The objetive of this work was to evaluate the effect of the addition of different enzyme levels plus yeast in the cattle diet on apparent nutrient digestibility and cattle performance in feedlot. Is was used 18 crossbred bulls (Taurino x Zebuino) of milk dairy origin with average LW of 190±10 kg and age of 12 months and 27 steer of the Guzerá breed with LW and age of 325 kg and 27 months. The levels of enzyme plus yeast were zero (control), 5 g of enzyme (E) plus 5 g of yeast (Y) and 10 g E plus 5 g Y for animal day. All animals received the identical diet with 65% silage (50% corn:50% sorghum) and 35% of concentrate composed of corn (24.6%), cottonseed meal (7.4%), urea (1.2%), mineralized salt (.54%) and limestone (.86%). This diet showed 12.4% CP, 10.1 MJ ME/kg DM and 41.1% NDF. The enzyme plus yeast did not affected DM intake (3.3% LW or 126.6 g/kg LW.75) and ACD of DM (63.3%), CP (68.2%), EE (83.3%), TCHO (61.3%), NDF (47.2%), ADF (43.8%), and TDN value (62.8%). The ADG and DMI decreased of quadratic form and feed:gain ratio worsed linearly, in function of feedlot days. The feeding of enzyme plus yeast for beef cattle did not bring nutritional and performance benefits.
additive; ruminant; xylanase; Saccharomyces cerevisiae
