the objective of this study was to evaluate low and high brix diets, treated or not with 5 g of calcium oxide per kg of natural matter, and corn silage on intake, digestibility and performance of beef cattle. forty cattle with initial body weight (bw) of 350 kg were used: five composed the control group, 30 were distributed into random blocks (control) and the other five were distributed in a 5 × 5 incomplete latin square, with the objective of determining digestibility. the 30 animals evaluated for performance were slaughtered and empty body weight (epw), carcass dressing and meat cuts were determined. the diet with corn silage (cs) presented the best intake of the other ingredients and the best weight gain, except for neutral detergent fiber intake in g/kg of bw. only carcass dressing, in relation to bw and ebw, was not affected by the treatments, and the others were greater for animals fed diets with sugar cane silage. animals fed diets with high brix sugar cane silage and treated high brix sugar cane silage presented lower intake of indigestible neutral detergent fiber and neutral detergent fiber corrected for ash and protein (g/kg of bw) in relation to diets with low and high brix sugar cane silage, respectively. animals fed diets with corn silage presented higher digestibility, except for crude protein and non-fibrous carbohydrates. animals subjected to diets with corn silage presented low excretion of nitrogen compounds and higher microbial crude protein synthesis. animals fed sugar cane silage present greater intake, performance and digestibility. the use of lime during 15 or 20o brix sugar cane ensilage does not alter intake, digestibility or performance of beef cattle.