Using Enzyme Supplemented, Reduced Protein Diets to Decrease Nitrogen and Phosphorus Excretion of Broilers

An experiment was conducted to investigate the effect of dietary protein levels and supplementation of phytase and pentosanase in wheat-soybean meal diet on the performance and output of N and P in broilers. Addition of phytase alone or in combination with pentosanase to reduced or control protein diets did not affect average final body weight of mixed sexes. However, addition of phytase and pentosanase in combination to reduced protein diets in male broilers significantly depressed body weights. Intestinal viscosity of 21d broilers was significantly decreased by addition of phytase and pentosanase alone or in combination. Tibia ash content was significantly increased by phytase supplementation. Supplementation of phytase alone and in combination with pentosanase to reduced protein diets significantly decreased P in manure and daily output of P. Daily N output was lowest in the reduced protein diet supplemented with phytase and pentosanase combination. The retention of DM, N and P was highest in the reduced protein diet supplemented with phytase and pentosanase combination. In conclusion, supplementation of phytase alone or in combination with pentosanase to reduced protein diets can decrease output of N and P. But the combination of the enzymes has no beneficial effects on the performance of broilers, especially those on wheat-soybean meal diet with reduced protein level.