In the experiment, six pigs fitted with a T-cannula at the distal ileum were fed six diets in a 6 × 6 Latin square design. Treatments were corn-soybean meal diet (CS), diet containing wheat by-products (WBP), and diet containing corn distillers dried grains with solubles and canola meal (DDCM) without or with xylanase (X) supplementation (CS-X, WBP-X, and DDCM-X). The WBP and DDCM diets had higher apparent ileal digestibility (AID) of lipids and acid detergent fiber (ADF) (P < 0.05) than CS diets. A xylanase × diet interaction was observed for the AID of neutral detergent fiber (NDF) (P < 0.05) showing larger impact of xylanase in WBP than in the other diets. Using similar dietary treatments except for CS-X, growth and body composition of the sixty males (83.0 kg) at the end of the 28-day growing phase showed that pig fed the CS diet had greater average daily feed intake (ADFI) (P = 0.004) and average daily gain (ADG) (P = 0.014) for period 0–14 d but not from 15–28 d. Overall performance (0–28 d) showed higher ADFI (9.5%; P = 0.015) in CS but no difference was observed for ADG and gain to feed ratio (G:F). These results showed that diets containing a high proportion of by-products can give equivalent performance to a CS diet and that adding xylanase for this short period had limited effects.