Monensina para Bezerros Ruminantes em Crescimento Acelerado. 1. Desempenho

Abstract

Effects of monensin supplementation on the performance, the carcass characteristics and the composition and the partial economic analysis, were evaluated in a 120-d trial, using 20 Holstein bulls calves, with average weight and age of 90.8 kg and 80 days, respectively. The treatments consisted on different levels of monensin (0, .4, .8, and 1.2 mg of monensin/kg LW). Results with the increase of the monensin levels were observed for weight gain (1.064, 1.312, 1.372, and 1.252), dry matter intake (4.158, 4.774, 5.028, and 4.752), hearth girth gain (32.60, 37.00, 39.80, and 36.60) and croup height (19.42, 23.64, 23.68, and 23,18) being the highest values obtained at .8 mg monensin/kg LW level. The feed gain did not differ among treatments. The carcasses analyzed after the slaughtering of all calves, at the end of the trial, also showed advantage yield results, with the application of the monensin, showing no changes in its composition. Economic analysis showed higher benefits with the use of ionophore, recommending its use in dairy bulls calves feeding management.