The demand for foods and its derivates that would not be used in the human diet or in the monogastric animals diet in addition with supplement forms are important aspects in the search for alternative sources for ruminant nutrition and reduction in the slaughtered time. This work had as objective to evaluate growing levels of concentrate in the fattening of nelore bullock gazing supplemented during the raining seazon. The experiment was carried out in the Vitorinha farm, property of Fundação de Apoio ao Ensino, Pesquisa e Extensão - FAEPE, of the Universidade Federal de Lavras - UFLA, in Lavras, South region of Minas Gerais State from January to May of 2001. It was used 24 nelore steers average with age of 17 months old and body weight average of 308,0 Kg. During the experimental period, the animals were kept in a pasture of Brachiaria decumbens of 11,2 ha with average production of 5,400Kg DM/ha in the beginning of the experimental period. The treatments were constituted of increasing levels of concentrate calculated as body weight percentage as follow: T1 - 0%; T2 - 0,15%; T3 - 0,300/o; T4 - 0,45%. lhe experiment was done in casualized blocks design using initial body weight as block factor, being 6 blocks and 4 treatments totalizing 24 experimental units. The data were analyzed using the statistic software SISVAR. (Variance Analysis System for Balanced Data). There was not significant difference in the body weight daily gain (P<0,05) therefore when considering the rate income:cost, supplementation shown itself economically viable in function of the additional gain obtained.
Brachiaria decumbens; live weight gain; crossbred of nelore; level of the suplementation