In cycling goats, luteolysis may be induced by administration of PGF_2α (2.5–5 mg, IM) or cloprostenol (62.5–125 μg, IM) as early as day 4. In sheep, PGF_2α (≥15 mg) or cloprostenol (125 μg) is effective after day 5 of the cycle. Estrus may be synchronized by 2 doses of PG, 11 days apart in does or 9 days apart in ewes. Estrus may also be synchronized in cyclic or anestrous does and ewes by administration of progestagens; impregnated intravaginal sponges (medroxy-progesterone or fluorgestone) have been the most widely used agents for control of ovulation but are not currently available for clinical use in the USA. A portion of a bovine norgestomet implant (3 mg/goat) or injection of progesterone in oil (10 mg/day, IM) has also been effective. Progestagen treatment is administered for 10–14 days in sheep and for 14–21 days in goats. Ewes should be joined with rams the day after cessation of treatment; does return to heat on the second or third day after treatment ends. Injection of eCG (500 IU) at the end of treatment increases synchronization of ovulation or ovulation rate, or both, but may result in superovulation, shortened estrous cycles, and problems with multiple lambs or kids. Alternatively, in does, progestagens may be given for 11 days with eCG and PG administered on day 9, and fixed-time insemination performed on days 12 and 13. In regimens involving treatments other than PG alone, fertility may be reduced on the first estrus after treatment in ewes but not in does.

Last full review/revision July 2011 by Steven P. Brinsko, DVM, MS, PhD, DACT