Exogenous enzymes have been used in pig feed to reduce the antinutritional factors in the cereal components of the diets and, as a consequence, improve energy and protein digestibility. The predominant fibre components in barley are soluble β-glucans and insoluble arabinoxylans, both of which are known to have anti-nutritional effects in the pig but through different mechanisms. In wheat both soluble and insoluble arabinoxylans are relevant, for the same reasons (Partridge, 2001). Consequently a product with a combination of β-glucanase and xylanase may be necessary to elicit a performance improvement in pigs fed diets containing both barley and wheat. Furthermore, much work in grower/finisher pigs has been undertaken at single inclusion levels of enzyme product. The object of the current study was to compare the response of growing and finishing pigs fed diets containing barley and wheat supplemented with a β-glucanase and xylanase product included at different levels in the diet.