Effects of microbial phytase supplementation of a barley-soybean meal diet on the performance and bone mineralization of growing-finishing pigs

The study evaluated the effect of a phytase supplement, produced by Aspergillus niger, on the performance of 72 growing-finishing pigs (28-101 kg). Chemical and physical parameters of the tibia and fibula bones were measured. The control diet (diet 1) was formulated to be adequate for pigs with respect to all nutrients, and diets 2 and 3 with respect to all other nutrients except total phosphorus (P). The P source of the control diet was dicalciumphosphate (dihydrate), while no inorganic P was added to diets 2 and 3. Diet 3 was supplemented with phytase, 720 U/kg feed. The average daily gain (ADG) and the feed conversion ratio (FCR) of the control pigs were significantly better than those of the groups without inorganic P. Phytase improved the ADG (