Effects of peri-mating and peri-partum supplementary feeding on the reproduction of indonesia female sheep and goats

SUPPLEMENTARY FEEDING ON THE REPRODUGTION OF
INDONESIAN FEMALE SHEEP AND GOATS

CAKULTAS PASCASARJANA
INSTITUT PERTANIAN BOOOR

1987

ABSTRACT

THAMRIN DJAMIN CHANIAGO. Effects of peri-matkng and
peri-partum supplementary feeding on the reproduction of
Indonesian female sheep and goats (under supervision

of
R

ASIKIN NATASASMITA, as the main supervisor;A. PARAKKASI,
A.A.

MATTJIK,

I.C. FLETCHER as the supervisory members

and MANIKA COCKREM as the other supervisory member).
The aims of the research were :
reproductive
feed

rate

(1) to compare the

and efficiencies of

utilization

for reproduction of Etawah Cross Goats and

Gbats

maintained

on low quality feed with and

supplementation during the pe/ri-mating and

peri-lambing

maximum

Kacang
without

peri-kidding

(2) to define the minimum period of peri mating

period,
and

of

supplementary

reproductive

feeding

needed

performance for sheep

for

maintained

on low quality feed in a continuous mating system during
two \years,

( 3 ) to develop a comparison of reproductive

performance

between goats and sheep on the same

treat-

ments.
The
and
tion
and

reproductive performance of

Indonesian

sheep on maintenance with and without
with

a commercial concentrate during

peri-partum

was

studied.

It was

supplementaperi-mating

designed

factorial

experiment

with two breeds of goat plus

breed

sheep

four

of

and

nutritional

goats

as

treatments

a

one
as

,

ovulaticjn rate, percentage of does kidding, litter size,
percentqge
/

weaned

of preweaning kid mortality,

number of kids

does kidding and weaning weight of kids

not difqerent in ECG

and KG.

mortaliay in the KG was
of the ~ c Gdoes.

Percentage

of embryonic

significantly higher

However,

were

than that

birth weights of litter

or

kid,

wdaning weight of litter and liveweight of does at

four

wdeks before

of

ECG

mating up

to the end of

were significantly heavier than

Supplemeptation with 300 g of

experiment

those

Beefkwik 16

of

KG.

weeks during

peri mating and peri kidding significantly increased the
percentage of does which ovulated,

ovulation rate, lit-

siz~eand liveweight of does at the end

ter

However,

of

mating.

supplementation did not significantly increase

percentqge of does kidding,

percentage of embryo survi-

val, percentage of pre-weaning kid survival rate, number
of kids weaned / does kidding, blrth weight of litter or
kid,

weaning weight of litter or kid and live weight of

does peqi-mating and peri-kidding except for the

weight

at the and of mating.

2.

The

lambing
it

minimum

period of peri-mating

supplementation for sheep.

and

From the literature

is known that supplementation during peri-mating in-

creases ovulation rate and litter size.

Supplementation

during peri lambing will reduce pre-weaning lamb
lity

peri-

and

increase the weaning weight

of

morta-

lambs.

The

longer

riods of supplementation durinp peri-mating and

or peri

ambing, the better lamb production is achieved.

To

define

the minimum period of

peri-mating

and

peri-la

ing

ductive

performance,

using

ur groups each of 16 ewes which were run conti-

nuously

ith fertile rams until they lambed three

and wea

d tpeir lambs.

On

supplementation needed for optimum

t (SO).

plement

y

supplem

ted

plementc

plus

th

fore

a]

last

f,

weeks a
Th,

times

The other three groups were given sup-

feeding at different times.
during

One group

four weeks before mating

was

and

during four weeks before and up to six
Ling and the last four weeks of each

t

The

out

the

weeks of each pregnancy (54). Another was sup-

last fo

I

an investigation was carried

group was fed at a maintenance level throughout

experim

after

repro-

first six weeks after each

weeks

pregnancy

lambing

(S(4+6)).

i group was supplemented during four weeks

be-

up to the first 12 weeks after mating and

the

-

weeks of each pregnancy plus

3r

each lambing (S(4+12)).

percentage of ewes which

the

first

ovulated,

12

ovulation

rate,

1

-centage of ewes lambed, litter size, number of

lambs

wl

led/ewe ltrntbing, percentage of embryonic morta-

lity,

I

weight

t

treatme]

-centage

of pre-weaning lamb mortality,

lltter and lambing interval among

birth

nutritional

groups was not statistically different.

How-

ever,

birth

weight of lamb,

weaning weight

of

lamb,

weight of litter and liveweight of ewes

weaning

experiments

were significantly affected by

treatments,

those

in

during

nutritional

supplemented being heavier

than

those in control groups.
The percentage of ewes which
of

ewes

which lambed,

weaned/ewe

lambing,

ovulated,

litter size,

percentage

number

of

percentage of embryonic mortality,

pre-weaning lamb mortality,

weaning weight of litter or

lamb and liveweight of ewes during two years of
ment among three successive lambingd were not
cally different.
of

litter

lambs

However,

experi-

statisti-

ovulation rate, birth weight

and birth weight of lamb

was

significantly

affected by the sequence in observed lambing.

The
lambs

average

birth

weight and weaning

weight

weaned at three months of age increased

sively

1.7 kg to 2.0 kg and from 5.9 to

from

respectively

with increasing duration of

feeding at peri-lambing.

of

progrea9.1

kg,

supplementary

There were however, no signi-

ficant differences among nutritional treatment groups in
mean

interval

between successive lambings (202

ovulation rate (2.26),
lamb

mortality (37 % )

litter size ( 1 . 5 8 ) .

,

number of

lambs

days),

pre-weaning
weaned/ewes

lambing (1.02) or embryonic mortality (27.3 % ) .

3. Comparison of the performance of goats bnd sheep

in the same nutritional treatments.
litter

The o v u l a t ~ o nrate,

size and the number of progeny

weaned/bam

that

kidded or lambed in SO groups tended to be much lower in
goats

than

in sheep,

but in the S ( 4 + 1 2 )

similar in the two species.
or

lambing

grobps

The percentage

were

of kidding

and percentage of embryo survival

rate

in

both nutritional treatment groups, tended to b e lower in
goats tHan in sheep.
Overall mean birth weight of kids in SO groups
slightly

lower

than of lambs,

thei* birth weight was similar.

but in

groups

S(4+12)

However,

was

oveball mean
I

birth weight of litters of kids in SO groups waf slightly lower than birth weight of

but in

litters of lambs/
4

S(4+12)

groups

their litter birth weight was

Isimilsr.

