ABSTRACT - The effect of the combination of energy sources (corn or cassava hull) and protein sources (cottonseed meal or yeast + meat and bone meal) in four diets, using corn silage as forage source, on the performance and intake of DM, CP, OM, ME, ADF, NDF, starch, Ca and P, using heifers. The effect of the addition salt or mineralized salt was also evaluated. A total of 28 heifers with average 303 kg LW and 18 months of age, confined during 76 days, was used. There were differences on nutrients intake among diets, however, there was no effect of the sources of energy, protein and salt on the average daily gain, carcass yield and feed:gain ratio. Therefore, yeast could substitute cottonseed meal as protein source, so as cassava hull could replace corn as energy source, without affecting the performance of feedlot heifers. The calcium intake by the heifers was higher in the mineralized salt diets as compared to salt diets.
cassava hull; carcass; feed:gain ratio; weight gain; intake; yeast; heifers
