effect of vitamin e –selenium administered during estrus synchronization on antioxidant activity, hormonal profile, and lamb rearing of moghani ewes

The study was conducted with 200 mature, non-lactating ewes aged 2–5 years and weighing about 70 kg, during the non-breeding season under natural photoperiod conditions. in the control group, only estrus synchronization was performed. the second group received two intramuscular injections (5 ml total) of e-se (selenium as sodium selenite at 0.5 mg/ml and vitamin e as dl-α-tocopheryl at 50 iu) on the days of sponge insertion and sponge removal. estrus synchronization involved placing intravaginal sponges for 14 days, followed by 400 iu ecg at sponge withdrawal. two days after sponge withdrawal, ewes were mated with fertile rams. three weeks after ram exposure, 20 ewes from each group were randomly selected for blood sampling. hormone concentrations and antioxidant activity were measured. after parturition, reproductive traits were recorded for each group. the results showed that there was no significant effect of e-se on the lamb body weight at birth, body weight at 90 days, total weight gain and average daily gain. in e-se treated group, number of lambs/ewe was significantly different (p < 0.05) compared with control. progesterone concentration in e-se groups was greater (p < 0.05) than the control. e-se supplementation exerts a significant (p < 0.05) increasing effect on serum triiodothyronine (t3) concentration and the ratio of t3/t4. total antioxidant capacity 3 weeks after ram exposure was significantly higher (p < 0.05) in e-se than control. a significant (p < 0.05) increase in serum glutathione peroxidase concentration was observed in ewes supplemented with e-se compared with the control group. selenium concentration of serum was significantly higher in group receiving e-se three weeks after mating (p < 0.05). however, there were no significant differences in serum malondialdehyde, superoxide dismutase, and hemoglobin concentrations between the e-se and control groups. in summary, administering vitamin e-se enhanced reproductive efficiency, antioxidant status, and serum progesterone levels in estrus-synchronized moghani ewes during the non-breeding season.