LAUSR

This study was designed to determine the effect of dietary supplementation of xylanase on growth performance, nutrient digestibility, organ weight, digesta pH, and concentration of short-chain fatty acids (SCFA) of weaned pigs fed wheat-canola meal (CM) diets over a 35-d period. A total of 144 piglets (72 barrows and 72 gilts) weaned at 18 ± 2d of age, with initial body weight (BW) of 6.2 ± 0.7 kg, received one of 8 dietary treatments based on randomized complete block design. Body-weight and feed intake were recorded weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Treatments consisted of a control wheat-SBM-based diet and wheat-regular (RCM), dehulled (DCM), or coarse (CCM) CM without and with 16,000 BXU/kg xylanase (Econase XT). All diets contained 500 FTU/kg of phytase (Quantum Blue 5G), and titanium-dioxide (0.3%). Apparent total tract digestibility (ATTD) of neutral detergent fiber (NDF), crude protein (CP), phosphorous (P), calcium (Ca) and dry matter (DM), and diet were determined. On d 35, one pig per pen was euthanized to evaluate the main factors of protein, xylanase supplementation, and sex on organ weight, ileal and colon digesta pH, and colon digesta concentrations of SCFA. The main factors did not affect growth performance. Xylanase supplementation improved nutrient digestibilities in all diets and increased ileal and colonic digesta pH without affecting the growth performance of weaned pigs fed wheat and canola meal-based diets. A protein-xylanase effect (P < 0.05) resulted in increasing the ATTD of NDF from 28 to 32% and from 29 to 37% for RCM and DCM, respectively. The ATTD of CP was greater (P < 0.05) with xylanase supplementation (75 vs. 70%). Xylanase supplementation increased ATTD of P and Ca. A three-way interaction (P < 0.05) for protein-xylanase-gender for colon pH, acetic, and propionic acid in the colon digesta of pigs indicated that in addition to the protein source, piglet sex could have influenced how xylanase works. Xylanase supplementation increased (P < 0.05) the weight of the liver and spleen and tended (P < 0.10) to increase the size of the kidney. In conclusion, dietary supplementation of xylanase increased nutrient digestibility and digesta pH but did not influence the growth performance of weaned pigs fed wheat and canola meal-based diets over a 35-d period.