Phosphorus Availability

A German research study compared the effects of phytase additions to a corn soybean meal diet for ducks. The control diet contained 3.2 g/kg phosphorus and 5.5 g/kg calcium. Phytase from Aspergillus niger was supplemented at levels of 0, 150, 300, 450, 600 and 1500 U/kg of diet. The results of the five-day digestion study when the ducks were fifteen days old indicted that phytase improved phosphorus utilization. The research group calculated that including 100 U/kg phytase increased the amount of phosphorus released by 0.12g at low levels of supplementation and 0.06g at the highest level of supplementation. They suggested that replacement values for inorganic phosphorus could be calculated when the ability of phosphorus from different ingredients is considered. They found that the utilization of calcium was also significantly improved by phytase supplementation.

Wendt, P., R. Timmier and M. Rodenhutscord. 2003. Dose-response relationship between a supplemented microbial phytase and utilization of phosphorus from a maize/soybean meal-based diet in Peking ducks. Archiv Fur Geflugelkunde 67(5):193-197.