Assessment of progesterone impregnated intravaginal sponges and gonadotrophic treatment on reproductive performance of local sheep breed
1988
Amhaz, M.
At AREC, 4 tests were conducted to determine the effect of Progesterone and PMSG treatment on the induction of fertilie oestrus during and outside the breeding season of the local fat-tailed Awassi breed. During the regular breeding season low conception rates and fertility (33% and 39%, respectively) were observed. However, the increased prolificacy and twinning rate in treated groups indicated the relevance of these treatments. Hormonal administration allowed utilizing AI on a fixed time basis due to the concentration of onset of oestrus 36 hrs after PMSG injection. Also, this practice lead to a condensed lambing during a short period which made management practices easier and within one week period. The treatments used during breeding season or anoestrus did not effect the length of gestation period (150-154 and 144-148 days, respectively). Similarly, birth weight of animals did not differ between seasons (4.5 and 5 kg, respectively). However, differences in birth weights were observed between single born and twin born lambs
显示更多 [+] 显示较少 [-]