Effect of artificial insemination methods on reproductive efficiency of Zandi ewes inseminated with fresh and frozen sperm

The aim of this study was to determine the effect of artificial insemination methods on reproduction efficiency of Zandi ewes inseminated with fresh and frozen semen. Two hundred and forty Zandi ewes (three- to four-years old, 55 kg weight) received CIDR for 12 days and at the time of CIDR removal, received 400 IU of eCG and were artificially inseminated 54 h after CIDR removal. Groups one to three included 120 ewes that were assigned into three equal groups and inseminated vaginally, by laparoscopy and transcervically, respectively with fresh semen. Groups four to six included 120 ewes that were assigned into four equal groups and inseminated vaginally, by laparoscopy and transcervically, respectively with frozen semen. The results showed that during using fresh semen, differences between artificial insemination methods were not significant, but during using frozen semen, the fertility rate was higher in laparoscopy method than other methods (P