The effect of different xylanases on carbohydrate digestion and viscosity along the intestinal tract in broilers

The mode of action of two xylanase products on the digestion of non-starch polysaccharides (NSP) and digesta viscosity along the gut was examined in broilers fed two wheats with different metabolisable energy values. Significantly (P<0.01) higher viscosity values (mPa.s) were observed in the duodenum (3.68 vs 2.58), jejunum (5.14 vs 2.6) and ileum (18 vs 10.6) of birds fed the low-ME wheat compared with those fed the normal wheat. In the duodenum, both enzyme products lowered (P<0.05) the viscosity regardless of wheat type, but in the jejunum, a reduction in viscosity was observed only in the birds fed the low-ME wheat. Both enzymes caused an increase in the ileal viscosity. The relative level of soluble NSP in the ileum was significantly (P<0.01) elevated by both enzymes and this coincided with a decrease in the insoluble NSP level. The enzymes did not release substantial amounts of monosaccharides and oligosaccharides.