2-Hydroxy-4 (methylthio) butanoic acid as a drinking water supplement for broiler chicks

Two experiments were conducted to study the effects on chick performance of a commercially available liquid methionine analog [2-hydroxy-4 (methylthio) butanoic acid; HMB] supplied through drinking water. Methionine activities of .025 and .05% were added to drinking water and compared with levels of .03, .06, or .09% included in a low-methionine basal diet from 0 to 21 days of age. Mortality was not significantly altered by any dietary treatment. Neither feed nor water intake was affected adversely by HMB inclusion in drinking water. Only male body weight in Experiment 1 did not respond to HMB feed supplementation. Equivalent levels of total sulfur amino acid intake among water treatments were associated with significantly heavier body weights than the control. In both experiments, body weight and feed efficiency of birds receiving .05% methionine activity as HMB in water were equal or superior to those of groups that received supplemented feed. The results indicate that, under the study conditions, HMB provided in drinking water can be effectively assimilated by broiler chicks, at least through 21 days of age.