Abstract: The following experiment was conducted to compare wheat and corn as energy sources and to determine if the performance of broiler chicks fed wheat or corn-based diets can be improved by supplementation with xylanase, protease or the two enzymes in combination. A total of 480, one-day old, male broiler chicks were randomly assigned to one of eight dietary treatments. Four of the diets were based on corn and soybean meal and four of the diets were based on wheat and soybean meal. The diets were either fed unsupplemented or supplemented with a xylanase enzyme (200 g/tonne), a protease enzyme (200 g/tonne) or the two enzymes in combination (125 g/tonne xylanase and 75 g/tonne protease). The chicks were housed in raised-floor battery cages with mesh grate floors overtop of fecal collection trays. There were five birds per pen and 12 replicate pens per treatment. Chromic oxide (0.35%) was added to all diets as a digestibility marker and was fed throughout the 21-day experimental period. During the final three days of the experiment, feces were collected from each pen. There were no significant differences in weight gain (P=0.17) or feed intake (P=0.78) between broilers fed diets based on wheat or corn. Feed conversion was modestly improved for birds fed wheat compared with corn-based diets (P=0.09). Enzyme treatment had no significant effects on body weight gain (P=0.26). Feed intake was lower (P=0.06) for birds fed the enzymes in combination compared with the other three treatments. Feed conversion was improved (P=0.06) for birds fed protease either alone or in combination with xylanase. Birds fed wheat-based diets had significantly higher digestibility coefficients for dry matter (P=0.03) and energy (P=0.05) than birds fed corn-based diets. Nitrogen retention was unaffected by choice of cereal grain (P=0.26). There were no significant effects on dry matter digestibility (P=0.82), energy digestibility (P=0.61) or nitrogen retention (P=0.91) due to enzyme supplementation. In conclusion, the results of this experiment indicate that both corn and wheat can be successfully utilized in broiler diets. Supplementation with xylanase or protease produced modest improvements in performance with feed conversion being enhanced for the wheat-based diets. When the enzymes were fed in combination, there was some synergy as feed conversion was significantly enhanced for the wheat-based diets.