Effect of Exogenous Xylanase Supplementation on the Performance, Net Energy and Gut Microflora of Broiler Chickens Fed Wheat-Based Diets (Report‪)‬

INTRODUCTION Wheat is one of the most commonly used cereal grains in poultry feeds. However wheat contains significant amounts of soluble non-starch polysaccharides (sNSP). High levels of sNSP can result in increased viscosity in the small intestine of chickens, and depress nutrient utilization and performance (Choct and Annison, 1992). It has been proven that supplementation with exogenous xylanase is an effective solution to lower the viscosity of intestinal contents and improve digestibility of nutrients in broilers, leading to greater apparent metabolisable energy (AME) of wheat-based diets (Choct et al., 1992; Bedford and Morgan, 1996). It is known that the effectiveness of the enzyme addition is dependent on the source of xylanase and the quantity of wheat included in the diet. As a common field observation, and based on the summary of several research reports, the application of xylanase in wheat-based diets can improve broiler performance by 4-6% in terms of feed conversion ratio and increase the AME content of wheat by up to 6% (Cowieson et al., 2005, 2006; Scott, 2005).