Pre-weaning kid mortality in SO groups ten4ed to be
I

]However.

much higher than pre-weaning lamb mortality.
in
was

S ( 4 + 1 2 ) groups the pre-weaning kid or lamb

similar.

litters

The

4

ortality

weaning weight of lambs or 4f

sheep

in both nutritional treatment groups tdnded

to

I

be much higher than weaning
litters.

weight of

kids or

1!

of goat

ABSTRAK

AMRIN D J A M I N CHANIAGO.

Pengaruh pemberian sup-

lernentan,i sekitar perkawinan dan sekitar kelahiran terhadap r~!produksidomba dan kambing betina. (dibawah bimbingan P . S I K I N NATASASMITA,

sebagai ketua, A. PARAKKASI,

A.A. MA'J'TJIK,dan I.C. FLETCHER sebagai anggota serta di
tambah PANIKA COCKREM+yang melanjutkan tugas I.C.
CHER )

FLET-

.

1

Tu uan

penelitian

ini

adalah

(1)

membandingkan

tingkat reproduksi dan efiaiensi periggunaan pakan

untuk

tuk .re roduksi pada Kambing Peranakan Etawah (KPE)

minimum pemberian suplementasi yang

dan

diperlukan

erkawinan dan sekitar kelahiran untuk mendapatpilan reproduksi yang maksimum pada domba

yang

akan yang berkualitas rendah pada sistem perkang terus menerus selama dua tahun;

( 3 ) memban-

penampilan reproduksi antara kambing dan

domba

akuan pakan yang sama.
rnpilan reproduksi kambing dan domba di

I

sia

yan

dup

pok k dengan dan tanpa diberi suplementasi

Indone-

diberi makanan hanya cukup untuk kebutuhan hikonsen-

trat sel ma sekitar perkawinan dan sekitar kelahiran di-

dalam penelitian ini.
ngan ra
je

dua

kuan pa
Se

an

seb

berbaga

K

ekor

angan percobaan faktorial acak lengkap,

n

sebagai faktornya.

na karantina dan 12 bulan penelitian pendahuluian besar dari kambing KPE dan KK

mati

karena

Dua puluh empat ekor KPB betina dan 27

sebab.

betina sisa yang masih sehat,

dialokasikan

ke

kelompok perlakuan pakan. Enampuluh empat ekor
iangan (DP) betina dialokasikan ke dalam

kelompo, ~erlakuanpakan.

empat

Beberapa-dari perlakuan pakan

antara

smbing dan domba dibuat sama,

banding1

1

sama

dengan

s kambing dan satu jenis domba dan empat perla-

dalam d
Domba P

Penelitian dilakukan de-

supaya dapat di-

antara kambing dan domba pada perlakuan

yang

.
1.

?nampilan reprodukai dan bobot hidup Kambing.

24

SeBumlal

ekor KPE betina (gigi seri 2 - 4 )

-

dan

27

ekor KK

:tins (g-igi seri 2

kasikan

;e dalam dua kelompok perlakuan pakan berdasar-

kan

be1

. hidup

4),

setiap jenisnya dialo-

dan jumlah gigi serinya pada

permulaan

penelit:

I .

semula direncanakan

akan

berlansi

: selama dua tahun untuk mendapatkan tiga

kali

karena banyak ternak percobaan

yang

kelahirz
sakit

c

akhirnyr
asal

dr

disapih .

Penelitian

tetapi
I

ini

mati pada kelahiran kedua

dan

ketiga,

maka

diputuskan data yang dianalisa hanya yang berkelahiran pertama saja sampai
Satu

semua

anaknya

kelompok diberi pakan hanya cukup

untuk

kebutuh~~nhidup pokoknya saja aelama
Kelompok: kedua

penelitian

diberi suplenentasi pakan selama

kambing yang

(SO).
empat

berovulasi, tingkat

induk kambing yang melahirkan, jumlah anak/kelahiran,
lah

persentase kematian pra-sapih, jum-

anar sapihan/induk yang melahirkan dan bobot

anak a n t ~ r aKPE dan KG tidaklah berbeda nyata.
tase

sapih

Persen-

ke~natian janin pada KK adalah nyata lebih

tinggi

dari KPE, tetapi bobot lahir litter atau anak, bobot sapih

1itl;er

dan

minggu sc!belum

bobot hidup induk kambing

pada

empat

kawin sampai dengan akhir penelitian, K P E

adalah n:-ata lebih berat dari K K .

Pemberian suplemen de-

ngan 300 g Beef kwik selama 16 minggu sekitar perkawinan
ar kelahiran secara nyata meningkatkan
uk yang berovulasi,

winan,

persen-

tingkatan ovulasi,

jumlah

ahiran dan bobot hidup induk pada akhir

perka-

tetapi pemberian

suplememtasi pakan tidak nyata

meningkatkan persentase dari induk yang melahirkan, persentase

dari

daya hidup janin,

persentase daya

hidup

anak

s

elum sapih,

jumlah anak sapihan,

lahir

litter, bobot sapih anak atau litter dan bobot

amak at
hidup

duk

kecuali

ada akhir masa perkawinan.

2.

bobot

sekitar perkawinan dan sekitar

kelahiran,

enentuan periode minimum pemberian suplementasi

pakan

kitar

kepusta

%n diketahui bahwa suplementasi selama

perkawi

n

kelahir

.

mengura

i

bobot a

ih anak domba.

supleme

asi

hiran,

skan

perkawinan dan

akan

kelahiran

domba.

Dari
sekitar

meningkatkan ovulasi dan jumlah

anak/

Suplementasi selama sekitar kelahiran
kematian

anak

pra-sapih

dan

meningkatkan

Semakin lama periode pemberian

sekitar perkawinan dan atau sekitar
semakin

akan

tinggi

tingkat

kela-

produksi

yang

dicapai
Un

menetukan periode minimum pemberian

r

pakan y:

suplemen

diperlukan sekitar perkauinan dan sekitar ke-

lahiran

intuk mencapai penampilan reproduksi yang opti-

mum,

r penelitian dilakukan menggunakan empat kelom-

ml

pok mas

:-masing 16 ekor induk domba yang selalu bersa-

ma pe j a ~ Ln dan
anaknya
Sa'

yang melahirkan

tiga kali sampai semua

.

