The Effects of Different Doses of eCG Injection on Reproductive Parameters in Nulliparous Merino Ewes During the Non- Breeding Season

In this study, the effects of adding 400, 500, and 600 IU eCG to progesterone treatment on rate of estrus, conception, pregnancy, fetal mortality, lambing, multiple birth and litter size in nulliparous Merino ewes the out of breeding season were investigated. A total of 90 nulliparous Merino ewes were utilized in the study. On day 0, a vaginal sponge containing 60 mg medroxyprogesterone acetate was inserted for a seven-day period. Ewes were randomly divided into three groups at the time of sponge removal. Group I (G-400), comprising 30 ewes, received 400 IU of eCG. Group II (G-500) received 500 IU of eCG (n=30), while Group III (G-600) received 600 IU of eCG (n=30). The statistical analysis revealed that the conception rates between the groups were statistically higher in the G-600 group than in the G-400 and G-500 groups (G-400 vs. G-600, P=0.091; G-500 vs. G-600, P=0.080). Pregnancy rates between the groups were found to be statistically higher in the G-600 group than in the G-400 group (P