The aim of this study was to investigate effect of different sodium bentonite (SB) levels on performance, carcass characteristics and passage rate of broilers. Two hundred eighty eight day-old Ross strain mix broilers were allocated to 6 experimental diets with 4 replications in a completely randomized design. Treatments levels of sodium bentonite were 0.00, 0.75, 1.50, 2.25, 3.00 and 3.75 percent. Broilers fed SB containing diets consumed more feeds (P<0.05) and showed better weight gain (P>0.05). However, there was not any difference between diets, but diet content 3.75% SB had the best FCR. Relative weight of liver decreased as percentage of SB increased in diet while control group had highest relative weight of breast (P<0.05). Supplementation of diets by SB increased retention time and decreased passage rate of them. The use of SB in broiler diets hah no adverse effects on performance; addition SB to broiler diets had benefits effects on performance, carcass characteristics and passage rate, therefore resulted in improved efficiency of production.

Key words: Carcass characteristics, Feed conversion ratio, Retention time, Sodium bentonite