Effects of Organic and Inorganic Selenium Supplementation with Vitamin E during the Flushing Period on Reproductive Performance of Ghezel Ewes

Minerals and vitamins play an important role in animal nutrition with beneficial effects on animal reproductive performance. To investigate this issue, 44 Ghezel ewes weighing 55±  2 kg (Mean±SD) and 2-3 years old were randomly divided into groups (n=11), to investigate the effect of the selenium and vitamin E supplementation on blood hormones and metabolites and possible reproductive performanceof Ghezel ewes. Treatments were consisted of group A: as control, B: flushing diet containing barley grain (73%), C: flushing diet + vitamin E (48 mg/day) + organic selenium (selenoproteins, 13.5 mg/day) and D: flushing diet + vitamin E (48 mg/day) + inorganic selenium (sodium selenite, 1.35 mg/day). The estrous cycles of the ewes were synchronized by application of a controlled internal drug release (CIDR) for 14 day. The results showed that the highest lambing rates (136.4%) and numbers of offspring (n=15) were in group C. Hormonal measurements including estrogen, progesterone and insulin revealed the relationship of these hormones with reproductive performance of ewes with the highest concentrations of estrogen and insulin (in estrus) and progesterone (in three weeks after mating) in groups C and D (P<0.05). Glucose and cholesterol levels of groups C and D increased significantly during the day prior to CIDR removal, estrus and three weeks after mating (P<0.05). Total protein and blood urea nitrogen (BUN) levels of B, C and D groups enhanced significantly in all times compared to the control group (P<0.05). Using inorganic and organic selenium in flushing diet had similar effects on blood metabolites and hormones related to reproductive performance.