~sapih
kelompok diberi pakan hanya cukup untuk

kebu-

tuhan h

ap pokok selama penelitian (SO).

lainnya

Liberi

sebelum

:rkawinan dan empat minggu terakhir dari setiap

kebunti~ rn

(S4),

Tiga kelompok

suplementaai pakan selama empat

minggu

atau selama empat minggu sebelum

dan

di terusl

n sampai enam minggu setelah perkawinan dan em-

pat

mil

gu terakhir dari aetiap masa kebuntingan ditam-

bah

en1

atau

12

SI

min~

minggu pertama dari aetiap kelahiran

(S(4+6),

ama empat minggu sebelum dan diteruskan
setelah perkawinan dan empat minggu

J

sampai

terakhir

dari sei

%p kebuntingan ditambah 12 minggu pertama

setiap 1

Lahiran (S(4+12)).

Pel
kat

5ntase dari induk domba yang berovulaai,

o v ~i

,

persentase induk yang melahirkan,

dari

tingjumlah

anak/ kc

shiran, jumlah anak sapihan/induk yang melahir-

kan, pel

?ntase kematian janin, persentase kematian anak

pra-dapj

,

lahiran

lntara

berbeda ,
bot

saE

bobot lahir dari litter dan jarak aetiap kekelompok perlakuan pakan

adalah

tidak

tetapi bobot lahir anak, bobot sapih anak, boI

litter dan bobot hidup induk

selama

peneli-

tian nya

r dipengaruhi oleh perlakuan pakan,

diberi

lplementasi pakan adalah nyata lebih berat dari

kelompok

~ontrol.

Per
yang m e 1

yaitu yang

!ntase induk yang berovulasi, persentase
irka an,

induk

jumlah anak/kelahiran, jumlah anak sa-

pihan/in

~k yang melahirkan, persentase

persenta

kematian anak pra-sapih,

kematian janin,

bobot sapih litter

atau ana

dan bobot hidup induk selama dua tahun peneli-

tian di

~taratiga kali kelahiran yang berurutan adalah

tidak ny

a berbeda, tetapi tingkat ovulasi, bobot lahir

dari lit

r dan anak secara nyata dipengaruhi oleh nomor

observa
RI

kelahiran.
an bobot lahir dan bobot sapih anak yang

disa-

pih pat

umur tiga bulan meningkat secara cepat dari 1.7

kg

.O

ke

urutan
pada

kg dan dari 5.9 kg ke 9 , l

zngan
r

peningkatan periode

itar kelahiran.

kg,

aecara

suplementasi

berpakan

Tidak terdapat perbedaan

yang

nyata

tar kelompok perlakuan dalam rataan jarak kela-

hiran I

2 hari), tingkatan ovulaai ( 2 , 2 6 ) , jumlah anak/

kelahix
anak se
janin (

'3.

(1,58), kematian anak pra-sapih (37 % ) ,

~an/indukyang melahirkan (1,02) atau

kematian

3%).

'erbandingan penampilan produksi dan reproduksi

kambing

hn domba pada perlakuan pakan yang sama.

kat ovc

ci,

dilahir

I/

SO

pun

induk yang melahirkan pada kambing
tendensi jauh lebih rendab dari

kelompok

pada

la kelompok S(4+12) tidak berbeda nyata.

sentase

elahiran dan

kedua

ompok perlakuan pakan,

lebih r

lah dari domba.
.n

Ting-

jumlah anak/kelahiran dan jumlah anak yang

tetapi

Ra

jumlah

domba,
Per-

persentase days hidup janin pada
pada kambing

bobot lahir anak kambing pada

cendrung

kelompok

SO

lebih r

ah sedikit dari anak domba, tetapi pada kelom-

pok

2) bobot lahirnya sama.

S (

Rataan

bobot

lahir

litter

au anak kambing pada kelompok S O lebih

rendah

sedikit

ri bobot lahir litter atau anak domba,

tetapi

pada

mpok S ( 4 + 1 2 ) bobot lahir litternya tidak

k

ber-

t kematian anak kambing pra-sapih pada kelomdrung lebih tinggi dari tinskat kematian pradomba,

tetapi pada kelompok

S(4+12)

kema-

pih anak kambing atau anak domba tidak berbeBobot aapih anak domba atau litter domba pada
mpok

perlakuan

cendrung lebih

anak atau litter kambing.

tinggi

dari

YFECTS O F PBRI-MATING AND PERI-PARTUM
.EMBNTARY FEEDING ON THE 'REPRODUCTION O F
INDONESIAN FEMALE SHEEP AND OOATS

A dissertation
;ed to the Institut Pertanian Bogor

Subm

(Bogor

Agricultr

il University) as fulfilment of the requirements

for the

tree of Doctor of Agriculture in Animal Sciences

I

by

THAMRIN DJAMIN CHANIAGO

FAKULTAS PASCASARJANA
INSTITUT PERTANIAN BOGOR

Title

:

EFFECTS OF PERI-MATING AND PERI-PARTUM
SUPPLEMENTARY

FEEDING

ON

THE REPRO-

DUCTION OF INDONESIAN FEMALE SHEEP AND
GOATS
candid at^

:

THAMRIN DJAMIN CHANIAGO

IC No

:

81521

Approved by
1.

(

C o m m i t t e e in Charge

Prof. Dr. Asikin Natasasmita

)

The m a j o r supervisor

a
l

(Dr.Ir. A.

, --

A. Mattjik

-

(Dr. I. C. Fletcher)

Dean of Fakultas
Pascasarjana

1

BIOGRAPHY
Ujung batu Riau on the twentieth

of

My father is the late Mohamrnad Djamin
I

he late Baniama.
ptember 1964 from
Jakarta.

graduated
S.M.A.

from

Negeri

I

I gain the first degree Doctor of Veterinary
Faculty of Veterinary Medicine Bogor
rsity
1974

in 1974.

I

have

been

working

in

the

for Animal production, the Department
a research scientist.
Science (MSc)

My

second

was obtained from the

a 1 Veterinary Science the Faculty
ok University, Queensland

,

of

Australia

egistered as a full-members PhD

stu-

sca Sarjana Bogor

Uni-

Agricultural

September 1981.
married to . M a r n y
boy and two girls.

and now

we

have

ACKNOWLEDGBMENT

my

sc

Meif rit

Hendryas

and

my

daughters

Frieda

and

syani encouraged m y spirit to complete my study.

