Effect of vitamin E supplementation on fatty acid composition of muscle and adipose tissues of indoor lambs with special attention on rumen-derived trans monounsaturated fatty acids.

Thirty male lambs were assigned to one of 3 concentrate diets supplemented with 45 (E0), 286 (E1) or 551 (E2) mg/kg DM of dl-α-tocopheryl acetate to test the effect of vitamin E supplementation on muscle, caudal and perirenal fatty acid (FA) compositions. Specific attention was paid to C18:1 10t, usually observed in high proportions with high-starch or high-unsaturated FA diets. Vitamin E supplementation increased the α-tocopherol plasma concentrations of lambs. It did not modify lamb growth and slaughter parameters. Vitamin E supplementation did not modify FA composition in most tissues but it increased the C18:2 n-6/C18:3 n-3 ratio in muscle and adipose tissues of the E1 group compared to E0 and E2 groups. Vitamin E supplementation enhanced the C18:1 10t proportion in muscle and adipose tissues and it decreased the C18:2 9c,11t proportion in adipose tissues, especially in the E2 group. These changes may not be favourable for the nutritional value of lamb meat.