Effects of a mono-component endo-xylanase supplementation on the nutritive value of wheat-based broiler diets

1. Two trials were conducted to evaluate the effects of a mono-component thermostable endo-1,4-β-xylanase derived from Thermomyces lanuginosus on the nutritive value of wheat-based broiler diets. In a 5-week growth trial, the efficacy of xylanase supplementation at 0, 100, 150, 200, 400 and 4000 FXU/kg diet was evaluated. A short-term balance trial was carried out according to a 4?×?2 factorial arrangement of treatments, involving 4 wheat cultivars and endo-xylanase at 0 or 200 FXU/kg.

2. In the growth trial, enzyme supplementation from 0 to 400 FXU/kg reduced feed intake and improved feed conversion linearly. Digesta viscosity was significantly reduced by all enzyme inclusion levels by 49·6–56·9%, in a quadratic manner.

3. In the balance trial, xylanase supplementation resulted in a significant improvement of protein, lipid and dry matter apparent digestibility coefficients of diets, accompanied by improved dietary AME _N values. There was a significant wheat?×?enzyme interaction on AME _N and lipid digestibility. There was a significant effect of wheat cultivar on dry matter digestibility.