We evaluated efficacy of xylanase (X) on apparent ileal (AID) and total tract digestibility (ATTD) of energy, nutrients, and fiber in growing pigs fed corn- or wheat-based diets. The corn diets had 40% corn DDGS and wheat diets had 25% wheat middlings. Diets were fed without or with 2,000 X U/kg to individually housed ileal cannulated growing barrows (n=6). All diets contained phytase (500 FTU/kg) and celite (0.3%) as indigestible markers. Pigs were fed a daily amount of feed equivalent to 3% of BW, equally divided into 2 feedings at 0800 and 1600 h. The experiment lasted for 9 d: 5 d for adaptation, d 6 and 7 for fecal samples, and d 8 and 9 for ileal digesta sample collection. Interaction between diet and X was only observed for the neutral detergent fiber (NDF) digestibility such that X improved ATTD (P = 0.04) of NDF in corn diets only. Xylanase effects were observed for digestible energy (DE) such that pigs fed X had higher DE (3,732 vs. 3,644 kcal/kg, P = 0.04) that corresponded to higher AID (P < 0.05) of nitrogen and fat than non-X-fed pigs. Generally, wheat diets had higher (P < 0.05) AID of DM, nitrogen, and NDF than corn diets. Although diet type impacted digestibility, xylanase improved DE independent of diet types as a result of improved nutrients digestion in the ileum.
- Nutrients digestibility