UNIVERSITI PUTRA MALAYSIA SUPEROVULATION AND EGG...
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UNIVERSITI PUTRA MALAYSIA SUPEROVULATION AND EGG RECOVERY IN GOATS ROSNINA BTE. HAJI YUSOFF FPV 1989 2
Transcript of UNIVERSITI PUTRA MALAYSIA SUPEROVULATION AND EGG...
UNIVERSITI PUTRA MALAYSIA
SUPEROVULATION AND EGG RECOVERY IN GOATS
ROSNINA BTE. HAJI YUSOFF
FPV 1989 2
SUPEROVULATION AND EGG RECOVERY IN GOATS
By
ROSNINA B TE . ��JI YUSOFF
The s i s Submitted in P a rt ial Ful f i lment of the Requirement s f o r the Degree of M a s t e r o f S c ienc e
in the Faculty o f Ve t e r inary Medic ine and Animal S c ienc e
Unive r s it i P e r tanian Malay s ia
June 1989
ACKNOWLEDGEYiliNT S
P ra ise t o the Almighty Al l ah . H a d it not b e en H is Wil l the c omp l e tion of this study woul d not have b e en poss ib l e .
I woul d l ik e t o exp ress my s inc e re gratitude and app reciat ion t o:
i . Professo r M . R . Jainud e en , my sup e rvisor , invaluab le guidance , a dvi c e , encouragement and throughout this study .
f o r h is patience
i i . Dr . Sharifuddin Wahab f o r h is a dvic e , inte rest and support throughout this study .
i ii. D r . Mohd. Ali Rajion and the staff o f U.P . M Goat Uni t for the ir kind c oope ra t ion .
iv . laid O thman , my husband. for his support , c onc e rn , understanding and patienc e throughout this s tudy .
v . My , mother, family and friends for their patienc e. encouragement and supp o r t .
vL Unive rsiti P e rtani an Malays ia through P roj e c t 5 0 3 03/J02 IRPA .
i i i
for f inancial suppo rt
TABLE O F CONTENTS
Page
ACKNOWLEDGEMENTS
L I S T OF TABLES
L I S T OF FIGURES
LIST OF PLATES
i i i
v i i i
x
xi
L I S T OF ABBREVIATIONS xii
ABS TRACT
ABS TRA..T{
xii i
xv
CHAPTERS
1.
I I .
INTRODUCTION • .- • .• • • ..• • e-._ . . . . . .. . . .. . . . . . . . . . . e - • • • •
REVIEW OF LITERATURE
Introduc t ion
Female Rep roduction
Pube rty
1
3
3
4
4
O e s trous Cyc le . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
S e a s onal ity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Cyc l e L ength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
O e s t rus
Ovulat ion
iv
7
8
Ovum T ranspo r t
Induc t ion o f Oest rus
Male E f f e c t
Photoperiod Alterat i on
Ho rmones
Folliculogenesis
Superovulat ion
Gonado t rophins f o r S up e rovulation
G onadotrophin Pre.parations
S ource
Biologic a l Half- l if e
Treatment S chedule
Ova rian Response
P roblems
Egg Re c ove ry
Technique
S ite and Time o f C o l l e c t i on
Factors Influenc ing Re cove ry
III . MATERIALS AND METHODS
Animals
Establ ishment o f the Oest rous Cyc l e
Detect ion o f Oest rus
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Page
12
12
13
1 4
1 5
1 7
20
2 0
2 1
2 2
2 2
23
2 4
2 8
3 2
3 2
3 4
35
38
38
38
39
Honnonal Preparat ions
Ho rmonal Reg ime
Exp e r imental De s ign
Eva luat ion of Ovarian Re s p on s e
Laparoscopy
Egg Recove ry
Day of Rec ove ry
F lushing Technique
Micro s c opic Examinati on o f Flush ing
Analy s i s o f Data
IV . RESULTS
O e s t ru s B ehaviour ·
Inc idence of Oestrus
Onset and Duration o f Oest rus in Cyclic Doe s
Onset and Durat ion o f O est rus in Supe rovulated Doe s
S igns o f Oest rus
Supe rovulato ry Response
C l imatic Data and E f f e c t of S e asons
Unovulate d Fo l l ic les
C o rpora Lutea
Egg Recove ry
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Page
39
41
42
42
43
47
4 7
4 8
4 9
5 1
52
52
52
53
55
56
57
5 7
59
61
63
Page
v. DI SCUS S ION 67
Inc idence , Ons e t and Duration o f O est rus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
De tec t ion and S igns o f O es trus 68
T iming of Supe rovulation 68
Sup e rovulatory Response 69
Egg Recove ry 71
VI. SUMMARY AND CONCLU SIONS 7S
BIBLIOGR...:4.PHY 78
APPENDIX 9 0
vii
L I S T OF TABLES
Tabl e Page
1 . Inc idence o f O e s t ru s F o l lowing Two Method s o f O e s t rus Induct ion in Goat s . . . . . . . . . . . . . . . . . . . . . 52
2. Ons et and Duration o f O e s t ru s in PMSG and. FSH-
3.
