One hundred andeighty Isa Brown laying hens at 60 weeks of age were arranged in a completelyrandomized design in a 2 × 2 factorial scheme, with two levels of phytase(0 and 500 ftu/kg ration) and two levels of sunflower meal (4 and 8%) totalizingfive diets, evaluated with six replicates with six birds. Diets were formulatedfrom a control ration based on corn and soybean meal free from phytase and sunflowermeal, valuing the nutritional phytase matrix in diets formulation. The experimentalperiod was divided in four 28-day cycles. The nutritional matrix suggested forphytase completely met the requirement by hens, even when diets were formulatedwith reduced nutritional levels when the nutrients present in the enzyme nutritionalmatrix were not considered accordingly to recommendations by the manufacturer.Addition of phytase in the diet reduces excretion of phosphorus by the birdsand it improves the economical parameters. Inclusion of sunflower meal at 8%level negatively affects egg production, but it does not affect the other performanceparameters and egg quality.
