2017-12-082017-12-082008PIRES, A.V.; OLIVEIRA JUNIOR, R. C.; SUSIN, I.; FERNANDES, J. J. R.; MORAIS, J. B.; MENDES, C. Q. Fontes nitrogenadas em rações contendo bagaço de cana-de-açúcar hidrolizado no desempenho de bovinos confinados em terminação. Arquivo Brasileiro de Medicina Veterinária e Zootecnia, Belo Horizonte, v. 60, n. 1, p. 163-168, 2008.e- 1678-4162http://repositorio.bc.ufg.br/handle/ri/13119Eighty-one young bulls (27 Nellore, 27 Canchim, and 27 Holstein), averaging 18-month-old and weighting 360kg of initial body weight (BW), were used to evaluate the effects of nitrogen sources on feedlot performance. Treatments were assigned in a completely randomized block design using three steers per stall and nine per treatment. Blocks were defined by initial BW and breed. Experimental treatments were: 1) soybean meal, 2) urea, and 3) starea. Diets were isonitrogenous and isoenergetic composed by 50% concentrate and 50% forage (45% hydrolyzed sugarcane bagasse + 5% in natura sugarcane bagasse). Dry matter intakes (DMI) were 8.99, 7.43, and 7.69kg/day, average daily gains (ADG) were 0.983, 0.368, and 0.404kg/day and feed efficiencies were 9.56, 20.14, and 19.54kg DM/kg of gain for soybean meal, urea and starea treatments, respectively for steers fed. Diets with soybean meal showed proportionally higher (P<0.01) DMI, higher average daily gain and better feed efficiency compared to urea and starea diets. No differences (P>0.05) between urea and starea treatments were observed. Replacement of soybean meal by nonprotein nitrogen sources decreased the finishing beef steers performance.porAcesso AbertoNovilhoAmiréiaFarelo de sojaUréiaConsumoGanho de pesoSteerSoybean mealStarea,UreaIntakWeight gainArtigo10.1590/S0102-09352008000100023