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.
A thesis presented in part ial fulfilment of the requirements for the Degree of Mas ter of Agricultural Science at Massey University .
John Martin Rendel 1985
ABSTRACT
Performance records on 2 1 9,000 ewes and 23 1 , 000 lambs from 48 Coopworth f locks were ob tained from Sheeplan files . The f locks were divided into 5 climatologically similar regions : Northland ; no rth of Taupo excluding Northland ; remainder of the North I sland ; the South Island north o f Palmers ton , excluding the Wes t Coas t ; the South Island south of Palmerston . Flock records were edited in an e f fort to remove recording errors .
Within-flock environmental estimates were obtained using o rdinary least squares procedures for continuous characters or iterative weighted least squares for binomial characters . The wi thin-flock es t imates were weighted by the inverse of their standard error ' s and weighted means o f the regional and nat ional fixed effects were obtained . Paternal half-s ib heritability e s timates were obtained for each flock .
There were few signif icant dif ferences in the environmental estimates between regions .
The trai ts examined (wi th the average of the heritability
e s t imates) were : weaning weight (0 . 1 7 ) ; ram autumn liveweight ( 0 . 24 ) ; ewe autumn l iveweight (0 . 26 ) ; ram winter liveweight (0 . 26) ; ewe
winter liveweight (0 . 3 1 ) ; ram spring liveweight (0 . 29) ; ewe spring l iveweight (0 . 34) ; ram hogget fleece weight ( 0 . 29) ; ewe hogget fleece weight (0 . 33 ) ; survival o f all lamb s ( 0 . 04 ) ; s ingle lamb survival
( 0 . 05) and mul t iple lamb survival (0 .05) ; proportion o f a ewe ' s lambs surviving (0 . 04) ; number o f lambs born to a ewe present at mating (0 . 1 2 ) ; number o f lambs weaned per ewe lambing (0 . 07 ) ; given a ewe lambed, d id she bear multiples ( 0 . 1 4 ) ; weight of lamb weaned p er ewe rearing lambs (0 . 1 0 ) . Selec t ion and non-random mat ing may have biased the est imates .
ii
ACKNOWLEDGEME�TS
To my supervisors, Dr G . A . Wickha�, Pro fessor A . L . Rae , and Pro fessor R . D . Anderson , I extend my gratitude for their as s i stance and advice given during this s tudy and for the critical reading o f the manuscript .
I thank tho s e Coopworth breeders \.)'ho allowed their flocks to be inc luded in this s tudy, and the :1inistry o f Agriculture and Fisheries for organizing quest ionnaires to breeders requesting access to their Sheeplan data f iles . To Mr R . Delahunty , Minis try of Agriculture and Fisheries , I o f fer my thanks for the extraction of the data from Sheeplan files .
I o f fer my appreciat ion to the staff and pos t-graduates o f the Department of Animal Science for provid ing a stimulating environment in which to s tudy .
I thank the computer staff for overcoming small computer
"hiccups" due to the size of my data s e t .
The financ ial assistance given b y the Leonard Condell Farming Scholarship Trus t , the Dr Hugh Wenham Coopworth Fellowship , and the Sir James Gunson Scholarship is gratefully acknowledged .
A spec ial thanks is extended to :1r s V . Hansen for skilfully typing the thes is .
ABSTRACT
ACKNOWLEDGEMENTS
TABLE OF CONTENTS
CHAPTER ONE : INTRODUCTION
CHAPTER TWO : REVIEW OF L ITERATURE 2 . 1 Introduc tion
2 . 2 Methods o f Estimat ing Correct ion Fac tors 2 . 2 . 1 S tatistical Procedures
2 . 2 . 2 Mul tiplicative and Additive Adj ustments 2 . 3 Evaluat ing Me thods o f Est imat ing Correction Factors
2 . 3 . 1 Equalize Means and Variances 2 . 3 . 2 Heritabilities
2 . 3 . 3 Intra-class Regress ion and Correlation Coefficients
2 . 3 . 4 Repeatability
2 . 3 . 5 Herd-by-age Variance Components
2 . 4 Environmental Estimates for New Zealand Dual Purpose Breeds
2 . 4 . 1 Weaning \.Jeigh t 2 . 4 . 2 Late Liveweight 2 . 4 . 3 Hogget Fleeceweight 2 . 4 . 4 Reproduct ive Traits CHAPTER THREE : MATERIALS AND METHODS
3 . 1 Source o f Data 3 . 2 Prel iminary Editing 3 . 3 Traits
3 . 3 . 1 Weight Traits
3 . 3 . 2 Reproductive Traits 3 . 4 Stati s t ical Methods
3 . 4 . 1 Estimates o f Environmental Effects for Continuous Traits
3 . 4 . 2 Estimates of Environmental Ef fects for Binomial Data
iv
Page No .
