Understanding efficacy of xylanases from different microbial origin could assist nutritionists to identify appropriateenzyme activities that optimize hydrolysis for a particular cereal co-product during feed formulation. It was hypothesizedthat xylanases of different microbial origin will differentially influence growth performance and nutrient digestibility ingrowing pigs fed different diet types with added phytase. Thus, the objective of the present study was to evaluate the effectof five xylanases from different microbial sources on growth performance, coefficient apparent ileal digestibility (CAID) andapparent total tract digestibility (CATTD) in growing pigs fed wheat-wheat bran-based or corn-corn distillers dried grainswith soluble (DDGS)-based diets with added phytase.