Purina Impact 12% All Stages Pelleted Horse Feed makes feeding all of your horses easier. made with top-notch nutrients and a flexible recipe that works for horses of all sizes and energy levels. Nobody is more knowledgeable about horse nutrition than Purina, thanks to their extensive research and experience spanning over a century, as well as their committed staff of Ph.D. equine nutritionists and equine veterinarians. With only premium ingredients that have been shown through years of feedings to improve overall horse health and performance, Purina Impact is designed to give premium nutrition.