private study only. The thesis may not be reproduced elsewhere without the permission of the Author.
A 0 F
STUDY 0 F T HE IN HERI T ANCE
S 0 M·E PRODUCTIVE TRA ITS
IN P ERE NDA L E SHEEP
A thesis presented in partial fulfilment of the requirements for the degree of
Master of Agricultural Science in
Animal Science at
Massey University
KENNETH HAMI LT ON EL L IOTT
1975
A c K E o , , r..� :::: n CJ. :s r,1 E n T s
I wh;h to express my gratitude to all persons Vlho were involvc;o in some way 'Nitll assistan ce in the preparation of this thesis.
It is with special e;rati tude that I ackno':!ledge my supervisors, Pr ofessor A.L. Rae and Dr. G.A. ·,"/ickham. I
nm gre�tly obliged ror the direction and guidance they have given me.
Gro.terul aclr...nmvledger.1ent is made to the stoi'f of l.:assey
University w�o �ere involved �it� collecting, com�iling and RnAlysine the data used. Special tha�ks
Crotty and �r. �. Udy (respect ively, past I:."1Yi8.,Sers of "Tuapska"); I.:r. B. Thatcher,
" 'I rnh � r ( 1.. ·p • 1 · ) d
•.. ::·s. L . L a �,c,:er nee . . 1co .'J.lsen an
go to l.�r • r.; • T .
and prese:1t
Uiss P. Riseborough, P. Su tcliffe
(Technic ians Sheep Husbandry Dept.);
G. Black (�ool Room staff) .
11!essrs. R. Gunn an d
'l'hanks are extendec to �.:r. D. ·,"/ilson qnd ;',:r. D.
Jo�nstone for their assistance �ith co��uter procramme
�riting and operation; �esda�es E. Farrelly, L. Downey and E. Ellis for typing this thesis; the hlassey University Computer Unit and the l.l"EJssey Un iversity Library staff.
Financial assistance from the Perendale Sheep Society of Nevv Zealand and the New Zealand ·Nool Boa.rd is gratefully
acknowledged.
K.H.E.
i i .
ABS'J' D ACT
Genetic p8romct�rG w�rc cntim8tcd using 3,31 3 half-sib
recorc'll> from 62 sj_rDs �J.nrl .1720 daughter-dam pairs . The d3tn u�cd were obtained over the period 1957 to 1972.
Tl1c cstjin·Jtc:::> o::' hc;ritnhility b;:,r paternal half-sib cmd d0u r:;l1 ter-c'lnm r cgre:::>s ion ::malysi s were respccti ve ly:
�can1nc weiGht (0.20 and 0.16); hogget body neight
(0.27 and O.LJI: ) ; fleece v1ei2ht (0.32 and 0.30); quality
number (0.26 and 0.31); fibre ,diameter (0.54 and 0.47);
staple length (0.49 and 0.35); character (0.23 and 0.23).
An estirn�te of 0.03 ·;ras obtained for lambs vleaned/ewe lambing (L'.'I/EL) by the daughter-dam regression analysis trom 665 daughter-dam pairs.
Estimates of genetic correlations were in the following ranges:-
Medium negative
( -0 • Lj. t 0 -0 . 6 )
Low negative
( -0 2 • t 0 -o . 4)
Low positive
(0.2 to 0.4)
!.lediurn p osi ti ve
(0.4 to 0.6)
High positive
(0.6 and over)
. .
. .
Hogget body weight with character.
Quality number with staple length.
',leaning weight Yv'ith quality
number, fibre diameter and
character.
Quality number with fleece weight and fibre diameter.
Hogget body weight with weaning weight and quality number.
Staple length with character.
Fleece weight with fibre diameter and character. ·· ·) Fleece weight with staple
length.
Phenotypic and environmental correlat i ons were also cstimC1tec1. Fhenotypi c correlation� generally agreed with the genet i c cor relat i ons. Important exceptions were hogget body weicht with fl eece we igh t , s taple length and fibre
d:Lamctcr.
Among the environment a l f ac tors stud ied, age of dam on� rear ing rank effect s f or t h e wool tra i t s were generally smnll. These effects ha� a marked i nfluence on weaning wei�ht and hoggot body weight. At weaning, singles were
�.2 kg heavier than tw i n s , whi� a t 14 mon th s . thi s d ifference had been reduced to 2.1 kg. ·."men comparing a two-year-old ano mature age of dam eff ect s , a 1 .�4 kg diff erence a t
weaning in favour of the mA.ture age of dam reared ani::Jals ,
wus reduced to a 1.11 kg �ifference at 14 months.
Tb e C:-3 t i mn ted IJo.rnrncters o.nc1 env ironmental off c;cts •:1ere discussed with refer ence t o the ir i mplications in s elect ion programmes.
