ield and

the daughiter' . erning frade and yearlinp .=.*ighlt for Angus pairs

..-ereC sgnificant (P<.05). These cstimatesp .-re obtatined from small









TABELE : COE F FIC lrNTS OF REC IPROCA L D.4UGHTE R-D.4M
PH-EN:OTYPIC COREE LATlION BETWSE EN~ .i:'ERA.GE
M.ILK Y11E LD .AND .4LL TRAIT~S OF THIE ."OGUSr .;rND
HTFE FOR.D COWVS


Dam7.lkYild Daughterl Milk YIield

rpP rp M(


Co-i. traits


.ANGICUS

0. 26

0. 30

0. 28




0. 20



~E RE FORD

0. 10




-.02

-.22


WeLaning gradei (5)

Ye~arling% .*right (6)











1Yean~ing -.neigt (3)

Wea-ning gride (5)

I'ejrling ~r ...*ight (0

32 -moint h v~. -i ht (7)


Djlughter mIILk *,eld (I)


0.0j3

0. 20,

-.00

0. 10

1. 00~


0.05




0.07

-.15

1. 00


a t r.;Iit codet num!-ber ;n pa T-rlent ses

- (P<.05)









numl:.ers (-19 Angus and 45 He reford diiughte~r-dam- pairP) ..hachi

nlnminanns confidence in obser.ed~ diffe-rence~s. Su"ejeti'. e trends,

ho.~r ev rc.rc jppsrent. In both breeds. ~rnilk ,ield jnd daughter

growth trrite *:ere mosre close-ly co~rrlated than ~..ere th~e recipFr cala

;or iefici nts. Thi ~s suggested that malt- rnal efct .*.er rIcre in:-.olv.e d,

u~suall aff;-je cur In t he re ilrati h rip pos jit Ively ?. He refo rd c o effi1c i ent s

of c orrtl ition btct".*een milk .:ield and daiushte r ac o. thi t raits :-.ere

smi-alle r thian thet corre pondinp Angun tst~imates, .C*.*ile th2

reciprocal cor rrltioins for both breezds -. ere similarl ;nmall.

The lirct brFeed differtlnccs in~ the co-ifficints of co~rrclation

bt~t.=*een milk Iield and daughter miilk yield (t ible 7) juge~t st

that itro~ne OppositeZ forCesf afect this reltionshiFip the- ta.i bre~ds.

.ppl)nFing qation 3, and using thei heritabilit, estjimates for iverage

mlk yie;ld of 0. 11 jrd 0. 13 (obtain.=d by rth intirrier correlation

meithlod) for Ang~us jtid Hterifords, rESpji~.--an.es the direct effZEt

of dam's n-ill- ield on daught~e r's m--ilk Iyield (Irn ) :. ij c alculated

for echcl brteed. These estimates, ilones with th~oct for th~e direct

effects of miilk l.mi~2d are. reported in tible 8 In [ Terms of standard

partua l iand Paria~l rey re ss!u.ion-[ 1 coef acirs.

The ne gati'.*e direc t effct ai dam-i rnik yze4ld jr daughter

mnik 1ield found~ in the He record data ruPpo'rts the findings of




acic bei!it.;...-n gcne r;tions in t1E' HTer ford cattle the-y studird.









TABLE 8. C OE FFICIENITS OF STANrDARD PARTIAL ANjD PwRTIA L
REGRESSIONJ OF DAUGHTER TRArITS OI Ai'lER.1GE
LIETIP.1E LIULK YiEFLD OF THE; ANGCUS AljD HEREF~ORD
DAM~S





Standard Partial Partial
Cor. traite R.egrsslan Regre~sszn


ANiGUS

0. 25

0.Oib

0 37




0. 12



HER.EFORD

0. 10

0. 30



0.20


We-aning grade (5)

Yea;rling h. weight (0)

32-mionth v.=.ight (;)


7.99

, 0)5


19.00

7. 14

0). 14


We~ar.ing v..*ight (3)







32-r~raonth~ esphF1-t (7)

XA. erjge miilk I, itld (4)


2. 8

0.25



13L. 35

-., 30


a tr ait code numbrl- in i part nth~ e se










Thi* y ou~~nd that cow.~- reseiving~ a fcood pre-.e ning en.-lronmrent

ten~lded to proiid: ra poor~ envirjnmernt for their offlsprrni2, v.*h.o,

in turn, pro.aa.idcd the nczt gene-rition i good en.iro~-nment. Totu-.ek

(1C0t9I rtported that earl; .:ea.iild Asngus and Hreirefrd cows~ produced

her:2-. r c al .-e at -i.*.w ning thasn no:r nisll'. ,---. eaned ind c re ep-fedr

nor-mj l:.- ea.t ned coo .e~. Th-e . eani ne -.-. eight of He r c ord co.

-.s-se n-rgati., ly assocli.2te -.=.ithi sub-equent nuilk. yield In s s-tudy

by Christian, Hiauser andi Chapmian (19c.5b). The co!-clusion of all

these;i studdies has b~c-n that high- lei els of plr~ejleanin notaltionn

tend to lirnit jisubseuent miilk~incg ablit.:. Fati dcposiitron~ in the

aidder, as found by S.anso~n (145"' in !!air:,; 1-eiiers iittened until

'lI-i onths ofi ige, is jenerilly consids rerd i 12rnlitln,2 factor orn

mar -i !nmar ;, de~. clpme nt Cr~th r researdi:I re-.ie .ed b:; 5 :. rnson-c

(106-1 ind~ic te nolr significant = ffict onr nu~lk -,-add du~e toc .*ariable

nulltricainali le.els '.ithir. the, no~rmali range fo~r de*:eloping dair, hjifers.

