socio-sexual cues as a proximate factor affecting reproduction behavior and physiology in sheep
DESCRIPTION
Presented by Mourad Rekik, ICARDA, at the EIAR-DBARC-ICARDA-ILRI (LIVES)-FAO Training Workshop on Reproduction in Sheep and Goat, Debre Berhan, Ethiopia, 13-15 October 2014TRANSCRIPT
Socio-sexual cues as a proximate factor affecting reproduction behavior and
physiology in sheep
Mourad Rekik
EIAR-DBARC-ICARDA-ILRI (LIVES)-FAO Training on Reproduction in Sheep and Goat, Debre Berhan,
Ethiopia, 13-15 October 2014
Three Environmental Influences
Photoperiod
Other Pituitary Hormones
ProlactinACTH-Glucocorticoid
Somatotrophic systemThyrotrophic system
Puberty
Lactation
Nutrition
Gonads
Reproductive tractMammary glands
Sex steroids
Gonadotrophins
Socio-sexualSignals
(pheromones)
AutonomicNervousSystem
Nutrition
Socio-SexualSignals
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
Effect of peripheral induced anosmia on the response of anoestrous Merino ewes to the ram effect
Treatment N Ewes ovulating Ovulation rate
Control (no males)
14 2 (14) 1.00
Control (with males)
13 9 (69) 1.11
Anosmic*(with males)
12 8 (66) 1.38
* Anosmia was induced by irrigating the nostrils with a 5% solution of zinc sulphate
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
Mar Apr May Jun Jul Aug Sep Nov DecDec Jan FebSep Oct Nov
Breeding Season Non-breeding Season Breeding Season
% Females ovulating
100
50
0
Northern Hemisphere
Socio-sexual responses in goat and sheep
1) Breeding out of season2) Breeding postpartum3) Advancing puberty4) Synchronised pregnancies
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
Response of post-partum anoestrus ewes to the ram effect
0102030405060708090
15 25 35 45 60
Jours après mise bas% d
e fe
mel
les
qui o
vule
nt
IsoléesEffet bélier
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
PG
F2
TREATMENT MALE EFFECT + P4 PROGESTAGENS PROSTAGLANDINS
FEMALES 1584 600
FERTILITY 64,6% 46,8%
A.I.P
4
MALE EFFECT