Effects of a xylanase on individual bird variation, starch digestion throughout the intestine, and ileal and caecal volatile fatty acid production inchickens fed wheat

1. The effects of a xylanase on digesta viscosity and starch digestibility throughout the small intestine and volatile fatty acid production in: the i leum and caeca were investigated in broilers fed on a low-metabolisable ene rgy wheat diet. 2. The xylanase reduced (P<0.01) duodenal (2.9 vs 1.7), jejunal (4.6 vs 2.3 ) and ileal (14.0 vs 3.9) digesta viscosities (mPas) and increased AME (P<0 .01) of the wheat and starch digestibility (P<0.5) in the jejunum and ileum . Between-bird variability in ME and digestibility of starch was also reduc ed. 3. Enzyme supplementation reduced (P<0.05) fermentation in the ileum, but i ncreased (P<0.05) it in the caeca. 4. The anti-nutritive effect of soluble non-starch polysaccharides (NSP) is related to their ability to increase digesta viscosity along the gut; this in turn causes changes in gut microflora and efficiency of nutrient utilis ation by the chicken. Use of appropriate enzymes is an effective way of dea ling with grains with high NSP content in poultry diets.