.4 -L;2ght~ ~~, ln- r in.*e productions~ beneIcfit fr om le'.. 10.'61 ic fed,,ng -.*'as

ind~iitcate b: the 'L..*rk o Crlchton, .11tk~en ind Bo5ne (1900).

Excsisji:e- ft in thIE c alv S ...j- not an appi'!ren problem

undeilir theF conditr~Ions of this Itud,. Thep poSiti'.e associiaiOn

bert rccn mill ~ield of !.ngs1..s d~ime; id daugh.[iter ind;i~cad thit such

a n gat .-- efec .. .5nota p-.:.bern 2n he ..n us ar .~ lu i"p s lv~es

ob-er,ed durin: this rtud ~..ere larttr it ~..ewinL than Hereford

cal.*e-,asIndcatd b: utrasona bcidt masuemets.The .e








findings suggEst thait the responje of thie t'VO breeds- to early

en.ironmrent mayl. diffe-r. This pojssibility is supported by a

smaller standard partial rcgression of v.*eaning gride rn milk~

yield of 0j.Oc. for the Angu as com-pired -.*.ith 0. 30 for thr He record

(table 8). The Hrreford could be morre usceptalbe to udder fat

depofition, or ther negati.:e assaicinonn may be the result ofi a

benefcia~l e~ffect from the lose l.Evels of nutrition as suggested by.

Crich~ton, Ac~ttk~n and Bojyne (1'960:). The je author- rrasoncd that

meirc a jd rumnen developm e nt in cattle on the low.' nutrition le el

mayi hir.e e~nhanccd subsequler n p~roduction.

T~he: jiluencet thit the direct effect of mil~ yield on

diaughter milk yield may hate hadl on other reciprocal correltions

and the resulting rstimatre of direct m-rilk yield effect and genctic

co-I~.ahr tance wa I i not de te rrmi ned.

Estimatest c of direct milk yicld erect on progeny gro-.v~th

trails Itiblr 8) for the Ainguc .~..re highelst for the various **.eights,

...hile being o*.. for .r.-ening Sridc. Thec He record cstimater

differed lirtltl romr thei A~ngus rtrsults except for -.; eininL1 grade

...hich d...*s muc~h higher. 'pparently. the positive tffeti of milk

;ield an pre:-.eaning trrats is maiintainecd to mhturit;, posi~blv

due o erlystrcturl d~elpmet. hese eiffets mrighit be

com-rpared iost i s~ily in thie p.:lrt'l regSression coie ffici nt s .r.hic h

eresy.r ho=. rn-an) pounds or grade-2 a growth trarit ihangSc for

eachl- pound change~ in a~t ragE 1-nlk .Ield.








Regrtssion cOeficiients for gro-.=.h traits on milk yleld

-= hichl la\ been pre-.iou~sly rcporttd :"etri -stirnated~ o:n milk

*,idd and gro..th re-cords resulting fromn the silme~ lactation.

The~refore, th;-se prcolously reportted cocifficient tstima~ltes -holuld

be larger thajn those of this1 stud:. -..hlsh rcsu.lted fromn milk yield

and groor.T.h riecords stEm~ming from different Ilatations. Th.-

diiiferencesp ii the r stirnates~ void ber a function ofi the repe~atablity

of milk .,ieltd rticords js dfi~ned in the procedureS. The pre-.ious

estamatc could be biased cithecr up..ard or doan..;r..rd L, the genetic

-ffects '.*.hich ** ere nt removedi- ar- they ..ere in the~ preselt study.

Dre'.;.rg, BTr*.hT. an: Hen.nea (195i1 reported standard parrnal

rer d.s;;'"ioncoaticie~nt Istimate- s o 0?.1 i, U.6. a nd 0).0 f( or cum-ulative

prc..caning gain on r-n ik :;ld it the first, third .and fi:-.th month

of lactatiin. E estimates of pa rt ial r g rejs i on c oeficiji t ls iof pre -

.:eaning~ an~d posr.t.=.*eanin ;ro .th trrees on 100-pound~ unit of 210-

day: mill- ;ield oi Her frdiJ~ iio.*.r on thr--c le:'ei l s at nutritzo. .;.er-

reported~. b;, fle*ill e (1 -2Ihi and, r'e'.'ill- at1 a l. 96 2). respeti~; .' ly.

The raing ae of these i est inmates for c i;ng *.- ei ght s Iaugl ht er **.*c Ight

.ind laughtrc grad- .;.rre -3. !3 rco O3.0 -1.15. ri. '?.01 ind 0.00i5 to

0.02,repeci'*ey.The Ilo.-..r .3llues iof ac~h rjanc rended to

be a socate v.lthcatl- n te h ghe t lselof utrtio Uir ng

the o w.i r sion f acto:rS utilltre..i L, t'aitler ut al. to: ejirstim t 2~-10

day milk yield frrom 1-1-br m-ilk Ileld, it can; be jhea..ni thst a one-

pou'nd u~nit of the- presntlr lo-hr milk ,-zled is cqul.alentt to sl-*i.rcs-









imate-l,- three 100-pc~und units used In the7 Nilc.lle studies. TherE-

fore, the Nevc\ille and Ne'.-alle et al. partial rrgressic~n coeff;~icient

should be mu~ltiplied b; appro::Imately three for comparlsoi v.*ith

the current estim~ates.