4 .
c: ..I.
6.
7.
treated Goat s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Ovarian Re spons e in FSH and PMSG - tre a t e d G o a t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Numb e r o f Egg s Recove r e d PMSG and FSH-treated Goa t s
and Fe rtil ized in
Chi- Square t e s t o n the Inc idence o f Oe s trus Following Two Me tho d s o f Induc t ion o f O e s t ru s . . .
Analy s i s Treatment
of Varianc e on the E f f e c t s o n End o f_ T reatment to
o f FSH O e s t ru s
60
66
91
Inte rvals in Goats . . . . . . . . . . . . . . . . . . . . . • . . . . . . . 92
Analy s is of Varianc e on the E f f ec t s of Treatment on Duration of O e s t ru s in Goat s
FSH 92
8 . Analy s i s o f Variance on the E f f e c t s o f FSH Treatment in Goats
on Numb e r of Unruptured Follic l e s
9. .Analy s is o f Variance o n the E ffects o f FSH Treatment on Numb e r of C o rp o ra Lutea in
93
Goats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
D.
11.
12.
Analys is of Variance on the E f fe c t s of FSH Treatment on Numb e r of Eggs Rec ove red in Goats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analys i s o f Variance on the E f f e c t s o f FSH Treatment on Numb e r o f Egg s Fertilized in Goats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analy s i s o f Varianc e on the E f fe c t s o f PMSG Treatment on End of T reatment to Oe s t rus Inte rva l s in Goat s . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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94
9 4
95
13 . Analy s is o f Variance on·· the E f f e c t s o f PMSG Treatment on Durat ion o f O e s t ru s in Goat s
14. Analy s i s o f Varianc e on the E f f e c t s o f PMSG Treatment on Numb e r o f Unruptured Follic l e s in Goat s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 5 . Analysi s o f Variance on the E f fe c t s o f PMSG Treatment on Numb e r o f C o rp ora Lutea in Goat s
16. Analysis o f Variance on the Effec t s o f PMSG Treatment on Numb e r o f E gg s Re cove red in
95
96
96
Goats • . . . . . . . . . • . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
17. Analysis o f Variance on the Effects o f PMSG Treatment on Numb e r o f E g g s F e r ti lized in G. o_ a.t_ s . • . . -,.�. _ . .. .. . . . . . .t ..• e - .- . e -" e · • • • • ,. . . ... . . ... . . .. e -,. • • • . .• - .• .•••..•. " 9.7
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L I S T OF FIGURES
Figure Page
1. Ons e t of O e s t ru s Fol l owing Two Method s o f O e s trus Induct ion i n Goats . . . . . . . . . . . . . . . . . . . . . 53
2 . Duration o f O e s t ru s F o l l owing Two Method s o f O e s t rus- Induct ion i n Goat s . . . . . . . . . . . . . . . . . . 54
3 . E f fe c t s o f Rainfall, T emp e rature and Day-�ength on Ovulatory Re sponse in Goats . . . . . . . . . . 5 8
x
Plate
1.
