High levels of production and efficient feed conversion are characteristic of the
modern poultry industry. Attaining this status has, in part, been due to a
sophisticated knowledge of the nutrient requirements of commercial stocks and the
nutrient content of feed ingredients. Coupled with this knowledge is the use of
computer technology to formulate diets which provide the nutrients required for
high levels of production at the least cost. Major improvements in nutrition in the
future are unlikely to come from the discovery of new nutrients or refining nutrient
requirements, instead improvements in the efficiency of production must rely on
obtaining maximum nutrient utilization from feedstuffs, which would also enable
the use of a wide range of ingredients currently considered inferior. It is recognized
that a proportion of the nutrient content of feeds is not digested and absorbed by
poultry. Some feedstuffs are overlooked or under-utilized because of poor nutrient
availability, high levels of non-starch polysaccharides and/or the presence of antinutritional
fractions. Exogenous enzymes, added to the feed or used during
feedstuff processing, have the potential to improve feed efficiency, reduce
pollution associated with poultry manure and increase the use of low cost feed
ingredients.
Although the field of enzyme technology is still in its infancy, there is evidence
to suggest that enzymes have a useful future in poultry feeding. The objective of
this chapter is to provide information on the effect of dietary enzymes on the
nutritional value of the common cereal grains, wheat, triticale, rye, barley and
oats. Topics to be considered include the substrates for enzyme action, effects of
substrates on poultry performance, source and activity of enzymes, in vitro
methods of predicting enzyme response and factors affecting enzyme response.