Phytase in broiler diets with reduced nonphytate phosphorus levels

This work evaluated the inclusion of phytase in diets with reduced nonphytate phosphorus (NPP) levels in relation to the performance and carcass yield of broilers and litter characteristics. The experimental design was completely randomized in a 2 x 3 factorial arrangement – two phytase levels (0 and 25U/kg) and three NPP levels (100, 85 and 70% of the requirement), in a total of six treatments with fi ve replicates. The reduction of the NPP to 70% of the requirement decreased the weight gain and feed intake and increased the feed:gain ratio. Phytase inclusion increased the weight gain and the feed intake at 21 days. The NPP x phytase interaction was signifi cant with regard to the weight gain at 42 days. The reduction of NPP to 70% diminished the feed intake at 42 days and increased the liver and heart relative weight. Nitrogen content was lower in the litter of broilers fed diets with phytase and decreased phosphorus content, due to the NPP reduction in the diets. It was concluded that diets with 85% of NPP, supplemented with 25U/kg of phytase, can be used with no negative effect on performance or carcass and litter characteristics