Factors Affecting Superovulation and Embryo Transfer in Boer Goats*

Despite many studies, results of superovulation protocols are not consistent in farm animals. In this study, 151 Boer goats were superovulated to examine the factors affecting superovulation and embryo transfer (MOET). An optimal regime for superovulation treatment was identified as a 4-day treatment with decreasing dosages of 6-7 mg Chinese FSH or 240 mg Canadian FSH. The 4-day treatment with decreasing dosages of 6-7 mg Chinese FSH was, therefore, adopted to study effects of the age of does, season and repeated treatments on superovulation and embryo transfer. The best season for superovulation and embryo transfer and pregnancy was autumn, and the best age range was 12-35 months old. Within animals there were no significant differences in the number of ovulations and the rate of transferable embryos between the first and the second superovulation. However, these parameters declined significantly for the third superovulation. No marked effects of the number of ovulations on the proportion of transferable embryos were noted. The parturition rate of the recipients receiving single embryos was not different significantly from those receiving two embryos, and the kidding rate calculated from embryos transferred did not differ significantly between recipients receiving one and two embryos. (Asian-Aust. J. Anim. Sci. 2006. Vol 19, No. 3 : 341-346)