Response to Methionine Supplementation of Leghorn Hens Fed Low-Protein Corn-Soybean Meal Diets

Abstract

When 0.05% or 0.10% methionine was added to diets containing 12% protein and daily feed consumption of control hens was near 90 g., feed intake was depressed, resulting in lowered egg production, egg weight and body weight. When 16% protein diets were methionine-supplemented and daily feed consumption was 90 g., egg production and egg weight increased.Because the reduced performance could not be explained by expressing the amino acid concentrations as a percentage of the diet, percentage of the protein or percentage per kcal. of M.E., an experiment was conducted to study the additions of 0.05% and 0.10% methionine to diets of different nutrient density, but containing a constant calorie:protein ratio, thereby studying the feasibility of expressing methionine concentrations as a (percentage of methionine/kcal. of M.E./kg. of diet)/percentage of protein. Methionine additions to a diet containing 13.5% protein and 2600 kcal. M.E./kg. resulted in reduced production as methionine concentration was increased from 0.0056 to 0.0071 to 0.0085. Methionine additions to a diet containing 15.5% protein and 3000 kcal. M.E./kg. resulted in methionine concentrations of 0.0050, 0.0060 and 0.0071 and a marked linear improvement in performance. The expression of the methionine concentrations in this manner provides a useful means of predicting the hen’s response to methionine supplementation under different conditions if the resulting concentrations can be compared with a reference diet known to respond to methionine additions.