Vitamin E and Selenium have long been recognized for their antioxidant effect in animals. However, in large repeated doses some harmful effects may be recognized on the animal's health. This study was carried out to investigate the effects of withdrawal time of combined vitamin E and selenium toxicity on reproductive characters of ram. Sixteen mature Barki rams (50-70 Kg) were randomly divided into two groups, eight rams each. The first group was kept as control and injected IM with 3ml saline twice/week for 64 days. The second group was injected IM with a combination of vitamin E and selenium at a dose of 3 ml (4.5 mg sodium selenite and 204 mg vitamin E)/ head twice weekly for 64 days then serum and semen samples were collected till 134th day. The obtained results showed that injection of combined vitamin E and selenium decreased semen volume and semen concentration, activities of seminal plasma catalase, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), alkaline phosphatase (ALP), acid phosphatase (ACP), Ascorbic acid levels and total antioxidant capacity (TAC) from day 36 till day 78. These parameters restored to the normal ranges from day 92 to day 134. Moreover, sperm abnormalities, and malondialdehyde concentration in seminal plasma were increased from day 36 to day 78 then it decreased to attain the normal ranges on day 134.
This study indicated that the withdrawal time of combined vitamin E and selenium toxicity from the ram semen to return to the normal range is 70 days from the last dose.