Evaluation of conception rate improvment in Lori-Bakhtiari ewes using eCG and oxytocin hormones

The aim of this study was to determine the effect of eCG and oxytocin (OT) on heat and pregnancy rate of Lori-bakhtiari ewes during breeding season. Eighty four ewes، 3 to 4 years old، 65±2. 5 kg weight، were received CIDR for 12 days، and at the time of CIDR removal assigned into 3 groups in which received 0، 400 and 500 IU eCG، respectively. Before artificial insemination، the groups divided into 2 subgroups and one of each 2 subgroups received OT (100 IU) intramuscularly. Fifty four hours after CIDR removal the ewes were inseminated and conception rate were recognized via ultrasonography 50 days after artificial insemination. The result of this study showed that eCG injection improves heat rate in comparison to control (78. 56 % vs 42. 85 %، P<0. 05). But OT had no effect on heat rate (50% vs42. 85 %، P>0. 05). Cervical penetration was higher (88. 09% vs 11. 90 %، P<0. 05) in ewes received OT. Administration of eCG increased conception rate (57. 14 % vs 14. 28 %، P<0. 05). The ewes received OT injection had higher conception rate then control group (42. 85% vs 14. 28%، P<0. 05). The dose of eCG had no effect on pregnancy rate increasement (57. 14 % vs 57. 14 % without OT and 71. 42 % vs 78. 57 % with OT، P>0. 05). The ewes received eCG and OT had a tendency to higher conception rate (74. 99% vs 57. 14 %، P<0. 1). In conclusion، eCG and OT injection improved conception rate in CIDR synchronized Lori-Bakhtiari ewes during breeding season.