Dose-responsive efficacy of heat-stable xylanase in weaned pigs fed corn–soybean diets

Context Xylanase hydrolyses xylan into simple sugars, aiding the digestion of fibrous diets and enhancing nutrient absorption in weaned pigs. Aims This experiment measured the effect of dietary xylanase on the performance of weanling pigs. Methods A total of 320 weaned Landrace × Yorkshire × Duroc pigs (5.95 ± 0.6 kg) were randomly assigned to four treatments: A corn–soybean meal-based control (CON), CON + 0.01% (DG1), 0.02% (DG2), or 0.03% xylanase (DG3) over 42 days, in two phases (0–21 days and 22–42 days). Key results Final body weight increased (P < 0.001) in all xylanase treatments, with a quadratic effect (P = 0.049). In phase 1, ADG increased (P < 0.001) in DG2 and DG3 with a linear effect (P = 0.015). ADFI had linear (P < 0.001) and quadratic (P = 0.042) effects in DG3. Digestibility of DM, xylan, and non-starch polysaccharides (NSP) increased (P = 0.027, P < 0.001, P = 0.001) as xylanase increased, with a linear effect in DM, gross energy, xylan and NSP (P = 0.017, P = 0.036, P < 0.001, P = 0.003). In phase 2, ADG and ADFI increased (P = 0.012, P = 0.034) in DG2 and DG3, with linear effects in ADG, ADFI, and feed efficiency (P = 0.047, P < 0.001, P < 0.044). Digestibility of DM, gross energy, xylan, and NSP degradability increased (P = 0.012, P = 0.048, P < 0.001, P = 0.034) with linear effects (P = 0.012, P = 0.031, P < 0.001, P = 0.016) in xylanase treatments. Overall, ADG and feed efficiency increased (P < 0.001, P = 0.018) in xylanase treatments, with a linear effect (P < 0.001, P = 0.030). The ADFI showed linear and quadratic effect (P < 0.001, P = 0.024) in the xylanase treatments. Intestinal viscosity decreased (P < 0.001) in the xylanase treatments over CON, with linear and quadratic effects (P < 0.001). Ileal Lactobacillus showed linear effect (P = 0.041) in DG2 and DG3. Ileal and faecal E. coli decreased (P = 0.027, P = 0.038) as xylanase increased, with a linear effect (P = 0.010, P = 0.046). Duodenal villus height (VH) increased (P < 0.001) in the xylanase treatments, with a linear effect (P = 0.001). Jejunal VH increased (P < 0.001) in DG3 over CON, with a linear effect (P = 0.028). In the ileum, VH and VH/crypt depth ratio increased (P < 0.001) as xylanase increased, with linear effects (P = 0.043, P = 0.017). Conclusion Trichoderma citrinoviride xylanase demonstrates dose-responsive potential, enhancing the performance of weanling pigs as supplementation levels increase from 0.01% to 0.03%. Implications The incorporation of xylanase into weaned pigs’ diets enhances nutrient digestibility, improving farm efficiency and sustainability.