Nutritional Overview

Horses and ponies are herbivores and are further classified as “hindgut fermenters”. This means that bacteria and other micro-organisms in the large intestine break down components of the food, e.g. fibre, that can not be normally be digested. This fermentation takes place in the caecum where significant amounts of the B vitamin complexes and volatile fatty acids are produced as a result.

The size of the horse’s stomach is also quite small and hence many classes of horses are not able to consume enough forage to meet their nutrient requirements. Therefore concentrates are sometimes needed to supplement their nutrient requirements. The stomach of the horse is small because in the wild the horse obtains all its dietary needs through grazing for up to 18 hours a day. Due to this lifestyle their gastrointestinal tract has adapted to enable them to absorb the maximum amount of nutritional value from a diet of roughage.

Due to present day feeding and management practices, the modern day horse is placed in a situation where the feed is much reduced in quantity and frequency while the quality given is far greater. They are also not exposed to large areas of diverse grazing where they can roam freely.

Today’s horse’s dietary needs are greatly influenced by its breed and the lifestyle imposed upon it. The most important aspect of any horse’s food intake is to make sure that the main proportion of feed comprises good quality forage.

Each horse should be treated as an individual. By monitoring feed intake and body condition closely, optimum condition and a healthy happy horse is easily obtained.

Equine nutrition is a complex subject and thus we will only provide a basic overview here. Your veterinary surgeon will be able to give nutritional advice specific to your horse’s individual requirements.


Energy requirements are determined by age, weight, activity level and other factors such as pregnancy. Carbohydrates are the main form of energy used by horses. These are obtained from grass and hay but the best source is cereals (corn, oats) as the level of carbohydrate is a lot higher. The requirement for energy is related to the amount of work the horse does so a horse retired to pasture may only require grass and hay whilst a thoroughbred racehorse will require larger quantities of grain.


Protein is the building blocks of a horse’s body. They make up about 20 percent of an adult horse’s weight and are important for building muscle and replacing lost or damaged cells. Younger, growing horses have a much greater requirement for protein than mature horses. Sources of protein are hay, pasture grass and grains but the quality does vary. Additional protein may be also be obtained from supplements such as soybean.

Minerals and Vitamins

Minerals are needed for metabolic functions, proper working of the skeletal system, and hormone and enzyme regulation. For horses, important minerals include calcium, magnesium, sodium, chloride, potassium and phosphorous.

Sufficient vitamins are usually acquired through foraging and grains, but in some cases supplements are given. Indications include stress from illness or excessive training. Below are some general rules on basic nutrition and feeding. You should contact your veterinary surgeon for specific advice for your horse.

  • Allow free access to hay and water.
  • Follow a regular feeding schedule.
  • Little and often i.e. small amounts frequently should be fed
  • Give water first, then hay, then grain. This gives the digestive system time to begin working and can help prevent problems such as colic.
  • Amounts of food should be based on the horse’s weight, activity level and overall condition.
  • Make changes to the amount or type of feed gradually.
  • Give plenty of pasture grass and hay.
  • Be sure hay is not mouldy, musty, or too green.
  • Wait at least one hour after feeding to work a horse.
  • Let the horse rest for at least an hour after riding before he is fed.
  • Pay attention to your horse to be sure he is not getting too fat or too thin.