It was evaluated the financial result of the confinement of Nelore bovines, subdued to different levels of substitution of sorghum silage by sugarcane or sugarcane bagasse ammoniated with urea. It were confined 35 young bulls with age average of 2 years, initial average weight of 448,2kg distributed in 7 treatments: 100% of sorghum silage; 70% of sorghum silage + 30% of sugarcane; 30% of sorghum silage + 70% of sugarcane; 100% of sugarcane; 70% of sorghum silage + 30% of sugarcane bagasse ammoniated with urea; 30% of sorghum silage + 70% of sugarcane bagasse ammoniated with urea and 100% of sugarcane bagasse ammoniated with urea. Concentrate was provided in the amount corresponding to 1.2% of body weight. It were analyzed the different components of the fodder used in the trial and the results of weight gain acquired, with final average weight of 512.3kg. The treatment with 100% of sorghum silage showed the best economic efficiency, followed by sugarcane and sugarcane ammoniated bagasse used alone, covering the total operational costs and showing positive residue. Different combinations of sorghum silage with sugarcane or with sugarcane ammoniated bagasse showed insufficient performance to cover the total variable costs. The treatment did not show economic efficiency to cover the total costs that include the opportunity costs.