The authors doesn’t explain the difference in costs of the conventional and lower crude protein (CP) diets. For UK conditions, the results obtained in this publication show that the use of CP diets are economically not interesting to producers unless they produce manure in excess to dispose properly on the land that is available for them. Economical incentive would be necessary to integrate such practice. Further data are needed to evaluate pig performance and to assess the true economical situation for the U.K.