In 2 experiments, dose response efficacy of a xylanase and β-glucanase blend (XB) on growth performance and ileal nutrient digestibility was investigated in nursery pigs fed pelleted wheat (Triticum aestivum)- and barley (Hordeum vulgare)-based diets. A basal diet (meeting NRC [1998] specifications for 6 to 30 kg BW, except for 5% lower DE) was supplemented with XB to give 4 diets (0, 50, 100, and 200 g/t). The xylanase and β-glucanase blend was formulated to contain guaranteed activity of 12,200 and 1520 units/g, respectively. In Exp.1, 192 nursery pigs (initial BW of 6.5 kg) were randomly assigned to 4 diets to give 12 pens (4 pigs/pen) per diet to study growth performance for 42 d. In Exp. 2, apparent ileal digestibility (AID) of energy and AA was evaluated in 4 individually housed ileal-cannulated barrows (21 kg BW) according to a 4 × 4 Latin square design. In Exp. 1, XB linearly and quadratically increased (P < 0.05) G:F compared with control. Adding 200 g/t increased overall G:F by 20% compared with control. In Exp. 2, XB linearly increased (P < 0.05) AID of DM, CP, energy, and AA. In conclusion, supplemental xylanase and β-glucanase in nursery pelleted wheat- and barley-based diets deficient in DE increased energy and nutrient use, resulting in better G:F. In conclusion, an enzyme product containing a combination of xylanase and β-glucanase allowed young pigs to derive more nutrients and energy in a wheat- and barley-based diet deficient in energy.