Chicken growth has been accelerated during recent
decades, and leg problems in the barn, as well
as bone fractures during processing of the carcass,
are considered major threats in the poultry industry
(Chen and Moran, 1995). Selected fast-growing
strains have shown lower bone-ash content than slowgrowing
strains (Williams et al., 2000), which may
suggest that diets should be higher in Ca and P
than current recommendations [10 g Ca/kg and 4.5 g
nonphytate P (NPP)/kg at ages 1 to 21 d (NRC,
1994)] in order to reach skeletal integrity for modern
strains.