The Partial regression coeffiicint ho.' n in table 8 are

dFpc:lapprIma l 1,'-1 to. 1/2 the~ magnitudd e ofi othr pub!iched =.alues

r..hen : corre cte d to comparablbl e nIllts. Ho-.:i.e-.--, the rilative effect

o~bServed at =.arlc~us ages- is sim~ilar. REcspons of .*.-ening v~.might to

m-ilk yield .i.js mlallntalned toj 32-month~l : ~elht In~ this study and to

slautghter v'eight in the study by TNo~ille -t al. Iloi.2). Simple

correlation coefficients~ riporte~d by *:liticrd (19F31 bet-;.ten milk~

:ield aind offispring ...erght at 8j, 1Z, 24 anid 3o monc~rthe iri highl;

sign~iicjnt hrough~~~- the .'.6th month, Indicating~ a conrtinuJing as~sician o

to mlturlrty. 'The responser~ of Angus g~rade. tc. m-i~lk: yied ..as compa1Frabl e

to~ that of th-e stud.- b: I Neville ct jl. I.11rad sco~re for H-Erciierd as

irdlluenced more by mzllk yield IIn the prisclnt rtudy- thai, -..a the




Gcncti c o;.irialnce isi-stima s ri listed in table ". Due to

the relati'.El1.5111 Imal~lb nubr of daughteE r -dam pair; utili~ed and

the sbjen~c of a E uitablt statistical tes of I si gndllj ici Ce the~ de gr~e

of reliabilit.- sf thee resuilts Es not knoe.*n. Neverthelessf it is of

interest thiat thei 5ign of tec.*rl arc iC''eiTi Stimates~ obtalined froml [he

daughrter-dnlm drata rtend to agre-e :n-lhln breed; '.vith the .-stimate s









TABLE 9. ES~T!IMATES O3F THE GENETIC COV.c"-.RlACE BETWEEN
A'.'EP.AGE: I.I1LK 'IiE LD .'J-JD GP.01TH TRAITS OF THE
ANGT~US AN!D HERFF OP.D COW~S






Gro--.t traitsCo'"' 4G




ANJCUS



W~eaningd ...eig- .t (1)0. 2


Wear~inrin gi:~ra (5) 0i. 4550





iE REFORDD

Weanng -eigh (S)-.0190

Weanng rade(5)-.6054

I'1' rling ..; c-ight (c) 0.0092






j triit icode nu~mbcr in parcnthese









fromn the half-sib data. The one e:--ceptin inl both breeds Is that

of yera rl i ng i ght.

The combined re sults ofJ the half- sjb and the daughter -dam

anajlyses tend to suggest i positi-.e gene"tic rlationship b tvc.*en

milk yield and gro-.Lth traits In A~ngus cattle, wvhle the relaninr-hip

may be negati.e- in He record catrtl. E ve n through irrm~ conclur-lons

cannot b- d ra.vri frors, the se re sult s dur; to the large stand rd

errors, th-se flndings shiruld -luesdatle thie need for further res--arch

before gelneral conclusions aIrr mide condemning the grnetic Ijssociition

bet..een grol...th jnd milk~ yield in b~ee cattle.


Simmiry



The objectrues of this study '.*.*re to e- -timaJtr eni~rinme~ntal

effects on mli;lkyeld ofI be-l co-..s,, to estimated genetii parameters

associated .vit~h mi-lk y;ield and cow.r gro*.vt'h trrats and toj istimate




1.I:I!k yield data (ther nrnen of three- withinn lactanlon observationsn

osbt ined by- the iilf-no~rs Ing me thod after 9n 3verage 16-br separtiojcn)

u rd resor drd In 1069 ind 1970 fojr 262 iid ;101 lacrat ion -1, re aspect i ely,

of 1613 Angus- co-.'.s by 45 h re s aln 137 H re ford coi.i.s b y :.3 4ires.

The- data:~e r- j nalyz e d by the le ast square method' to estim~rate

sigifi ant -nmIi ronmntal effects 4 within : chi br eed. Ge ntle i

anjlyscs v.etre made~ fromll the m~lk fiild data adJIpasted for th-~es









si gn i ic antr eni ronmn-t llt li eet s. The; Angus data metre adjusted

for thie cilect of co.- age (P<.01) and thiE effect of se': of calf

nu~r sed (F<. 01). Hi re ford milk yield data w~ere adjustred for the

effect~ of co.; ige (P<.05) Thc sco.*.~ gro*..-th traits, birth weight,

eunililing *.eight, .-.eaning grade, yecarlingS uveight and 3.2-month

.e!ght~ *;e~rc o~btained fromr thet station reor-ds. 'These gros~th

trait records -.rer utiibred In the ge~netic aalyes -..ithout idjust-

mcnt, e>.cept for ..Leaning .~..eight .hich had been pre.ously idjusted

for c;. and calf age.

