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.
REPRO DUCTIVE EFF ICI ENCY IN
TOWN SUPPLY DAIRY HERDS IN NEW ZEALAND
A thesis presented in partial ful filment o f the requirements fo r the degree of Mas ter o f Philos ophy in Ve terinary Science
at Mass ey Universi ty
Sundar Lal SHRESTHA 1978
ACKNOWLEDGEMENTS
I wish t o express my deep es t grati tude to my sup ervisors Pro fessor E . D . Fie l den and Dr K . L. Macmi l lan for their inte res t , encouragement and gui danc e during th e cour s e o f this s tudy . Wi thou t
their h elp the inves tigat ion would ne i ther have been ini t ia ted no r comp l e ted .
Dr R. E . Harris provided valued a s s i s tance with the considerable vo lume o f c omputer programming an d s ta t i s tical analyses requi red ; I am indeb ted to him for und er taking th is task and to Pro fessor
R. E . Munford fo r valuable s ugge s t ions as to how cer t a in sec t ions of th e da ta should b e dea l t with .
There are many o thers who con t r ibuted willing help wheneve r needed and I thank them. They inc l ude a l l s ta f f of the Mas s ey Computer Uni t
( especial ly Co l in Reed ) , Mas sey Lib rary s taff , Mr I . Hook and Mrs Moosely o f th e Wel l in g ton Hawkes Bay Lives t o ck Improvement As socia t ion , and all farmers who al l owed their records to b e us e d .
The h e l p o f Ms An ge la Low w i t h th e typ ing o f this the s i s a�d o f Ms Caro l B lack wi th the prepara tion o f th e f igures is grea t ly
app reciated.
Financ ial suppor t for these s tudies a t Mas s ey Unive rs i t y was granted under a b i l a teral aid pro gramme by the New Zealan d Government an d H i s Maj es ty ' s Governmen t of Nepal and for this as s i s tance I am mos t grateful.
Fina l ly I would l ik e to thank my dear wife Mohan Devi Shres tha whose s uppo r t and forbe arance dur ing a long period away from Nepal , made
this opportuni ty for higher s tudies poss ib l e .
iii . ABSTRACT
The obj e c tive of the study was to examine the repro duc tive p erformance o f dairy cattle in Town Mi lk Dai ry Herds in New Zeal an d . B reeding and production d a t a f o r parous animals were collected from th e reco rds of twenty herds which ranged in s i ze from 75 to 300 cows . Herd owne rs were members o f the Wel l ington Hawke ' s B ay Lives to ck Improvemen t As sociat ion whi c h pro vided h erd testing and a r t i ficial b reeding s e rvices . There were 12 , 056 c alvin gs recorded involving 4 , 050 cows. Of these 9 , 898 were for Friesian , 672 Jersey , l , Oii 6 Fries ian Jersey cro s s cows and the rema ining 420 o ther breeds and crosses .
Th e p ar ame ters measured were calving interval , calving to firs t service in t e rva l , firs t s e rvice to concep ti on interval , days open , inter-s e rvi ce in terval , c alving rate to firs t s ervi c e and s ervi ces per cow c al ving and were 383 . 7, 84. 8 , 1 1. 3 , 106 . 9 , 4 3 . 7 day s , 49. 3%
and l. 7 respe c t ive ly for the pooled population . Data fo r c alving interval and f irst servi ce to conception int erval were t rans formed for al l anal y t i cal procedures - the unadj us ted values for these p arame ters we re 388 . 7 and 19. 3 days respec tively . The mean milk yield was 3 , 7 30 l i t res and th e wean lac tat ion l ength 29 1 days .
Age , h erd , s eason and year had highly significant effects on b oth producti ve and reproductive p e r formance al though the amount o f variat ion th at could b e exp lained by these variab les was small as far as reproduc t ion was conce<rne d . Any b reed dif ferences which may have b een present were conf ounde d wi th herd effects and no s igni f
icant rel a t i onship was found b e tween herd size and repro duc t i w:�
effic iency . This may have been due to an inadequate number o f s,maller herds i.n th e s a,mple .
S i gnifican t nega,t iye correl ations were found b e twe en average daily milk yield and calving , c &lving to firs t s ervi ce and f i r s t s ervi ce to concep tion in t erva l s . The ir values w·ere so l ow as to be of lit t l e consequen ce .
Rep ro duct ive e f fi c i ency inc reased up to the age of four y ears and then gradually decl ined whereas milk p roduc tion inc reas ed up to the a ge of eightye ars b efo re it dec lined . Th e youngest c ows , particularly
two y ear ol ds, whi ch . comprise a high p ropor t ion of the herd , p e r fo rmed poorly in nearly all reprodu c t ive parame t e rs s t udied.
