Efficiency of short time protocols based on combined fga, pgf2α, gnrh and ecg treatments on oestrus synchronization and reproductive performance of kermani ewes during the breeding season

Abstract

The objectives of the present study were to determine the efficiency of short time protocols based on combined FGA, PGF2α, GnRH and eCG treatments on oestrus synchronization and reproductive performance of kermani ewes during the breeding season. Seventy-five multiparous non-lactating kermani ewes weighing 45 ± 0.5 kg with a body condition score (3.6 ± 0.1) were allocated into five groups. The treatment are shown in article body. The ewes were checked for oestrus by teaser rams at 8 h intervals. The ewes were hand-mated (male to female ratio 1:5) at the beginning of oestrus and subsequently 12 h intervals until the end of oestrus. The percentages of female in estrus and the interval to oestrus (h after treatment), fertility and prolificacy rate were recorded. The obtained data were analyzed using the GLM procedure of SAS system. Treatments had no significant effect on incidence of oestrus, however, ewes received T4 tended to show a lower oestrus. Hormonal treatments significantly affected the interval to oestrus which was earlier in treated control ewes than in T4 and T2 (P < 0.05). Fertility rate tended to be higher in T3 and T2 groups compared to that of control group also Prolificacy rate was higher in T4 group. Results of the present study showed that PGF2α–FGA–eCG as well as FGA–PGF2α–eCG short term 5-day treatments is effective in synchronizing oestrus in ewes during the breeding season. Also GnRH–PGF2α–eCG 5-day treatment has been found effective to provide high level of oestrus followed by acceptable levels of fertility after natural mating.