2.
3.
4.
5.
6.
7.
8 .
9.
L I S T O F PLATES
Detection o f O e s t ru s in Goat . . . . . . . . . . . . . . . . . . .
Laparos copy in Goat
Supe rovulated Ovary of a Goat at Laparos copy and Laparotomy . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Surgical Re cove ry o f E g g s on Day Five o f the O e s trous Cyc l e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Right Ovary o f a Goat Inj e c t e d with 1500 i . u of PMS G . . • . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . -. . • .
Laparo s copic View o f L e ft Ovary o f a Supe rovulated Goat Showing Re g r e s s e d C o rpora Lute a on Day 5 o f the O e s trous Cyc le . . . • . . . • . . . . . . . • .
Laparo s c op ic View of Right Ovary o f a Superovulated Goat Showing Multip l e Corpora Lute a on Day 5 o f the O e s t rous Cyc l e . . . . . . . . . . . . . . . . .
A Goat Moru l a C o l l e c t e d f rom the Ute rus on Day 5 o f the O e s t rous Cycl e . . . . . . . . . . . . . . . . . .. .
A Goat B l a s t o cy s t C o l l e c t e d from the U t e rus on Day 6 o f the O e s t rous Cyc l e . . . . . . . . . . . . . . . . .
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Page
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50
62
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63
64
64
CL
cm
FSH
h
GnRH
HCG
i . u
k g
LH
LHRH
mcg
mg
ml
mm
ng
p c t
p g
PGF2 aHa
PMSG
rpm
LIST OF ABBREVIATIONS
c o rp o ra lut e a
c entime t r e
F o l li c l e S timulating Hormone
hours
Gonadotrophin Re l easing H o rmone
Human Chorionic Gonadotrophin
Inte rnational Unit
kilogram
Luteinizing Hormone
Luteinizing H o rmone Re leasing Hormone
mic rogram
mil l ig ram
mil li l it.r e
mil limet r e
nanogram
p e rc ent
pic o gram
Pros taglandin F2 a l fa
Pregnant Mare S e r�� Gonadotrophin
revo lutions p e r minute
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Ab stract o f the s i s pre s ent e d to the S enate o f Unive r s it i Pe rtanian Malay s ia a s p artial fulfilment o f the requirements for the degree of Maste r of S c ience
Supe rvis o r Faculty
SUPEROVULATION AND EGG RECOVERY IN GOATS
By
ROSNINA BTE. RAJI YUSOFF
June 1989
P rofe s s o r M . R . Jainude en Vete r inary M e dic ine and Animal S c ience
Re s e arch on s up e rovulation , e gg r e c ove ry and emb ryo
tran s fe r in goat s has been c onducte d in many deve loped
c ountr ies of the wor ld , but s imilar studie s in trop ical goat s
a re l imit e d in S outh-East As ia . The r e fore a study was
unde rtaken t o dete rmine i f the indigenous goat, Kambing
kacang , and the i r c r o s s e s c ould b e s up e rovulated and e g g s
r e c ove r e d b y technique s p reviou s ly report e d for goat s i n the
tempe rate z one . A total of 70 Kamb ing kacang doe s we re
s upe rovulated with eith e r P re gnant Mare Se rum Gonadotroph in
( PM S G ) o r Follicle Stimulat ing Hormone ( FSH-P ) . PMSG (500,
1000 and 1500 i . u ) was admini ste red int ramu s cularly a s a s ingle
do s e , two days b e f o re the withdrawal o f 60 mg
medroxyp roge ste rone ac etate int ravag inal sponge s . FSH-P
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(19 , IS .and 2 0 mg ) was divid e d into four dec re a s ing daily
do s e s ( 4 , 3 , 2 , 1; 6 , 4 , 3 , 2; 8 , 6 , 4 , 2 mg ) and admini s t e re d
subcutaneou s ly a t 0 7 0 0 h and 1 9 0 0 h . The inte rval f rom end o f
supetov�lato ry treatment to the ons e t o f o e s t ru s wa s long e r
among the PMSG- treated g roup s ( 38 to 63 h ) compared with the
FSH-treated group s (19 to 3 9 h ) . The supe rovulatory r e s pons e
was. le s s than S O p c t dur ing the hot months of Feb ruary , June
and July when the monthly rainfall was b elow 1 0 0 mm. The
average number of urr ruptur e d fol l icles d id not vary greatly
b e tween and w ithin_gonadotrophin- t re a t e d g roup s but the average
numbe r o f CL was high-er in the FSH - t re a t e d g roup s ( 7 to 10 CL
p er doe) than in the PMSG - t r e a t e d group s (1 to 5 CL p e r doe ) .
