Nutritional requirement of digestible lysine for white-egg laying hens in production

Abstract

The objective of this research was to determine the nutritional requirement of digestible lysine for white laying hens in old age. Two hundred eighty-eight Hy Line W-36 laying hens at 60 weeks of age were distributed in a completely randomized design, with six levels of digestible lysine (6.0; 6.6; 7.2; 7.8; 8.4 and 9.0g kg1) and eight replications with six birds per experimental unit. There was linear effect of lysine levels on lysine intake and efficiency of utilization of lysine. For the production and egg mass, the levels of digestible lysine in the diet from which the plateaus occurred were of 6.57g kg1 and 7.10g kg1, respectively. There was quadratic effect of lysine levels on yolk weight, with the estimated level of 7.6g kg1 of digestible lysine. The digestible lysine requirement of white laying hens from 60 to 76 weeks of age is 7.10g kg1 in diet, corresponding to daily intake of 690mg bird-1 of digestible lysine.