A study on the inheritance and phenotypic and genetic interrelationships among some physiological and productive variables in Jersey cows : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science, Massey University of Manawatu, New Zealand

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 STUDY ON THE INHERITANCE

AND

PHENOTYPIC

AND GENETIC INTERRELATIONSHIPS Af.10NG SO£.�

Phl'SIOLOGICM, ATW PRODUCTIVE VAPJ:ABLES IN

JERSEY

COWS.

A

ThP.sis pre3ented in }'9.rt1a1 fulfilment of

^t!:le

requirements for

the decree

of r�3ter of A�ricultural 3ci�nce

by 3.

^P.

SHAm· !A

NaSi]ey University of f·lanawatu, New Zealand.

October,

1964

'-IIU•V

MASSEY UNIVER51TY OF MANAWA'fU

PAU.\EIUTON NORTH, N.Z..

"The

key is man 1 s power of accumulc:•.ti ve selection:

nat'lre t;ives successive variations; man

adds

^them

U}J

in

certain directionR useful to him." - Darwin, p.

35,

sixth edition

of

^"The

Ori�Sin

of Species", 1920 (Quoted

by

Hazel, L.N., 1943).

ACKNOWLEDGEMENTS

The author is indebted to Dr.

D.S. Flux,

Dairy Husbandry Department, Hassey University of l'ianawatu, for his advice, guidance

and

constructive

criticism during his supervision of t�1is study; to Dr.

R.E .

l-iunford who acted

in

a

supervisory capacity in the absence of Dr. Flux; to Professor

A.L.

Rae, Sheep Husbandry Department, for his advice on statistical procedure.

Appreciation

is also

9xtended to other members of the Dairy

Husbandry Department

for their

help

in

the initial stac;

e

s of this study; to the farmers who put animals at tt!e disposal of t!1e au. thor for the collection

of

data;

and

to

the library staff for procuring important literature.

Special thanks are du� to l'ir. R.

Ball a�1c

i'1r. To.P. Tripathy whose

sincere

assistance

ⁱⁿ the fin::tl presentation of

this

thesis was a e;reat h'=lp;

and

to Hiss A.

Whitehead

for her care ,.,nd

consideration in typine;

the manus�ript.

'l'he study was undertaken duri.nc; the tenure of a Colombo Plan Scholarship

avrarded

by the Govern."llent o.:' Nevr Zeeland to v;hon the author expresses l1is

sincere

appreciation.

Finally, my

thanks

to everybody else who has

contributed

in e.ny way to this research work.

Chapter

I

TABLE OF CONTENTS

PART I

IN'l'RCDUCTION

REVIEW OF LITERATURE

1.1 Variation Encountered in the Physiological Variables

1

5

1 .2 Influence of EnvironnJPntal Factors on the Physiological

Variables

9

A. Animal Factors

(i) Coat

8haracteristics (ii) Ae.;e

( iii)

Body \Vei;:;ht

(iv) .Stage of Fregnancy

(v) Stace of Lactation and

Production

B.

Climatic

Factors

(i) Air Temperature and

Humidity

(ii) Solar RadiRtion

( iii) Rain and

i/ind

12 14 16

Le

v

el^s 17 20

24 1.3 Techniques for

R

ecordi

n

g the Physiological Variables 26 1.4 Repeatability of the Physiolo

� ca

l Variables 30 1.5 Heritability of the Physiological Variables 35

1.6

Phenotypic and Genetic Correlations Between the

Physiological Variables 38

1.7 Phenotypic and Genetic Correlations Between the Physiological Variables and the Productive

Variables 40

Chapte:!' II

III

IV

PART II Page

PRELH1INP.RY INVESTIGATIONS IN TEE JV!ASSEY UNIVERSITY

^HERDS

41

2.1 Introduction

2.2 Purpose, Ma.terials, Methods and Conclusions 42 2.3 Methods Used for Recording the Physiological Variables 46

REPEATABILITY OF

THE

PHYSIOLOGICAL VARIABLES

3.1 Introduction

� 3.2 Repeatability of Consecutive Readings

(i) Materials and Methods

(ii) Statistical Methods (iii) Results

( i v) Discussion

3.3

Repeatnbility of the Physiolocical Variables when

48

50 51

Observetions were taken at Longer

Intervals 53 ( i)

