Sequential administration of cronolone and prostaglandin F2alpha for estrus synchronization in goats.

Fifteen does received intravaginal pessaries impregnated with 20 mg fluorogestone acetate (Cronolone) at various times after the end of estrus for a period of fourteen days. The does were then treated on days 2, 4, 5, 12, or 16 after onset of estrus following the progestin treatment, with 15 mg of prostaglandin F2_α (Lutalyse) injected intramuscularly. Seventy three percent of the does showed estrus within 2 days after withdrawal of progestin treatment. Ten out of 11 does treated with prostaglandins 4 to 16 days after the end of estrus exhibited estrus within 44 to 72 hours after treatment. Breeding following the use of prostaglandin in these does resulted in a high pregnancy rate. It is concluded that a sequential use of progestin and prostaglandin may be a useful method for achieving estrus synchronization associated with high fertility in does.