Supplemental effect of xylanase and mannanase on nutrient digestibility and gut health of nursery pigs studied using both in vivo and in vitro models

Non-starch polysaccharides (NSP; arabinoxylan, mannans) are present in high concentration in distiller's dried grain with solubles (DDGS). These NSP are not degraded by endogenous digestive enzymes of pigs. The purpose of this study was to determine if supplemental enzymes could increase the apparent ileal digestibility (AID) of nutrients in nursery pigs fed corn DDGS, alter short chain fatty acid (SCFA) production, and affect gut health. Two independent studies were carried out using an in vitro porcine model and in vivo model. For the in vitro study, enzymatically digested residue of DDGS was used in a 2 × 2 factorial arrangement of treatments: supplemental xylanase (0 or 1500 endo-pentosanase unit of xylanase/kg of the diet) and supplemental mannanase (0 or 400 unit of mannanase/kg of diet). For the in vivo study, corn-soybean meal based diets with 15% corn DDGS were formulated using thirty-two newly weaned pigs in a randomized complete block design for 4 treatments in the similar fashion as in vitro study. Plasma and mucosa were collected for tumor necrosis factor-α (TNF-α) and malondialdehyde (MDA) measurements. Digesta samples from jejunum and ileum were collected to measure viscosity, pH, and AID of nutrients including NSP components. Supplemental xylanase increased (P < 0.05) concentration of SCFA, acetate, and propionate, and AID of total NSP, arabinoxylan, and GE. Supplemental xylanase also increased (P < 0.05) villus height in the duodenum, proliferation rate in the crypt of jejunum, and the concentrations of claudin, occludin, and ZO-1 in jejunum, whereas reduced (P < 0.05) the viscosity of jejunal digesta. Supplemental Mannanase increased (P < 0.05) production of butyrate and AID of mannan and occludin concentration, whereas tended to decrease (P = 0.057) MDA level in the jejunum. An interaction effect (P < 0.05) was found between xylanase and mannanase for digestibility coefficient of arabinoxylan and ZO-1 concentration. In conclusion, the use of supplemental xylanse and mannanase were able to improve digestibility of targeted NSP and improve gut health. Hence, these enzymes can be used separately or together depending upon the type of ingredients used in the feed and amount of substrate (xylan or mannan) available for enzymes to degrade in diets for nursery pigs to enhance utilization of different fibrous coproducts and improve gut health.