The Effect of CIDR and the Number of FSH Injections on the Ovulation of Kermani Sheep in Non-Breeding Season

In this study, the effect of the number of follicle-stimulating hormone (FSH) injections with progesterone on ovulation in the non-reproductive season (winter) was studied in Kerman region, Iran. For this purpose, 160 Kermani sheep were selected with the same average weight 60 days after delivery and ranged in age from 5 to 7 years. They were divided into 4 groups according to age and weight; all groups except for the control treatment were treated with progesterone for 12 days via CIDR. After CIDR withdrawal, the first group was injected with 25 mg FSH on one day while the second group received 25 mg on the first day and 10 mg on the second day. The third group was injected with 25 mg FSH on the first day, 10 mg on the second day and 5 mg on the third day. After five days, the ewes were slaughtered and the number of corpus luteum on the ovaries was counted. The results showed that the number of days of FSH injection had a significant difference in the ovulation rate (P <0/05). The results of this study suggest that the injections of FSH on three consecutive days had the greatest impact on oocyte maturation and ovulation rate.