All rabbits need high fiber to keep their digestive systems working properly, plus basic vitamins and minerals to maximize their health. Essentials - Adult Rabbit Food combines needed fiber with stabilized nutrients to assure a well-balanced diet when served with Oxbow loose grass hays. Oxbow Animal Health’s founder and owner John Miller created the industry’s first timothy hay-based food for rabbits and other small herbivores, the basis of Essentials - Adult Rabbit Food.