Effect of Excess Methionine on Growth, Feed Intake, Energy Utilization and Plasma Amino Acid Pattern in Chicks

Abstract

In order to investigate the effects of dietary excess methionine on growth, feed intake, energy utilization and plasma amino acid pattern in chicks, 7-day-old single-comb White Leghorn chicks were fed diets adequate and excess in methionine for 14 days, and then body composition and plasma amino acid pattern were determined.Excess methionine markedly decreased body weight gain, feed intake, and efficiency of feed utilization. Body composition was not affected by feeding excess methionine, but the chicks fed the methionine excess diet retained significantly less fat, protein and energy than those fed the methionine adequate diet. Metabolizability of dietary energy was not altered by excess methionine, wheress utilization of nitrogen and energy was decreased.Excess methionine drastically increased plasma methionine level, and levels of some other amino acids in plasma were also changed by excess methionine.