This study was conducted to evaluate the efficacy of a novel Buttiauxella phytase to pigs fed P-deficient, corn-soybean meal diets. One hundred and twenty crossbred piglets (9.53 ± 0.84 kg) were allocated to one of five treatments which consisted of four low P diets (0.61 % Ca and 0.46 % total P) supplemented with 0, 500, 1,000, or 20,000 FTU/kg phytase as well as a positive control diet (0.77 % Ca and 0.62 % total P). Each treatment had six replicated pens with four pigs per pen. Pigs were fed the experimental diets for 28 days. Phytase supplementation linearly improved (P < 0.05) average daily gain (ADG), feed conversion ratio (FCR), and apparent total tract digestibility (ATTD) of dry matter, gross energy, crude protein, Ca, and P in weaned pigs. Super high dosing with phytase (20,000 FTU/kg) further increased (P < 0.05) ADG compared with 500 FTU/kg phytase inclusion group, as well as ATTD of Ca and P. Metacarpal bone characteristics and several trace mineral concentration in bone, plasma, or organ tissues were linearly (P < 0.05) improved at increasing dose of phytase. Super high dosing with phytase (20,000 FTU/kg) supplementation improved (P < 0.05) Mn and Zn concentration in bone compared to normal dose of phytase supplementation (500 or 1,000 FTU/kg). In conclusion, supplementation of 500 FTU of Buttiauxella phytase/kg and above effectively hydrolyzed phytate in a low-P corn-soybean diet for pigs. In addition, a super high dosing with phytase (20,000 FTU/kg) improved macro- or micro mineral availability and growth performance.
Keywords: Bone characteristics; Buttiauxella phytase; Digestibility; Growth performance; Minerals; Pigs.