Increases Chyme Viscosity in Intestinal Tract, and Impact Animal's Digestion & Absorption Function.Monogastric animals themselves are incapable of secreting enzymes which decompounded xylan. While animal makes a meal of feed containing high ratio of water-solubility xylan, dissolubility xylan in animal intestinal tract forms stickum，and increase viscosity of the contents in intestinal tract. The increased viscosity will reduce the passing speed of chyme through intestinal tract, then leads to a decrease of feed intake, disturbs the mixing between the digestive juice and the substrate，postpone the digestion of digestive enzyme to the substrate. At the same time, it also reduces the diffusion velocity of nutrient substance in chyme in intestinal tract, and disturbs the absorption of nourishment.