Th e correl a t i on b e tween c alving to first service and fir s t s e rvi ce to concept ion in t ervals was -0 . 09 and th e s t andard par tial regress ion coeffic ient s CS value s) for c alving to f ir s t servi ce and fir s t s e rvice to c oncep tion int e rval s on c alvin g interval were 0.63 and 0.73
respe c t ively . Thi r ty nine per cen t o f the variation in calving int erval was explained by d ays from ca lving to f i r s t service and 4 5% by days
from firs t s ervi ce to concep t ion .
A high inc idence o f sho r t ( 1 1 . 6%) and long ( 49. 5%) re turns, toge ther with an average inter-service interval of 4 4 days , indic a ted that de tec t ion e r rors and heat detec t ion effic ien cy were imp or tant problems contrib utin g to delays in breeding and increased numb er s o f s ervices per cow calving . Cons cious management decisions to with-hold cows from breeding to mee t specific seasonal needs may h ave compo unded thi s prob lem.
Si gnif i c an t seasonal e f f e c ts were obs erved with s uperior res ul t s during the spring i rrespec t ive of whe ther cows calved or were bein g bred at tha t t ime . Year dif ferences in b o t h produ c t ive and reproduc t
ive p erformance were also no ted with b es t r esul t s o c curring during y ears which reco rded c l imat ic c ondi t ions as bein g mos t s u i t ab l e for pas ture grow th .
The numb er o f ab ort ions recorded during the course o f th e inves ti ga t ion were few . Where abo r t ing cows were re tained theic b reeding performanc e during the year following ab or tion was poor but this effect did no t app ear to carry-over to their performanc e in s ub sequent y ears .
ACKNOWL EDGEMENTS AB STRACT
L I S T O F TABLES L I ST OF FIGURES
INTRODUCTION LITERATURE REVIEW
CALVING INTERVAL
TABLE Of CONTENTS
Days Open ( Calving to conception int erva l ) Calving to F i r s t Service In terval
First S ervice to Concep t ion Interval Fac tors Af fec t ing Days Open
a . Hea t De tect ion
i . Intens i ty o f hea t i i . Durat ion o f heat iii . Me tho d of detec tion
iv. Frequency , leng th and time of ob s e rvation v . Ab i l i ty an d interes t o f ob s erver
vi . Shed and y ard des ign
v .
i i . i i i . viii . x .
1 3 3 4 6 7 8 8 8 9 9 9 10 10 vii . Herd size and number o f cows per labo ur unit 12
b .
viii . Ac curacy o f rec ords and use of re c ta l 12 p a lpation as a means of predi c t ing heat
ix . Synchronisation procedures 12
Interval to Fir s t Pos t Par tum Oes trus i . Age
i i . Suckl ing and f requen cy o f milking iii . Season
iv . Level of product ion v. Inbreeding
vi . Nutrition
vii . Abno rmal i t ie s at par tur i t ion
vii i . Pos t par turi en t dis e ase c ondi t ions Live Cal f Rate
1 3 l 3 15 15 15 1 6 1 6 1 7 1 7 1 7 1 8 1 8 20 20 ' Concep t ion Ra te '
a . b . c .
Fir s t Service ' Con cep t ion Rate ' Numb er of Servi ces per ' Concep t iont Re t urn to Service In terval
Fac tors Influencing 'Concep tion Ra t e ' i . Pos t par tum inte rval
i i . Semen quality and ins eminator ski l l i i i . Cor rec t t ime t o breed
iv . Cow age v . Seas on vi . Nut ri t ion
vii . Level of mi lk p ro duct ion
20 22 23 2 3 24 24 25 vii i . Other ind ividual c ow fac tors 26
Los s e s During Pregnan cy 26
a. Temp erature 2 7
b . Ageing o f th e game te 2 7
c . Nu tri t ion 2 8
d . Endocrine dis turbance 28
e. Diseas e 2 8
Los ses During Parturi t i on 2 8
MATERIALS AND METHODS 30
Me thod o f Analys is 3 1
RESULTS 33
PERFORMANCE FOR ALL HERDS 3 3
PERFORMANCE O F THE DIFFERENT AGE GROUPS O F CATTLE 4 1 ASS OCIATION BETWEEN S EASON AND REPRODUCTIVE PERFORMANCE 4 5 AS SOCIATION B ETWEEN Y EAR AND REPRODUCTIVE PERFORMANCE 45 ASS OCIATION B ETWEEN BREED AND REPRODUCTIVE PERFORMANCE 5 5 AS S OC I AT ION B ETWEEN ABORTION AND REPRODUCTIVE PERFORMANCE 55 THE RELATIVE IMPORTANCE OF DAYS FROM CALVING TO FIRST
S ERVI CE AND FIRST SERVICE TO CONCEPTION ON CALVING
INTERVAL 55
THE RELATIONSHIP B ETWEEN CALVING TO FIRST S ERVI CE AND
FIRS T S ERVI CE TO CONCEPTION INTERVALS 55
THE E FFECT OF HERD S IZE ON INTERCALVING INTERVAL , CALVING TO FI RS T S ERVI CE AND FIRST S ERVICE TO CONCEPTION
INTERVALS 58
THE EFFECT OF MILK PRODUCTION ON INTERCALVING INTERVAL , CALVING TO FI RST S ERVI CE AND SERVI CE TO CONCEPTION
INTERVALS 58
THE IMPORTANCE OF H ERD, AGE , S EAS ON , YEAR AND BREED ON THREE PARAMETERS OF REPRODUCTIVE PERFORMANCE AND ON
MILK PRODUCTION 58
vii .