TABLB OF CONTENTS

ABSTRACT
BIOGRAPHY
ACKNOWLEDGEMENT

LIST OF FIaURES

LIST OF TABLES

..........................
XI . REVIEW OF LITERATURE
.................
1.
SMALL RUMINANT REPRODUCTION
......
1.1.
Puberty
.....................
1.2.
Oestrus
.....................
1.3.
Ovulation
...................

I

.

INTRODUCTION

1.4.

1.5.

1.6.

Pregnancy
a

.

Ovum period

c

.

Lactation and suckling

.............
.........
b . Embryonal period
...........
c.
Foetal period
Parturition
................
Post-partum reproduction .....
........
a . Ovarian activity
b.
Involution of the uterus
.
d

2

.

.

...

.................
........
REPRODUCTION

Oestrus

'qUTRITION AND
2.1.

...................

Nutrition on oestrus and ovulation

. 2.

Nutrition and pregnancy

.
b.
a

I

1

l

I
I
l

t.2.

4

I11

.

.

t

t

The seco.
nd and third month

.

The last two months

..
a . Ovarian dysfunction ......
b . Ovulatory failure
........
c . Fertilization failure ....
Prenatal mortality
...........
a . Embryonic mortality
......
b.
Foetal mortality
.........
Failure before fertilization

1

I

..........

.....
Nutrition and lactation
.....
a . Nutrition of dam during
...............
lactation
b.
The importance of milk
for offspring gro'uth
.....
c

1.3.

The first month

.....

.3.

Perinatal and neonatal mortality

RE-WEANING GROWTH OF OFFSPRING

MATE IALS AND METHODS

....

..................

PRODUCTIVE AND LIVEWEIGHT PERFORMANCE
GOAT

...............................

PRODUCTIVE AND LIVEWEIGHT PERFORMANCE
SHEEP

..............................

3 . COMPARISON IN REPRODUCTIVE PERFORMANCE

BETWEEN GOATS AND SHEEP IN THE SAME
NUTRITIONAL TREATMENTS

................

V.

D I S C U S S I O N

VI. COlrlCLUSIONS AND SUGGESTIONS

112
124
150

L I S T OF TABLES

Number
1

2

Text

Page

Some examples of the effecta of plane of
nutrition in.early pregnancy on the survival and growth of embryos

31

Daily nutrient requirements of sheep and
goats (Kearl, 1982).

57

Composition of elephant ,grass and;Beefkwik.

57

Composition of mineral licks
(Fermafos Block)
Feeding plan.

61

The number of animals involved in each
group of experiment 1 and 2.
Percentage of does that ovulated, mean
ovulation rate and kidding from Etawah
Crossbred Goats (ECG) and Kacang Goats
(KG) on two nutritional treatments.
Embryonic and pre-weaning kid mortality,
litter size and mean number of kids weaned
per doe kidding of ECG and KG on two nutritional treatment groups.

75

Birth weight of litters and kids and
liveweight of kids at four weeks of age
( k g ) of ECG and KG on two nutritional
treatments.

77

Weaning weight of litter and kid (kg)
of ECG and KG on two nutritional treatments.
Liveweights (kg) of ECG and KG does
before and during joining time on
two nutritional treatments.

Liveweights (kg) of ECG and KG does
around kidding on two nutritional
treatments.
Liveweights (kg) of EGG and KG does
during lactation on two nutritional
treatments.
Percentage of ewes ovulated, ovulation
rate and ewes lambed from ewes ovulated
of Priangan Sheep (PS) on four nutritional treatments and three times of observed successive lambings.

90

Litter size and number of lambs weaned
per ewes lambing in PS on four nutritional treatments and three time of observed successive lambings.
~ m b r y o n i cand pre-weaning laib mortality
of PS on four nutritional treatments and
three time of observed successive lambings.

95

Birth weight of litter and lamb (kg) in
P S on four nutritional treatments and
three time of observed successive lambings.

97

Weaning weight-of litter and lamb (kg)
in PS on four nutritional treatments and
three time of observed successive lambings.

99

Liveweight changes of PS ewes around
lambing (kg) on four nutritional treatments and three time of observed successive lambings.
Liveweight changes of PS ewes during
lactation (kg) on four nutritional
treatments and three time of observed
successive iambings.
Effects of different periods of supplementary feeding on lamb production over
three time observed successive lambings.
Pre-weaning mortality, growth rate and
weaning weight of surviving lambs in relation to birth type and birth weight
(parenthesis represent numbers contributinf to each mean).

23

Percentage of does and ewes ovulated,
mean ovulation rate and percentage of
kidding and lambingof goat and sheep
on two nutritional treatment

24

Percentage of embryonic mortality,
litter size. % pre-weaning mortality
of kids and lambs and number of kid
and lamb weaned per dam parturition.

25

Birth weight and weaning weisht of
each progeny and litter of goat and
sheep (kg) on two nutritional treatments

26

Liveweights (kg) of does and ewes
from four weeks before joining until
12 weeks post the beginning of joining
on two nutritional treatments

27

Comparison of liveweights (kg) of ewes
and does at four weeks before parturition, at the end of pregnancy and
immediately post-parturition on two
nutritional treatments

L I S T OF FIGURES

Number

1
2

Text

Page

Pattern of oestrogen (a) and progesterone (b) in sheep and goat.

16

Diagramatic summary explaining how the
fetal lamb control the onset of labour.
Experimental procedures that lengthen
or shorten pregnancy are shown.

17

Relationship between age and weight of
the sheep foetus. The continuous line
represents the mean of 4 5 5 observations
(Joubert, 1 9 5 6 ) and the dotted lines indicate the approximate upper and lower
range.

33

..........

........

3

................................

4.

Ewe body weights during period of supplementary feeding.

.....................

11 1

I.

There

are

INTRODUCTION

about 8.1

and 4.1 million

goats

and

sheep, respectively in Indonesia (Juwarini and Petheram,
Goats and sheep form an important component of

1983).

the

Indonesian farming system,

especially among

and landless farmers ( D e Boer et a1.,1982).
kept for multiple purposes, such a s

small

They

quick cash

income,

a source of manure for fertilizer and a means of
ding

employment

ruminants
systems
They

for families of

farmer.

are

provi-

Most

small

are managed under scavenging or minimum
in

the traditional way of

convert

human use,

husbandry

cost

systems.

the natural vegetation into products

for

utilize crop residues and stubbles and

help

to maintain soil fertility.
The

pressure of increasing human population asso-

ciated with a low rate of animal production results in a
very

low per capita meat oonaumption.

sheep is

acceptable

restrictions,
dustries

to

most people

Meat of goats and
with no religious

so the development of goat and sheep

in-

for the production of food is a very important

objective.

