Quantitative Measurements of the Lysine Requirement of the Laying Hen

Two experiments were conducted to determine the quantitative dietary lysine requirement of Shaver Starcross 288, White Leghorn hens. In Experiment 1, rations calculated to contain .457, .557, .657, or .757% lysine were fed. The protein of these rations was supplied by corn, corn gluten meal, and soybean meal, and all rations contained 15.2% protein and 3050 kcal metabolizable energy (ME)/kg. The basal ration of Experient 2 contained corn and corn gluten meal as protein sources. Supplemental lysine ·HC1 was used to attain a lysine level of .570%. Lysine ·HCl was added in increments of .03% to obtain seven additional treatments; .60, .63, .66, .69, .72, .75, and .78% lysine. The rations contained 13.3% protein and 3015 kcal ME/kg. Experiments 1 and 2 were 140 and 84 days in duration, respectively. An average daily lysine intake of 567 mg/hen daily, or more significantly (P<.05) increased egg size and improved efficiency of feed conversion as compared with an intake of 481 mg lysine/hen daily in Experiment 1. Maximum rate of egg production was obtained when daily lysine intake was 702 mg/hen. Regression analysis of data obtained from Experiment 2 and the fit of a polynomial equation to the data showed that maximum egg size and rate of egg production occurred with average daily lysine intakes of 690 to 710 mg/hen. Thus, data from both experiments indicated a quantitative lysine need of approximately 700 mg/hen daily for maximum performance of White Leghorn fed rations based on corn-corn gluten meal or corn-corn gluten meal-soybean meal.