Efficiency of Oestrous Synchronization by GnRH, Prostaglandins and Socio-Sexual Cues in the North African Maure Goats
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.