Mpreover,

protein

rather than

energy

is

often more deficient in human diets in the tropics.
Despite
are

some small differences,

considered

larities in size,

similar

the two

because of their

reproduction.

basic

nutrition and

species
simigrowth.

As

the population of sheep in the world

outnumber

goats and goats are concentrated in the

tropics,

the
there

has been a situation of relative neglect of goats as far
as research and development are concerned.
Goats

and sheep are capable of high

reproductive

maintained experimentally

on

continuously

high levels of feeding (Obst et al.,1980a).

I n the vil-

rates

when

lage,

the average number of lambs born per breeding ewe

per year

is only about

et &.,1983).
-

half of their

potential

(Bell,

Nutrition could well be one of the factors

contributing to differences in the productivity of Indonesian

sheep

and goats under experimental and

village

conditions.
There

is considerable evidence for sheep and

mited evidence

for goats in temperate environments that

reproduction may be affected by levei of feeding
-and
and

at mating,

during the last few weeks of

during early lactation.

feeding,
stages

Feeding

systems

supplemented

or

before

gestation

Continuous high levels of

feeding are almost certainly wasteful,
expensive.

li-

because they are

based on a
improved

of the reproductive process,

low

only

at

level

of

critical

should allow

more

efficient use of available feed t o improve productivity.
There are three main aims of this
first

aim

efficiencies

is

to compare

the

research.

reproductive

rate

The
and

o f utilization o~f feed for reproduction of

goats

maintained

supplementation
period.
of

during the peri-mating and

without

peri-partum

The second aim is to define the minimum period

peri-mating

needed

on low quality feed with and

for

maintained
system.

and peri-partum

supplementary

feeding

maximum reproductive performance for
on low quality feed in a

performance

continuous

third aim is to compare the

The

sheep
mating

reproductive

between goat and sheep in the same nutriti-

onal treatment.
Hypotheses to be tested are :

1. Supplementary feeding from four weeks before parturition until parturition (the period of maximum

foetal

development)

reduce

will

increase birth weight and

neonatal mortality.
2.

Supplementary feeding from four weeks before parturition

until

six

weeks

post-partum

(including

the

period of maximum lactation, involution of the uterus
and resun~ptionof ovarian activity) will improve lamb
growth and marginally improve post-partum rebreeding.
3. Supplementary feeding from four weeks before parturi-

tion

until 1 2 weeks post-partum (including the

period

main

of conception) will additionally improve lamb

or kid growth and post-partum rebreeding.

4. Without

supplementation,

than sheep

goat

will perform

because of their superior

low quality feed.

better

utilization of

I
I

5.

With

supplementation,

goat

and sheep will show ap-

proximately similar performance.

11.

1..

REPRODUCTION OF SMALL RUMINANTS

1.1.

Puberty
Considerable

within
rua,

the

RBVIEW OF LITERATURE

differences

exist both between

and

breeds in the age and body weight at first oestand

ewe

there ia a general agreement that puberty
is determined by both genetic and

environmen-

Age at puberty depends o n the precocity of

tal factors.
the breed,

in

the level of nutrition,

the system of mana-

gement and the season of birth in temperate zone animals
(eg.Devendra and Burns, 1970; Doney et a1.,1982).
Female goats show their f,irst oestrus around 5
months of age,
female sheep.

whereas 6

-

-

7

9 months is more typical for

Early maturing breeds such a s the pigmy

goat or the Finnsheep may reach puberty a s early as 3 or

4 months of age (Hulet and Shelton,

1980).

The first

oestrus is not always accompanied by ovulation (Chu

and

Edey, 1978).
The
ted

age at which a doe and a ewe first can be ma-

is of cbnaiderable practical importance in

sing goat and sheep productivity.

There is a relation-

ship between general body growth and sexual
in

ewes,

and

puberty

increa-

may b e delayed o r

development
advanced

by

varying the plane of nutrition during rearing (Allen and

Lamming,
Thus,

1961b; Dyrmundson, 1983; Sutama et al., 1985).

lambs reared on a high plane of nutrition tend to

attain puberty at an earlier age and heavier body weight
than those reared on a low plane of nutrition.
it

However,

has not been possible to distinguish between the se-

parate effects which varying the plane of nutrition have
on general body growth and sexual maturation.
In
length
birth

zones where the differences in

are obvious the relationship between
and

appears
may

temperate

the

onset

of first oestrus

to be very important.

season

in

attain

of

ewe

lambs

It seems that ewe

lambs

first experience oestrus in their first autumm

winter months.

day

and

Lambs born early in the season tend to

puberty at higher ages and heavier body

than lambs born later.

weights

However, lambs born very late in

the season may fail to attain puberty during their first
breeding season (Dyrmundsson, 1973).
Age

at

first oestrus,

and whether or not

ewes have exhibited oestrus by certain ages,
be

appear

to

determined also principally by the liveweight of the

lamb.
age

Many differences between strains with respect

at

first

differences

from

oestrus usually could

be

explained

in liveweight between the various

(Tierney, 1979

in

young

).

to
by

strains

Age at first oestrus is seen to range

163 days for Finnish Landrace x Polled Dorset ewes

Scotland

to 900 days for Hungarian Merino

ewes

in

Hungary.

Similarly wide ranges also exist in the mean

liveweight at first oeatrus, from 28.8 kg for Corriedale
in Uruguay to 54.7 kg for Rambouillet ewes in

ewes

U.S.A.

the

(Dyrmundsson, 1973).

It

has been said that the tropica.1 goat and

sheep

non-seasonal in sexual activity and doe kids or

is

lambs

ewe

also have this reproductive pattern and may

pre-

sent their first puberal estrous at any t i m e o f the year
(Obst et a1.,1980a; Riera, 1982).

1.2. Oestruss.
The physiology of oestrus and the oestrous
has

not

been as closely studied in goats as in

but appears to be similar in most respects.

