The addition of phytase at 1500 FTU/kg to low-P and adequate-P diets was examined for changes in bone and plasma minerals, as well as nutrient digestibility. There was no change in growth data due to the addition of phytase. Additionally, phytase did not affect bone calcium in either the splint or third metacarpal. Phosphorous in the splint bone was decreased by the addition of phytase (P< .05). The mineral levels between the two bones types were different (P<.0001), with the third metacarpal containing nearly double the percentage of calcium and phosphorous. Plasma minerals were not affected by phytase or the different diets. In addition, there was no effect on energy or calcium digestibility. Phosphorous digestibility was affected at day 120 by the diets. The low-P diet had higher digestibility percentages. Phosphorous digestibility was also improved by the addition of phytase to the adequate-P diet.