, 2015. Broiler chicken performance in response to various levels of raw and autoclaved rice bran. Bulg. J. Vet. Med., 18, No 4,[348][349][350][351][352][353][354][355][356][357][358][359][360] The inclusion of raw or autoclaved rice bran (RB) into broiler chicken diets was evaluated. A total of 420 broiler chickens (Ross 308) were assigned to a basal diet (without RB) or diets containing 6, 12, and 18% raw or autoclaved RB with 3 replicates of 20 chickens. By polynomial orthogonal contrasts, a significant reduction in body weight gain and feed intake (L: P =0.048), the weight of abdominal fat (L: P=0.048), ether extract digestibility (L: P=0.025), villus height (L: P=0.046), and crypt depth (L and Q: P=0.043) was achieved by increasing the inclusion levels of raw or autoclaved RB in the diets. On day 42, significant decreases were found in the weights and the ash contents of tibia (L: P=0.003) with increasing the level of raw RB in the diets. Decreased serum cholesterol was obtained following the inclusion of increasing levels of raw RB (Q: P=0.015) or autoclaved RB (L and Q: P=0.015) in the diets. The inclusion of RB in the diets resulted in poorer nutrient digestibility and performance, although it had some modulation effects on blood lipid biochemistry. It is suggested that the inclusion of raw RB in the diets should be limited to 6%, however, autoclaving allowed inclusion of RB up to 12% in the broiler diets.