The Effects Of Xylanase On Oligosaccharides Generation And Action Mechanism Of Xylanase In Wheat-Based Diet

In order to improve the nutritional value of the wheat, this study was conducted to investigate the effects of xylanase supplemented to wheat-based diets on performance, nutrient digestibility, oligosaccharide generation and metabolism in vivo and in vitro. The objective of this study was to explore the action mechanism of xylanase.1. The effects of xylanase on nutrient digestibility, oligosaccharides generation and relative viscosity in wheat-based diet in vitro.The results showed that the digestibility of crude protein and hemicelluloses in wheat-based diet was significantly improved (P<0.05). When adding 2560FXU/kg xylanase to wheat-based, the digestibility of crude protein could increase by 5.12 percentage point. The relative viscosity of xylanase-extracted solution from wheat-based diet was significantly reduced due to xylanase addition (P<0.01). However, the relative viscosity of xylanase-extracted solution was in a quadratic response to the prolongation of xylanase-hydrolyzation time. The concentrations of arabinose, glucose and arabinoxylooligosaccharide in xylanase-extracted solution from wheat-based diet were significantly enhanced (P<0.05). The value of arabinose/xylose in arabinoxylooligosaccharide was significantly decreased.2. The effects of xylanase on broiler chickens performance, digestion and metabolism.The results showed that 0.3% and 0.1% xylanase supplementation increased body weight gain by 3.08%-5.92% and decreased feed to weight gain ratio 2.5%-5%. The 0.1% xylanase supplementation significantly improved body weight gain and feed conversion efficiency (P<0.05). The relative weight of digestive organs and the length of the intestine were decreased with enzyme supplementation (P>0.05) . The pH value of chyme was increased with enzyme supplementation (P>0.05 ) . The ileal apparent digestibility of crude fat and fecal apparent digestibility of protein was significantly improved (P<0.05) with enzyme supplementation. The ileal and fecal digestibility of hemicelluloses was very significantly increased (P<0.01). The supplementation of xylanase significantly improved the concentration of arabinose in crop, proventriculus, duodenum, jejunum and ileum (P<0.05 ), the concentration of xylose in crop, duodenum, ileum (P<0.05 ) and the concentration of glucose in ileum(P<0.05). The supplementation of xylanase also significantly improved the concentration of arabinoxylooligosaccharide in duodenum, jejunum, ileum and caeca (P<0.05). However, the supplementation of xylanase had no effect on the concentration of isomaltose, panose, isomaltriose and kestose (GF2) (P>0.05).The supplementation of xylanase respectively increased the level of total protein, albumin, uric acid and glucose of blood serum by 26.6%, 44.5% (P<0.05), 7.6% and 25.1% (P<0.01). The supplementation of xylanase respectively decreased the concentration of cholesterol and triglyceride of blood serum by 19.1% ( P<0.05 ) and 16.9%. The supplementation of xylanase respectively decreased the level of glucagon and T3 by 18.06% and 5.53% and respectively improved the level of insulin and T4 by 6.96% and 29.07%, but all were not significant (P>0.05).