The determination of the methionine requirement of laying pullets by a diet dilution technique

Abstract

A method for the determination of amino acid requirements of laying hens is described. This involves the dilution of a high protein “ summit” diet with an isocaloric nitrogen‐free mixture. By ensuring that the amino acid to be assayed is first‐limiting in the summit diet, the response to dilution can be interpreted as a response to a single amino acid. The method is applied to the determination of methionine requirement and it is shown that the response to methionine obtained is virtually independent of the protein level of the diet and is not influenced by direct effects of the dilution mixture. From the results of the present and other published experiments, the “ available “ methionine required for maximum egg yield of pullets in the early stages of lay is estimated to be 275 mg per bird per day.