Studies of productive traits in a New Zealand Romney flock : the effect of some environmental factors, heritabilities and repeatabilities : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey University

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Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author.

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STUDIES OF PTIODUC'riVE _TR!'JTS ll� A l;EH ZEJ..L.i!l-TD Rm'INEY FLOCK�

T'".till EFFECT OF SQT.ill ENVIRO.lTIVIENTi _..L ?ACTORS 9

HERIT!LBILITIES _;·,ND REPE..W.:i.BILITIES

A tb.osis pr0sentocl in partial fulfilr.wnt of tlle requiror.wnts for the degree of aaster of .·l{;Ticul tural Scionce

:.n .,.ni;:-Jo.l Sci cm c. e

at

Massey Univorsity

ROGER SCOTT LUNDIE

197 1

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ACKUOULEDGEHENTS

The candidc.te is (.;Tco.:tly obli2;od f�l' ^th0 t,uⁱd.ru1co of ^his

surerviso:r9 Professor ;�.L. H2.e.

Spocie�l t.t.anks :-..re duo to Mrs. K.L. T�atchor9 r,Trs. P.C. Kirklnnd9 Hr. B. T.u.atchor ani Mr. C,G.R. ^Nuir ^for theil' assistanc8 in compiling t�10 d.ato.. Gr<xtoful acknovrl oucor,1en t is !::::cle tc tllo s^taff of tb.o

Mo.ssey University Con:putor Unit aml tlw ^!·,lassey University Libro.ry for their Hillinz 2..:.81:;::>.

T�:.n.K:s _are als:) oxtcmd0rl to Iili3s S. T.f.I. Boynton ^for^�10r

assistance duriw; thu pre:c;c:'.:r,cticm of t�lis tllcsis.

;r�is \Wrk u.:::ts ^:1idurl '::y ::... :LTm; Zoe.l':ln8. \Tool Board Schola.rsl:i:;;.'

�nd for ^t�is tllo co.nliJ.o.to l·iisl.os t:J ;:;:;;:1.;ross his tll2.11.ks.

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TABLE OF CONTENTS

ACKNO\'/LEDGMENTS LIST OF Ti!..BLES

Chapter

I. INTRODUCTION

II. REVIID/f ^OF LITER.�TURE

. .�.. '·

1 ^• (ⁱ) (ⁱⁱ) (ⁱⁱⁱ) 2.

)^.

B.

1 •

(ⁱ) (ⁱⁱ) 2.

c.

1.

2.

\'lEANING llEIG,IT

Environocntal effects

T�e magnitude of environmental effects

Interactions between Qain environmental effects Partitioning t�e components of variance

Estimates of heritability _and repeatability Summary

HOGGET GRE:\.SY FLEEC..E \rlEIGHT

Environmental effects

The magnitude of environmental effects Partitioning the components of variance Estimates of heritability and repeatability

Summary

REPRODUCTIVE RA·rE Introduction

Environmental effects

Page

ii

vi

1

5 5 5 5 10

11 12 14 15 15 15 15 15 19 21 21 22

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( i) 'rlle magnitude of enviroru.1ental effects 22

(^a) :;...:;e of GT:ie effect 22

(^b) Date of laJ:Jbi·,.g iTi t_�_1in the larnbinc; season 27 (c) ::sffect of t_he body 'Nei(Silt of the evre 28

(d) Yenr effect 29

3. Partitionin� t�e components of variance 30

4. ^Estimates of repo�tability and heritability

(i) Repeatctbilit;;r (n) :Barrenness

(b) Nur.1ber born per e;Te joined

(^c) ^lfunber ^1•reaned per ewe joined

(d.) ^Number ^{torn per} ^eHo ^lar:1bing

(ⁱⁱ) ^lleritabi^lⁱ^t^y (^a) lJarrenness

(b) .i'Jur:�ber born pel' eHe joinsd

(c) _Nunber>voanell per eue joined

(cl) _NurJber born pe_,_' e;·Te lambing

(ê) ^{Sine; le} ôr ^r:tul^tiplo ^bi^r^t^'.l^s (f) ^Nur.:ber^vleaned ^per êue ^lnmbing

s. Summary

D. vlEIGHT OF L .. ',M.B \!EiJ.'TED

III. SOURCE OF DATA

HISTORY AND !·'L'I.N":,G.EIIIENT ^OF 1'riE ^FLOCK B. DATi>. AND DATil. COLLEC'l1ION

c. THE CASE OF 'I'HE INFERTILE R:lllli USED IN 1962

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32

33 33 34

Yl-

35 36

36

37 38

40

44

46

49 50

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IV o THE ME.iSUI\.ElVIEi'J'rS USED L'J ·.r.a� ^STUDY

.a.o /,

B.

CORP..ZCTIOn F ^...^CTORS FOR IS'I'Il'-LTll'JG VlEIJHT OF L�J.·ffi

\f:I:iJT:sD

V o riE'YtiOD OF ;i.J:L..LYSIS ;,::m RJSUL'l'S

1 •

2.

3.

Solution vf equ.atj_ons

Tcstine for _3.n inter·action te^t•^;lêêⁿ_;if:e ôf dar;;

e.nd Birt�1 ::1nd ^rearin:::,· off ect for >r<Jani:'lC;

ueit;llt and :20,;get floocc ueieht

:1-. J�nalysis of v2ri:::.nce of envirumientill effects anJ

partitioninG t�:e variance co1:,ponents

s. ^Results and �is0ussion ESTIH.'1'l'IOH _OF HEP:::::.: ^..'Li.BILITY

1 ^• Introd•.1ctiun and r:;ct:2od of ,"-nalysis

2. Results anJ discussion

c.

