WASHINGTON, June 28 (TNSjou) -- The U.S. Department of Agriculture's Agricultural Research Service issued the following news: Brewer's yeast used to make beer is typically discarded once it's no longer needed. Sometimes, though, the leftover yeast is mixed into livestock feed as a source of protein and vitamins. Now, there may be even more reason to continue this practice, according to findings by a team of scientists with the Agricultural Research Service (ARS), Warren Wilson College, (WWC) an  more