Effects of Adding Multi-Enzymes to Growing Pig Diets Containing Wheat and Corn Fiber Sources on Growth Performance, Nutrient Digestibility, and Digesta Viscosity

This study evaluated the effects of multi-enzyme supplementation on growth performance, digestibility of GE and nutrients, and characteristics of intestinal content in growing pigs fed diets containing corn distillers dried grains with solubles (DDGS) or wheat middlings (WM). Fifty-four individually housed pigs (25.33 ± 0.41 kg) were blocked by BW and sex and assigned randomly to 1 of 6 dietary treatments (n = 9) in a 2 × 3 factorial design with 2 levels of carbohydrases (0 vs. 100 mg/kg;1,500 U/g xylanase, 1,100 U/g beta-glucanase, 110 U/g mannanase, 35 U/g galactosidase) and 3 basal diets (corn-soybean control, CSB; CSB + 40% DDGS; or CSB + 30% WM). Titanium dioxide (0.5%) and phytase (1,000 FTU/kg) were added to all diets. Pig BW and feed intake were determined weekly. On d 28, pigs were euthanized and intestinal content was collected to determine digestibility, pH, and viscosity. Pigs fed diets that contained DDGS or WM had less (P < 0.05) ADG (755 and 751 g/d, respectively) and ADFI (1,474 and 1,435 g/d, respectively) compared with pigs fed CSB diets (803 g/d and 1,582 g/d, respectively). Carbohydrase supplementation tended to improve (P < 0.10) ADG (787 vs. 752 g/d) and ADFI (1,529 vs. 1,465 g/d) regardless of basal diets. Pigs fed CSB diets had greater (P < 0.05) AID and ATTD of DM, OM, and GE compared with pigs fed DDGS and WM diets. Carbohydrase supplementation improved (P < 0.05) AID of DM, GE and CP and ATTD of ash in WM diets, but not in DDGS or CSB diets. The liquid to solid ratio (centrifuged at 3500×g for 10 min) were negatively associated with (P < 0.01) peak shear stress (maximum value measured at 0.1 s^-1 shear rate for 2 min) and consistency constant (K) of jejunum, ileum, and cecum digesta. The viscosity of digesta supernatant in jejunum and ileum were decreased (P < 0.05) by DDGS inclusion compared to the CSB diets. The addition of carbohydrase increased (P < 0.05) viscosity of cecal digesta supernatant only in CSB diet, but decreased peak shear stress (14.2 vs. 28.2 Pa, P < 0.05) and K (16.6 vs. 20.9 Pa, P < 0.05) in jejunum digesta regardless of basal diets. In conclusion, adding DDGS and WM to CSB diets decreased GE and nutrient digestibility and impaired growth performance. Carbohydrase supplementation improved digesta rheology characteristics and tended to improve growth performance of growing pigs.