The objective of this study was to evaluate the intake, total and partial dry matter (DM) digestibility and the nutrients and ruminal parameters of steer fed diet based on cottonseed processing residue (CSPR) supplemented with sugarcane dried yeast. Six steers, with rumen and duodenal cannulae were fed diets consisting of 80% CSPR and 20% concentrate, consisting of corn, urea and yeast at levels of 0, 20 or 40%. A randomized block design was used to analyze intake and digestibility and the ruminal parameters were analyzed in split plots. The DM, OM, EE, NDF and ADF intake and digestibility were not influenced by yeast supplementation, possibly because of the high value of the C fraction of the CSPR (44.51% DM) and the low protein fraction of slow degradation of yeast that prevented synchronization energy/nitrogen for greater residue degradation. The ruminal liquid pH decreased linearly in the animals kept on yeast supplemented diets. In all treatments the pH and ammonia nitrogen concentration were adequate for microbial growth. The ruminal concentrations of acetate, propionate, butyrate, total fatty acid and the acetate: propionate ratio values were not influenced by yeast supplementation. Cottonseed processing residue can be used as ruminant feedstuff.
agroindustrial residue; intake; digestibility; ruminal fermentation
