Horses are fundamentally non-ruminant herbivores, which means that they are suited to eating high fibre diets due to continual microbial fermentation within the caecum and colon. The horse evolved to eat mainly grass with some other herbage and when available 'wild' cereals and other starch containing feedstuffs. The horse naturally is a social animal, living in groups and spending the majority of its time foraging in a diverse and seasonally variable environment.
Domestication has meant that horses now tend to be kept in stables and/or on managed pastures and we are responsible for their feeding. Optimal feeding of horses uses both art and science. The science provides the information about the digestive and metabolic processes, the nutrient requirements and the principles behind feeding practices. The art is the ability to convert this theory into practice for the individual horse, its needs, likes and dislikes.
Fortunately many horses will flourish because of, or despite, the diets we feed them. Although good nutrition cannot improve the basic ability of a horse, poor nutrition may limit performance. Understanding the digestive processes of the horse helps us to appreciate how we should feed, to maintain health and performance and minimise gastrointestinal disturbances caused by inappropriate feeding regimens.