In this experiment it was aimed to determine the best levels of digestible lysine for laying hens in production period. Performance, nutrients intake, metabolism, egg quality, blood parameters and development of reproductive tract for 160 Hy-Line W-36 hens at 25 weeks of age. Hens were distributed in a completely randomized design with four levels of digestible lysine (600, 700, 800 or 900 mg of Lys/kg) and four replicates by using a split spot scheme was used at evaluation of nitrogen balance, blood parameters and reproductive tract. Lysine levels in the diet affected food, protein and energy intakes whose maximum point was noted at the level of 720 mg of Lysine. For egg production, food conversion, and nitrogen balance, the best levels of lysine was 800 mg, 900 mg, and 700 mg, respectively. The digestibility of ethereal extract, egg quality, development of reproductive tract and blood parameters were not affected by levels of digestible lysine in the diet. It is suggested 700 and 800 mg of digestible lysine for metabolism and performance, respectively, and 600 mg for egg quality and better development of the reproductive trait.
amino acid; blood; egg production; egg quality; oviduct
