The Possibility for reducing Water Pollution resulting from Concentrated Animal Feeding operations and the impact of Phytase

Poultry, swine, and pre-ruminant calves have limited ability to digest phytate, the storage form of about 80% of total phosphorus in plant-based feedstuffs. The resulting excess phosphorus excretion in manure, upon application to farmlands, can leach into and pollute water bodies. Even so, a 1989 report to EPA on the costeffectiveness of Best Management Practices to reduce non-point phosphorus pollution of water bodies indicates that animal exclusion is not necessarily the most cost effective among the available options. Since 1989, however, the use of phytase in feeds has gained increasing popularity in poultry and swine industries. Phytase, an enzyme that is added to the feed to break down phytate, can reduce phosphorus excretion by up to 60%; decreases in nitrogen excretion from phytase supplementation of feeds have also been reported.