The objetive of the experiment was to evaluate the effect on animal performace of the addition of soybean hulls in substitution to sorghum grain in the concentrate fraction of the diet of feedlot finished steers from of 19 to 23 months of age. The treatments were the different levels of substitution of sorghum grain by soybean hulls: 0, 25, 50, 75 and 100%. The diet with roughage: concentrate ratio of 60:40, contained 12% crude protein. Analyzing the data by regression, a quartic behavior was verified for daily weight gain and feed conversion, with values of 1.040, 1.242, 1.167, 1.264 and 1.208 kg for daily weight gain and of 8.490, 7.340, 7.611, 7.029 and 7.201 for feed conversion, respectively, for the 0, 25, 50, 75 and 100% substitution levels of sorghum by soybean hulls. Linear behavior was observed for daily dry matter intake per 100 kg of live weight, with values of 2.43, 2.46, 2.40, 2.37 and 2.32%, and per metabolic weight, with values of 106.5, 107.6, 105.4, 104.4 and 102.2 g, respectively. The contrast analysis demonstrated that animals fed with diets that included soybean hulls showed better weight gain and feed conversion than those fed with the diet that included only sorghum.
feed conversion; feedlot; daily weight gain; sorghum grain; soybean hulls
