Wu, Y. B., V. Ravidran, D. G. Thomas, M. J. Birtles and W. H. Hendriks 2004. Influence of phytase and xylanase, individually or in combination, on performance, apparent metabolisable energy, digestive tract measurements and gut morphology in broiler fed wheat-based diets containing adequate level of phosphorus. Br. Poult. Sci. 45:76-84.