The use of dry yeast or concentrate of vinasse, associated to auto hydrolysed sugar cane (BAH) in rations for feedlot, was compared to BAH rations containing cotton seed meal as a protein source. A feed lot trial (initial body weight = 316kg) was carried out during a 122 day period. The rations, formulated to provide 1,0kg of weight gain per day, were composed by 50% of BAH and 12,7% of the protein source (cotton seed meal or concentrate of vinasse or yeast), 17,8% of corn and 12,5% of sugar cane stalks as roughage complement. The mean weight gain was 843, 989 and 580g/animal-day for the rations containing cotton seed meal, yeast and concentrate of vinasse, respectively. The rations containing yeast and cotton seed meal provided higher weighing gains (P < 0,01) when compared to the ration containing concentrate of vinasse. No significant differences were observed between the rations containing yeast and cotton seed meal, even at 5% by the Tukey test. The results have shown that the cotton seed meal be completely substituted by the dry yeast in complete rations of feedlot containing auto hydrolysed sugar cane bagasse (BAH). However, one should consider the economic aspects of such substitution.
Feed lot performance; hydrolised sugar cane bagasse; yeast and vinasse; by products of the sugar and alcohol industry