Xylanase has been widely used in monogastric animal feed. The role of xylanase in efficiently hydrolyzing xylan is receiving increasing attention, especially in broiler chickens' wheat-based diets, aiming to improve animal intestinal health.
Endogenous digestive enzymes are crucial for nutrient digestion. According to the "encapsulation effect" hypothesis, xylanase can exhibit a significant cell wall disruption effect in broiler chickens, effectively increasing the contact of digestive enzymes with cell contents, thereby enhancing the efficacy of endogenous digestive enzymes. Studies have found that adding xylanase to wheat-based diets can significantly increase the pancreatic trypsin activity in 21-day-old broiler chickens. The increase in pancreatic trypsin activity may be due to supplemented NSP enzymes breaking cell walls, releasing more digestible proteins. Similarly, it was found that adding xylanase to wheat-based diets can improve pancreatic lipase and trypsin activity.
Studies have found that an increase in duodenal chyme viscosity can cause an increase in intestinal total weight and length, especially under very high viscosity conditions, the weight of the intestine can double. Research has found that adding xylanase to wheat-based diets can significantly reduce the relative weight of duodenum and jejunum. Adding xylanase to wheat-based diets can significantly reduce the relative weight of the duodenum (17.8%), jejunum (15.8%), ileum (14.6%), and small intestine (15.5%). However, some studies have observed that xylanase enzyme does not significantly affect the relative weight of the duodenum, jejunum, ileum, and small intestine of broiler chickens.
The intestinal morphological structure is of great significance for the functioning of the small intestine. Xylan usually increases the viscosity of the digestive tract chyme, inhibiting effective contact between villi and nutrients, leading to the degeneration and weakening of intestinal mucosal structure and function. Xylanase enzyme can alleviate the negative impact of NSP on intestinal morphology by reducing the viscosity of the digestive tract chyme.
Xylan can increase the viscosity of the broiler chicken digestive tract chyme, reducing intestinal motility, which will lower oxygen tension, promote the colonization of pathogenic microorganisms that affect intestinal tissue growth. Diets containing a large amount of water-soluble NSP can increase the abundance of E. coli in the broiler chicken small intestine. Supplementing xylanase enzyme can accelerate the digestion, absorption, and utilization of nutrients by the body, which may reduce the substrates available to the microbiota in the ileum, thereby reducing microbial activity.
The concentration of volatile fatty acids and lactic acid in the broiler chicken intestines can to some extent reflect the microbial activity in the intestines. High-viscosity small intestinal chyme will slow down the flow rate of intestinal contents, altering microbial balance, reducing intestinal tension, promoting bacterial fermentation. Excessive fermentation in the broiler chicken small intestine may not be conducive to the digestion and absorption of nutrients. However, adding xylanase can reduce chyme viscosity, decrease the time for substrates and microbial action, thereby relieving excessive fermentation in the small intestine. Adding xylanase to rye-based diets can significantly reduce the concentration of lactic acid and total volatile fatty acids in the broiler chicken ileum. However, adding xylan to the diet can increase the abundance of Lactobacillus in the small intestine, thereby increasing lactic acid concentration, but the concentration of other volatile fatty acids (especially acetic acid) in the small intestine is not affected by xylanase. Therefore, the impact of xylanase on the concentration of ileal lactic acid and volatile fatty acids still requires further research.
Related Articles
No.28 Huiyuan Street, Economic Development Area, Shanghe County, Jinan, Shandong Province, China
E-mail
[email protected]
Jinan Office: +86-531-5577-2899
Nanjing Office: +86-025-5270-3891