Chick bio‐assay of methionine and cystine

Abstract

Synopsis A chick bio‐assay procedure has been used to measure the relative potencies of DL‐methionine, L‐methionine and methionine hydroxy analogue as sources of methionine for the chick. The two isomers showed approximately equivalent potencies whereas the analogue was some 15 per cent less. The relative potencies of several batches of soyabean meals, groundnut meals and meat meals were also determined. The values for soyabean meals, of low urease activity, were uniformly high. The meat meals were rather variable and the groundnut meal values rather low.