Influence of dietary vitamin E supplementation on meat quality traits and gene expression related to lipid metabolism in the Beijing-you chicken

Abstract

1. The effects of dietary vitamin E (DL-α-tocopheryl acetate) on carcase and meat quality, oxidative stability, fatty acid composition of muscle lipids, and gene expression related to lipid metabolism were studied in Beijing-you chickens. 2. A total of 360 female birds were distributed among 6 treatments, containing 6 replicates, each of 10 birds. The feed for each treatment was supplemented with vitamin E (0, 10, 50, 100, 150, or 200 mg/kg feed). At 120 d, 30 birds from each treatment were slaughtered to examine the effect of dietary vitamin E supplementation on evaluated traits. 3. The results showed that supplemental vitamin E in diet significantly increased α-tocopherol contents of breast and thigh muscles, reduced the drip loss and improved tenderness but did not influence carcase yield, meat colour or pH value 24 h after slaughter. 4. Thiobarbituric acid reactive substance (TBARS) values decreased with increase in dietary vitamin E, and the addition of 100 mg/kg or more vitamin E had a beneficial effect on oxidative stability as indicated by TBARS values during storage up to 7 d. 5. Dietary vitamin E supplementation significantly altered fatty acid composition of breast muscle. Supplementing with 200 mg/kg vitamin E led to lower saturated fatty acids and greater polyunsaturated fatty acids proportions in breast muscle than control and 10 mg/kg vitamin E treatments. 6. Vitamin E supplementation significantly inhibited expression of the cytosolic phospholipase A2 gene (cPLA 2) in breast muscle, while enhancing that of the peroxisome proliterator-activated receptor beta (PPAP-β) and heart fatty acid binding protein genes (H-FABP). The results indicate that dietary supplementation with vitamin E increased lipid stability in muscle and improved meat quality and fatty acid composition, probably by its influence on the expression of genes related to lipid metabolism.