heart, proventriculus, gizzard, small intestine, caeca, spleen and bursa of Fabricius were removed and weighed. Organ weights were expressed as a percentage of live body weight. Liver tissue was sampled from the left lobe for determination of antioxidant enzymes of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and malondialdehyde (MDA) concentrations and stored at 21 °C until further analysis.