Effects of selenium, vitamin E, and β-carotene administration on fertility of Awassi ewes synchronized for estrus in non-breeding season

The aim of this study was to evaluate the effect of selenium, β-carotene, and vitamin E administration on fertility of Awassi ewes synchronized in non-breeding season. A total of 80 multiparous Awassi ewes, aged 2 to 6 years were enrolled in the study. Intravaginal sponges containing flugeston acetate (20 mg cronolon) was inserted into vagina and allowed to remain in vagina for nine days. Ewes were randomly divided into two groups. Group I received intramuscular injections of 1 mg sodium selenite, 60 mg vitamin E, 75 mg β-carotene, and 100 mg DL-α-tocopherol acetate at sponge insertion, sponge removal, and 18 days after the introduction of ram. Group II remained as control group and received no treatment. On the removal of the sponges, 500 IU eCG and 0.075 mg D-cloprostenol were injected intramuscularly. Ram was introduced for 1 hr twice a day 24 hours after the sponge removal. Interval between sponge removal and estrus, estrus rates, conception rates, pregnancy rates, lambing rates, and fecundity rates in group I and group II were 45.30±1.71 and 43.94±1.72 hours, 79.1% and 86.6%, 66.66% and 72.41%, 54.05% and 58.33%, 100% and 100%, and 135% and 138%, respectively. There were no statistical differences between the groups (p>0.05). In conclusion, the administration of Se, β-carotene, and vitamin E in estrus synchronization protocols in non-breeding season had no positive effect on the fertility characteristics of Awassi sheep.