Relative Biopotency of Three Methionine Sources for Laying Hens

Three feed grade sources of methionine were evaluated with laying hens fed a 14.6% protein basal diet containing .229% methionine and .21% cystine. Supplemental levels of .025, .05, .10, and .15% of each source were fed for 28 weeks to hens in colony cages. The supplements were DL-methionine (DL-Met), methionine hydroxy analogue acid (MHAA), and the calcium salt of methionine hydroxy analogue (MHA-Ca). Each was fed in equimolar amounts using values of 99.0, 88.7, and 82.8%, respectively, for the amount of active ingredient present. Regressions of egg output (g egg/bird/day) on total sulfur amino acid intake (mg TSAA/bird/day) showed significant linear responses to each of the three sources over the supplemental range tested. The slopes (regression coefficients) and intercepts of the three regressions were not statistically different (P>.05). It was concluded that mere were no significant differences in the effectiveness of the three materials for laying hen performance.