(Doney et al., 1982)
(Pretoriocs,l973).
of

with

can be

days

of 20.2 days

In-sheep oestrus occurs at intervals

approximately 17 days,

tions

an average

sheep,

The length

the oestrous cycle in goats is normally 18-22

of

cycle

expected

although considerable varia-

and the range of 14-20 days

is

regarded as normal (Robinson. 1977; Doney et al., 1982).
The

duration

Shelton,

only

species

normally

35 hours with a range from 24 to 48 hours

about
and

of oestrus in both

22

1980),

(Hulet

though in Angora goats it may

hours (Robertson,

1977;

Hulet

and

is

be

Shelton,

1980).
The

measure

duration of oestrus is comparatively easy

by observation and shows important

to

variability

which
The

may be correlated with reproductive
mean

longest

duration of oestrus varies with

oestrus

breeding

season

Lindsay 1979).

coinciding

with

the

(Fletcher and Lindsay,

the

eeason,

middle

of

1971 cited

Environmental stress may shorten

duration of oestrus (Doney and Gunn,
extend

performance.

1976).

the
by
the

1981) and may also

interval between the preovulatory LH

and ovulation (Cumming,

the

surge

In some conditions. for

example at the beginning of the breeding season,

during

lactation, or in response to an exceptionally low nutritiopal

state,

ovulation may occur without

behaviouraf

oestrus.
The behavioural and physical signs of oestrus are
much

more pronounced in does than in ewes (Edey &

1977).

In

a free mating system does actively seek

the male and so do ewes.
when

&,
out

Oestrus appears to be shorter

rams are with ewes continually rather than

inter-

mittently (Hulet and Shelton,l980). Oestrus exhibited by
ewe lambs is of a

relatively low

intensity as compared

with that of adult ewes (Hafez, 1951). The low intensity
or even intermittent absence of behavioural

oestrus

in

ewe lambs may be associated with deficiencies in steroid

secretion by the developing puberal ovary (Cupps et al.,
1969).

a

Chang (1958) reported that ewe lambs grazed over

period

substances

of time on
with

red

potent

clover

pasture,

oestrogenic

containing

effects

probably

showed

oestrus without ovulation at an earlier age than

the normal age for puberty.

Ovulation.

1.3.

Follicles

undergo three major changes during

the

ovulatory process :
a. Cytoplasmic and nuclear maturation of the oocyte.
b. Disruption of cumulus cell and cohesiveness among the

cells of

the granulosa layer.

c. Thinning and rupture of the external follicular wall.
Little
qhich

is
of

known

about the factors

that

the follicles that begin to

determine

develop

will

reach maturity and ovulate (Hafez et a1.,1980).
The time of ovulation in ewes varies from 11 hours
before

the end of oestrus

of oestrus.
of

to seven hours after the end

However, it generally occurs before the end

oestrus and is more closely related to the end

the beginning of oestrus.

than

In goats, ovulation occurs a

few hours after the end of standing oestrus.
Large variations
breeds of animals.
etic

control,

in ovulation rate

exists

Ovulation rate is partly under gen-

as evidenced by large breed

differences

and also by the fact that highly fertile strains
breeds

among

have been developed.

within

Within breeds and strains,

ovulation rate increases to about

four or five years of

age, and then declines slowly with advancing

age (Hulet

and Shelton.

1980 ) .

It is also strongly influenced by

nutrition (eg. Coop, 1966).

1.4.

Pregnancy

.
in

Variation

the average duration of

pregnancy

among breeds has been reported from 143 to 151 days

and

individual normal pregnancies vary from 138 to 159 days.
The

genotype of the foetus is the major determinant

the duration of pregnancy (Bradford et al.,
and Jainudeen, 1974; Liggina,l982).
ried

longer

twins.

than

Duration

ewe lambs and

of

1972; Hafez

Male lambs are carsingles

longer

than

of gestation appears to increase with

age of dam (Hafez and Jainudeen, 1974).
Pregnancy extends for about 150 days in both sheep
and goats (Hulet & Shelton, 1980), but basic differences
between the two species nevertheless exist. For example.
at all stages of pregnancy the goat is dependent on progesterone

from the corpus luteum for the maintenance of

its pregnancy.
days

In contrast, in the sheep after about 60

of gestation,

sustain pregnancy
luteum.
might

expect

is

more

precise agreement between

where one
the

two

there is the suggestion that the reduction

weight that accompanies increases in litter

less

can

in the ewe in the absence of a corpus

Even in the area of foetal growth,

species,
birth

progesterone from the placenta

pronounced in goats than in sheep (Donald

Russell, 1970 ) .

in

size
and

Description

of the

growth and development of

ovum

from its initial weight of around 2 ug to

term

foetus some 20-21 weeks later with a weight

valent

the

a

full
equi-

to 15 - 25% of the metabolic body weight of

its

dam has been studied extensively.
Although prenatal

growth is a continuous proceas,

it is often divided into three periods(Bleck.1983).
Period of the ovum;

1. 4.a.

This

period lasts from ovulation until

of .the blastocyat

to the endometrium

later.

Fertilization,

regions

of

uterus

about

15

which takes place in the

the Fallopian tubes,

hours of ovulation.

attachment
days
upper

must occur within

On day 3, fertilized ova reach the

and are at the eight cell

stage.

Losses

this period are around 6 - 8% (Long and Williams,
and

24

they can be atributed to chromosomal

in

1980)

abnormalities

and cracked zona pellucida (Gunn et a1.,1972).
1.4.b.

Embryonal period;

This
become

period lasts from the time

that

blastocysts

associated with the endometrium until about

day

34 of gestation of full placentation.

As a result of embryo migration between day 1 0 and
14,

in

followed
sheep

by implantation which starts about day 15

(Rhind et al.,

1980) and by

fusion

of

the

allantoic
the

and

- 20,

chorionic membranes around day 19

tendency is towards establishing a balance

in

distribution of the embryos between the two horns.
balance

can,

mortality.
lambs

however,
The

the
This

be subsequently upset by embeyo

consequence is smaller

for their particular litter

than

average

size (Rhind

et al.,

19801, if embryonic mortality is late.

10

Another

-

20% of fertilized eggs are

lost before the end of embryonal period,
day

18.

Knowledge

usually

mostly

is lacking as to whether the

ation between estimates of basal loss is mainly
or environmental in origin (Edey,
can

be

mental

increased
factors

above the basal

vari-

genetic

1976). Embryonic loss
level

by

environ-

such as high temperature, severe short-

term undernutrition,
stress syndrome.

before

diseases and perhaps by a

general

In many studies, embryos arising from

twin ovulations have proved more vulnerable than

single

ones though the reason for this is not completely understood.

