Milk co-products are used in pig diets to provide lactose and, in some cases, high quality protein. In addition, milk co-products also provide calcium to the diets. However, this calcium can potentially bind to the phytate contained in the plant ingredients in the diets, which would reduce its digestibility.
The inclusion of microbial phytase in diets fed to pigs frees calcium that is bound to phytate. An experiment was conducted to determine if the apparent total tract digestibility (ATTD) and the standardized (STTD) total tract digestibility of calcium in milk co-products is improved when microbial phytase is added to the diets.