This study was conducted to evaluate the effect of electron beam-irradiated cottonseed meal on performance, carcass characteristics and some blood parameters of broiler chicks. Treatments were cottonseed meal (CSM) at levels of 12% and 24% (raw and irradiated at 30 kGy) and corn-soya bean meal diet (as control, without CSM and without irradiation) that used with five dietary treatments, four replicates and 10 birds of each for 42 days in completely randomized design. Feed intake (FI) and body weight gain (BWG) were recorded weekly. At 42 days of age, two birds per pen were randomly selected for the determination of carcass characteristics and blood parameters. BWG decreased with increasing levels of dietary CSM during the experiment (p < 0.05). In addition, radiation had significant positive effect in broilers fed 12% compared with those fed 24% CSM. FI in chicks fed control and diet containing 24% CSM were increased significantly in starter period. But FI was significantly decreased in broilers consumed CSM compare to the control in grower and during the experiment. Feed conversion ratio (FCR) increased with increasing levels of CSM in the diets. Relative weights of liver, gastrointestinal tract (GI), pancreas, gizzard and abdominal fat were increased by increasing levels of CSM in the diet (p < 0.05). Glucose, cholesterol, HDL, triglyceride and phosphorous concentrations increased, and LDL concentration decreased as the dietary CSM levels increased (p < 0.05). But radiation had not significant effect on blood parameters. Electron irradiation seems to be a good procedure to improve the nutritional quality of CSM, but it seems higher dose of it was needed to improve performance of chickens.
