Revista Brasileira de Zootecnia
Print version ISSN 1516-3598
BARBOSA, Breno Augusto Campolina et al. Nutritional requirements for lysine in white-egg and brwon-egg layers in second production cycle: 2. productive traits. R. Bras. Zootec. [online]. 1999, vol.28, n.3, pp. 534-541. ISSN 1516-3598. http://dx.doi.org/10.1590/S1516-35981999000300014.
This work aimed to establish lysine requirements for white-egg (Lohmann Selected Leghorn) and brown-egg (Lohmann Brown) layers hens in the second producing cycle, from 83 to 98 weeks of age. A completely randomized design with six replicates and eight birds per experimental unit was used. The treatments consisted in a 2 x 6 factorial involving two commercial lines and six lysine levels. The birds were fed diets containing 2860 kcal of ME/kg, 14.37% CP, and .50% lysine, supplemented with six levels of L-lysine HCl 98% (0, .00, .08, .16, .24, .32, and .40%). Feed intake (g/bird/day), egg production (%), egg mass (g/bird.day), egg weight (g), and feed:egg ratio were evaluated. The white-egg layer hens presented high egg production however and the brown-egg layer lenspresented better results for average egg weight. Egg production, egg weight, egg mass and feed:egg ratio (g/g and kg/dz) were influenced by the lysine level. The nutritional requirements of lysine for eight and brown-egg layer lens were obtained by the quadratic model and estimated in .76 and .80% for eight and semi white-egg layer hens, respectively, corresponding to 836 and 880 mg of lysine intake by bird/day.
Keywords : nutritional requirement; lysine; white-egg and brown-egg layer hens; second production cycle.