The. adju-!cd mrrilk e~ld data of .::ach breerd c; r.: subjeicte

to separately nested analyses5 of :arian~ce nesting siresj with-in co..

o_ri2in. c o .s =ithiI s Ire and re cords .' within cowr, t o obt ijn he ritaibiljty

and re~peatabiity estimates b;, thei intraclass ~correlatlon merhod

Heiritibjiity of mzrilk vield ***as estin-asted to be- 0.10+. 1.' anid 0. 05+

.21, respect't rely for th? .1.ngusi and Hereford co.*.'. Corlresponding

i jtimtes ofl repeajtabilit*: .-. re 0. 22 +. 103 and 0~. 419+. 0?, res p:cti ly.

:.1ilk ;i;cld rtecord (onei sr r.=.o ini nun-~ber) we re i\vrage~d

fo~r each .o.** ~;Lto obtinl.. -erage~ nIzik;, -acid I per co-v..1.rg nl

,.ield Irnd the~ gro~t.th trlit5 ''.
:riiinice and icoi.~rari~ ce nest ing -irces .;rihin cowv origin and Cov...

.ithiin sires, to obt 1in comTpolnents for i stirriaing: bcritability sind

gien.:tic, phe~notyplc and on-.ironowrntil correlltion coefflicients b)

the~~H hl-bmto.Hrirtab iit. iesir-,utes for ave rage~ milkF








yield, birth weight, wecaninq *..eight, -.veaning grade, y~earling

.<*eight and 32-rnconth weight -r..ri 0. 14+. 30, 0. 56+. 33, 0. 71+

. 34, 0. 10+. 3', 1. 54+~. 341 and 0. 94+. 34, respectively:, for the Angus

co:.s and 0.13+. 33, 0. 73+. 3;, 0.04+. 3', 0. 71+. 3-, 1. 46+. 37 ,and

C0. 50 37, respectii'.*ely fo~r the He record co*,. j. Coeffiiciens of

correlation bet-L...-cn mnll.: yieldl and the jabo.'e growthi tralit, res-

pect''c-;. ly, ere is follo*.=-s brns the Angus data: 0. 6j+. 83, 0. 17+

0. 76i, ?. 39+2-. 23, 1. 22+1. 06 andl 1. 93+1. 60 fo~r ginetric corre-lations,

0. 13+0. 09, 0. 05. 0. 06, -. 014-01. 0,0. 11+0.05 an~d 0. '1 0. 05 for pheno-

typic correlations; and -. 10+0.39,, -. 20+0. IS, -. 81+0-. -14, -. 26+

0. 15 and -2. 07 +6.1 f or an Ii-.iron n !t ecr rel jt ion Fo~r the He~reford,

colrresponding coeffiients *ere -.73tl. 14, -t.75 t5.94,~ -1. 45+

1. 60, -. 310. 71 .nd -. 0840.; 77 r g~enets correlations; -. 07+

0. OT, -.05+0. 03, 0.08+~0. 11, 0. 06+0. h3 and 0.1240. 21 fo~r pheno~typl

correlations, and 0.324-0.50, 0.47+0.32, 1.0440..56, 0.19+0.206

and 0.. 3410. C64 icr en.:iro1lnmentsl ;orrelatio~ns.

An indirect dasughtcr-dh lm corre~laItio me-thoDj utilizing

rec~iprocali p'henc'lt:'Fiic~ cr~ relton and t n~rh pat h c oelfic ient conceipt

*<*as dc*:eloped~ tor estimated genetic co\arxanic bety.*een m~lk .~ield


and gro...~th traits and to, estimat~i e rlhe direct effects of j=.erjge life-

timel milk~ yi;9eld o all [rrm[-. These cosrlmates =.vere obtained from


40 .1ngus and 45 Herefojrd daughter-dhn m pjirs. Estimaters of genetic

co-ariance bttime an i-:orige mllk*,ield and the? gr o..th t rjits, :=.anjng










~.;, ighet, :-ea~ning grade, I',-erlin g ''elghl t adll 32mont~ .= e~igh t ere

0.02 0.7 -15, -.'1 slnd 0J.12, respe-cti. i:; y for th1 Angus~ cows~ irnd

-02, -. ol, n. 01 and -.-17, ;crespe.cti*ely for the He reford co.*s.




dbughter m~ilk~ yi-=Ld, caning .reighit, weanin g
.....aght aInd ??-mlonth i.einh, esipre~ssed- aj standard partial rtgressiion



for the An u ow n 2, 0. 10r~, 0.~ 3, Id. 20 Ind 0. sF, re pec t-cely



fur the Heref-ore1 co*.*.*a. Co~rrCespondingFIIliL partial rgesin iCofici ents






1.111 li..ld F~arr pr; toe onl; rlightly hri~trable as meisurvd

in t~i s E r.ud:.. r, e-.tabilit:. ofi m~;ilk :eld performa-n~ce is moide rsft

to~ lo-;. ;In the ge.netls;c~ assoi ation betu cerl' miLk~ y'ieJld d grel.l..th is






apparsto e n..gti.e i th Heefod.The dir?-:e t effects of milk

idd oni gro-.=-th if positi'. e and relati*.*el y conscjlnt fromn .*.*ean~rn

to matiure -.=-Ight.) Ar a1Int Sonlistic l-fec~t ofi cl m m~ilk )'ierld and

da~u ghte' r ilk: j-ield --lj !yi todozated in the Hereforjd, -.vbil? ? th-i effect

**.as pos'j'iti-- in th.= .;Ugu; E en through firm concilusions ca3nnot be

dir a.. n f r om these r sul ts du to~i ti he lar Ie sr and rd crrr s, ti, I he;

fInings1-~ s hess:i d Iluci datet the need fojr further : cres rchl before l gneral1









co~nclusionis re rnade conce rning the genetic association between

~rox.th rand r~nill- yIeld in btef cattle.

































