Comparative Effects of Phytase Derived from Escherichia Coli and Aspergillus Niger in Sixty Eight-Week-Old Laying Hens Fed Corn-Soy Diet (Report‪)‬

INTRODUCTION Phosphorus has been identified as an essential mineral in the formation of eggshells and the metabolism of laying hens (Sohail and Roland, 2002). Phytate is the primary storage form of phosphorus found in plant feed ingredients; however, phytate P is poorly utilized due to the limited inherent phytase activity in the gastrointestinal tract of non- ruminants (Adeola et al., 2004). Previous studies have shown that supplemental phytase exerts beneficial effects in poultry (Rutherfurd et al., 2004; Francesch et al., 2005), cheaper and more effective sources of phytase would hasten the use of phytase in the poultry industry.