feed; strangles

Livestock production: How to feed your horse

Question: I recently bought a horse and would like some advice on how to feed it correctly. Can you help, please?

Correct nutrition is the foundation of a happy, healthy horse that performs to the best of his ability.

When feeding horses our aim, first and foremost, is to maintain health and condition by providing sufficient energy and other nutrients. We also, however, aim to maintain gastrointestinal health, replenish energy stores and allow the horse to perform to the best of its ability.

  • Horses have small stomachs – with a capacity of 8 litres to 12 litres – so they should either eat small quantities continuously or receive feed in several small meals.
  • The large intestine, with a capacity of around 85 litres, contains bacteria, which ferments the fibre that the horse can’t.
  • These bacteria are vitally important and feeding strategies should prioritise the health and well-being of the horse’s bacterial population.
  • The main nutrients needed by the horse are water, proteins, carbohydrates, fats, vitamins, fibre and minerals.


  • The fibre in forage, either fresh grass or hay, is the basis of a horse’s diet.
  • Fibre feeds are sympathetic to the horse’s bacteria and digestive system.
  • Bacteria living in the hind gut ferment the fibre forming volatile fatty acids, which are a valuable sustained energy source.
  • Good quality hay or grazing should always be available.
  • Hay should never be mouldy or rotten, as this can cause diseases like botulism and aflatoxicosis.
  • Hay also shouldn’t be dusty.
  • Dusty hay can cause allergic lung disease in horses.
  • Preferably feed from the floor.
  • This allows for natural drainage of the nose and lungs and also makes chewing more efficient.


  • Water makes up 70% to 75% of the body and plays a role in metabolism and temperature control.
  • Adult thoroughbreds drink between 20 litres and 36 litres of water a day.
  • If they are eating dry hay, they can drink up to 45 litres a day.


  • The amino acids that make up proteins are the building blocks of muscle, connective tissue, skin, hooves and hair.
  • They also supply the animal with enzymes and hormones.
  • An average adult horse needs at least 540 g of protein in its diet daily (around 8% of the diet). Protein is needed primarily for tissue growth and repair, although it can also be used as a source of energy.
  • The horse’s body can produce 10 types of amino acids.
  • But a further 10 amino acids cannot be produced by the animal and must come from its diet. Lysine is the most important amino acid because, without it, the horse can’t manufacture the proteins its body needs.
  • While horses need only small quantities of omega-6 fatty acids in their diets, fats can safely be fed at up to 20% of the diet on a dry-matter basis.
  • Fats are often used to supplement calories for hard-working horses or hard keepers.
  • Omega-3 fatty acids may help reduce inflammation of the skin and lungs in an allergic horse. Feeding more calories from fat rather than from carbohydrates may reduce excitability in some horses.
  • Although traditionally not a large component of horse feed, fat in the form of vegetable oil has been proven to be both palatable and well digested by horses.
  • Fat can be supplied as corn or soya oil, or from high-fat content feeds such as cooked linseed or rice bran.
  • It’s an attractive energy source for endurance horses as it can provide nearly 2½ times as much energy as carbohydrates on a weight-for-weight basis.
  • Remember to supplement extra vitamin E when extra oils are added to the diet.


Carbohydrates – the body’s energy source – come in the form of simple sugars, such as those from molasses and grain, or from “complex carbohydrates” such as cellulose, hemicellulose and pectins, which are found in fibrous plant material.

  • Simple forms of carbohydrates are digested mainly in the stomach and small intestine and produce glucose from which energy can be generated in a hurry.
  • Bacteria-fermented complex fibres in the horse’s hindgut provide a slow and sustained release of volatile fatty acids that are available to produce energy.
  • Fibre that is higher in complex carbohydrates are more difficult to digest, but also help to hold water in the gut.
  • Horse with higher energy requirements are often supplemented carbohydrates in the form of cereals, oats and grains.
  • This is known as the concentrate ration and is often fed as a combined commercial cube, although some owners mix their own ration.
  • Rather feed regular smaller meals than one bigger meal, for example feed 1 kg 3 times a day rather than 3 kg as a once off.
  • This is better for digestion and more closely mimics natural grazing behaviour.


As well as supplying a source of energy, feed must also satisfy the daily requirement for a variety of vitamins, minerals and trace elements including electrolytes.

  • These micronutrients are involved in a myriad of body processes.
  • The need for energy will obviously increase as exercise increases and feeding a balanced diet with respect to vitamins, minerals and trace elements also becomes more important.
  • The horse requires small quantities of vitamins for essential metabolic functions, although the horse’s body is able to manufacture some of the vitamins it needs.
  • Vitamins are divided into fat-soluble (vitamins A, D, E and K) and water-soluble vitamins.
  • Horses need several minerals for essential body functions.
  • These are broken down into macro (such as salt) and micro minerals or trace elements that are required in smaller quantities.

Horses can lose large quantities of salts in their sweat and their diet may need supplementing. A salt lick can be made available at all times (this is also said to decrease boredom in horses) or coarse salt can be added to the diet if you are not using a commercial supplement.

Most grasses and hay don’t contain all the vitamins and minerals horses need.

There are 4 ways to add vitamins and minerals to the horse’s diet:

  • Vitamin and mineral supplements and licks
  • Ration balancers (minerals plus protein)
  • Concentrates
  • Complete feed (roughage, concentrates and vitamins and minerals all in one)


  • All horses should be fed as individuals.
  • Their dietary needs vary depending on their age, exercise, sex, breed and individual factors, such as if a horse is an easy keeper (maintains condition easily) or a hard keeper (battles to maintain good condition).
  • Some horses may need to be fed more in certain weather condition, such as extreme cold to prevent weight loss.
  • Keep an eye on a horse’s condition and weight to see if their diet needs to be adapted.
  • Weight loss is one of the clearest signs that the diet is incorrect or it could signal disease.
  • You can monitor your horse’s weight using a weigh band that fits around the horse’s girth and gives an estimate of weight.
  • Body condition or fat covering also needs to be considered.
  • Body condition is scored from 1 (extremely thin) to 9 (obese or extremely overweight).
  • The ideal condition for horses is somewhere in the middle, a score of around 4 to 5.
  • Call in a qualified equine nutritionist to help compile a balanced ration for your horse.
  • This can mean the difference between success and failure in horses competing at a high level.


  • Clean water should be available at all times.
  • Good-quality roughage is the best investment you can make.
  • Good quality hay or grazing should always be available.
  • A general guideline is around 3% of body weight; which is around 15 kg hay per day for a typical 500 kg thoroughbred horse.
  • Never make sudden dietary changes, as this can have serious repercussions.
  • The bacteria in the gut cannot cope with sudden changes, and a sudden increase in grain could cause laminitis (inflammation of the hoof walls) Always gradually adapt diets in terms of both amount and type of feed.
  • Feed to condition; do not allow horses to become too fat.
  • When using concentrates, a good rule of thumb is to avoid feeding more than 1% of body weight (around 5 kg in a 500 kg horse).
  • Don’t feed concentrates as one large meal.

Also read:
Livestock production: How to buy a horse
Crop cultivation: The benefits of animal traction

  • This article was written by Dr. Marc Walton and first appeared in Farming SA.

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