Reproductive performance with short-time controlled internal drug release (CIDR)-based synchronization protocol for fixed-time artificial insemination in nulliparous and primiparous Saanen goats

In this study, it was aimed to evaluate the reproductive performance of primiparous and nulliparous Saanen goats following the insemination made cervically via frozen commercial buck semen with short-time controlled internal drug release (CIDR, Eazi-Breed, Pfizer)-based synchronization. In the study, a total of 50 Saanen goats, 26 of which were aged 9 months and 24 of which were aged 2 years, were used. The CIDRs including 0.33 g of progesterone were applied to all the goats for 7 days and while the CIDRs were taken out of the vagina, the 500 IU equine chorionic gonadotropin (eCG) was injected intramuscularly. The first dose was administered in a fixed-time manner with mini straws of 0.25 ml including 300x106 motile frozen spermatozoa 24 hours after the injection without making estrus detection, and the second dose insemination was applied 24 hours later. In the study, although the pregnancy rate, fecundity, prolificacy and multiple birth rate values (83%, 1.25, 1.50 and 60%) obtained in the primiparous goats were found to be higher than those found in the nulliparous age group (80%, 0.84, 1.05 and 38%), they were not statistically significant. It was concluded that the effects of the CIDR-based double-dose insemination applications in the primiparous and nulliparous Saanen breed goats in breeding season for 7 days on fertility were similar and the cervical insemination method, a quick and more practical option compared to the intrauterine insemination, could be used successfully in both age groups.