Environmental regulations have set strict limits on the
level of P to be discharged in swine effluents (Vats et al., 2005;
Selle and Ravindran, 2008). In addition, the inclusion of
excessive levels of inorganic P results in higher feed costs.
Because available P reserves are finite, even higher costs are
expected in the future (Cordell et al., 2009). Hence, there is a
need to develop nutritional strategies to use the concept of P
bioavailability, thus, we can provide only adequate P to satisfy
the animal's needs. Supplementing phytase is becoming
increasingly common as a method to improve the availability
of P in plant ingredients containing high levels of phytate P
(Selle and Ravindran, 2008).
Previous research has shown that substantial bone
formation occurs during the first 12 weeks of life, concurrent
with the period of extensive muscle formation and weight