Though effects of undernurition are surely

more

pronounced in twin pregnancies.
At

about on day 13 and 14 the trophoblast

starts

formed

trophoblastin to secrete an antiluteolytic

stance

that prevents luteolysis by PGF

oestrus (Marta1 et al., 1979).
day

12

and return

Death of embryos

to

before

results in the ewe returning to oestrus at

normal time.

sub-

the

If the death occurs later than day 12 then

the next oestrus

is delayed.

In these cases since the

ewe is not in oestrus and the progesterone level in

her

peripheral

may

plasma

may be still elevated,

the ewe

erroneously be still assumed pregnant.
1.4.c.

Foetal period;

This

period

until birth.
variable
to

lasts from about day 34 of

gestation

The placenta of the sheep consists of

number of highly vascular structures

as cotyledons.

These are located in the

a

referred
chorionic

membrane 'and each is attached to a specific area of the
uterine

epithelium

development of
the

caruncle.

The

begins on about day 16

when

normally called

cotyledons

a

trophoblast fills the lumen of the uterus and comes

into contact with the caruncles, but it is not until the
fourth

week

that

the tissues of

the

caruncles interlock (Boshier, 1969 ) .
two months

cotyledons

and

Within the next

there is a rapid increase in

the

size

and

weight of the cotyledons.
Looking at the general pattern of prenatal growth,
the

foetus of twin bearing ewes increases from 5

day 40 to 66g and 170 g on day 60 and 70,
By

day 90,

birth.

acquire
the

respectively.

they only achieved 15% of their

weight

The newborn lambs from wellnourished

about 25,

last 2 ,

on

when the weights of the individual foetuses

are about 7 0 0 g .
at

g

50 and 85% of their birth weight

4 and 8 weeks of

gestation,

ewes
in

respectively

(Robinson. 1982).
Parturition.

1.5.

Parturition

is defined as the physiological

pro-

cess whereby the pregnant uterus delivers the foetus and
placenta from the dam.

Parturition commences with

the

onset of regular peristaltic uterine contractions accompanied by progressive dilatation of the cervic.
are three recognised stages of parturition :
tion

of

cervix,

2.

1.

expulsion of the foetus

expulsion of the placenta (Jainuddeen & Hafez.
Uterine

There
dilataand

3.

1980

).

contractions begin about 12 hours before partu-

rition and these contractions are responsible for
tation of the cervix.
soon

The placenta usually is expelled

after the foetus being born.

first

lamb

of a

lamb is born.

twin is

The placenta of

expelled before

the

Robinson

the

second

Dystocia is not a serious problem in many

breeds of sheep and goats (Hulet & Shelton, 1980).
ever.

dila-

(1982) reported that the

How-

incidence

of

dystocia varies with breed and tends to be higher in ewe
lambs than adult ewes. It is suggested that about 10% of
perinatal lamb deaths is caused by dystocia.
The onset of parturition is regulated by a complex
interaction of endocrine, neural and mechanical factors.
The
low.

mechanisms of initiation of parturition are as folThe fetal genotype is not of only a single origin,

but it has also a single ending, the release of prostag-

15

landin

and it consequences.

formed by the uterus is PGF

PGF

In

is

The major

prostaglandin

from the endometrium

the important prostaglandin for

parturition.

goat where pregnancy i s maintained to term

gesterone

from

the

corpus

PGF

luteum.

and

by

pro-

from

the

endometrium contributes to the initiation of luteolysis.
The
enzyme
vated

synthesis rate of PGF

phospholipase A 2 .
by

ratio,

the

Enzyme phospholipase is acti-

an increase of the

which

is controlled by

:

oestrogen

progesterone

is commonly caused by both a fall in pro-

gesterone and a rise in oestrogen (Figure 1.).

The mech-

anism of initiation of parturition in sheep in which the
placenta is the source of progesterone and contains
hydroxylase is shown in Figure 2.
relative

of the sheep

The goatpis a close

but its source

of

progesterone

depends on the corpus luteum rather than placenta.
vertheless,
with the

the

hydroxylase

Ne-

mechanism is very like with the

exception

that activation

17-

of

sheep

placental

17-

enhances metabolism of progesterone

coming

from the corpus luteum rather than the placenta.

The

resulting

oestrogen-stimulated release of PGF

causes

luteolysis first and uterine activation second (Liggina,
1982).

The

maturing

foetus

plays an important

determining the time of parturition.

role

In sheep,

in

plasma

progesterone levels decline during the last seven to ten

SHEEP

LL

0

W

4 z

W
0
>
a

Y E

GOAT

V)

C)

0

0

-J

W

w

0

a

m a

4

1

- 5

- 3

I

- I

I

0

DAYS BEFORE PARTURITION

- 5

-

3

- 1

0

DAYS BEFORE PARTURITION

Figure 1.
Pattern of oestrogen (a) and progesterone
(Adapted from Liggins 1982)

(b) in sheep and goat.

Ablation causes
prolonged pregnancy

:L1

$g:;

AH
6

pituitary

A r t i f i c i a l i n f a s i o n o f e i t h e r a g e n t causes
premature labour
P r o s t a g l a n d i n FZ0
increased
Oes t r o g e n
increased
:zagg;$erone

F i g u r e 2.
~ i a ~ r a m m a t summary
ic
e x p l a i n i n g how t h e f e t a l lamb c o n t r o l s the o n s e t
of labour. Experimental p r o c e d u r e s t h a t l e n g t h e n o r s h o r t e n pregnancy
a r e shown.
(Adopted from G.C.Liggins.
I n f o e t a l Anatomy. o d t . G.F.W.
Wolstenholme
and M. 0 Connor. C h u r c h i l l London 1 9 6 9 ) .
( C i t e d by L i g g i n s ,

1982)

days of pregnancy
tion.

reaching the lowest level at parturi-

This is primarily due to a decline in placental

production

rate

clearance

an

increase

in

metabolic

rate of progesterone (Jainuddeen and

In goats,

1980).

pidly

and/or

just

plasma progesterone levels fall

luteum.

ra-

prior to the onset of parturition and

is believed to be due to regression of the

fall

Hafez,

The

corpus

luteum

is the major

this

corpus

aource

of

progesterone throughout pregnancy in the goat ( Thorburn
et al., 1977).
-

Plasma oestrogen

.levels which are

low

during gestation, rise sharply during the 48 hours prior
to parturition.
shown in Figure 2.

The

increase

in

foetal

cortisol as

is responsible for both the decrease

in progesterone and the increase in oestrogen production
rates (eg.Thorburn et al., 1977).
Post-parturn reproduction.

