This work aimed at evaluating egg production in Isa Brown hens fed diets with different levels of digestible lysine and chelate zinc. It was used 720 brown laying hens, in two evaluation periods, from 24 to 36 and from 48 to 60 weeks of age. The diets were evaluated in a completely randomized design in a 5 × 3 factorial scheme composed of five levels of digestible lysine (0.482; 0.527; 0.582; 0.644 and 0.732%) and three levels of chelate zinc (20, 40 and 80 ppm), so each combination was tested in 6 repetitions of 8 birds per experimental unit. In the phase from 24 to 36 weeks of age, there was an influence of digestible lysine and zinc on average feed intake of the ration and on laying percentage. During the phase from 48 to 60 weeks of age, the interaction was evidenced only on the average feed intake. The increase of digestible lysine concentration favored feed intake at all zinc levels. In both phases, the lowest zinc concentration meets poultry production needs. The estimated average value of ideal digestible lysine was 0.732% for the phase from 24 to 36 weeks of age and 0.578% for phase from 48 to 60 weeks of age.
Isa brown; mineral; performance; requirement; synthetic amino acid