However, the ave rage rate o f e gg recove ry and fe rtilization
f rom both the gonadotrophin- t re a t e d g roup s we re poo r . F rom
the s e r e sult s it may be concluded that a s tudy on the
fo l liculogene s is of the Kambing kacang doe s should b e condu c t ed
to dete rmine the optimum t ime o f gonadot rophin inj ections so a s
to imp rove the supe rovulato ry re s pons e . Te chniqu e s o n recove ry
of eggs via lapa ro s copy or via the c e rvix shou l d a l so b e
deve loped t o prevent adhe s ions and thu s , improving g r e a t e r u s e
o f dono r s .
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Abs trak t e s is yang dikemukakan kepada P e rtanian Mal ay s ia bagi memenuhi s eb ahagian s yarat untuk ij azah Mas t e r S a in s
S enat Unive r s it i daripada s yarat-
P eny e l ia Fakult i
SUPEROVULASI DAN PENGUMPULAN TELUR DARI KAMBING
Oleh
ROSNINA BTE. RAJI YUSOFF
Jun 1989
Profe s or M . R . Ja inude en Kedoktoran Vet erinar dan Sains P e ternakan
Penye lidikan t e rhadap supe rovula s i. p engumpul an t elur dan
pemindahan embrio pada kambing t e lah dilaksanakan di negara-
nega r a yang telah maju t e tap i kaj ian ter s ebut pada ka, .. nhing-
kambing trop ika mas ih t erhad di As ia Tenggara . Dengan itu ,
s uatu kajian te lah dilaksanakan bag i menentukan sa.TUaada
kambing t empatan , Kamb ing kacang dan kacukannya boleh
disuperovula s ikan dan t e lur - t e lurnya dikumpul mengikut t eknik-
teknik yang t e lah di lakukan k e ata s kamb ing-kamb ing d i z on
t emperate . S ejumlah 7 0 ekor Kamb ing _�acang b e tina t e lah
disuperovula s ikan dengan " Pr egnant Mare S erum Gonadotrophin "
( PMSG ) atau " Fol l i c l e S t imulat ing H ormone " ( FSH- P ) . PMS G
( 50 0. 1 0 0 0 .dan 1 5 0 0 i. u ) d i s untik me lalui otot untuk satu dos
sahaja , dua hari s ebe1.um " sponge " yang mengandungi 60 mg
medr oxyproge s t erone a c e ta t e d itarik ke luar dar i faraj
xv
kambing . FSH-P ( 10 , 15 , 20 mg) dibahagi kepada 4 dos s e c ara
menu run ( 4 , 3 , 2 , 1 ; 6 , 4 , 3 , 2 ; 8 , 6 , 4 , 2 mg) s e l ama 4 hari dan
disuntik di bawah kul it kambing pada j am 0 7 0 0 dan 1 9 0 0.