ii iii 1 2 2 3 3 6 7 7 9 1 0
1 1 1 2
1 3 1 3 1 3 1 7 1 7 2 0 2 0 2 1 2 2 2 2 2 3 2 4 2 4 2 7
3 . 4 . 3 Analysis of Regional Dif ferences 3 . 4 . 4 Heritability Estimates
CHAPTER FOUR : RESULTS AND DISCUSSION 4 . 1
4 . 2
Environmental Es timates 4 . 1 . 1 We ight Traits
4 . 1 . 1 . 1 Regional Comparisons 4 . 1 . 1 . 2 Nat ional Es timates
4 . 1 . 1 . 2 . 1 Weaning �-leight 4 . 1 . 1 . 2 . 2 Autumn Liveweight 4 . 1 . 1 . 2 . 3 Winter L iveweight 4 . 1 . 1 . 2 . 4 Spring Liveweight 4 . 1 . 1 . 2 . 5 Hogge t Fleeceweight 4 . 1 . 2 Reproduc tive Traits
4 . 1 . 2 . 1 Regional Comparisons 4 . 1 . 2 . 2 Nat ional Estimates
4 . 1 . 2 . 2 . 1 4 . 1 . 2 . 2 . 2 4 . 1 . 2 . 2 . 3 Heritabi lity Estimates 4 . 2 . 1 Weight Traits
4 . 2 . 2 Reproductive Traits
NLB , NLW and MULT
ESURV , LSURV 1 and LSURV2 Wt . L . W . and Wt . L . W . BR .
CHAPTER FIVE : SUMMARY B IBLIOGRAPHY
29 30 3 1 3 1 3 1 3 1 44 . 46 49 50 5 1 5 2 5 3 5 3 65 65 65 67 69 70 82 94 96
2 . 1 2 . 2 2 . 3 2 . 4
3. l
4 . 1
4 . 2 4 . 3 4 . 4 4 . 5 4 . 6 4 . 7 4 . 8 4 . 9 4 . 10 4 . 1 1 4.1 2 4 . 1 3 4 . 1 4 4 . 15 4 . 1 6 4 . 1 7 4 . 18
LIST OF TABLES
Weaning �.Je ight Environmental Es timates for the New Zealand Romney and Romney Based Breeds
Livewe ight Environmental Es timates for the New Zealand Romney and Romney Based Breeds
Hogge t greasy Fleecewe ight Environmental Es timates for the New Zealand Romney and Derived Breeds
Envi ronmen tal Es tima tes of Reproduc t ive Performance for the New Zealand Romney
Definition of the Birth Rearing Rank Subclasses
Within-flock Wi thin-region Estimates of Environmental Effects on WWT
Number of WWT Records in Subclasses and Flocks
Within-flock Wi thin-region Estimates of Environmental Effects on ALW
Number of ALW Records in Subclasses and Flocks
Within-flock Within-region Estimates of Environmental Ef fec ts on WLW
Number o f WLW Records in Subclasses and Flocks
Within-flock Within-region Estimates of Environmental Effects on SLW
Number o f SLW Records in Subclasses and Flocks
Within-flock Within-region Estimates of Environmental Effects on HFW
Number of HFW Records in Subclasses and Flocks
vi
Page No .
