The objective of this work were to estimate the requirement of lysine from 0 to 6 weeks and to evaluate the posterior effect on the performance of two egg-type strains. Three hundred egg-white pullets from 0 to 6 week of age and three hundred egg-brown pullets from 0 to 6 week of age were allotted to a randomized block design with five treatments and four replicates. A basal diet with 18.50% of crude protein (CP) and 2900 kcal metabolizable energy (ME) was supplemented with L-lysine HCl to obtain 0.75, 0.80, 0.85, 0.90, and 0.95% of total lysine in the diet. During the laying period all hens received the same diet with 16.5 CP, 2822 kcal ME, 3.81% Ca+2 and 0.755% of lysine. The pullets requirement estimates of lysine based on feed: gain was 0.86% or a daily intake of 254 mg for white-egg and 0.87% or a daily intake of 238 mg for brown-egg. Egg production, feed intake and egg dozen and egg mass ratio were quadraticly affected. Egg mass and egg mass ratio of brown-egg, and egg mass ratio of white-egg were linearly affected. During the growing phase the white-egg pullets showed worse feed:gain ratio than brown-egg pullets. During the egg production phase the brown-egg pullets showed lighter eggs, but the egg mass and egg dozen ratio were higher than white-egg pullets.
amino acid; egg mass and production; growth
