Interactions between dietary phosphorus level, phytase supplementation and pelleting on performance and bone parameters of broilers fed high levels of rice bran

Maize and soyabean-based diets containing 100 g rice bran kg−1, which is high in phytate, were used to determine stability of a phytase preparation to commercial-type pelleting (85 °C) and the effect of dietary dicalcium phosphate on losses in enzyme activity due to pelleting. The basal diet was phosphorus deficient (1.6 g available phosphorus kg−1) and the addition of 280 FTU of phytase kg−1 improved BWG, FI, and FC. The pelleting process did not affect phytase activity negatively. Additional dicalcium phosphate did not modulate the effect of pelleting on phytase activity. The increment of dietary phosphorus by a standard source (NaHPO4H2O) was effective in increasing bone ash and breaking strength, but was not related to bone elasticity.