Abstract

The feasibility of a juvenile MOET (multiple ovulation and embryo transfer) scheme in sheep was evaluated in three trials using 6-7 month-old animals. Ovulation rate was not affected by the dose (1.3 vs 1.1) or the time (1.5 vs 0.9) of PMSG administration, but it was higher in adults than lambs (2.0 vs 1.15, P<0.05) (Trial 1). Adults also showed a higher percentage of animals in heat (89 vs 60, P<0.05) and a higher percentage of eggs recovered (87 vs 56, P<0.05) or fertilised (82 vs 48, P<0.05). In Trial 2, a higher response was achieved with PMSG than FSH-P, Ovagen or PMSG + Ovagen (4.18 vs 1.78, 1.06 and 2.05, P<0.05). GnRH did not affect the ovarian response to gonadotrophins (2.29 vs 2.25, P<0.05). Embryo viability appeared higher in lambs treated with Ovagen alone. A combination of Ovagen + PMSG and with or without GnRH did not improve significantly (P<0.05) the response compared to the administration of PMSG plus GnRH (2.3, 2.8, 2.2 and 2.8 vs 1.7) (Trial 3). The superovulatory treatments involved failed to induce satisfactory ovulatory responses in these prepubertal sheep.

AJ, Molenaar, SR Davis, and RJ Wilkins

Proceedings of the New Zealand Society of Animal Production, Volume 51, , 97-102, 1991