Control means for estrous cycle control in sheep
Mourad Rekik
EIAR-DBARC-ICARDA-ILRI (LIVES)-FAO Training on Reproduction in Sheep and Goat, Debre Berhan,
Ethiopia, 13-15 October 2014
Control Means
Introduction
Synchronisation of oestrus and induction of
ovulation
Natural method
Hormonal treatments
Improvement of litter size
• Long seasonal anoestrus : 2-6 mois
• Pregnancy: 5 months• Postpartum anoestrus: 1-3
months• An inherent low prolificacy
Physiological causes of reduced reproductive efficiency in sheep and goats
In most production systems, sheep and goats give birth once a year, produce single litters and the production is seasonal.
Improvement of fertility
Breeding season
Anoestrous season
Synchronisation
Induction
Synchronisation
Control over the events of the oestrous cycle
Mating Synchronisation Lambing Compactness
The best mating time
(Maximise fertility)
Nutritional requirements
and provision from cheap natural feed
According to the market
requirements and the
consumer demand
CHOOSEADJUST PRODUCE
Olfactory senses
hypothalamus
Pituitary gland ovary
Male stimuli (Pheromones)
Central nervous system Reproductive tract
LH
FSH
GnRH
Natural method: The «male effect»
How it works
Types of Ovulatory and Estrous Cycles of Ewes in Response to Ram Introduction.
Variation Factors
• Age : Maiden/Adults (75 % vs 95 %) • Breed : Temperate/Meridional• Season
– Stage of seasonal anoestrous– Association seasonal and postpartum
anoestrous• Body condition : Females in depressed BC do
not respond• Male sexual aggressiveness: sex ratio and
maturity
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 300
1
2
3
4
5
6
7
8
Percent of mated ewes in 5 flocks (6 years, 5894 observations; anoestrous season)
Jours
(%)
67% of females
Rekik, 2011
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 260
2
4
6
8
10
12
14
16
Distribution des 1ers oestrus dans le troupeau expérimental
Jour
Pour
cent
age
des f
emel
les e
n oe
stru
s (%
)
11
Synchronisation using the ram effect and a single injection of 20 mg of progesterone in
oil
APPEARANCE OF OESTRUS
0
10
20
30
40
50
1 2 3 4 5 6 7 8 9 10 11 12
EM
MALE EFFECT IN GOATS
P4
MALE EFFECT
0
10
20
30
40
50
1 2 3 4 5 6 7 8 9 10 11 12
EM
EMP
MALE EFFECT
Days 0 9 50 hours
PGF2
TREATMENT MALE EFFECT + P4 PROGESTAGENS PROSTAGLANDINS
FEMALES 1584 600
FERTILITY 64,6% 46,8%
A.I.P4
MALE EFFECT
Hormonal Methods: FGA+eCG in sheep
1
5
FGA plasma levels(ng/ml)
Sponges left in12 - 14 days
eCG
LH
Oestradiol
Ovulation
Corpus luteum(Progesterone)
Time+ 48 h + 60 h
Sponges in
OESTRUS
Controlled mating
Sponges out 2 days
Not before 150 days postpartum
11 days (± 1)
eCG
Sponges 45 mg FGA
In Out Natural mating or AI 43-45 hours
After withdrawal of sponges
Short protocol for synchronisation of oestrus in goats
PgF2
48h prior to sponges withdrawal
250 to 600 IU
98 % of goats are in oestrus between 24 and 72 hours after withdrawal of sponges
ALTERATIONS CAUSED BY PROGESTATIVETREATMENTS
LACK OF RESPONSE
LACK OF SYNCHRONIZATION
ALTERATIONS IN THE OVULATION
ALTERATION IN MOBILITY AND VIABILITY OF SPERM
0
0,5
1
1,5
2
2,5
3
-2,5 -2 -1,5 -1 -0,5 0
Días respecto celo
Est
rad
iol
(pg
/ml)
ALTERATIONS CAUSED BY PROGESTATIVETREATMENTS
Days to oestrus
26
27
28
29
30
31
32
33
34
0 1 2 3 4 5
Inte
rval
sp
on
ge
wit
hd
raw
al-
oes
tru
s (h
)
Number of treatments
Panel A
0
10
20
30
40
50
60
70
80
20 40 60 80
Fer
tili
ty (%
)
Interval sponge withdrawal-oestrus (h)
No oestrus
Panel B
Alterations caused by eCG:
Relationship between the interval withdrawal of sponges-oestrus and the number of eCG treatments (Panel A) and
between the same interval and fertility of the does (Panel B) (Redrawn from Chemineau et al., 1999).