Page
DIS CUSS I ON 62
THE INTERCALVING INTERVAL 62
CALVIN G TO FIRS T SERVI CE INTERVAL 64
CALVING TO CONCEPTION INTERVAL ( DAYS OPEN) 6 7
THE INTER-SERVICE INTERVAL 68
CALVING RATE 7 3
Calving Rate to Firs t S e rvi ce 74
S ervi c e s per Cow Ca lving 7 7
Firs t S e rvi ce to Conc ep tion Inte rval 7 7
HERD DI FFERENCES 7 8
AS SOCIATION BETWEEN S EASON AND REPRODUCTIVE PERFORMANCE 79 AS SOCIATION B ETWEEN YEAR AND REPRODUCTIVE PERFORMANCE 80 AS S OCIATION BETWEEN B REED AND REPRODUCTIVE PERFORMANCE 80 AS S OCIATION BETWEEN ABORTION AND REPRODUCTIVE P ERFORMANCE 80 THE RELATIVE I MPORTANCE OF DAYS FROM CALVING TO FIRST
S ERVI CE AND FIRST S ERVICE TO CONCEPTION ON CALVING
INTERVAL 8 1
THE RELATIONSHIP B ETWEEN THE CALVING TO FIRST S ERVICE
AND FIRST SERVICE TO CONCEPTION INTERVALS 8 5
HERD S I ZE 8 5
EFFECT OF PRODUCTION ON REPRODUCTIVE PERFORMANCE 86 THE I MPORTANCE OF HERD , AGE, S EASON , YEAR AND BREED ON
THREE PARAMETERS OF REPRODUCTIVE PERFORMANCE AND ON MILK PRODUCTION
GENERAL CONCLUS IONS REFERENCES
APPENDICES
86 89 92
Tab l e I .
I I . I I I .
LIST OF TABLES
E CONOMIC EFFECT OF CALVING INTERVAL IN A 40 COW HERD
CALVING INTERVAL REPORTED BY NUMEROUS RESEARCHERS FIRST S ERVICE TO CONCEPTION INTERVAL REPORTED BY
VARIOUS RES EARCHERS
I V . EFFICI ENCY OF VARIOUS METHODS OF OESTROUS DETECTION OBS ERVED BY DIFFERENT RESEARCHERS
V . CALVING TO FIRST POST PARTUM OESTROUS INTERVAL IN
3 5 7 1 1 DAIRY CATTLE REPORTED BY VARIOUS RES EARCHERS 14 VI . FIRST S ERVI CE ' CONCEPTION RATE ' REPORTED BY VARIOUS
RESEARCHERS 19
VII . VII I .
