Abstract

The objective of this study was to compare between two methods of estrus synchronization (progestin-impregnated vaginal sponges and intra-muscular (i.m) progesterone analogue injection ) and its influence on estrus occurance and pregnancy rate in Awassi ewes . Twenty eight ewes were equally divided into two groups ( A and B ) . Vaginal sponges impregnated with 20 mg of fluorogestone acetate ( FGA ) were used to synchronize the estrus in group A-ewes . The animals in group B were i.m. injected with 7 mg/day of progesterone analogue for 12 days . Post – withdrwal of sponges and at the end of progesterone injection , 500 IU of equine chorionic gonadotropin ( eCG ) were injected to both groups of ewes . The ewes were naturally mated with fertile rams ( 1 ram/group ) . the rams were left for 48 hrs. to ensure a good conception rate . The differences between two groups in estrus signs appearance lacked significance . On the other hand , group A – ewes exhibited higher ( P < 0.05 ) pregnancy rate than group B ( 78 VS 50% ) . In conclusion , estrus synchronization of ewes using vaginal sponges impregnated with FGA in conjuction with eCG treatment is effective and low-cost regime that achieved agood reproductive performance .