Comparison of DL-Methionine, DL-Methionine-Na, DL-Methionine Hydroxy Analogue-Ca, and DL-Methionine Hydroxy Analogue Free Acid in Broilers by Using a Crystalline Amino Acid Diet

Abstract

The biological methionine activity of DL-methionine, DL-methionine-Na, the calcium salt of methionine hydroxy analogue (DL-MHA-Ca), and methionine hydroxy analogue free acid (DL-MHA-FA) was studied in a chick feeding test by using a crystalline amino acid basal diet. DL-Methionine and DL-methionine-Na were, as measured by gain and feed conversion efficiency, equally effective methionine sources on an equimolar basis. Performance of the chicks fed the DL-MHA-Ca supplemented diets was distinctly inferior to those fed equimolar quantities of DL-methionine. From our results, it was deduced that the biological activity of DL-MHA-Ca was approximately 81% that of DL-methionine on an equimolar basis, which is 67% on a weight basis of the commercial product. The poorest results were obtained with DL-MHA-FA as a methionine source. The DL-MHA-FA was only 76% as effective as DL-methionine on an equimolar basis, which is 66% by weight of the commercial product used.