. iPPE N DIX










TAiBLE IA~. SUBCLASS ?.IEAN!5 F~OR I.11LK YILELD OF ANlGUS COWS






r!umber of \lYed
Classification Obser--atlons (PcoundE)


Total


20


Year of record
1~969
I1970

SE>: of calf
Ma1Le
F~emale


Year .x seX
1%6? 1.1ale
1%9B Female




O~rigjn of co-...

Intoduce


5. 80J
5. 51



Uj. 00C
5,. 't8




5. 31

5. ?l



5. 33;
5. ;5





;1




T."BLE 2.A. SUBCLAS~S f IE.\NS FOlR '.1ILK/ YIE LD OF IERiE FORD






rLum~ber of I1l il






T ot l 10 1 5. 5 1

Yeair ofi record
1909~c 105, 5. 51
1070 90~ C 50



.lite I 10 .5


10eG h~- 'i [ae0 5


10 1970 1Ial 505 -13
1970- E rnal 405. 5'



? lies ity mt~auce 485. 3Q
:-blesr C it,- los~al Pt 51'. L9
Br ooks.11ell local 7 5. 52










T.-.BLE 3.4. LF:.ST SQUARPE S ANA]~LY SIS OF ?.'.i R ANI~C E: OF E.11LK
YIE~LD FOR THEL AiIJGIS C3WS






Soucedi Meac:ns iSquares t'





Yerc.freod I G c300 3 21

Sex ojf calf I '0.9'4331.

Ye~ar : jse~ 1 1.2io5 0. 59



-Linelar 1 2. 30261. 9
-Qua;dratar 1 0 4510. 09'

Cilf a~ce at first
clllatlion
-Linei r 1 22 0. 5g
-Q ad atc I 2 13'0 4 03

.1.cragei ;iepration
iinte r -al
-L i er I 0.35 0.02
-Qujdritic 1 0 049 0. 02

Re;mjinder 151 '.0O057


(Fc.Oi~











TBOLE -1.4. LE AtT -SQiJ.:-P.ES :.1.4EN, CONST.ANTSS .JD 5T.'NJDARD
ERF.OFS FOP. J.11L1 Y1'E LD OF THE. .ANGUS-: COWS





N~un.~-'oe~r of Standaird
c~lassification Lacitations Constant Error


5. rro



0. 18
-. 18










-.07


-I. 07


0). 093



0~ 141
0). 13



I:. 13
0). 11



0. 19?


0. 18
0J. 19


Ye ar ofi r-cord
19t,9


F~malc


' -- arx sex

19 t0 Female


-Quas:rsrtic


CalfJage it first collectionl
-Lin-ar






-LQuad~atic


0. 6.092
-.03638



0.0- 92
-.0029



-. 7133
0j 02t,76


0. ItalS





lj.051-1






O 1;23<,











TABLE 5Ai LE.?ST-SQU.'.RES A'N.-iLYSIS OF VAREIANICE. FOR MIlLK
Y'IE LD O~F THiE HE PI FRD COWS





Sou~rce dl !.1cjan Squa~res F~



Total 200

Year of record I 1. 4087d 0. 72

Sex of call 1 0.0690 0 03

Year x jse 1 0 0001 0. 00



-Line ir 1 12 12 5 07;
-Quadrat lc 1 8 1 .0

Calf age ar first
collie ti on
-~~ Linea 1i~ 3.04 00l
-Quadratic 1 0).0080 0. 00

.w..e,,rg: separation
mnt : r '.* l
-LinarI .,9 09
-Quadratic 1 1. 5;78 .7

FRemainde~r 1 1 2 3ad


S(P<.05)













TAiEL7 t~.A. LE AST -SQUAR\lES I1EAiN, CONISTANTST .'.N~D STArNXDAR
ERP.O~R5E FOR3. :.I11K 'IIELD OCF THE 1--: PEREFCR.D COWSS






Ns~rl..e ofStandird
Cl is i filc ition Lict tirons Cornjtant Error


s. 49



0. 18
-. 18



0.02
-02



-00 1
0:.0 gr
0.00
-.00


0. 10



0. 23


0. 24




0. 14



0. 5'

0.*


Sc:. ofi c~ 111
~1ble


10l 0 .


