Effects of Varying Levels of Oxidized Fat and Copper Sulfate on Broiler Performance, Carcass Traits, Blood Metabolites and Immune Cells

This experiment was conducted to investigate the effects of different levels of oxidized fat (yellow grease) and copper sulfate on performance, carcass traits, blood metabolites and immune cells of broilers. this study was carried out as a 3 × 2 factorial experiment with 3 levels of oxidized fat (0, 2 and 4%) and 2 levels of copper sulfate (0 and 300 mg/kg) in 6 treatments, 3 replicates and 12 birds in each replicate. in this ex-periment, 216 day-old broiler chicks (ross 308 strain) were used for 42 days. the results showed that there were significant difference between groups in performance, blood metabolites and immunity parameters (p < 0.05). the highest amounts of daily feed intake (43.51 g) and the best feed conversion (1.88) were re-sulted by inclusion 2% of oxidized fat in broiler diets, whereas in these respects they were not significant difference between control group and group with 4% of oxidized fat. the lowest level of triglyceride (34.34 mg/dl) and highest percent of lymphocyte (88.58%) were obtained by the addition of 4% oxidized fat into the broiler diets. the overall results showed that inclusion of 4% oxidized fat into broiler diets compare with the control group do not have desirable effects on their performance and improve the blood metabo-lites and immunity parameters.