Direct vs. difference method to determine amino acid digestibility in ingredients fed to pigs

It may not be practical to use the direct method to determine the digestibility of amino acids in cereal grains or in high-fiber or low-palatability ingredients, because the test ingredient cannot be fed as the sole source of amino acids for a long enough period of time to determine the digestibility. In these cases, the difference method can be used. In this presentation, Dr. Maryane Oliveira, a postdoctoral research associate in the Stein Monogastric Nutrition Lab, presents the results of an experiment that was designed to test the hypothesis that the direct method and the difference method yield the same values for SID of amino acids in cereal grains and fiber-rich ingredients. Adapted from a presentation at the 2019 ASAS Midwestern Section meeting, Omaha, NE, March 11-13.