Non-starch polysaccharide-degrading enzymes improve intestinal health by reducing digesta viscosity and gut permeability in young broilers fed high-fiber diets

Young broilers are sensitive to dietary stressors such as increased level of non-starch polysaccharide (NSP) because their intestinal morphology and function are still developing and not yet fully mature. Viscous grains such as rye and barley with high NSP content can increase digesta viscosity, impair nutrient absorption, increase gut leakage and reduce performance. This study evaluated the effect of a xylanase-β-glucanase enzymes combination (XB) and a consensus bacterial 6-phytase variant (PhyG) on gut health and growth performance in young broilers (0 to 14 d old) fed diets containing rye and barley. A randomized complete block design was used and 180 Ross 308 male chicks was assigned to 5 treatment diets with 6 replications per treatment: 1) corn-wheat-soybean meal-based positive control (PC); 2) the PC reformulated with addition of rye and barley served as negative control (NC); 3) the NC supplemented with 1,000 phytase units (FTU)/kg of phytase (NC+PhyG); 4) the NC supplemented with phytase and XB (at 100g/MT providing 1,220 XU/kg xylanase and 152 U/kg β-glucanase, NC+PhyG+XB100), and; 5) the NC supplemented with the same phytase dose but XB at double dose (NC+PhyG+XB200). All diets were fed ad libitum as a mash. Compared with the PC, the NC increased ( P < 0.05) ileal and jejunal digesta viscosity, increased intestinal permeability and reduced overall weight gain, all of which were fully ameliorated ( P > 0.05) by the NC+PhyG+XB200 treatment. The results indicate that combining phytase and XB is efficacious for supporting gut health and maintaining growth performance in young broilers from 0-14 d of age fed a NSP-rich diet.