The effect of diets containing antioxidant vitamins and trace elements on chicken tissue activities of SOD, CAT, GSH-Px and of LPO levels was investigated. Chickens, 45 weeks of age were divided into six groups: control group, Cu group (13.2 mg Cu kg−1 diet); Se group (0.07 mg Se kg−l diet); vitamin E group (70 mg DL-α-tocopherol acetate kg−1 diet) and a constant level vitamin C, 200 mg kg−1 diet); vitamin A group (240 mg retinol acetate kg−1 diet) and vitamin C group (500 mg ascorbic acid kg−1 diet).
Significant variation of these antioxidant enzyme activities and LPO levels according to gender was demonstrated statistically. In the Cu group, CuZnSOD activity in the liver, erythrocyte, kidney and heart significantly increased by 75, 40, 12, 12% respectively (P<0.05). MnSOD activity in the heart, liver, kidney and brain of the vitamin C and in the heart of Cu group were found to be increased by approximately 15%, while in liver tissue of the Cu group it was reduced by 19% (P<0.05). GSH-Px activities in the Se, vitamin E and C groups were significantly increased, conversely LPO levels decreased (P<0.001). CAT activities in the liver and heart of the vitamin C group were significantly decreased (by 32%), but in kidney tissue only that of the Cu group was increased from 30.2 ± 4.767 to 144.49 ± 6.93 U mg−1P<0.001. The resistance to stress of the vitamin E and C groups, which had significantly increased activities of antioxidant enzymes and decreased lipid peroxide levels, were determined in 60% moisture medium at 45°C. Copyright © 2001 John Wiley & Sons, Ltd.