The effects of different levels of canola meal and copper on performance, susceptibility to ascites and some blood metabolites of broiler chickens

An experiment was conducted in order to assess the effects of different levels of dietary canola meal (CM; 0, 10 and 20 %) and copper (0, 125 and 250 mg/kg) on performance, susceptibility to ascites syndrome and some blood metabolites of broiler chickens. During a six week period of experiment, a total of 495 male broilers (Ross 308) were used in completely randomized design with a 3×3 factorial arrangement with 5 replicates (11 birds per replicate). Feed intake was not significantly affected by treatments during starter, grower and whole periods of the experiment (P>0.05). Body weight gain and feed conversion ratio were significantly impaired (P<0.05) during the starter period when 20% CM was added to the diets. Body weight gain (P<0.01) and feed conversion ratio (P<0.05) were significantly improved by copper supplementation during the growing and the entire periods of the study. Replacing soybean meal by CM significantly increased (P<0.05) the proportions of liver, heart and right ventricular weight:total ventricular weight ratio (RV/TV) at 42 d of age. However, concentrations of haemoglobin, packed cell volume and total erythrocyte count were not affected by the treatments (P>0.05). At 42 d, the concentrations of plasma total protein and enzymes (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase and lactate dehydrogenase) were similar among the treatments (P>0.05), but concentration of plasma albumin was significantly reduced, when 20% CM was added to the diets. In conclusion, the results of this study did not show any adverse effect for added CM up to 20% on the performance, susceptibility to ascites and plasma enzyme activities. Also, copper supplementation significantly improved growth performance of broiler chickens