1 4 16 18 19
26 32
33 34
35 36
37 38
39 40
4 1 Nat ional Estimates o f Environmental Effects on Weight Traits 45 Nat ional Estimates of Environmental Effects on Weight Traits 47 as Percentages of the General Mean of each Trait
Within-flock Within-region Estimates of Environmental Effects on NLB
Number of NLB Records in Subclasses and Flocks
Within-flock Within-region Estimates of Environmental Effects on NLW
Number o f NLW Records in Subclasses and Flocks
Within-flock Wi thin-region Estimates of Environmental Effects on MULT
Number o f MULT Records in Subclasses and Flocks
54
54 55
55 56 56
4 . 1 9 4 . 20 4 . 2 1 4 . 22 4 . 23
4 . 24 4 . 25 4 . 26 4 . 2 7 4 . 28 4 . 29 4 . 30 4 . 3 1 4 . 32
4 . 33 4 . 34
4 . 35 4 . 36
4.37
4 . 38 4 . 39
\.Jith in-flock Within-region Estimates of Environmental Effects on ESURV
Number of ESURV Records in Subclasses and Flocks Within-flock Within-region Estimates of Environmental Effec ts on LSURV
Number of LSURV Records in Subclasses and Flocks Within-flock Within-region Estimates of Environmental Effec ts on L SURV 1
Number of LSURV1 Records in Subclasses and Flocks Within-flock Within-region Es timates of Environmental Effects on LSURV2
Number of L SURV2 Records in Subclasses and Flocks Within-flock Within-region Es t imates of Environmental Effects on Wt . L . W .
Number of Wt . L .W . Records in Subclasses and Flocks Within-flock Within-region Estimates of Environmental Effects on Wt . L .W. BR .
Number o f Wt . L . W . BR . Records in Subclasses and Flocks National E s t imates of Environmental Ef fects on NLB , NLW, MULT , and E SURV
Nat ional E s t imates of Environmental Ef fects on LSURV , LSURV 1 and LSURV2
National E s t imates of Environmental Ef fects on Wt . L . W . and Wt . L . W . BR .
\.Jithin-flock Heritability Estimates , S tandard Errors of Heritability Estimates , Number o f Observations and S ires Nested Within-years for WWT
Within-flock Heri tability Es t imates , S tandard Errors of Heritability Estimates , Number o f Observations and Sires Nes ted Within-years for ALW
Within-flock Heritability Estimates , S tandard Errors of Heritability Estimates, Number o f Observations and S ires Nes ted Wi thin-years for WLW
Within-flock Heritability Estimates , S tandard Errors of Heritability Estimates , Number o f Observations and Sires Nes ted Within-years for SLW
Within-flock Heritability Estimates , S tandard Errors of Heritability Estimates , Number o f Observations and Sires Nes ted Within-years for HFW
New Zealand Heritability Estimates for WWT
Page No . 57
57 58
59 60 60 6 1 6 1 62
62 63
64 66 66 68 7 1 72 73 74 7 5
7 6
4 . 40
4 . 4 1 4 . 42 4 . 4 3 4 . 44 4 . 45 4 . 46
4 . 4 7 4 . 48 4 . 49
4 . 50 4 . 5 1 4 . 52 4 . 53 4 . 54 4 . 55 4 . 56
viii
Page No .
New Zealand Heritability Estimates for the Equivalent 78 of ALW
New Zealand Her itability Estimates for the Equivalent 79 of WLW
New Zealand Her itabil ity Es timates for the Equivalent 80 of SLW
New Zealand Heritability Estimates for the Equivalent 8 1 o f HFW
Hithin-f lock Heritability Es t imates , Number of 83 Observat ions , and Sires Nested Wi thin-years for NLB
Within-flock Heritabil ity Estimates , Number o f 84 Observations, and Sires Nes ted Within-years for NLW
Within-f lock Heritabili ty Estimates , Number o f 8 5 Observat ions , and Sires Nes ted Within-years for MULT
Within-flock Heritabil ity Estimates , Number of 86 Observat ions , and Sires Nes ted Wi thin-years for LSURV
Within-flock Heritabili ty Estimates , Number of 87 Observations , and Sires Nes ted Within-years for LSURV 1
Within-flock Heritability Estimates , Number o f 88 Observations , and Sires Nested Within-years for LSURV2
Within-flock Heritability Estimates , Number of 89 Observations , and Sires Nested Within-years for ESURV
Within-flock Heritab ility Es t ima tes , Number of 90 Observations , and Sires Nested Within-years for Wt . L .W.
Within-flock Heritability Es t imates , Number of 91 Observat ions , and Sires Nested Within-years for Wt . L . W. BR . New Zealand Heritabil ity Est imates for NLB 92 New Zealand Heritability Es timates for NLW 92 New Zealand Heritability Est imates for MULT 93 New Zealand Heritability Est imates for Wt . L . W. 93
