Efficiency of Oestrous Synchronization by GnRH, Prostaglandins and Socio-Sexual Cues in the North African Maure Goats
Authors:
This study aims to develop at different seasons, for local North
African Maure goats, synchronizing protocols simultaneously
to the standard ‘S’ protocol using progestagens in association
with prostaglandins and gonadotropin. In late May, 40 goats
were assigned to either the ‘S’ protocol or to a protocol where
oestrus and ovulation were induced by the buck effect in
single-injection progesterone-treated goats and provoking
early luteolysis using prostaglandin 9 days after exposure to
bucks ‘B’. During the 72 h after the treatments ended, 15 and 5
goats expressed oestrus in the ‘S’ and ‘B’ protocols (p < 0.01).
Mean time to oestrus was shorter for ‘S’ than for ‘B’ goats.
Ovulation rate averaged 2.1 0.22 and 1.60 0.35 for,
respectively, ‘S’ and ‘B’ goats (p > 0.05). During mid-September,
60 goats were assigned to either ‘S’ treatment, ‘PGF’
treatment where oestrus and ovulation were synchronized
using two injections of prostaglandin 11 days apart or to
‘GnRH’ treatment where the goats had their oestrus and
ovulation synchronized with a GnRH (day 0)–prostaglandin
(day 6)–GnRH (day 9) sequence. More ‘S’ goats were detected
in oestrus over the 96-h period after the end of the treatments
(88.8, 73.7 and 55% in ‘S’, ‘PGF’ and ‘GnRH’ treatments,
respectively; p < 0.05). Mean ovulation rates were 2.3 0.27,
1.33 0.27 and 1.33 0.27 for, respectively, ‘S’, ‘PGF’ and
‘GnRH’ goats (p < 0.001). Despite a similar ovulatory
response to ‘S’ protocol, efficiency of prostaglandin and
GnRH-based treatments should be tested in mid-breeding
season.