1.6.

1.6.a.

Ovarian activity.
The

ovaries are relatively inactive at four

days

after parturition and contain a few small follicles
degenerated
After

five

crease

corpora
days

lutea

(Chamley

post-partum activity of

and large follicles were present by

&.,

1973).

ovaries
the

and

in-

tenth

day (Van Niekerk. 1979).
1.6.b.

Involution of the uterus.
Uterine involution is referred to as a process

by

which the uterus after parturition returns to the original

size before pregnancy.

kidding a year,
one

In more than one lambing or

post-parturn involution of the uterus is

of the factors which affects the

riod.

Foote

e e.,
(1967) made

size of the uterine horn a t 3,
post-partum.

10,

interlambing

pe-

a study on the

mean

38, and 6 5 days

24,

They concluded that uterine

involution

was complete by 24 days post-parturn in sheep.
Van Wyk et al.(
the

1972) made

an experiment studying

effect of exogenous hormones and season of

on uterine involution of ewes.

lambing

They found that

there

was no significant effect of hormone treatments.

The

breeding

season

uterine
than
the

involution

was faster in the

in non breeding season,

baaed on the diameter

of

longest caruncle in the previously pregnant horn at

15 days post-partum.

During the breeding season there

was little effect of lactation on the involution of
uterus.

the

During the non breeding season involution was

already complete by 3 0 days in non lactating and 36 days
in lactating ewes (Van Niekerk, 1979).
1.6.C.

Lactation and suckling.
In

term

of

production

of

milk,

it

has

been

generally found that under similar conditions the number
of lambs suckled has a greater effect on milk yield than
nutrition during
ewes

pregnancy and lactation.

Twin suckled

produced approximately 40% more milk than

single-

suckled

ewes,

and differences in total milk yield bet-

ween

suckling groups were mainly due to differences du-

ring

the first 3-4 weeks of lactation (eg.Peart et al.,
There is evidence that the initial milk yield of

1972).

ewes is influenced by the number of lambs born or
weight

of

the concepta.

influence

milk

greater

on milk production than ewe genotype ( Moore,

Langlands.

1966;

Lamb genotype has a

total

with

1972).

Interactions of appetite for

intake of solid food by lambs have

a

major

influence on milk yield (Peart, 1967).
Evidence on the effects of lactation and

suckling

on post-partum reproduction is conflicting. The interval
from lambing to first oestrus

took 41.4(30-64) days

in

non lactating and 86.2

(38-153) days for lactating

(Van aiekerk,

Hunter and Van Aarde (1975) found

1979).

ewes

that 67,0% of lactating ewes which lambed in July showed
first oestrus in 56 days and 68.0% of non lactating ewes
showed first

oestrus in 42 days.

Smith (1964) reported

that non lactating ewes showed a mean interval to
oestrus

at

39 days and lactating ewes 46 days after

March lambing.
were

first

After a November lambing the

a

intervals

97 days in lactating and 81 days for non lactating

ewes.

On

crossbred
tation

had

the

other hand Hunter (1968) found

Border Leicester x German
no significant effect on

first ovulation.

that

Merino ewes,
the

in

lac-

interval

to

Nel (1965) reported that lactation had

an

effect on interval to either post-partum

ovulation during the non breeding season,

oestrus or

but not

du-

ring the breeding season.
Fletcher (1971) who studied the relationship
ween

frequency

behaviour

of Merinos,

correlation
first

of suckling and

between

bet-

post-partum

oestrus

found that there was a

positive

frequency of suckling

during

the

two weeks post-partum and time of first oestrous.

In another study however, Fletcher (1973) found that the
mean

post-partum

anoestrous interval of ewes in

which

lambs were suckled, were allowed restricted suckling, or
were

not

suckled

were

47.8,

49.5

and

44.7

days,

respectively. Also Barker and Wiggins (1964). found that
post-partum anoestrous intervals in Rambouillet

average

ewes which did not suckle lamb, suckled single lambs and
suckled

twin

lambs

respectively.
did

In

were 57.7,

72.1 and

86.6

Indonesia seems to be that

days,

suckling

not have any significant effect on post-partum

oestrous

an-

.

The fact that 90% of Merino ewes returned to cyclic
oestrous
season
of

activity

at 90 days post-partum

during

of low sexual activity suggests that the

the

effect

both lactation and season can be overcome by the use

of a sufficiently high plane of nutrition (Van
1979).

However,

this

breeds which will not

is not true for other

cycle no matter

Niekerk,
temperate

how well w e feed

them in spring-summer.
1.6.d.

Oestrua.
Oestrus accompanied by ovulation can occur in ewes

between

30 to 40 days after

parturition,

during the normal breeding season.
that

conception rate is very low,

particularly

However, it appears
particularly

during

the first oestrous period (Timariu et al., 1975).

rakul

Nel (1965) from his study using non-lactating

Ka-

ewes found that conception within the first

four

weeks after parturition is very low ( ' 7 . 7 % ) . and the conception

rate increased to 30.8% between 30 to 34

but was only normal after 60 days.

days,

2.

NUTRITION AND REPRODUCTION.
Nutrition

the

undoubtedly plays an important role

reproduction of sheep and goat.

The

in

reproductive

performance of naturally breeding goats and sheep varies
considerably throughout the world, due to the large number

of genetically distinct breeds and a wide range

of

management systems, climatic conditions and socio economic

constraints.
restict

will

endocrine

Under-nutrition

of the young

both growth rate and the

function.

animal

development

of

So nutrition will have short

or

long term effects on reproductive

performance (Rattray,

1977)
Reproductive
the

performance

is limited not only

total annual nutritional provision,

but more

the seasonal fluctuations in

its

by

par-

avail-

ticularly

by

ability.

Where nutrition ia the first limiting factor,

genetic
any

improvement

alone is less likely to result

real increase in productivity.

So assessment

the effects of nutritional factors on reproductive

in
of

rate

is essential in any program for improvement.
The adult reproductive cycle can be separated into
some

recognizably different periods:

oestrus

and

ovulation,

pregnancy

mating
and

lactation

seasonal anoestrus in temperate zone animals.
will

including

Nutrition

have special effects on the each period of

ductive cycle.

and

repro-

Measurement of the reproductive response to nutrition is in the forms of fertility and,fecundity.
dity is defined as breeding rate which can be
in terms of litter size.
of

Litter size is a

Fecun-

expressed

consequence

ovulation rate in the oestrous cycle