I~liie
Feim le


-ualldratic





Ca ] i- a i r t ole t n
~Lin 'Jr It


0. 5130
-.0~3370



-. !0026



I. 0000 r,


0.,222


0.01700










TABELE TA.i MIEANS AN\D STANIDARD ERRORIPS F~OR THE CONTIN~UOUS
'. ARkRTABLES INC~3L UDEDS J 'IN HE ENVj~'IRONMI.E ;T AL
ANAlLYSES OF THE AN:GUS ANJD HE RECORD COW~S



S:snda rd
Va r lable le.- n Er ror



ANGUS


AIgc- ofi cow~ 5. 3-1 2. 70

Cllf ige at first
colletion 95. 91 10. 14

N.*eri ge sepa r3tion
interval 1i5. 53 0. t7



HE RE F ORKD


..ger of co... 5. ??2.-t

Calf1 agr- ht firt
co~llectionn tS. 2; 15. 26;


Avetra ge iep'Lratson
inte-r val 16. O 1 1. 25












TAB LE: SA-. NjU .[EER, OF L~C TAiTION!S BY' .-\GE OF CO:'S .\NID
BRiEED


~


.AngusHe record


oal















10


11!


12


















a .





v v



tc

























[- a 0
O r, r- J









C.








Li


o c
a






-c*~













C N





0 -- r-
f rJ p

c- rl c~






a e. r-
r- 7 .r
a3 a 7 -r
rt -c cO rCI


N~ "O N








0 N 3 rg
PJP






C-


OrBU


o
In
o
a
13
Cr
W
d

CI
-1
Lil




-]



d
rJ
Lr.

CI]
U
Z
r~ Ir~
3
a

LI
i
n
G.
CI

Ir~G.

In
it
r
Lil
-I
-I
Z


O
W ~j


r;l%
%a


r.
,-

I;]



r.
























r c

*.]


\n




































ito






. U"



Z



.J


ii
r









-In

z



c



~



L

j


Ir


-3


L

it




.~


'il


C

5

j





80










r o a r-


..0 ..0 r- s ~

L' ~an r-


r; .0 .Ij r I.
.4







~I I --












0- a














Io I





TABRLE 11. COttIPON1E jT S OF~ ''. 1R.].INjC E .\NfD C ~i'.1RlF..-.N]C E


TT..11TS OFI~ THE .'.NGIUS ..ND H1EP.EFOR.D CO;'.'S


'.' s nce:
r i


.1 NGUS


C. 5C053 30i. 8527




0 0951 0. 51:12



1003 -18 2 2 09. 291


Cc-'. CC--.*. .~~


Co.< traits


Birtht .'.ltht (1)


?'.,'eain: n; -e;ht (3)


We'anlnr: jad.e (5)




3 --noonthltl 1 ;J eight (T)


.I. 172 I ~






11. I 02 ~


0i. 7096


0) 501-4


-.1866



-1. 3051


I l EP. E F OR.D




15.9531




I:0. 1C.53


21i.5.'01.6. c


12- rronthi -.e i ht ( 71


1 t.-13;


62.9-l.S










~501. 1610


6-.60-1


-i. 4.j1-1



-.~ 115.5


-5.7 rt 7


3. 03b6



". ?-130



12.9599


tr.B:t :;de number~ In pare~r.t he~- -c. f










TAiBLE L1A. 1.1E.'INS, STAND ~D.R DE:'I.TIONPS AND COEFFICIENTS
O3F 1'AiRIATION1F FOR .''ER .GCE: j.11L Y1'ELD .4N~D
GROW7~TH TP.A1TS CF lb2? ANGIUS AND137 14EIrrR.E FOR.D
COWlG'S




standard Co~cificient of
Co*.* traits .la D;. iajtion v~a Iriatin


.1NGUS

5. 6-1

5-1. i9




12.04


-:..crjq e rnillk ;-1eld (1)"

Birth -r. eilct (1)


liningning *.~rleiht (3)

'.*'e .ining y rade (5)


feariling "..caght (6)

32mnh .-igt()


0. I?.



0. II




0.08


1.22

i. 77


39! c4

j 98

i5. 47


t83.70


II?E FORD

5.18 1. 33



:C7. 0 9



11. 39 .



951 -1 7381


Birth, --.e cjh~t (1)

?'..rening ..='eighr (j)







3 r.-,anth .'.-itht (;)


0. 2-1

0. 15

0. 11i



0. 11

0.05


triall COde nintlill-l" in


pkY*.*Intho***"












LITEF /:TURIIE IITEDr


f...nerica. Techniq~ucr an! Pro~educes in .'.rirnil Prodclition
?.s earch. .'im. So~c. o .in.. Prod.



S~aclinE ind T. B. Pittercon. 1959!. -. ehquofecrn
milks produ.:rlrn data f.:r beef co s nulrsing cal.ee in nut~rltiln




a ther crl mp:-ns snt- of la~ ct it ion in ,icket ing for rnitk p rroductjon
in HaIriirn carttle J. Dai~ry S.i. 5::100-1.




rnati o~n and~ n-.ilk product on. J. Diir, Sea. -11.!i50.

P..-c: .. i.' ."-. iGO r ~ l Pr oI.:e~ -!itPe i n Q =. i:t. t.lt si ..


G~ ..i~ e '''s igo tt n~r iyP e P lm n






C.ild--.ell, J. 19011. H.:ritaibl:it ,- in repe~ati bilt ;it of wal pr~od uctionn

In::c ..5. The 1 u rnln.* -t Au.n labim.i.