^Jv:a

terials and Hethods

(ii) Results (iii) Discussion

PART III

COMMERCIAL

HERD

STUDY 4.1 Introduction

4.2 Characteristics of Herds, Stock and Management

(

i) Herds (ii) Stock

(

iii) Management

4.3

_Recording

(

i) General procedure

(

ⁱⁱ⁾ Number of Recordings Obtained

54

55

56

57

Chapter

V

VI

4.4.

General

Materials and

Methods ( i ) M

at

e

r

i

al

s

(ii)

Methods

PF.ELH!INARY INVESTIGATIONS CN

THE

^RA'Ii

DA'l'A

F'OR THE PHYSIO­

LOGICAl VARIABLES 5.1 Introduction

5.2

Between

He

rd

s,

Within Herds and Between

A

ge

G

r

o

u

ps

59

61

Within Herds Variance 62

( i )

^t'Iate

r

i

a

ls and Hethods (ii)

Model Used

5.3 Results

5.4

Discussion

( :i_)

^B

et

^1Neen

Herd

^Variance

(ii) W

i

th

i

n Herd Variance

( iii )

Between Age

Groups

Within Herri

s Varianc e

HERITABILITY 0}'

'l'HE

PHYSIOLOGICAL VARIABLES 6.1 Introduction

( i ) The

^Concept

of

Heritability

( ii ) Methods for Estimation o f Heritability

( iii) Decision on the Method for the Present Study

6.2

Materials and Methods 6 .3 Results

6 .4 Discussion

(i) Correction Factors (ii) Heritability

66

69

70 72

73

75 76 79

81

Chapter VII

VIII

IX

PKENOTYPIC

AND

GENETIC CORRELATIONS BETWEEN THE PHYSIOLOGICAl, VARIABLES

7.1 Introduction

84

7.2 Common Materials 87

7.3 Phenotypic Correlations Between the Physiological

Variables 88

( i) Method ( ii) Results 7.4 Discussion

GENETIC CORRELATIONS BE'r:HEEN THE PHYSIOLOGICAL VARIABLES

8.1 Methods

8.2 Results 8.;, Discussion

PART IV

PH�NOTYPIC AND GENt<;TIC CORRELATTONS BETV:'EEN PHYSIOLOGICAL VARIABLES

AND

PRODUCTIV1; VARIABLES

9.1 Introduction 9.2 l-1aterials 9.3 Methods

9.4 Correction for Age

(i) Lactation Milk and Fat Yie ld (ii) Month's Milk and Fat Yield 9.5 Results

(i ) Variation in Month's Milk and Fat Yields (ii ) Heritability

(iii) Phenotypic Correlations (iv) Genetic Correlations

9 0

93

95 97

99

100

101

102

106

107

111

112

ChaEter Page

9 .6 Di scussi o n 114

(i ) Correc tio n Fac tors

(ii ) Heritabi li ty

115

( iii) Phenotypic Co rre latio n s 1 17

(iv ) Ge netic Corre lations 118

X S�illRY AND CONCLUSIONS

120

LIST OF TABLES

Table No .

1 Ranges,

standard

deviations

and coefficients of

variation of the physiological

variables as

r

e

p o

r

te d

by

Patchell ( 1951) a nd

Q.uartermain

( 1959). 7 2 Comparison of

the

repea tabilities

of single

r

ec

or d

⁶

of

the same cow for the 8 hottest days, V8rsus the entire test period ( repcr�ed

by Seath,

1947).