20
40
60
80
100
120
140
160
180
0 200 300 400
% c
on
cep
tio
n r
ate
or
pro
lifi
cacy
Dose of eCG (IU)
Conception rate
Prolificacy
The effect of increasing doses of eCG on conception rate and prolificacy at the induced oestrus of local Tunisian female goats (N. Lassoued and M. Rekik, 2010, unpublished results)
MELATONIN
Utilisation Protocol
7 d. 42 to 49d. (6 to 7 weeks)
Implant insertion
Isolation of rams
Ram Introduction
Mating
150 d+/- 5 d
After ramintroduction
3 implantsram
1 implantEwe/ewe lamb
Lambing
Awassi breed- Syria
84
12
84
16
92
28
84
40
0
10
20
30
40
50
60
70
80
90
100
MélovineControl
Fertility %
Implantin : 9 April 23 April 7 May
Mélovine (CEVA®)
26 March
Mating : May End MayJune
mid Junemid July
end JuneJuly
Maiden ewes during anoestrus
Breed Treatment Females lambing (% fertility)
Lambs born(% prolificacy)
Noire de Thibar
Mélovine: 70 49 (70%) 52 (106%)
Control: 70 34 (48%) 34 (100%)
Sicilo-Sarde
Mélovine: 60 30 (50%) 30 (100%)
Control: 60 23 (38%) 23 (100%)
+ 22%
+ 12%
Rekik, 2010
Estrus synchronisation with Prostaglandin (PGF2α)
I: intramuscular injection of 125 mg of Cloprosterol (Estrumate®)
1st I 2nd I
10- 14 days 36 to 48 h after the second injection
Estrus
• Cycling ewes• does not interfere with subsequent cyclicity of sheep in 90% of cases : "natural“estrus
Estrus synchronisation with Ovsynch Protocol
7 days 48 h 16-24 h
GnRH (Receptal /Fertagyl 2.5 ml)
PGF2α
(Estrumate 2 ml)
GnRH (Receptal /Fertagyl 2.5 ml)
G P G
Fixed time AI
Ovulate the dominant follicleIntiate the new follicular wave
Induce luteolysis
Induce ovulation of new dominant follicle
Synchronisation of estrus
Synchronisation of ovulation
Improvement of prolificacy
• Possible but difficult
• Low genetic progress: low heritability of
the trait
• Indrect selection on prolificacy: ovulation
rate,
Embryo mortality
• Several generations: 20
• Tunisia: W strain of th Barbarine breed:
160% vs 120% for ordinary Barbarine
Selection
h2 <0,1
Fast way to improve litter size Heterosis: 3% for prolificacy
QFO D ’Man X QFO
Nb. 36 31LW (Kg) 45,7+5,7 40,5+5,9
Fertility(%) 77,7 90,3Prolificacy(%) 1,14+0,351,43+0,50
+ 20%
Crossbreeding with prolific breeds
Mating
2 weeks
prior
2 weeks
after
Short feeding supplementation
Distribution of concentrates (60% above maintenance)
Ovulation
rate
Embryo losses
Nutritional method: Flushing
Between 20 and 40 % in terms of lambs born
Hormonal methods : eCG
Response of Noire de Thibar ewes in terms of ovulation rate to increasing doses of eCG
eCG dose (IU) Ovulation rate
0 1.41
400 1.47
600 1.76
800 1.63
1000 1.76
• Synchronisation of ovulations and oestrus • Variable effect according to
a. doses (High doses litter size)
b. breed
AD-HSA AD-HSA
Active
1st immunisation
3 weeks
2nd immunisation
3 weeks
Mating
Passive
Injection immune serum
Mating
Antibodies
Hormonal method : Immunisation against androstenedione (during breeding season)
Expected results
• Increase of ovulation rate from 0,37 to 1,17
(active immunisation, Land et al., 1982)
• Less variability in response
• Most increase is represented by twins
• Effective on non prolific breeds
• No adverse effects on immunised dams
• Reduced labor
Immunisation against androstenedione
Conclusions
• Several methods There is no best method
• Options are dependent upon:
• Physiological stage
• Potential of the production system
• Objectives, know how and financial asset of farmers
• Products availability and effectiveness
Thank you