Can onC Y J E. t r'e Jr an] J .".. im 19-12r.' Pr eacting




Inot~ F-"p.oducti:n ofi Herefordl co... 1!.5. Thests.. Tc.:ss .R&?
Un .:l~srsat Colleg~- e St.ationi, Te>~.:ss.




fr-ste rnal t **I~ di:t i . A i c .1 : .








Christian, L. L.., E. R.. Hsuser and A. B. Chspman.. L965b.
Asso cia~ t i on of prewu~i-an ing and post-. eanin g t ra it s .it h ...anli ng
*.rveight in; cattle. J. A~nim?. Sci. 24:652.

Clark~, P.. D. anid R. W~. Tcuchberr;-. 1902. Effctc ojf badi v.eightr
and jbge of casl.-ing on na;Ilk proJduc~to io in HiIol te-in c ttle.
J. Dair,- Sci. 45:1500~.

Colp, L. J. and 1. Jolhaisson.. 1933. The ;ield and cojmpcsition
ofi Irail: fromn Aberdeen-Angus~ll ;o. e. i. Dairr, ci. 16:565,

Coo~k, .5.. C., Wz. H. Black~, 13J. Kinipp, Jr. snd R. 19'. Ph-illips.
194-1. Re~lat i n hi p of nulk p rodcizt i n of mil i iing S hor th r n
dairns to thc iilrcass .pialit). of theirT st~ee progem.l
J. .3.nirn. Sci. 1: --15 (ibstr.).

Crichto~n, J. A., J. N. .t-stkcn jnd- A'. W,. Boyne. 19;J0. Thei effect
of p'line of nutritjon during ejining ojn gro-=.th, pro~du.tic".n
preproduction and health of dsiir . istll. III. I7Jilk~ productions
during the~ first three locrjratis. A.nim. Prod~. 1:9.

Dj*.**zon, iV.. J.1., A. C. C~ook: ind B. K~napp, Jr. 190~0. ;.lilk~
production of beefi Shortharn co*r..*. J .il.nian. ~si. I'"i.502.

Dzpse, R. E. irnd :.1. N(jSer, 1907~ flternal effects on prre*,aeaing
eco.r~hrat incatle.1. nunr. Sea. 26:250.

Dcutsichr, G. H., JT. '!:. 11'hitemain 3nd F~. W'. ::','bb. 190.


Ar:3'us -rossbreds is co~n-pired to grade Angus hiicr.-.
Okla. iS~r. Es:p ita. I.IP-j4:1-1.

Dickersonl G;. E. irnd 1. C. C~rimes. 19-1-'. Effective1ness oi








D~.re:vr, P. J., C. i. Brin and R. S. Hoanes. 1959~. Relstionahip s
among~~~ lctorr ja-50..xit te i-irl. smothering ail; ty, In befc csttle..





i'1sen, E. 1. 190r7. F.!:, tin:g design3 ifor ~etl-imating direc-t aln~ rn;;t-rnal
ip Il.11 ic vriince as and dji iel.:t-mater cInsl gEne.t;c '' .-artances':'.









Filc~oner, D. 5. 1954l. '.'aliity' oi the theo ry) ofi 5-nitic c-orrelati cn.




Ronald Parcs, N-e . 'l ork.


Fa-lconcr, D7. S. 1.03?. :.12te:rnal :-iicts -nd se.:.:t.ion response..
G.--~ntic To~h, 3:703.


Fur~r, R. D,. ind .1. E. I ela-n. 10br-l. Efec:t of li.el o su~PPl ementals


Ciir-.* t r f-:.: :3~.0 Rilf -.. iih .andor n in ill rod..a.:rors fcI frll-caling


ra-t nge beef rli l;.*.hp's. l J. ."\nio. Sci 23:775.Sci




bre-==jins. ~ ~ ~ ~ ~ ~ J hed 1l-..g. x.St.B l.51





Rcr. 15.1.


lide 'x E. S. E.~ 1363.ii 5,mp:r~.s n ro*hph i -. n ti f







per~ena and! postata 'r'.h J. Anim. Sci "i:"-0.


nel nitjs in a dairy ouaio J ar S i 26




11. jr c, P. 10,,3.; ; L 3~;.-e -: u r: n rn- im ik lh o



Columbu 01110


if ct L. DJ. 1 13 12 T~i., ge aicb si orc nsr ctn s lct









Heyni, H. I'i60. Thie gro-..rbr of thec. Afrllkantr caslf ;! rclation tio
th.. produc~tion irnd c;rropo itlan of the mnilk; of Its darn. 1.
Thei production and composition ofi the rnarlk. 11. Th.:- milk

LSet. 3:1: 349517. A. B. A. 21? 134.


Hil, ., r. 1 E Legates andl~ E. D~illair.1. 1"6; I nhe rsitne
of m tern l efectsin b ef c ttl '.ilnm. Set. L'S:264llabsr.).


HJh-nbrk.-n, V.. D. andi 1. S. Brinks~. 1'!71. RejTlarolasipFS tl.s "Clln
direct anr d mati rnail effects onr 1gran.'th1 !InHerI.I tard 11. Pi-ritrianing
of u..ur .ari anc 1-t -* ~c an relitt**es. .. Animi-. ScI. :.:b


Hiolls, E. ',;'., P. E. Erb anci .".. S. Homicl~;on. 1'161. Pcltlr..nship
bclt.=.-c l rat- ofi pain r ir; o~ hlrth 1.-- sl- montn h j of i.I and
sulb-equentI yrields ii JairY ce..*5. J. DjlTrr SI:I. 4-I 072.Z


-110* .*+5, J. P. I j61. The c.:i~-iroparats-e pli,siology; af Bos Tau~rus
and 805in icu ca tl on1-.*unutits..al eve s. Ph. D.




