The effect of orally administered L-carnitine on biochemical parameters was examined in lactating Tuj-ewes. Ewes were orally given 500 mg of L-carnitine daily for 3 weeks. To evaluate the changes on selected blood indicators (total protein, albumin, glucose, triglyceride, cholesterol, urea, aspartate amino transferase, alanine amino transferase, lipase, triiodothyronine and thyroxine), blood samples were collected at the beginning of the study, and at the end of 1st. 2nd and 3rd week of study. Oral administration of supplemental carnitine significantly decreased serum triglyceride (P<0.05), glucose (P<0.05), cholesterol (P<0.05) and triiodothyronine (P<0.05) concentrations. In addition, serum thyroxine (P<0.001) and albumin (P<0.01)concentrations were significantly elevated as a result of oral carnitine treatment. These results suggest that supplemental L-carnitine improves selected biochemical indicators in Tuj-ewes. (C) 2008 Elsevier B.V. All rights reserved.