31 3 Repeatability

of con

se

cu

^t

i

^ve

observations on the

physiolo0ical

v

a r

ia

b

l

es

^{, estimated}

for

dam and daughter

groups separately in five herds.

50

4

Re

pe

^at

a

b

i

^{li ty of}

obser>rations on the Fhysiolo;.:cical

Variables

tak

^{en at}

l o nger

intervals j_n

si x herds,

sep-

Arate

and comb:.ned. 53

5 The

least squares equations for

respiration rate data. 64 6

^{A tabular}

forn of

^the

Analysis of Variance for

testint:;

Interactions.

7 8

0 ./

10 11

An:;:.J.ysis of V

^ar

i

^an

c e

^:

Pulse :tate

Analysis of Variance: Respiro.tion Rate

Test o

f

Interaction (herd

^x

ate 0roup):

?espiration

rate

Analysis of Vari anc

e:

.Rec tal 'I'en:perature

Intra-herd heritability of pulse rate:

dam' s

record

r

epe

at

e

d

with

each daue;hter's

record

12

Int ra-herd heritability of respiration rate ( age­

c orrected) : dam's record repeated

with

e ach daughter's rec ord.

13 14

Intra -herd heritabi lity of rectal temperature: dam ' s record repeated with each daughter ' s record .

Comparison of the mean and variance of age-correct ed and uncorrec ted respiration rate data .

66

66

67 67

76

77 78

8o 15 Intra-herd heritability of respirate rate (uncorrected

data) : dam ' s record repeated with each daughter ' s record.79

Table No . Page 16 Comparison of the heritability estimates o f the

physiological variables estimated in hot and cold environments.

17 18

Phenotypic correlations (within herds) between the physiological variables.

Comparison of the phenotypic correlations between the physioloe;ical variables, estimated under various climatic conditions.

1 S Cross-correl2. tions (within herds) between the physioloEical variables.

20 Within herd mean cross-correlat ions

and within

herd

81 88

91 95

benetic correlations between the physioloGical variables.95 21 Least squares equations for month's milk and fat yields.105

22 23 24

Analysis of variance: m onth's milk and fat yields . Test

of

interactions (herd

x

age group): month's milk

and fat

yield s.

Intra-herd heritability of lActation milk yield (corrected f

o

r ace): dam's record repeated with each

daughter's

record.

25 Intra-herd heritability of lactation fat yield

(corrected for age ) : dam's record repeated with each daughter's record.

26 Intra-herd heritability of month's milk yield

(corrected for age ) : da m's record, repeated with e

a

c h

106 106

107

108

daughter's record. 109

27 Intra-herd heritability of month's fat yield ( corrected for age ) : dam' s record repeated with each daughter' s

record. 110

28 Phenotypic correlations (within herd) between the

physiological variables and the productive variables . 111 29 Cross-correlation ( within herd ) between the physiological

and the productive variables . 112

30 Within herd mean cross-correlations and genetic corre­

lations between the physiological variables and the

productive variables . 113

31 Comparison between the age correction factors used and

those of the Dairy Board . 114

Table No . 32

33

Comparison of the heritability coeffic ients for the produc tive variables, estimates in the present study, with those reported previously .

Estimates of repeat ability, heritability, phenotypic and genetic c orrelations .

116

126

App

endix No.

1 2

3 4

5 6

7 8

LIST OF APPENDICES

Example: estimation of the repeatability of the physiological variables.

Repeatability: analyses of variance for the entire data on the physiological variables.

Complete summa.ry of the data collected during the investigation.

Observations of the physioloEical variables, classified by age, to study the influence of age.

A tabular form of the methods used to calculate ae;e correction f�ctors for respiration rate.

Analysis of covariance for pulse rate, respiration ra"te

(

^age­

corrected

)

and rectal temperature

and

method for estima.ting phenotypic correlation coefficients.

Analysis of cross prociucts used to estimate within

herd

^cross­

correlation.

�ethod used to calrulate ace-corrected herd avera�e for lactation milk and fat yields.