Exogenous carbohydrases can be used in diets for pigs to increase digestibility of dietary fiber and energy in cereal grains and cereal co-products. The three main fibers in cereal grains and cereal co-products are arabinoxylans, cellulose, and mixed-linked beta glucans. The fermentability is different among these three types of fiber. Energy digestibility is often improved if xylanase is added to wheat-based diets, whereas positive responses to xylanase in corn-based diets have been difficult to demonstrate, indicating that fermentation of dietary fiber differs among ingredients. However, there is less information about effects of carbohydrases on digestibility of fiber and energy in sorghum-based diets. Therefore, an experiment was conducted to test the hypothesis that xylanase and cellulase improve the digestibility of energy and total dietary fiber in diets based on corn or sorghum with addition of high fiber co-products.