In intestinal tract, xylan can form reticulation with one another, cut the diffusivity of feed, prohibit incorporation between fat and bile salt, and make them can not form fatty mote，then restrains the digestion and absorption of fat.

 

Accelerates Proliferation of Harmful Microbial in Intestinal Tract, Impacts Animal Health

The increase of intestinal tract viscosity leads to an accumulation of nutrient substance in intestinal tract, and forms chyme containing rich nutrient substance, in which microbes ferment，then injure the normal structure and function of intestinal tract mucous membrane. For poultry, humid feces is prone to adhere around cloacae, pollute the fowls and  their eggs, and provide the microbe with location of proliferation, thereby substantive ammonia gas is produced，and can cause the proliferation of fungal spore as well，which will do harm to poultry health.

 

Effect of Physical Barrier, Impact Nutrient Digestion.

As the major composition of cell wall，xylan besieges nutrient substance，cutting down the nutrient utilization ratio  in feedstuff .

 

The Xylanase and Its Effect Mechanism

 

Xylanase is a group of compound enzymatic system which can degrade xylan into oligosaccharide and xylose. To do that, theβ-1,4-xylanohydrolase (1,4-β-D-xylanohydrolase: EC 3.1.2.8) is making the major effect. It acts on xylose bond randomly in the main chain, primarily selects non- substituting zone，decomposes xylan into xylo-oligosaccharides（xylo-disaccharide、xylo-trisaccharide and so on），so it is also called endo-xylanase; Whileβ-xylan xylohydrolase (1,4-β-D-xylan xylohydrolase: EC3.2.1.37) reacts on the bottom of oligosaccharides，releasing  xyloses. Andα-L- arabinofuranosidase, α-D- glucuronidase hydrolyze xylan's branched chains which bring different substituting group.

 

The Application Purpose of Xylanase and the Efficacy of Its Enzymolysis Products

The purpose of using xylanase in feed industry is to eliminate the anti-nutritional function of xylan, instead of decomposing it into monosaccharides thoroughly. Wherefore, only the endo-xylanase has practical application value. The decomposition products of endo-xylanase, i.e., xylo-disaccharide, xylo-trisaccharide and other xylo-oligomerizationses，not only have no anti-nutritional function，but are the most efficient bifidus factors for the time being also, which is able to regulate the microscopic ecosystem of animal intestinal tract, keep animal healthy. If in xylanase preparation the β-xylobiase content is too high, which will further decompose xylo-disaccharide, xylo-trisaccharide and other oligomerization xylose into xylose, then the function of  microscopic ecosystem regulating will lose. Wherefore, the xylanase preparation used in feed industry should contain little β-xylobiase and other exo-xylanase.