Su A Lee, a Ph. D. student in the Stein Monogastric Nutrition Lab, presents the results of her experiment to determine if any differences exist between gestating sows and growing pigs for standardized total tract digestibility and retention of calcium and phosphorus and for the responses to dietary phytate. Adapted from a presentation at the 2018 ASAS Midwestern Section meeting, Omaha, NE, March 12-14.