The effects of moderately oxidised dietary oil with or without vitamin E supplementation on performance, nutrient digestibility, some blood traits, lipid peroxidation and antioxidant defence of male broilers

Abstract

The experiment was conducted to determine the effects of dietary supplementation of oxidised oil with or without vitamin E on performance, nutrient digestibility, some blood traits, lipid peroxidation and antioxidant defence system of male broilers. The supplementation of oxidised oil with or without vitamin E to the grower diets did not significantly affect performance, the pH and viscosity values of excreta and nutrient digestibilities in male broilers. Oxidised oil supplementation slightly increased plasma triglyceride and cholesterol concentrations but did not alter plasma glucose concentration. Although malondialdehyde (MDA) and nitric oxide concentrations tended to be higher in the oxidised oil group, these increases were not significant. Birds fed the diet containing oxidised oil had significantly lower superoxide dismutase (SOD) activity. However, no differences were observed in glutathione peroxidase (GSH-Px) activity and uric acid concentrations of broilers fed oxidised oil as compared to the control group. Dietary vitamin E supplementation decreased MDA concentration whereas increasing SOD activity, suggesting that vitamin E supplementation reduced susceptibility to lipid peroxidation. The results showed that a milder oxidative stress occurred by supplementation of moderately oxidised oil to the diet of broilers and vitamin E supplementation had been helpful in alleviating lipid peroxidation.