Jangkamas a antara akhir rawatan superovula s i dan bermulanya
e s tr:us adalah lebih panj ang dalam kumpulan PMSG ( 3 8 hingga 6 3
j am) be rbanding dengan kumpulan FSH ( 1 9 hingga 3 9 j am) . Dalam
bulan Februari , Jun dan Julai dimana j umlah huj an adalah kurang
dari 1 0 0 mm sebulan , tindakbalas superovula s i kurang dari 5 0
peratus . Purata bilangan folik e l yang belum pecah tiada beza
antara kedua-dua kumpulan gonadotropin tetapi purata bilangan
CL lebih tinggi di kalangan kambing-kambing yang dirawat dengan
FSH (7 hingga 1 0 CL bagi s eekor kambing betina ) berbanding
dengan kumpulan kambing PMSG (1 hingga 5 CL bagi s eekor kambing
betina ) . Walau bagaimanapun , purata bagi kadar ova yang telah
dikumpul dan disenyawakan dari kedua-dua kumpulan gonadotropin
adalah kurang memuaskan. Dari keputusan-keputusan tersebut,
s atu kajian mengenai p embentukan dan perkembangan folike l
( folikulogene s i s ) Kambing kacang hendaklah dilaksanakan bagi
menentukan mas a yang optima untuk menyuntik gonadotropin bagi
memperbaiki tindakbalas superovulas i . Selanj utnya teknik
mengumpul ova s e c ara lap aroskopi atau me lalui s erviks hendaklah
diperkembangkan untuk menge lak penaupan tisu dan dengan itu
memperbaiki kegunaan kambing-kambing betina .
xvi
CHAPTER 1
INTRODUCTION
The location o f the wor ld ' s goat population is toward s the
e quatorial / tropical r e g ions where more than two - thirds are
within. 3 0° o f the e quator. Thi s i s because from the biological
s tandpoint , the sma l l s ize , l arge sur face are a relat ive to body
weight and l imit e d subcutaneous fat cover make it poorly
adapte d to cold climate s but relatively we l l adapt e d to high
tempe rature. In the arid trop ic s , it adapt s we l l becau s e of i t s
abil ity to cons erve wate r , trave l we l l, graze s e l e c tive ly and
take a wide varie ty of vegetation . Moreover , the indigenous
goat i s r e s i s tant to many di s e a s e s which plague other l ive s tock
spec i e s in the s e are a s .
The goat populat ion o f Mal ay s ia which compri s e d mainly o f
Kambing kac ang i s reared for me at , which provide s sma l lhol der
farmer s a s upp lementary income . B e twe en 1980 and 1984 , the goat
population has dec l ined rapidly from 352 , 300 to 288 , 980
( Jabatan Perkhidmatan Haiwan , Ma lay s ia , 198 4 ) . Thi s de c l ine in
number i s due to the incre a s e d extraction o f goa t s for meat
and , although the indigenou s goat bree d s throughout the year ,
two kiddings p e r year are not c ommon s ince they exhibit long
kidding int e rva l s .
1
2
To increa s e local pro duc t ion s o a s t o mee t local demand ,
the g ene tic improvement of the indigenous goat i s urgently
nee de d . The l ate s t high - t echno lo gy i s to dwe l l int o the
manipulation of gamet e s by embryo transfer technology which
inc lude s up e r ovulation , c o l l e c t i on and t ran s f e r o f emb ryo s t o
r e c ipient s .
Through emb ryo t rans f e r , the numb e r o f progeny f rom
genet ic ally s uperior female s c ould be inc r e a s e d which h e l p s t o
intens ify a b r e e ding progrannne and s igni f i c antly reduc e s the
t ime span requ ire d to achieve the s ame outc ome by natural
breed ing . With emb ryo t r an s fe r , the frequency of a particular
gene t ic charac ter i s tic s w ith in exi s ting populat ions c ould be
inc r e a s e d . The inc r e a s e d p ro g eny allows more intens ive
s e le c t ion f o r de s ir e d t rait s a s we ll as a dvancing the ove r a l l
numb e r s o f s upe rior animal s produced in a sho rt pe r i o d .
Eventually , emb ryo t r an s f e r a c t s a s an aid in the t ransport o f
. animal s .
The obj e c t ive s o f this s tudy a r e :
1 . T o e s tab l i sh a me thod o f o e s t ru s induc tion in the
indigenous goat , K amb ing kac ang and its c r o s s e s .
2. T o c ompare the supe rovulato ry re spons e to diffe rent
do s e s o f e ithe r Fo l l i c le S t imulating H o rmone (FSH ) o r
Pregnant Mare Se rum Gonadot rophin (PMSG ) .
