Turkish Journal of Veterinary and Animal Sciences

Abstract: An attempt was made to determine the effects of selenium and vitamin E supplementation on thyroid hormones in lambs. Sixteen Akkaraman lambs were used and divided equally into four groups. One group was used as a control. Second group was fed with selenium (sodium selenite, 0.3 mg kg -1 feed). Third group was fed with vitamin E (DL-a tocopheryl acetate, 250 mg -1 feed) and fourth group was fed with selenium (sodium selenite, 0.3 mg/ kg -1 feed) + vitamin E (DL-a tocopheryl acetate, 250 mg kg -1 feed) supplemented diet. Serum selenium, vitamin E and plasma thyroxine (T 4 ) and tri-ioda-thronine (T3) were measured at Ist, 5th, 10th weeks. Levels of T3 were slightly increased and both levels of T4 and ratio of T4/ T3 were slightly decreased when vitamin E, selenium and vitamin E plus selenium were supplemented to the diets of lambs. The levels of serum vitamin E were significantly higher (p<0.01) in vitamin E and vitamin E plus selenium supplemented groups than that in the control group. However, the levels of serum selenium were significantly higher (P<0.05, P<0.01) in both vitamin E and selenium supplemented lambs thant of that in control. Results in this study, there was no effects of selenium and vitamin E supplementation on plasma thyroid hormones in lambs. However, vitamin E had an increasing effect on serum selenium level, despite that selenium did not effect serum vitamin E levels.

Key Words: Selenium, vitamin E, thyroxine (T4), tri-iodo-thyronine (T3), Lamb.