Evaluation of the Interaction Between Phytase and Xilanase on Metabolizability of Energy-Reduced Broiler Diets

Abstract

To examine the association between phytase and xylanase in diets with nutritional adjustments on the metabolizability of feed by broiler diets, 250 chickens were used and distributed among five treatments and five replicates of 10 broilers each. The treatments were: positive control diet - without phytase or xylanase; negative control diet - with an energy reduction of 0.419 MJ/kg, without phytase or xylanase; and three diets containing xylanase and phytase and energy reductions of 0.209, 0.409 and 0.628 MJ/kg. For all energy-reduced diets, the nutritional matrix of phytase with phosphorus (0.15%), calcium (0.165%) and sodium (0.035%) was considered. The energy reduction of 0.628 MJ/kg with inclusion of the enzymes resulted in a higher metabolizability of the crude protein, also the apparent and apparent corrected metabolizable energy coefficients for nitrogen balance were higher in diets with a reduction energy of 0.209 MJ/kg, however had values similar to those obtained in the positive control diets and diets with energy reduction of 0.628 MJ/kg containing enzymes. The inclusion of phytase (500 FTU/kg) and xylanase (16,000 BXU/kg) in broiler diets, makes it possible to reduce metabolizable energy by up to 0.628 MJ/kg, available phosphorus, calcium, and sodium, and improve the metabolizability of the nutrients.