3. To a dapt a t e chnique f o r r e c ove ry o f eggs from the
reproduc t ive tract o f the s up e rovulated goat .
CHAPTER 2
LITERATURE REVIEW
Introduction
Emb ryo trans fe r procedure invo lve s a s e ri e s o f integrated
step s : supe rovulat ion o f dono r s , s ynchron i s a t ion o f o e s t ru s
between dono r s and rec ip ient s , recove ry , s to rage and tran s f e r
o f embryo s . The technique o f emb ryo trans f e r i s not only o f
c ons i de rable potent ial in genetic imp rovement , but b e c au s e the
numbe r , genotype , age of emb ry o s_ , s.ite of t ran s fe r and othe r
fac t o r s c an be controll e d , a l s o has many p otential app l icat ions
in re s earch .
In gene ral, emb ryo tran s f e r ha s the bene fit of inc r e a s ing
the number of p rogeny f rom gene t i c a l ly sup e rior femal e s ,
inc reas ing part icular gene tic characte r i s t ic s within exi s t ing
populat ions and acting a s a method o f t ransport o f anima l s
betwe en countri e s . F o r a bette r unde r s tanding o f emb ryo
trans fe r p rocedure in goat s and sheep , p e r t inent a s p e c t s of
female rep roduc tive phy s io l ogy , supe rovulation and c o l l e c t ion
of emb ryos are reviewed in this chap t e r.
3
4
Female Reproduction
Repro duc t i on in the fema l e i s a c ompl ex phenomenon . I t i s
dependent o n various fa c t o r s s uch a s here ditary charac t e r s ,
endoc r ine c on s t itution and p a tho l o gical c ondit ions , nut rit ion
and management. I f the phy s i o l o g ic a l pro c e s s e s are in harmony
and the above fact o r s are c onduc ive , the f emale will reach
pube rty and c ommence its reprodu c t ive c y c l e .
Puberty
Pube rty may be defin e d a s the age at which the generative
o rgans b e c ome functional and repro duct ion may occur but doe s
not s ignify full o r no rmal reproductive c apac ity (Robe r t s ,
1 9 8 6 ) . In the female , pube rty i s charac t e r i s e d by the ons e t o f
o e s t rus and ovulation .
Pube rty occurs at 5 to 7 months in doe s and 6 to 9 months
in ewe s (lainude en and Hafe z , 1987 ) . The M e r ino sheep and
Angora goat are 18 to 20 months o l d at f i r s t o e s t ru s . Early
maturing b re e d s s uch as Pygmy goat reach pube rty as e arly a s 3
to 4 months . Pube rty in t r op ical goat s occur at the age o f 249
to 293 days b u t mo s t g o a t s are b re d a f t e r they re ach 1 year o l d
(Raj a , 1977 ) . The indigenous g o a t o f Malay s ia, Kamb ing kacang
i s f i r s t mat e d b e tween 12 and 15 months (Devendra , 1983 ) .
5
Oestrous Cycle
In' a l l s p e c i e s o f dome s t ic animal s that have reached
pub e rty a new pha s e of the func t ional a c t ivity o f the
reproductive sys tem is expre s s e d by the ons e t of f i r s t o e s t rus
and if the animal i s not s e rv e d this t rans i ent pha s e is
followed by me toe s t rus , dioe s t ru s and p roe s t rus . The chain o f
the phys iological events that b e g in at one o e s t rus pe riod and
end at the next is t e rme d as o e s t rous cyc l e .
Dur ing the oe s trous cyc l e o f the goat , the change s in
proge s te rone c oncentrat ion in the p e r iphera l p la sma are s imilar
t o tho s e p revious ly repo r t e d in the ewe and cow ( Thorburn and
Schne i de r , 1972). The o e s t rous cycle i s hormonal ly c ont r o l l e d
b y the interrelated act ions o f the gonadotrophic hormone s
s e c reted by the anterior p ituitary and the gonadal hormone s
s e c reted by the ovary . FSH i s re s pons ible for f o l l icular growth
and maturation o f the ovum . As the f o l l ic l e s g row, the quant ity
o f oe s t rogen in the b l o o d is high (26. 9 pg/ml ) (Bono et a l . ,
198 3 ). When o e s t rogen leve l inc re a s e s , it suppre s s e s the F SH
lev e l and s t imulates the p ituit a ry to l ibe rate lute inis ing
hormone ( LH) . LH c aus e s p re ovul a t o ry enlargement of the
f o l l icle , induc ing ovulation and sub s e quently a c o rpus luteum .
