Nutritional requirements in methionine + cystine for white-egg laying hens during the first cycle of production

Abstract

A total of 288 leghorn laying hens were used in an experiment to determine methionine+cystine (TSAA) requirements. The addition of six levels of DL-methionine to a basal diet containing 14.4% of crude protein resulted in 0.484, 0.534, 0.584, 0.634, 0.684, and 0.734% TSAA contents. This experiment lasted from 22 to 38 week of age. Increasing TSAA from 0.484 to 0.734% had a quadratic effect on egg production, egg weight, feed intake, feed conversion, and body weight. Based on quadratic regression, TSAA requirements for maximum egg production, egg weight, egg mass, and body weight gain and the best feed conversion were 0.658, 0.681, 0.664, 0.683, and 0.665%, respectively. White-Egg laying hens required 0.67% TSAA in diets or 737 mg TSAA per hen daily from 22 to 38 wk of age (with feed consumption of 110 g). © Asian Network for Scientific Information, 2005.