The performance of steers fed diets using as roughage rice straw treated with anydrous ammonia, rice straw+urea, sugar cane + urea and sorghum silage were evaluated. Sixteen PO Simental steers, averaging 400 kg initial LW, were assigned to a completely randomized design. The experiment last 88 days, 15 days of adaptation and 61 experimental days, divided in three periods of 21 days. Total DM intake, that ranged from 7.1 to 10.0 kg/day, differ among treatments, where higher intakes were observed for the animals fed ammoniated rice straw and sorghum silage, that did not differ. Feed:gain ratio did not differ among different diets, and an average value of 6.6 was recorded. It was observed higherweight gain for the animals fed ammoniated rice straw (1.59 kg/day) in relation to the animals fed straw+urea (1.25 kg/day). The treatement with anydrous ammonia improved the rice straw nutritive value resulted in higher voluntary intake of this roughage and, consequently, in higher daily weight gain in relation to no treated rice straw and supplemented with urea.
alimentary conversion; bromatologic composition; intake; weight gain
