Effect of phytase on production parameters and nutrient availability in broilers and laying hens: A review

An increase in poultry production in recent years has led to greater use of poultry manure as fertilizer, which has, in turn, increased the amount of phosphorus runoff from fields fertilized with poultry manure. Phosphorus excretion in poultry manure can lead to water pollution when the manure is used as fertilizer. The need to maintain sufficient dietary phosphorus levels while reducing phosphorus excretion in poultry manure has led to an increase in the application of phytase to poultry feed in recent years. The use of phytase reduces phosphorus excretion in poultry manure by allowing the birds to utilize more of the phytate phosphorus. Phytate phosphorus has the ability to complex with cations such as calcium, magnesium, zinc, copper, and nitrogen and certain gastrointestinal proteases, thus reducing the availability of these cations and of amino acids. The use of phytase may free these cations and proteases bound in phytate phosphorus complexes and improve many production parameters and body structure characteristics in broilers and laying hens, such as body weight, bone ash content, feed consumption, egg weight, and eggshell quality. An excellent review article on phytase and its various effects on poultry was written by Sebastian et al. [1]. Herein, we examine more recent findings on the effects of phytase on body structure, production parameters, and nutrient digestibility and utilization in broilers and laying hens