Prog e s t e rone level on day o f o e s t ru s i s 0. 2 ng/ml in the goat
( Tho rburn and Schne ide r , 1972). The c onc entration inc rea s e d t o
a maximum o f 4 ng/ml on d a y 10 o f the 21 d a y s cyc l e and
d e c r e a s e d rapidly during the l a s t 3 day s of the cycle due t o
6
regression of the corpus luteum which in turn stimulates the
p ituitary to liberate more FSH . Thus , a new cycle commences .
Howeve r, during anaesthesia and surgery stress ( Thorburn and
Schne ide r, 1972 ) , progeste rone concentrat ions markedly increase
( 9 ng/ml ) .
Seasonality
Mariy wild s pecies o f bovidae are seasonal bre e de rs with
spring and .summer' b"ei ng the most suitable time of the year for
b irths . Dudng the course o f domestication, cattle we re
se lected against seasonality, facilita t ing them to ovulate and
concei:ve throughout the year . Sheep and goat in the temperate
zone are seasonally polyoestrus and young are born in sp ring,
the most favourable t ime 'of the y ear, whe r e as in the t ropical
zones, with less variation in day length, indigenous sheep and
goats tend to b re e d throughout, the yea r . 'Creole ' mea.t goats
maintained in good condition did not show marked sea'sonal
variations
(Chemineau,
in oestrus behaviour
1986) in the t ropics .
and ovarian activity
High environmental
tempe rature and lack o f fee d may restrict sexual activity
during some .months of the y e a r in the tropics, but shortly
after the otiset Df the rainy season, sexual activity increases,
probably due to the availabil ity o f feed and with decreasing
day light (Hafez and Jainudeen, 198 7 ) .
7
Cycle Length
The length o f the normal o e s t rous cycle in the ruminant
r ange s between 14 and 29 day s . The ave rage l ength o f o e s t rous
cycle i s 21 day s for cattle , wat e r buf falo and the goat ( Smith ,
197 8 ; BonDurant , 198 1 ; C amp e t a l . , 198 3) and 1 7 days for the
sheep ( Fo s te r , 1981 ) . The av e rage l ength of the cycle is 20
days for Kambing kacang ( Devendra, . 1983; Thangavelu and
Mukhe rj e , 198 3) , 20 day s f o r the Indian Pa shmina goat s
(Mazumde r and Mazumde r , 198 3 ) and 2 1 days f o r the Ango ra goat s
( Ilgaz and S e rnie , 1982 ) . I n the g oat , a c t iv e immunization
again s t oxytocin c au s e s a s ignificant p ro l ongat ion of the
o e s t rous cycle , r e fle c t ing a l engthening of the func tional
l ife� span o f the c orpus luteum ( Cooke and Home ida , 198 5 ) . In
gene ral , the re i s c on s iderab l e variation in sheep and goat
due to breed diffe rence s , s tage o f the bree ding s e a s on and
environmental s t re s s .
Oestrus
Signs of Oestrus
In ruminant s , s igns o f o e s t rus vary among s p e c ie s . The
prominent s igns o f o e s t ru s in cattle are b e l l owing ,
r e s t l e s sne s s , swo llen and hype r emic vulva , c lear , s t ringy mucus
d i s charge from the vagina , frequent urination and homo s exual
behaviour ( Z artman et al . , 1983 ) .
