Two experiments were carried out to evaluate different levels of digestible lysine (0.90; 1.00; 1.10; 1.20; e 1.40%) combined with zinc chelate (43 and 253 ppm) to male broiler. The considered periods were: initial phase - performance (1 to 11 days old) and nitrogen retention (1 to 7 days old). A randomized block experimental design in a 5 × 2 factorial arrangement was used. In performance assay, 7 replications and 15 birds per experimental unit was used. In the digestibility essay, 6 replications 6 birds for experimental unit were used. The diets contained 2.960 kcal/kg ME and 21.0% crude protein. In the initial phase, there was no digestible lysine × zinc chelate interaction on performance study, however a quadratic effect of digestible lysine on final weight, weight gain, relative weight gain and crescent linear effect in feed intake was observed. In feed: gain ratio did not differ with digestible lysine level and zinc chelate in the diet. In the performance, the better digestible lysine level for broiler raised in concrete floor is 1.19%. From 1 at 7 days old, there was no influence of the combinations of digestible lysine and zinc chelate on nitrogen balance. The nitrogen retention linearly increased as digestible lysine increased in the diet. This response coincided with linear increase of weight gain and feed: gain ratio. A digestible lysine requirement for male broilers from 1 to 7 days old is equal or bigger then 1.40% for male broiler from one at seven days of age.
amino acids; micronutrientes; nutrient depositions; nutrition
