Effects of dietary oleuropein supplementation on growth performance, serum lipid concentrations and lipid oxidation of Japanese quails

An in vivo experiment was conducted to compare the effects of dietary supplementation with oleuropein and/or -tocopheryl acetate on growth performance, serum lipid concentrations and lipid oxidation of Japanese quail meat during refrigerated storage. Performance and slaughtering parameters were not affected by dietary treatments. The diets supplemented with oleuropein at the levels of 150 or 200mg/kg were more effective in delaying lipid oxidation in breast and thigh meats compared with the control diet. The dietary inclusion of neither vitamin E nor oleuropein at different levels did not significantly affect the fatty acid compositions of the breast meat compared with the control diet. The diets supplemented with oleuropein at the levels of 150 or 200mg/kg had significantly the highest polyunsaturated fatty acid and omega-3 fatty acid contents in thigh meat compared with the vitamin E diet. The ratio of omega-6 fatty acids to omega-3 FAs in thigh meat of quails fed diet supplemented with vitamin E at the level of 200mg/kg was equivalent to those of quails fed the diets supplemented with oleuropein at the levels of 100 and 150mg/kg. The results showed that the dietary oleuropein supplementation at 150mg/kg level may be used in quail diets enriched with the polyunsaturated fatty acids of vitamin E as a natural antioxidant.