S ERVI CES PER CONCEPTION REPORTED BY VARIOUS RESEARCHERS 2 1 REPRODUCTIVE PERFORMANCE OF TWENTY TOWN SUPPLY DAI RY
HERDS IN THE WELLINGTON HAWKE ' S BAY LIVESTOCK
I MPROVEMENT AS SOCIATION ( 19 7 2- 7 6 ) 34 IX. RETURN INTERVALS AS A PERCENTAGE OF ALL FIRS T SERVI CE
RETURNS FOR TWENTY TOWN SUPPLY DAI RY HERDS
X . REPRODUCTIVE PERFORMANCE O F THE DIFFERENT AGE GROUPS IN TWENTY TOWN S UPPLY DAI RY HERDS IN THE WELLINGTON HAWKE ' S BAY LIVESTOCK I MPROVEMENT AS SOCIATI ON
35
( 19 72- 7 6 ) 4 2
XI . RETURN INTERVALS AS A PERCENTAGE OF ALL FI RST S ERVI CE RETURNS FOR TH E DIFFERENT AGE GROUPS IN TWENTY TOWN SUPPLY DAIRY HERDS
XI I . AS S OCIATION BETWEEN S EASON AND REPRODUCTI VE P ERFORMANCE IN TWENTY T OWN S UPPLY DAI RY HERDS
XI I I . AS S OCIATION BETWEEN YEAR AND REPRODUCTIVE PERFORMANCE IN TWENTY TOWN S UPPLY DAI RY HERDS
XIV . AS SOCIATION BETWEEN BREED AND REPRODUCTI VE PERFORMANCE 4 6 4 7 48
IN TWENTY TOWN SUPPLY DAIRY HERDS 56
XV . ASSOCIATION BETWEEN ABORTION AND REPRODUCTIVE
P ERFORMANCE IN TWENTY TOWN SUPPLY DAIRY HERDS 5 7 XVI . EXPECTED EFFECT OF BREEDING AT DIFFERENT POS T PARTUM
INTERVALS ON THE DEMAND FOR S ERVICES , NUMBER OF COWS
CALVING AND MEAN CALVING INTERVAL 84
XVI I .
XVI I I .
F VALUES AND TESTS OF S I GNIFICANCE FOR VARIOUS
MEASURES OF REPRODUCTIVE PERFORMANCE AND THE EFFECTS OF HERD , YEAR, SEASON, AGE, BREED AND THEIR
INTERACTIONS IN TWENTY TOWN S UPPLY DAI RY HERDS ASS OCIATI ON OF HERD , AGE, S EASON AND YEAR WITH
MEASURES OF REPRODUCTIVE AND PRODUCTIVE PERFORMANCE XIX . CALVING TO FIRS T S ERVICE INTERVAL REPORTED BY
XX.
VARIOUS RESEARCHERS
THE RATE OF MAT ING RECORDED BY DIFFERENT RES EARCHERS AT VARIOUS POST PARTUM INT ERVALS
59 60 65
65
Tab l e XXI . XXI I .
PERCENTAGE OF LONG RETURN INTERVALS REPORTED BY VARIOUS RES EARCHERS
IN CALF , CALVING AND NON RETURN RATES ( NRR) AT VARIOUS POST PARTUM INTERVALS RECORDED BY OTHER AUTHORS
ix .
7 1
75
Figure 1.
2.
3.
4 .
5.
6.
la.
7b.
8.
9 . 10.
1 1 . 1 2.
1 3.
14 .
LIST OF FI GURES
Reproductive Performance in Twen ty Town Supp ly Dai ry Herds
Dis t ribution of Calvin g In tervals in Twen ty Town Supp ly Dai ry Herds
Frequency Dis t ribution for Ebur B reeding Parame ters at Di- f feren t Pos tpar tum In tervals in Twen ty Town Supply Dairy He rds
Ass o ci ation of Pos tpar tum In terval wi th Cows Ma ted and Calvin g to 1st Service in Twen ty Town Supp ly Dairy Herds
Re turn Interval Pat tern s to 1st Service in Twen ty Town Supply Dairy Herds
As sociation Be tween Age and Reproductive Performan ce in Twen ty Town Supply Dai ry Herds
Associ ati on Be tween Age and P os tpar tum Interval on Cows Submi tted to 1st Servi ce in Twen ty Town Supply Dai ry Herds
As sociati on Be tween Age and Pos tpar tum In terval on Calving Rate to 1st Service in Twen ty Town Supp ly Dai ry Herds
Re turn In terval Pat terns to 1st Service Be tween the Di f feren t Age Groups in Twen ty Town Supp ly Dai ry Herds
Re turn Pat terns to 1 s t Se rvi ce in Two Year Old Cows in Twen ty Town Supply Dai ry Herds
Re turn Patterns to 1 s t Se rvi ce in Three Y ear and Older Cows in Twen ty Town Supply Dairy Herds Re turn Pat tern to 1st S e rvi ce in Cows of All Ages
in Twen ty Town Supp ly Dai ry Herds
Associa tion Be tween S eason and Reproduc tive Perform
ance When Corre cted for E f fect of Age and Herd in Twen ty Town Supp ly Dai ry He rds
Year Di ffe rences in Reproduc tive Perfo rman ce in Twen ty Town Supply Dai ry Herds
Relati onship B e tween Calving In terval and the
In tervals from Cal ving t o First Service and Fi r s t S ervi ce to Concep tion
36
3 7
38
39 40 4 3
44
44
49 50 5 1 5 2
53 54
8 2
