Impact of xylanase and an enzyme blend on gut barrier function and growth performance in nursery pigs

The objective of this experiment was to evaluate the effects of dietary xylanase and an enzyme blend (EB: cellulase, ß-glucanase, and xylanase) on nutrient digestibility, intestinal barrier function and integrity, and growth performance in weaned piglets fed a low energy diet (NE: 2.43 and 2.37 Mcal/kg for wk 1-2 and 3-4, respectively). A total of 460 pigs (6.43 ± 0.06 kg BW; F52 Gentaporc × 6.0 Gentaporc) were randomly blocked by weight and assigned to 4 treatments, in a 2 × 2 factorial arrangement. There were 12 blocks and 48 pens with 9 or 10 pigs/pen. The diets were based on corn, soybean meal, corn DDGS, and wheat middlings (5 and 10% each fiber ingredient for wk 1-2 and 3-4, respectively) with or without enzyme supplementation (Huvepharma Inc., St. Louis, MO), with 0.40% titanium dioxide as an indigestible marker. Body weight and feed intake were recorded weekly. Performance data were analyzed as repeated measurements using the PROC MIXED procedure of SAS (9.4) with pen as the experimental unit. Xylanase (0 or 0.01%), EB (0 or 0.01%), week and their interactions were considered fixed effects. The EB addition (12.45 vs. 12.08 kg; P = 0.044), but not xylanase (12.27 vs. 12.26 kg; P > 0.05), increased body weight. Neither enzyme treatment had an impact on ADFI or G:F ratio (P > 0.05). The EB treatment improved ADG (482 vs. 466 g; P = 0.024) from wk 1-4. There was no interaction between the two enzyme treatments for ATTD of DM, GE, and CP (P > 0.05). Xylanase supplementation tended to reduce ATTD of EE (61.05 vs. 62.82%; P = 0.073) and reduced the ATTD of NDF (46.10 vs. 48.95%), ADF (27.30 vs. 31.71%), and hemicellulose (52.77 vs. 55.23%; P < 0.01). Supplementation of EB improved ATTD of ADF by 22% (32.45 vs. 26.57%; P = 0.001). There was an interaction between xylanase and EB in ileal secretory IgA (SIgA) concentrations (P = 0.027), as EB addition alone decreased SIgA compared to control (1.72 vs. 2.72 mg/kg protein), but not in combination with xylanase. The EB supplementation also reduced urinary lactulose: mannitol ratio (0.51 vs. 0.68; P = 0.012), indicating improved small intestinal barrier integrity. In conclusion, EB but not xylanase improved growth rate in nursery pigs fed a low energy diet, which may be due to the improved intestinal barrier function and integrity.