Relationships between hogcet trai ts nnd the e�e s life
t ir.J.e production (four consecutive years) were analysed.
Records from 458 s h e e p w e re u s ed.
Cor relat i on co eff ici ents indi ca t ed that ho3ge t fleece weight, quality number, fibre diameter and s taple length were �ood i nd i cator s of l if e t ime ewe performance for ttese traits. The results indicat ed that a poor relat ion e x i s t s between hogget body w e i gh t and number· of lambs weaned by t he
ewe over four lambine;s.
A regression analysis of hogge t traits on life-time economi c value of the e w e ind ic a t ed thn t f l e e ce weight a n d hogget body Yle i.ght we r e the most important variables
i nfluenc i ng l i f e-t i m e econom i c valu e.
I mpl icat ions of the r e s ult s were discussed with d reference to selection and culling progr ammes at th� hogget age in ram breeding and non-ram breeding f lock s .
T AB L E OF CONTENTS
ACKNOV!LEDGE�.�ENTS • • • ABSTRACT •••
TABLE OF CONTENTS • • • LIST OF TABLES • • • LIST OF FIGURES.;.
Chapter
I II
I N T R 0 D U C T I 0 N .
R E V I A.
B.
c.
:S ·.'! 0 F L I T ER AT U RE.
3?NIRCrrr�ITTAL EF-:<'ECTS •••
REPSJ; TABILITY • • •
D . REL..t..TIONSEIP B�T�:IEEI-; EOGGET
CPARACTERS At-ID LIFE-TUffi PERFORHANCE •••
iv.
Page
i
ii
iv v i i
ix
Page
1
4 4 5 1 1
13
E. SSTH�l\TES OF H:SRITABILITY... 16
III
1 • Estimates for 7!ool Traits.. . 1 7 2. Estimates for Weaning and Hogget
Body Weight... 1 9
3. Estimates for Number of Lambs
F. ASSOCIATION BETWEEN PRODUCTIVE
TRAITS • • •
G. SELECTION FLOCK RESULTS • • •
S 0 U R C E 0 F D A T A •
21
23
·�6 38
Chapter IV
V
VI
E s T I i.: A T I 0 N OF HE R I T -
A B I L I T y A N D GE N E T I c
c 0 R R E I, A T I 0 N s .
.:'\ . INTRODUCTION ...
B. PATERNAL HALF -SIB AHALYSIS OF
V P.RI.ANCE AND COVARIANCE
(l..fethod 1 ) • • •
c. DAUG�TER-DAU REGRESSim�
(Method 2) • • •
D. RESL�TS A�� DISCUSSION • . •
1 • 3nvironmental Eff ccts . • • 2 . Heritability Es timates . • •
3. Association Between Traits • . •
R E L A T I 0 N s H T p 0 F � 0 G G E T CHAR A c T 1<' d R I s T I c s T 0
L I F E A.
T I �.� E PE R F 0 R M A N C E • • •
B.
INTRODUCTION . . •
r.�TPODS • . .
1 • Correl ation Between Hogget and Lifctine Ewe Performance • • •
2. r.1nl tiple Regression Analys is of
Lifetime Economic V alue on Hogge t Characteristics • . •
C. RESULTS A�� DISCUSSION . • •
1 . Correlation s tudy • . •
2. W.ultiple Regression Study • • •
D I S C U S S I 0 N • . •
Page
40 40
40
46 50 50 59 70
81 81 83 83
83 8 9 8 9 94
Geneti c Sele cti on for Wool Traits.�. 102 Genetic Sele cti on for Hogge t Body
','leigh t, i'/caning Weight • . •
Sele ction Ind ex • • •
1 06 1 07 Improv ement of Ram Br e eding Flocks • • • 109 Cur ren t Flo ck Impr ov ement... 11 0
Ferti lity... 115
�vins v Singles • • • 115
B I B L I 0 G R A P H Y . . .
vi.
