STABLE MIXElk Grove Milling's Stable Mix is a complete pellet, meaning that it contains enough fiber (max 32%) when fed as directed it can safely replace the other sources of forage in your horses ration. Stable Mix also contains almond hulls, a form of super fiber that provides more calories to your horse than hay, but in a safer form than grains. Almond hulls, like hay, are digested in your horses hindgut.