Effects of dietary vitamin E on muscle vitamin E and fatty acid content in Aohan fine-wool sheep

摘要

Background: Increasing the polyunsaturated fatty acid (PUFA) content and decreasing the saturated fatty acid (SFA) content of mutton can help to improve its nutritional value for consumers. Several laboratories have evaluated the effects of vitamin Eon the fatty acid (FA) composition of muscle in sheep. However, little informatic is available on wool sheep, even though wool sheep breeds are an important source of mutton, especially in northern China where sheep are extensively farmed. The present study was designed to address the effects of vitamin E on muscle FA composition in male Aohan fine-wool sheep.Methods: Forty-two male Aohan fine-wool lambs (5 mo old) with similar initial body weight were randomly divided into seven groups and fed diets supplemented with 0 (control group), 20, 100, 200, 1,000, 2,000, or 2,400 lU/sheep/d vitamin E for 12 mo. Three lambs from each group were slaughtered to measure vitamin E and FA content in the longissimus lumborum (LL) and gluteus medius (GM) muscles.Results: Vitamin E concentrations in the LL and GM increased significantly after 12 mo of vitamin E supplementation (P < 0.05). However, this increase did not occur in a dose-dependent manner because the muscl vitamin E concentration was highest in the 200 lU/sheep/d group. Dietary vitamin E supplementation also caused significant reduction in SFA content and an increase in monounsaturated FA (MUFA) content in the LL and GM {P < 0.05). All six doses of vitamin E significantly increased cis9 trans] 1-conjugated linoleic acid (c9f11-CLA) conten in the LL compared with the control group (P < 0.05).Conclusions: Dietary supplementation with vitamin E increased muscle vitamin E content and improved the nutritional value of mutton by decreasing SFA content and increasing MUFA and c9f11-CLA contents in Aohan fine-wool sheep. These effects were greatestin sheep fed a diet containing 200 lU/sheep/d vitamin E.