The objectives of this experiment were to evaluate the performance of young bulls fed total rations prepared with additive treated or untreated sugarcane silages and evaluate the additive effects on silages fermentation. Thirty young Canchim bulls averaging 312 kg were allotted to a completely randomized experimental design to evaluate three types of isoproteic and isoenergetic rations (roughage:concentrate ratio of 35:65): ration with silage without additive (control), ration with silage treated with urea (5 g/kg of fresh forage - FF) + sodium benzoate (0.5 g/kg FF), ration with silage inoculated with Lactobacillus buchneri (5 × 10(4) cfu/g FF). Silages had pH adequated to conservation (<4.2), low levels of butyric acid (<3 g/kg in DM) and high levels of acetic acid (>53 g/kg in DM). The silage treated with urea + benzoate and the inoculated silage presented lower ethanol concentration when compared to the untreated silage (43, 73 and 92 g/kg in DM, respectively). The silage treated with urea + benzoate had higher crude protein content and total digestible nutrients when compared with other silages. The type of ration affect neither body weight gain (BWG) nor DM intake, but feed conversion was better for animals that received control ration in relation to those fed ration with inoculated silage (5.71 vs 6.45 kg DM/kg BWG).
benzoate; ethanol; L. buchneri; live weight gain; urea; volatile fat acids
