Synchronisation of oestrus in goats: the use of different progestagen treatments

Abstract

The efficiency of medroxyprogesterone acetate (MAP), fluorogestone acetate (FGA) sponges and controlled internal drug release (CIDR) devices for synchronising oestrus in goats was evaluated during the natural breeding season. Ninety does (42 boer goat and 48 indigenous goats) were assigned to Group A ( n=30) 60 mg MAP, Group B ( n=30) 40 mg FGA and Group C ( n=30) CIDR devices. Intravaginal progestagen was administered for a 16-day period. Upon progestagen withdrawal, does received 300 IU PMSG intramuscularly. Cervical inseminations with fresh diluted semen at a fixed time (48 and 60 h) followed progestagen withdrawal. The three progestagen treatments did not show significant differences in oestrous response (97%) and duration (33.3±13.4) of the induced oestrous period. Time to the onset of oestrus significantly advanced in the CIDR (27.2±0.4 h) group, when compared to FGA the (30.9±0.4 h) and MAP (32.2±0.5 h) groups. The mean serum progesterone concentrations in the CIDR group were higher ( P<0.05) between days 4 and 16 of progestagen treatment, compared to the MAP and FGA groups. No significant difference was observed with respect to pregnancy rate 40 days after AI (52, 60 and 47% for CIDR, MAP and FGA groups, respectively). Results indicate that the use of MAP, FGA and CIDR intravaginal progestagen treatments are equally efficient in synchronising oestrus in goats.