Biological efficacy of liquid methionine and methionine hydroxy analogue-free acid in chicks.

An experiment was conducted to determine biological efficacies of DL-methionine-Na (Liquimeth) and DL-methionine hydroxy analogue (MHA)-free acid (Alimet) relative to DL-methionine in Single Comb White Leghorn male chicks. A crystalline amino acid mixture devoid of sulfur-containing amino acids was used for the basal diet, and the test substances were added at .1, .2, and .3% levels, equivalent to DL-methionine on a molar basis, in place of cornstarch. By a slope ratio assay using chick growth as a criterion, the relative biological efficacies of DL-MHA-free acid and DL-methionine-Na to DL-methionine were found to be 70 and 113%, respectively, on a molar basis.