The lysine level was evaluated for 1,050 male broilers from 12 to 22 days of age. The experimental design was completely randomized with five treatments, seven replications, and 30 birds per experimental unit. The treatments were: 1.05, 1.10, 1.15, 1.20, and 1.25% of digestible lysine. Weight gain, feed intake, feed: gain ratio, body composition, and nutrient deposition were measured. There were quadratic effects of digestible lysine on feed intake and an ascendant linear effect on carcass weight. In the carcass chemical composition, there was a quadratic response of lysine level in protein concentration. The deposition rates in carcass protein, carcass water, and whole body had a linear increase as response to lysine addition to diet. The lysine level increase however coincided with the mineral decrease on blood, offal, and whole body. Basing on performance, the digestible lysine 1.1% level attended the broiler needs from 12 to 22 days of age. On the other hand, considering the chemical composition and the nutrient accretion rates, the need for digestible amino acid was equal or higher than 1.25%
body composition; fat deposition; male broilers; protein deposition; performance
