Exogenous enzyme supplements are used widely in poultry diets in an attempt to improve nutrient utilisation, the health and welfare of the birds, product quality and to reduce pollution as well as to increase the choice and content of ingredients which are acceptable for inclusion in diets. Considerable advances have been made during the last decade in the manufacture, activity, quality, thermostability and specificity of supplemental enzymes for use in poultry diets. This paper attempts to give an overview of the advantages and disadvantages, as well as the interesting difficulties and variable effects observed when enzymes are added to poultry diets.
