This paper discusses the use of alternative feed ingredients in poultry nutrition. The importance and limitations, particularly the presence of anti-nutritive factors, of such ingredients are highlighted. The results of a series of studies recently completed or ongoing at the University of New England, Australia, suggest that the nutritive value of such ingredients can be improved through supplementation with microbial enzymes. As it is likely that such ingredients will be increasingly used with enzyme supplementation and other treatments, it is important to identify the anti-nutritive factors in alternative ingredients and develop the best enzyme combinations for diets that contain these ingredients