A.B.A. 13:1.


Jo~hanno rn, 1. I 64 . T he relati ini bet1 -*een bodyli s.:.r:, con fo~rm!-ati on-








and. mIlkyel n ar c tle .. 32 1



1?. -i H. FreemSjn and Corrpany San Francisco.j


Y~rnthrn, .I'5.lch and .i.I~lz Intrducio to Gneti Statistles.:




E.:l n. J. El. ind L '. D~. '.-n1.~1~.: 1. I hrr ). H: Itailut., esta rn tc

fo e t-h u ...a t g nd m l p ..uc i n J Ir









tEacih, R. I.I. and! R. T. Clad.~. 195E3. Ge~nrtic ind er. iro~nrnentl~t
r jr latin s hi p a mo:ng e con om-lic ch.i r act er, i n beef c a ttle. 1.
C or rr elat on urn ron pat _r nl a ndl trrat c-rn il hllf i i bs. I. -ni.



Koch,, R. I.1 jnd R~. T. CllrG. L' 5Sb. Genetic ard .-re Irconmental~lt
relai os n jIh Fip mo~ng I:. on :m ic hi r ac tfr i n beef r attle rii. 11.
Correlatrion bet reen aiffspring and rlsnm and~ offspri;ng ind~ cre.



Koch,I R;. F;;. .irnd Rj. T. Clark. 19 55c. C.-r~Ieic ind in -irronr-inrn.jl

E iluatirng r na tc rn. i11 en trl. i ru ,rn t. I. -n r e 1 : 7 .


I-rirncr, C. Y'. '1950. E::tenno~n io multiple rai~nge tests to grojup
rne=~i .ns- ithi urn*:-p.~.alnumblr- rs .l r I pli_ation~. 1im 27







L ul ei,, j. F. 19j6:. Generles of ~i i.e jtmi-. Impro. em.:nt. P-renitice -
Hrall, Inc., Englet God C~liff, Ne-~. Jeir41, .



cffects. J.I n m Se i ib (.lbstr. ).



an~d mater~rna ~l fciti. on-I Sro=*.Th in Hcrciford: I. En*.lranmental



cal-.es. 1.l iL Dalry 'icli. -15.990 '1~











e'.:.rrctctrs ini dual-purii3 e iatt~i le bre.:. :1i~ir.. Prod~.



11c~urc S. F. ll a d T N.i.T -sch n.. 196E. he ieffr: of









I.flt~lon, A. .., J. K. Riggs~, L. .-.. Nelson and T. C. Csrt-.*.rtght.
196*'.. f-lill production:~ ani call ga~ins rf F.*"angus, Chairrlais
and He~refords. J. ..rsim. Sci. 25.253 1,absr.).



1907.~ '.l prroduclion c orop j~l~c 5It ion a nl ca iiiSjin s of~ Angu 5,
Ch-arclais and I-clereord cows. J n m ci 68


I~taller, P., 11. .1nd L I.~ I.c ala d 195 R l l r.s bi,-t .e n
v~..uzight -t first cal.-ine andl Irnal produ~~tctin duiring the- firjt
1.-httio~n. JT. Di~jr* 'ji. 43: 1932.


:.10ntsms,, G. 1960. Oibsir. r*:atra.ss o m:lk ),*2.:d -andl ,-il gro th
car.dl i:on.r310on ratei c~ln three~I types. of cattsle In Ghajna. T ii
Trcy-.. Ar. 3;.-29.

!.;o0mama, G;. 1-02. Ob.--e st.li:n :n i of rlk; ,-1.=ld ind calf gr;e.tl .t
and co:n *:.r nocn rate on thrrc-. cr.n .:,i cattlr usi Ghsn a~. 11.
Effect of plan,= ofoor~trition. TLlnsda rc~.g. Agr. 33 123.

F.1u nfrd, R. E., I. L C.:mp~btll, F. 11. 2.1cDnr...al and A'. W'. L.
Ds.i;. 1901. The effecti re ri-itritcte pirazing du~ring3 a ringli





do, al--. ?' r. mil IdIF m ;ik i Conpo ito as nd butte r cfa jt ch race is

i;f Jerse, o.---i~. Ji. D 1~1.J ca. 1: .


Nelon A. B., D~,. F.irru~n, ar~d ?.1. 'd ec rr )61. 2.1111- product
of cn g, beefri c j~ro .. a s :; l cted; by''''' le:-'i' "l of up l m n al r *it r
feed.i~il; ~ C J. Asum.; Enr:1. 20: -1 ( b t . 'n i. 5:. ': -


Hea.llo. W. E Jr. 192l. E.Influence ofli dam's~ IntlP iprouto



He Ille, W~i ~ . F. r .-.1n. 11stid H.L.'.cm bel n





I-. E. Seill.J 1962. Ic~ nfluans~i.e of d:s n'-i m cik produtt




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