The objective of this study was to evaluate the effect of two sources of methionine, DL-Methionine (DLM - 99%) and Methionine Hydroxy Analogue Free Acid (MHA-FA - 88%), at three different levels of supplementation of this amino acids in commercial diets on the performance of broiler chickens. A total of 1.232 commercial Ross broilers was used, from 01 to 47 days of age, and allotted to a complete randomized design in a 2 X 3 factorial (source methionine X supplementation level) arrangement and a additional diet (basal) without supplementation, with eight replications of 22 birds per experimental unit. The basal diet was supplemented with 50, 100 and 150% of MHA-FA or DL-methionine in equivalent amount of 65% of the amount of MHA-FA used. Feed intake, weight gain, feed:gain ratio and production factor were determined. Within each supplementation level there were no significant differences between the diets containing 100 parts of MHA-FA and 65 parts of DL-methionine, except for the period of 01-10 days when there was significant difference for the weight gain at the lowest level of supplementation. In conclusion, 65 parts of DL-methionine is equivalent to 100 parts of MHA-FA.
biological efficacy; broiler chicks; methionine source; performance; sulphur amino acids
