Fibre content of cereal grains can be quite variable and are related to changes in digestible energy (DE) content. Because fibre content and DE are related, DE can be predicted using fibre analyses. Pigs, especially young pigs, have a limited capacity to digest fibre as they do not produce the proper enzymes. Therefore, pigs are entirely dependant on the large intestine for fibre digestion by intestinal bacteria. This process produces volatile fatty acids which are available for use as energy sources. This system is not nearly as efficient a use of energy compared to glucose absorption. Improvement of efficiency of overall energy utilization can be achieved through dietary enzyme supplementation. The supplemental enzymes are able to digest part of the fibre complex and may improve digestion of energy and amino acids for diets high in wheat or barley. A lack of response to these enzymes may be due to lower than average dietary fibre content. This study used two qualities of barely, low and high. Supplemental enzymes improved the low quality barley more than the high quality barley. However, the amount of energy digested by the small intestine was improved for both samples. It is essential that fibre analyses be apart of grain sample evaluation as the effect of enzyme supplementation depends on the sample. Overall, enzyme supplementation can be used to reduce the negative effects of fibre on nutrient digestibility.