Evaluation of a microbial phytase, produced by solid state fermentation, in broiler diets II. Influence on phytate hydrolysis, apparent metabolizable energy, and nutrient utilization.

摘要

The influence of a microbial phytase, produced by solid-state fermentation, on phytate phosphorus (PP) hydrolysis, AMEn, and nutrient utilization of male and female broilers fed a wheat-soy-canola diet was examined. Ileal phytate hydrolysis data provided direct evidence to the efficacy of phytase in hydrolyzing the phytic acid. Addition of 500 phytase units (PU)/kg to the wheat-soy-canola diet containing 0.28% PP increased the PP hydrolysis from 28.0 to 59.3% and from 27.2 to 51.9% in male and female broilers, respectively. Increased PP release resulted in corresponding improvements in apparent ileal digestibility and retention of phosphorus and lowered excreta phosphorus contents. Excreta phosphorus contents in birds fed the low phosphorus plus 500 PU/kg were 35% lower than those in birds fed the adequate phosphorus diet, during both starter and finisher phases. Phytase supplementation caused improvements in apparent ileal nitrogen digestibility, nitrogen retention, and AMEn. The overall responses observed with phytase supplementation may be partly reflective of the side enzyme activities present in this product and suggest that enzyme products with multiple enzymes may provide a competitive strategy to improve the nutrient utilization of wheat-based poultry diets..