Seasonal effects on caprine response to synchronization of estrus and superovulatory treatment

Nubian doelings (n = 21, 7 of which were repeats) were synchronized and superovulated with Norgestomet ear implants and follicle stimulating hormone-pituitary (FSH-p) and were then mated during early and late periods of their breeding season in the southeastern United States. A 100% response rate to estrus synchronization treatment was found in doelings (n = 15, 2 of which were repeats) treated early in the breeding season, and the superovulation regimen resulted in the surgical collection of an average of 15.1 viable embryos per doeling. But only a 66.7% response rate to estrus synchronization treatment was observed in doelings (n = 6, 5 of which were repeats) treated late in the season; only 50% of these doelings (or 33.3% of the initial doelings treated) responded to superovulatory treatment, resulting in an average of 3.33 viable embryos collected surgically per doeling. Thus, a significantly higher number of viable embryos can be obtained from Nubian doelings when treated for estrus synchronization and superovulation early in the breeding season.