Page
1 1 6
A PP E ND I C E S • • • 130 I Computntion of
R(JA.a.;,/.J;,/,C�e,d.e)
IR(;;..,a.,·,cit,dt) c(u,a;,AJ'J·lc,<,di) } J< clua; L } ' �<> c
J
-<• )
• • • 1"'0 �II Calculation of The Coefficient K • • • 134 III Coded "i/ool Quality Numbers... 135 IV Performance of Twins v Singles... 1 36
V Selection Index Study... 141
L I S T 0 F T A B L E S
Table Title Page
1 ESTnlATES OF ENVIRONMENTAL EFPECTS . .. 7
2 :···rnr:f\Tt.:S (l't<' ":NVIRONHENT.AL EF"'ECTS• • • 8 3 TIM'�C'rS OF SIMPLE CORRELATIONS AMONG TRAITS • • • 1 5 4 smm ESTIMATES OF HF.R.ITABILITY FOR WOOL
TnAITS • • • 1 8
5 sm�E ESTIHATES OF HERITABILITIES FOR
·:,'EA!Hl'-:-G ·.-/EIGHT Af-ID HOGGET BODY ','.'�IGHT. • • 20 6 HERITABILITY ESTIUATES FOR NUMBER OF LAMBS
7
8 9
·:,'EANED/E'.'.'E JOINED • • •
ESTIMATES OF GENETIC AND PHENOTYPIC
CORRZI,ATICNS BET'.r/EEN CHARAC'L'ERISTICS IN . M'SP.INO SRESP • • •
ESTH�ATES OF G:Z�TETIC Al\"D WENOTYPIC
CORRELATIONS IN Rm.�NEY SHEEP • • •
SOME PEENOTYPIC Alill GENETIC CORRELATIONS
BET\'!EEN C0:2RECTED ·.�lEANING 'iVEIGHT Al\'D OTHER CHARACTERISTICS FOR MEP..INO E'l/ES (Pat tie,
2 2
2 5 27
1 965b) • . • 34
1 0 1 1 1 2
1 3 1 4
1 5
ESTinATES OF F.NVIRONliEKTAL EFFECTS • • • HER ITABII,ITY ESTIUATES • • •
COI.�PARISON' OF RESULTS OF CH' ANG Al'!D RAE
( 1 970) Arm OF THI S THESIS FOR WEANING
V.'EIGHT A�� HOGGET BODY ':/EIGHT HERITABIL ITY ESTIMATES • • •
ASSOCIATICN BETWEEN TRAITS • • •
ENVIRONMENTAL CORRELATIONS BETV/EEN THE TRAITS 'NEANING '.�/EIGHT AND HOGGET BODY ':"'/EIGHT ·.nTH OTHER TRAI T S • • •
El'NIRON'MENTAL CORRELATIONS WITH THOSE
ASSOCIATIONS \VHERE GENETIC CORRELATION ESTIMATE S DIFFER IN SIGN • • •
}
51 60
74
77
T8ble Title
1 6 ZERO IJENGTH VAL1JES AFD PRICE INCREMENT PER STAPLE LENGTH INCPEME!\TT COEFFICIENTS FOR CO�PESPO�IDING 0UALITY !\�MBEP RECORDS •••
17
1 B 1 9 20
CORRELATION COEFFICIENTS BET\VEEN HOGGET .TRAITS AND IJIFETH';E E".VE PERFORMANCE • • •
MEAN LIFETIME VALUES • ••
1-WLTIPI,E R:<:GPESSION A�TALYSIS RESULTS • • • STAND_I\RD P/LT-{TIAL REGRESSION COEFFICIEl'l'TS USING QUALITY l'TIJMBER �ND FIBRE DIAMETER AS
T.:E BASIS OF ·�'/OOL VALUATION • • •
21 CORRELATION COEFFICIKN1'S F OP HOGGET TRAI TS WITH LIFETIME E'f/E PERFORMANCE • • •
Apnendix
III (1) CODED WOOL QUALITY NUMBERS AND MICRON
viii •
Page
87
91 94 95
100 1 1 1
VALUES • • • 135
tv ( 1 ) MEAN VALUES FOR RECORDS FROM TWINS A1'D SINGLES • • •
V (1 ) RESULTS FOR THE FOUR SELECTION I1�I CES
UNDER STUDY • • •
V ( 2) PARM!.STERS USED IN CONSTRUCTION OF THE
MAIN HIDEX • . •
V ( 3) V (4)
V ( 5)
RESULTS FOP THE MAIN IN DEX • • •
PARAMETERS USED IN CONSTRUCTION OF THE MAIN IND EX • • •
RESULTS FOP THE MAIN AI\TD RESTRICTED INDICES • • •
)
136 143
146 147 149 150
Fig.
L I S T 0 F F I G U R E S
Title
1 YEf..RLY VMn.ATION IN 0UALITY NUMBER AND FIBRE DIAMETER • • •
Page
56
2A EERITA3ILITY ESTIMATES... 61
2B EERITABII,JTY ESTIMATES. • • 62
3 PRODUCTION STATISTICS - UEAN PERFORI! • .ANCE... 89 4 A GRAPH OF STAJ\"TIARD PARTIAL REGRESSION
COE.F'l<'ICIENTS V RATIO ·vooL : LAMB VALUE FROM
FOUR MULTIPLE LINEAR REGRESSION ANALYSES... 97
Appendix
IV ( 1) LIFE-TIME E1.VE FLEECE •t/EIGHT... 137
V ( 2) LIFE-TIME EWE LA��ffiiNG PERFORMANCE... 1 39
)
