Evaluation of the estrus synchronization and reproductive performance of Afshari ewes during the breeding season following treatment with clomiphene citrate

The present study was conducted to study the efficiency of substituting conventional gonadotropin-based technique with clomiphene citrate (CC) on reproductive parameters and hormonal changes in sheep during the breeding season. For this this purpose, 30 Afshari ewes (3-4 years, 55 ± 1.3 kg BW, BCS 3.04±0.3) were treated with intravaginal CIDR for 14 days and the divided into three groups: one group was considered as the control, the other groups received eCG (300 IU, intramuscularly) and CC (600 mg, oral), respectively. Blood samples were taken from three days before until three days after CIDR removal. Reproductive parameters were calculated after parturition. Fecundity and multiple lambing were numerically higher in the eCG group; however, there was no significant difference in reproductive performance between treatments. Estradiol and progesterone concentrations showed similar trends between treatments. Results of this study showed that CC was not a reliable substitute for eCG to increase the ovulation rate in sheep.