Effects of Breed and Prostaglandin Administration on Reproductive Performance and Profitability of Egyptian Ewes

The object of this study was to investigate the influence of breeds, equine chorionic gonadotropin (eCG) and prostaglandin F2alpha (PGF_2α) administration on reproductive performance in Egyptian ewes in relation to the economic efficiency of these hormonal treatments. For the estrus cycle control, the ewes received on Day 0 an intravaginal implant with 40 mg of Flugestone acetate. On 12^th day the intravaginal implants were removed and animals were divided into other two groups: Group 1) 36 ewes received only 400 IU eCG at the time of removal of the sponges (Ossami, n = 15; Rahmani, n= 12; Crossbred, n = 9). Group 2) 32 ewes received 400 IU eCG plus 0.5 ml PGF2á at the time of removal of the sponges (Ossami, n = 10; Rahmani, n= 12; Crossbred, n = 10). Estrus response, onset of estrus, pregnancy rate, lambing rate, litter size and multiple births were recorded. The results revealed that, overall estrus response was slightly higher in ewes that treated with eCG+PGF₂α than those received eCG only. Administration of eCG plus PGF₂α had better effect on onset of estrus at first 32 h than groups treated with eCG only. Litter size within breeds was significantly higher in crossbred ewes treated with PGF₂α in comparison with local breeds. Rahmani ewes treated with eCG had greater percentage of multiple births than Ossemi and crossbred ewes. Administration of eCG plus PGF₂α increased multiple births in crossbred ewes in comparison with local breeds. It was concluded that crossbred ewes had a better reproductive response to prostaglandin administration than local breed ewes. Injection of eCG was more profitable than eCG plus PGF₂α administration through increasing mean litter size and multiple births.