Requirement of lysine for rearing egg-type pullets from 13 to 20 weeks of age

[摘要] - The objective of this work was to estimate the requirement of lysine from 13 to 20 weeks and to evaluate the posterior effect on the performance of two egg-type strains. Three hundred egg-white pullets from 13 to 20 weeks of age and three hundred egg-brown pullets from 13 to 20 weeks of age were allotted to a randomised block design with five treatments and four replicates. A basal diet with 14.0% of crude protein and 2900 kcal metabolizable energy/kg was supplemented with L-lysine HCl to obtain 0.39, 0.42, 0.45, 0.48, and 0.51% of total lysine in the diet. During the laying period, all hens received the same diet with 16.5 CP, 2822 kcal ME/kg, 3.81% Ca+2 and 0.755% of lysine. The pullets requirement estimates of lysine based on weight gain from 13 to 20 weeks were 0.48% or a daily intake of 354 mg for white-egg, and 0.49% or a daily intake of 365 mg for brown-egg. Egg production and mass and egg dozen conversions of two strains were quadraticly affected. Egg mass of white-egg was affected by quadratic manner. During the final growing phase, the brown-egg pullets showed better weight gain than white-egg pullets. During the egg production phase, the brown-egg pullets showed a lower feed intake and better egg mass conversion than white-egg pullets.

[学科分类] 兽医学

[关键词] amino acid;growth;egg production;egg mass     IntroduçãoO conhecimento da curva de crescimento das aves de reposição tem mostrado que 70% do peso adulto de uma poedeira deve ser atingido até as 12 semanas (FARIA e JUNQUEIRA;1998);82% até as 15 semanas;e 92% até as 22 semanas;enquanto os 8% restante deve ser ganho posteriormente (KWAKKEL;1992)