8
S igns o f oe strus are mor e c onspicuous in doe s than in
ewe s . The buck or h i s o dour w i l l stimulate most nonp re gnant
doe s to show de finite s igns o f o e strus . The s e s igns inc lude a
rapid s ideway s or up- and- down tail wag which continue s when
hand pre s sure is app l ied to the doe' s rump . The vulva may b e
swol l en while milk p roduction and appetite tend to decreas e .
Many doe s are more vocal than u s ua l; they fol low the buck o r
pace the perimet e r o f the enc l o s ure s e arching f o r the buck
(Smith, 1 9 7 8; Bo:nDurant, 1986). A doe may o c ca s ionally exhibit
homo s exual behavior (Smith , 1 9 7 8 ) . Thus, in the ab s ence o f a
male. oe strus is di fficult to detect in b oth the ewe and doe .
Duration
Duration of o e s trus i s inf luenced by b r e e d, age, s e as on
and p re s enc e of the mal e . In g eneral, durat ion o f o e s t ru s in
the ewe and doe l a s t s 24 to 3 6 h and 24 to 48 h r e s p e c t ive ly
( Jainudeen and Hafe z, 1987 ) . For the Kambing kacang o e s t ru s
l a s t s for 34 h (Devendra, 1983 ; Thangav e lu and Mukhe rj e , 1983 )
whe r e a s for the Indian P ashmina and Angora goat s, durat ion o f
o e s t ru s l a s t s f o r 2 5 ( Mazumd e r and Mazumde r, 1 9 8 3 ) and 35 h
r e s pe c tively ( I lgaz and S e rnie, 1 9 8 2 ) .
Ovulation
Ruminant s such a s c a t t le, sheep and goat s are s p ontaneous
ovulato r s . Ovulat ion is c ont r o l l e d by gonadot rophic hormone s :
FSH and LH . The Graaf ian fo l l ic l e i s the maj or s ite for the
9
product ion o f o e s t rogen s . Twenty -four h prior to ovulat ion , LH
re l e a s ed f rom the p ituitary in a surge ( ewe : 5 0 - 1 5 0 n g /ml)
( Ge shwind and Dewey , 1 9 6 8 ; P ant �.a l . , 1 9 7 7 ) ( goat: 3 0 - 5 0
n g / ml ) (Bono e t al . , 1 9 83 ) , induc e s the f inal preparation o f
the. follicle f o r ovulat ion . I n goat , the LH p r e ovulatory p e ak
occurs 8 to 2 4 h afte r the ons e t o f o e s trus ( Bono e t al . , 1 9 8 3 )
but the inte rval f rom the ons e t of o e s t rus to the LH d i s charge
in the ewe varies b e twe en and within breeds ( Th imonie r , 1 979 ) .
In the Ile-de-France a dult fema l e s , this interval i s l onge r f o r
ewe with 2 ovulation s than with s ingle ovu lation and in highly
p r o l ific Romanov e,ol e s (17 . 6 h) than in l e s s prol i fi c b re e d s (6
t o 7 h ) (Land e t a l . , 1973 ) . A t ovu lat ion in the goat , the
leve l of LH in the b l o o d re duc e s ( 0 . 5 - 3 . 0 n g / ml ) rapidly but
the FSH leve l b e g ins t o - inc r e a s e (11-17 ng{ml) (Bono et a l . ,
1983 ) . Aft e r the egg i s she d , the ruptu red f o l l i c l e reduc e s in
s ize and the g ranulo s a c e ll s b e c ome the lute in c e l l s which a r e
inf i l t rated with c ap i l larie s . T h i s newly f o rme d body i s the
c o rpu s luteum and i s r e s pons ib l e for prog e s te rone p roduction .
At ovulat ion , the p roge s t e rone l ev e l in the b lo o d i s at b a s a l
l evel ( 0 - 0.8 ng / ml ) but inc r e a s e s about 2 4 h afte r ovulat ion
( 1 - 4 ng/ml ) ( Bono et al . , 1983 ) .
Ovulation Time
Unl ike cattle, both ewe and doe ovu l ate dur ing the latter
half of o e s t ru s . The ewe and many b r e e d s of goat normally
ovulate about 24 to 27 h and 24 t o 36 h r e spec tiv e ly after the
