Exogenous enzyme supplements are used widely in poultry diets in an attempt
to improve nutrient utilisation, the health and welfare of the birds, prod
uct quality and to reduce pollution as well as to increase the choice and c
ontent of ingredients which are acceptable for inclusion in diets. Consider
able advances have been made during the last decade in the manufacture, act
ivity, quality, thermostability and specificity of supplemental enzymes for
use in poultry diets. This paper attempts to give an overview of the advan
tages and disadvantages, as well as the interesting difficulties and variab
le effects observed when enzymes are added to poultry diets.