The influence of xylanase on the fermentability, digestibility, and physicochemical properties of insoluble corn-based fiber along the gastrointestinal tract of growing pigs

Abstract

In theory, supplementing xylanase in corn-based swine diets should improve nutrient and energy digestibility and fiber fermentability, but its efficacy is inconsistent. The experimental objective was to investigate the impact of xylanase on energy and nutrient digestibility, digesta viscosity, and fermentation when pigs are fed a diet high in insoluble fiber (>20% neutral detergent fiber; NDF) and given a 46-d dietary adaptation period. Three replicates of 20 growing gilts were blocked by initial body weight, individually housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF) with 7.5% NDF, a 30% corn bran high-fiber control (HF; 21.9% NDF), HF+100 mg xylanase/kg [HF+XY, (Econase XT 25P; AB Vista, Marlborough, UK)] providing 16,000 birch xylan units/kg; and HF+50 mg arabinoxylan-oligosaccharide (AXOS) product/kg [HF+AX, (XOS 35A; Shandong Longlive Biotechnology, Shandong, China)] providing AXOS with 3-7 degrees of polymerization. Gilts were allowed ad libitum access to fed for 36-d. On d 36, pigs were housed in metabolism crates for a 10-d period, limit fed, and feces were collected. On d 46, pigs were euthanized and ileal, cecal, and colonic digesta were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment as a fixed effect. Compared with LF, HF reduced the apparent ileal digestibility (AID), apparent cecal digestibility (ACED), apparent colonic digestibility (ACOD), and apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), crude protein (CP), acid detergent fiber (ADF), NDF, and hemicellulose (P<0.01). Relative to HF, HF+XY improved the AID of GE, CP, and NDF (P<0.05), and improved the ACED, ACOD, and ATTD of DM, GE, CP, NDF, ADF, and hemicellulose (P<0.05). Among treatments, pigs fed HF had increased hindgut DM disappearance (P=0.031). Relative to HF, HF+XY improved cecal disappearance of DM (162 vs. 98g; P=0.008) and NDF (44 vs. 13g; P<0.01). Pigs fed xylanase had a greater proportion of acetate in cecal digesta and butyrate in colonic digesta among treatments (P<0.05). Compared with LF, HF increased ileal, cecal, and colonic viscosity, but HF+XY decreased ileal viscosity compared with HF (P<0.001). In conclusion, increased insoluble corn-based fiber decreases digestibility, reduces cecal fermentation, and increases digesta viscosity, but supplementing xylanase partially mitigated that effect.

Investigation of the nutritional and functional roles of a combinational use of xylanase and β-glucanase on intestinal health and growth of nursery pigs

“…Feeds with high soluble NSP cause an increase in the viscosity of digesta due to their high water-holding capacity [ 2 , 51 ]. However, arabinoxylans and β-glucans in feeds contain β-glycosidic linkages, requiring exogenous NSP-degrading enzymes for the degradation of these NSP fractions [ 52 , 53 ]. Recently, NSP-degrading enzymes have shown synergistic effects on the hydrolysis of NSP, effectively decreasing the digesta viscosity in the small intestine in relation to enhanced intestinal health and growth of nursery pigs [ 3 , 30 , 54 ].…”

“…The supplementation of XG had a positive impact on intestinal immune response, intestinal morphology parameters, and growth of nursery pigs in this study. The reason for this may result from the positive modulation of microbiota in the jejunal mucosa by the release of oligosaccharides [68,74,75], as well as an increase in nutrient availability with a reduction of digesta viscosity [10,13,53].…”

Dietary fiber and its role in performance, welfare, and health of pigs

“…The observed effects were due to the high amount of neutral-detergent fiber (NDF) in the diets resulting in decreased nutrient and energy digestibility, reduction in relative hindgut fermentation, impairment of pig performance and dilution of dietary energy, as explained by Petry et al . (2021).…”

“…A recent study in gilts receiving an HF diet based on corn bran (30% of inclusion) also showed a decrease in DM, CP, gross energy, and fiber digestibility accompanied by increased digesta viscosity and reduced cecal fermentation. The observed effects were due to the high amount of neutral-detergent fiber (NDF) in the diets resulting in decreased nutrient and energy digestibility, reduction in relative hindgut fermentation, impairment of pig performance and dilution of dietary energy, as explained by Petry et al (2021).…”

Stimbiotics Supplementation Promotes Growth Performance by Improving Plasma Immunoglobulin and IGF-1 Levels and Regulating Gut Microbiota Composition in Weaned Piglets

“…However, NSPs are also an important nutrient for monogastric animals, especially for gut bacteria fermentation, which depends on the NSP components. It has been reported that exogenous addition of non-starch polysaccharide degrading enzymes (especially xylanase, XYL) can degrade insoluble and large soluble polysaccharides in the diet to produce oligosaccharides [ 9 , 10 ], oligosaccharides can be well fermented by intestinal bacteria. In addition, xylo-oligosaccarides (XOS) with a degree of polymerization in the range of 2–6, were identified to improve intestinal health and stimulate immune responses in animals, acting in a prebiotic manner [ 11 ].…”