The horse is a non ruminant herbivore; in other words it exists on a diet of plants without the benefit of the complex stomachs found in ruminants such as cattle, sheep and goats. A lot of the information about horses is taken from feeding pigs. They have a simple non ruminant gut and are thus considered to be more like horses. Obviously since pigs are not trained to racing fitness, plus the fact that horses are too large and expensive for much field trial work to be done on them, means that many aspects of equine nutrition are a long way behind that of other animals and there is still a lot of mystique attached to good feeding.