GROWTH AND CARCASS CHARACTERISTICS OF BROILERS FED SALINOMYCIN IN DIETS CONTAINING GRADED LEVELS OF METHIONINE AND ENERGY

Abstract

In trial 1, caged broiler chicks were reared to 28 days on corn-soybean meal diets containing 60 ppm salinomycin or 99 ppm monensin with either 0, 0.05, 0.1 or 0.15% supplemental DL-methionine at metabolizable energy levels of 13.14 or 12.13 MJ/Kg. Monensin, but not salinomycin, depressed (P < 0.01) female body weight. Male birds were influenced by the salinomycin treatment resulting in increased feed efficiency. There were no significant interactions between treatments. Two subsequent trials involved floor-reared male and female birds to 49 days. Diets contained 0 or 60 ppm salinomycin in low (12.01 MJ ME/kg starter, 12.38 MJ ME/kg finisher) or high (13.33 MJ ME/kg starter, 13.63 MJ ME/kg finisher) energy regimens. Methionine levels were adjusted to the National Academy of Sciences-National Research Council (NAS-NRC) (1977) level of 1.56 g/4.184 MJ ME as a control treatment. Methionine treatments were obtained by supplementation or not of a corn-soybean meal basal. Salinomycin reduced feed intake (P < 0.01) of both male and female birds, and reduced body weight (P < 0.01) in males. Salinomycin improved (P < 0.05) feed efficiency in female birds. High levels of methionine supplementation reduced (P < 0.05) feed intake when the diet contained salinomycin, but not without the medication. There was a salinomycin × methionine interaction (P < 0.01) for feed efficiency. Salinomycin resulted in improved (P < 0.01) carcass fleshing grade at the low and standard levels of methionine. Key words: Salinomycin, methionine, broiler chicks, energy