Determining the Phosphorus Release of GraINzyme Phytase in Nursery Pigs

A total of 360 pigs (200 × 400, DNA; initially 21.9 ± 0.42 lb) were used in a 21-d growth trial to determine the available P (aP) release curve for GraINzyme Phytase (Agrivida Inc., Woburn, MA). Pigs weaned at approximately 21 d age, randomly allotted pens based on initial BW and fed common starter diets. From 18 post-weaning, all diet containing 0.11% aP. On considered 0 study, blocked by 1 8 dietary treatments with 5 per pen 9 treatment. Dietary formulated include increasing aP derived from either an inorganic source (0.11, 0.19, or 0.27% monocalcium P) levels phytase (150, 250, 500, 1,000, 1,500 FTU/kg). Diets corn-soybean meal-based contained 1.24% standardized ileal digestible (SID) Lys. trial, pig (weighing closest mean BW) was humanely euthanized right fibula collected bone ash using non-defatted processing method. Overall (d 21), had improved (linear, < 0.002) ADG, ADFI, F/G. Bone weight percentage increased 0.001) added phytase. Based these results, equations developed G:F, weight, are: = (0.255 FTU) ÷ (1299.969 + FTU); (0.233 (1236.428 (45999.949 (462529200 (0.272 (2576.581 FTU), respectively.