1. Introduction and i•let:.od3 ^of ^analysis 2. Dam--offsprinc relationslli:r; r:wtb.od

Paternal h.1lf-sib met�oJ Results ^and discussion SUMIVL:illY

11PPUTDICES

51 51 53

55

62

6) 75 75

79 79 30

31

87

90

1 00

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1 I S T 0 F 'rable

Es·ciw..:ttGs uf environmontnl effects on \Jeo.nint:: v10L�!.:lt

2 Pc:rti ti onin;:; the -h�J�::.anco cor:rf.JOrwtrts

3 Estir,tatos '·. ).p t!.::.o l::.eri tc.bih ty of -,Joc:tninc lleit.<ht 4 3stir:ntos of •Jnvironr;v_mtal of'feots en b.ogcet g:r.·e2.sy

fl:;oco ;:e::.,_,;J,t

5 P:::rti."Cionin[; tlle variance uor::ponents

6 T;;sti�J-: tes of l.!.eri tJ.oili ty I."Jf lJ.o�o'(sc:t �reasy fleece

�lOit�lyt

7 ^Estiuateb of repoe.tabili ty of lWJ'l:J'Oi c;rcasy

fleece �laic�llt

10

11

12

13

15

'rl:;_,:; eff·:;Gt ^ofc;,;;e on the ^num.bor of 8\Jes ^bc:trron 1'12.8 of-;_ ^·'30+, of El{':f:l ^;)f 1.CMO on roprocluct:i.VG f.tG3.SUI'GS b��-:.8d. Jtl t:1.n ;.1Uiilbcr of' eue�3 joined.

�18 effect of 270 of ewo en roprcductive w8asures

basod. on t�w nu.r:�ber of 0·-iuC lar.1bin._';

:P::trtj_ tior.in:, tl:o va.ri::;.nc0 coi:rponcn ts for ce.::sures of rcpl·od\cC-':-i vo ra tc, j_r:_ .".w:;trnli3.n Me:rinos

.Part:!. tioniiJ.t; t:�_-J v'-':cio.noo coc:pononts for i.lea.;:;ures of

rep:.·oc1.ucti7c ::.·nto i11. N.Z. ^Ror:moys

Matrix ·J e Lcsst-:::qu'lros equations I'or uoc1ning nei1sht

Nc:L'!;::t:·iJ: 2 g Loast-sq_uaros cqua tions ^{for fl}oece Hei(Sht

Nn.trix 3g Leo.st-sq_uares equation^s for oeasures of

reprcduc-tj_ve rate

16 _{�btrix 4}� Reduced least-squares equations for

1·1ean-Ln�; vreight

'1\lstj_ng for the j_nteraction betiveen age of <.la1:1 and l.Jirth and rearins· effect for neaning vTeight and hogget

fleece weig-ht

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P:?,ge

6&7 12 13&14

·j6

18

23 25 26 30

31

59

60 61 64

66

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1 0 Matrix 5g Reduced least-squares equations necessary for the e.nalysis of variance of the vlGanintr 1;rei:;ht year effect

19a Nagni tude of onvironraen-l -,1 effects as do^vi::.^tions frorJ tlle li1G2.n

1:Jb l·iagni tudo of onvironr.wntal effects .-·.s deviations fror.1 tho _raoan

20a ; .... Ylalys,is of va::>:'ianco _cf •,;e::ninr�· ',roieht anci fleece

>·roi;;t.t

20b ..'u"lalysi;:; of variance of ^cha.ra.ctc::rs raG.:::.surin::;·

6J

70 71

reproductive rate 71

21 a 'rl.w ^ni1-::7ni^tu:leof effects bet>leon subclasses of

environrJentnl factors 72

21b T�e n::tgnituJe of t�e effect of differont asas ^of dam

on various neasuros of repro_ductive rate 72

22 'rho v::t:rio.nco cor::ponents as a ];.Jercontage c:f tot::'.l vilriu.nco

23 Ropoatability estir::�tes

24 Hori tabili ty ostirntes by paternal h2.lf-sib r.1utl10d

25 Huritability esti��tes for tlt.L.W. _bydan-offsprin�

rcc-;rcszion

7-1 'T

26 Tho ⁱn^vers_e _of tho roducocl lcilst-squ:::.ros e^quations fJr Heanirlb \vOiG"ht for all ^•J:'fects oxcept tho set for years 103 27 The analysis of v_:o.riance ^1vi^t!:: t�e �1S expectations

Variance corilpononts .:;.c a percenta(·;o of total vari:mco 29 Sin diagon^{al ol}^OrJen^{t anCi}bkY Cl' a j? a ^2.-ndRHM so_guen t

of the SiJn equationi:' of the full (^sires ^included⁾

1 06 1 06

ue,.min{-.;' vloicht 1 10

30

31

A A A ,...

The bk, cl, aj, d and RIIJ:.1 ^segmênt of tho bk, cl, aj and d êquations ^{of the} full (^sires încluded)

vleaninc; weicht oodol

FUll (^sires ^included) ^weaninr;l'lOit5llt mn trix vli tho<,

ti and s8 equations absorbed

1 1 1 1 12