Nelson, Megan E., Su A Lee, Carrie L. Walk, April Zhang, Heng-Xiao Zhai, Hans H. Stein. 2025. Digestibility of calcium in calcium carbonate varies among origins, but is increased by microbial phytase regardless of origin. Animal Feed Science and Technology 320 (2025) 116230. doi.org/10.1016/j.anifeedsci.2025.116230 Link to full text.