Comparison of Estrus Synchronization by PGF2α and Progestagen Sponge with PMSG in Indigenous Ewes in Bangladesh

Abstract

The objective of this study was to compare the efficacy of two different synchronizing agents with different doses in indigenous ewes in Bangladesh. Indigenous ewes (n=65) were allocated initially into four groups and treated with intravaginal sponges containing two doses of Flurogestone Acetate (FGA 30 and 45 mg) for 12 days and two doses of PGF2α injection (Cloprostenol 100 and 175 μg) at 9 days apart. Ewes in estrus were identified using vasectomized rams. An investigation was made on vaginal smear in indigenous ewes. Fifty days after estrus and natural mating, pregnancy was determined by trans-cutaneous ultrasonography.. All the indigenous ewes used in four treatment groups exhibited signs of estrus during the observation period. Among sexual behaviors, firm standing, head-turning and soliciting were displayed more frequently. Ewes in Group I and Group II started to express receptive behavior between 48 h to70 h and in Group III and Group IV between 18-36 h following sponge removal. The time to estrus was slightly longer (58.6 ±2.64 h) in the groups treated with 175 μg Cloprostenol compared to the other groups (55.8 ±3.12, 32.9±1.60 and 30.8±2.04 h).There was significant differences (P
FGA compared with other range of time. Similarly, 52.9 and 62.5% of ewes in Cloprostenol (100 and175 μg, respectively) showed oestrus during 49 to 60 h. There was no significant difference in ewes of all treated

groups (P˃0.05). The estrus period was shown the predominance of superficial cells that was keratinized, largely anucleate, and had angular, folded cell margins or with pyknotic nuclei (Figures 5-6) in the vaginal smear of ewes in all the treated groups. The higher pregnancy rates observed in the 30 mg FGA based Group III (100%) compared with 100 μg Cloprostenol (88.2 %), 175 μg Cloprostenol (75%) and 45 mg FGA (93.8 %) group. It was concluded that though FGA sponge protocol presented superior results, PGF2α protocol was as efficient in synchronizing estrus as the former in indigenous ewes in Bangladesh.