Abstract

There are a few reports about the reproductive aspects or uses of both of flushing and estrus synchronization in Abou-Delik ewes grazing in the South Eastern zone of Egypt. Thirty-three Abou-Delik ewes were allocated to three experimental groups (n = 11 in each) to study the effects of estrus synchronization and flushing on reproductive responses and productive characteristics under arid conditions of South Eastern zone of Egypt. Group one served as control represent the system dominant in the area (without estrus synchronization and flushing ration). Ewes in group two were estrous synchronized with two doses of PGF2α, 10 days apart without flushing ration. Ewes in group three were estrous synchronized just like the second group and received 300g of barley grain/head/day as flushing meal for three weeks before the start of breeding season. All ewes were grazed Panicum turgidum (natural vegetation dominant in the area) for eight hours daily. Results showed that, the percentage of estrus exhibition in group three reached 100%, while the lowest percentage was observed in group one (81.82 %). Estrus activity signs in synchronized groups, occurred in 70 and 81.81% during the first 48 h after the second dose of PGF2α, for groups two and three respectively, compared to control group (22.22 %). The onset of estrus was earlier in synchronized groups than control group. Duration of estrus did not differ significantly. Estrus intensity in group three was higher (P< 0.05) compared to the other groups. Conception and lambing rates were 100% in group three. Third group showed the highest insignificant litter size that was 18% higher than the other groups. The overall mean of birth weight, weaning weight and average daily gain of Abou-Delik lambs were 2.91, 16.89 and 0.116 kg, respectively. There is no significantly effect on concentrations of plasma progesterone among groups. While there were significant differences between sampling periods. In conclusion, under grazing on arid rangelands conditions in the South Eastern zone of Egypt, using flushing and/or estrus synchronization can be useful to improve reproductive and productive characteristics of Abou-Delik sheep.