Estimation of important genetic and phenotypic parameters of some productive traits in the New Zealand Romney Marsh sheep : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University

(1)

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.

(2)

� thesis presented in partial

fulfilment of

the requirements

for the degree of �aster

of

rl�ricultural cicience

a t

Massey University

LAXMAN PRASAD

TRIPATHY

1966

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A C K N 0

,,'

L E D G E h :c; N

^T .S

rhe candidate is greatly obliged for the guidance of his supervisors, Professor h.L. Rae and

Mr

^T.S. ^Ch'ang.

Special

thanks

^{are due}

to �r

^B. Thatcher for his assistance in compilin� the data, and to Miss M.G. Campbell and her lib

r

^a

ry

^staff

for

promptly

^procurinb

the

reference a

r

ticles used in this work.

Grateful acknowledgement is made

to

^Kiss E.

Chris t iansen for

taking a speci�l c&re in

typing this

thesis anu to Miss

J.

Clare and Miss N. Jordon for their help in the processing of data.

This

work

was maae possible because of the Colombo Plan

�cholarship aNarded to the candidate and for this he wishes to

express

the

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Chapter

I

T A B L E 0 ? CON 'rENTS

ACKNO

.• LLl.K1 ^..

: J•1.wlH S EHRODUCriON

�.

I�f�OJUCTION

^•

1 .

.wnvironmental effects.

2.

�stimates of parameters •

C. HLiGGLr LIVL .,.c.,IGHT

^•

1 .

Lnvironmental effects.

2.

�stimates of parameters •

3.

^.Summary

D. :rt;.I.LUN.i:.SS ^•

1 .

Environmental effects.

2 .

^Estimates^of parameters •

3 .

Summary

E. MEAN FIBRE

DI

^METER. ^• ^•

1.

Environmental effects.

2 .

Estimates of parameters •

3.

Summary • • • •

•

• •

•

• •

•

• •

•

1

5

6 6 1 1 1 2

1 3 1 3 1 4 1 6

1 6 1 6 18 1 9

1 9

2 1

2 3

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Chap t e r

III

IV

F. .JTrtPL..:: L.bN3'l'H .

1.

Lnvir onmen t al e f f e c ts .

2. �s t ima t e s

o f

param e t ers

3.

.Summary

•

G . CHH1P0

P..::::< INCH

1. Env ironme n ta l

e f fe c ts

.

2.

J:.JStimate.s o f porame t ers 7, ;0

0ummary

00U:::(:.-:.w 0" .r ^� n l.l.� .Ll\

�;__,i_\·UD

OF ,,;·�

J.LY

^.

.j IS n.l:

^.!.- .rL ^..

JULT.S

.1-\.

..:.0 l'H�..l'Ivil OF ..:.NvL,O h

^...^.

J� .I',.L

1

^• ^{Leas t} s quar e s

m o

ciel

2 .

.-.1 e sul ts ana discu s s i o n

B. C0

^.."\.1.

.wC _'J:GI. F.,Ci'O.r{.;:)

1. Intr o duc t i on ^.

2.

Correction fac t ors for

r e c o r d s

•

2a.

Least squ ar e s

m o d e l

2b

. .r<esu lts an d

d i s c uss i o n

• • •

•

�.r·:r�.uC .2S

adjus t ing d am's

c. CORREC'riON F.A.CTOR0 FOR DJUuTING D UGHTER'S

RECORDS

. • • • • •

1.

Least squares

model

^• ^• ^•

2 .

Page

• 24

24

25

26

• 26

27

•

2 8

31

32

40

47 47

48

•

48

•

52

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Chapter Page

D. H.C:RirABILITY E.S rih

^..

cTES .

^• ^• ^• ^• ⁵⁵

1 . Introduction . •

55

2.

r•ie thod of analysis .

56

3-

.t<esults and discussion

58

E. E.:./I' H-'i"

TIOi"i OF

PH._;l\orYPIC

"'ND G�N£·ric

CORh....,Lrt'l'IONS

⁶¹

1 . Introa.uction . 61

2 .

^hethod ^of ^analysis ^.

64

3 .

^Results ^and discussion

72

V DL3CU...,.3 ION

^•

79

V I '-' UJ"·,I·-: ^{... n}

Y

•

8 6

VII J ^..:2 .::.: .-LNC.r-.:.:3 ^• ^•

89

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Tab l e

1

2

3

4

5

6

7

8

9

9a

L I S T 0 F T A B

L E

S

H e r i tabi l i ty e s tima t e s ( r e por t e d in the

l i t e ra tur

e

)

.

G e ne t i c c orr e l ations ( r epor t e d in the lit e ra tur e

).

Phen o ty p i c c o r r e l a t i o ns ( re�o r ted i n the li t e r

a

ture )

^.

Varian

c e- c o v

ar ian c e ma t r i x

( ma tr ix

ⁿ

)

^.

Var iance-c ovar iance ma t r i x

(

ma t r i x

B).

Varian c e-covar ian c e matr i x

(

ma t r i x

C ) .

Leas t squar e s e s tima t e s o f e f f e c ts.

Ana lys is o f varianc e o f t he leas t s quares

e s t ima

t

e s.

Comparison o f e f fe c ts within the c lass es .

Per c en tage o f the to tal var ian c e .

7

8

9

35

36

37

43

44

45

46

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Table 1 0

1 1

1 2

1 3

1 4

1 5

1 6

1 7

18

1 9

20

Estimates of effects for correcting dams' records.

Correction factors for dams' records.

Estimates of effects for correcting daughters' records.

Correction factors for daughters' records.

ndditional R.H.3.'s for B and C matrices

Variance-covariance matrix

(

^matrix

D ).

Fhenotypic variances, standard deviations and covariances.

Phenotypic correlations

(

this study

)

^.

Gene tic co v ariances .

Gen e ti c s tandard dev iations , co rrelati ons and s tandard e rrors ( this s tudy ) .

Heri tabili ty e s t ima tes ( this s tudy ) .

49

51

53

54

68

69

70

73

74

75

76

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11The qualitative, or enumeration d ata, are classified on the 'p assed' or 'failed' basis. The l ittle Victori an serv ant girl,

who confided to her mistress that she was just

a

tiny bit pregnant, would fall straight into the 'pregnant' class. In quantitative tiata, every individual h as a class, or me�surement of its own.''

( 1 962 )