When forage (grass, hay or haylage) on its own is insufficient to meet a horse’s nutrient requirements, a compound feed containing nutrients from a variety of sources may be necessary.  Many of the cereals used in mixes and cubes today are the same as those fed by horsemen for centuries.  These days, however, technology allows us to analyse their nutritional content and to cook them to enable the horse to digest them as easily as possible  . 

Contrary to popular belief, the ingredients of cubes are chosen according to the same stringent criteria as those included in coarse mixes and are not the “sweepings off the floor”!  Here we run through the most common feed components used in the UK and Europe, outline their nutritional contributions and help you identify them once cooked and included in a feed.
 

Cereals

Cereals provide energy primarily in the form of starch, a complex carbohydrate consisting of chains of glucose molecules packed into granules.  The starch in some cereals is more easily digested than others – oats, for example, are easier to digest than maize which, along with most other cereals, should be cooked to improve its digestibility. 

Micronising and extruding have superseded steam flaking as modern cooking methods because they “gelatinise” (cook) a higher proportion of the starch content.  This makes the cereals as digestible as possible for the horse, maximising the chance of the starch being digested and absorbed in the foregut, where it should be. 

Any risks associated with feeding cereals are generally due to undigested starch reaching the hindgut and upsetting the microbial balance that exists there.  This can result from the consumption of un-, or poorly, cooked cereals or over large meals which result in feed passing out of the horse’s small stomach before it is properly digested. 

Starch provides “fast release” energy because it is readily digested and absorbed by the small intestine as glucose.  This is the main food for the brain and other organs so is vital to help the competition horse maintain concentration and stamina and a complete exclusion of starch and sugars from the diet is therefore not necessarily a good thing.  Glucose is stored in the muscles as “glycogen” and can be utilised by the horse at all work intensities.

Oats

• High in fibre compared to other cereals.
• Usually lightly bruised to improve digestibility.
• Not usually cooked as starch is already relatively easy to digest.
• Quite long and thin shape.
   

Barley

• Requires cooking to improve digestibility.
• Has points at tips of grain.
• Fatter and shorter than oats.
• Golden yellow colour
  
   

Wheat

• Requires cooking to improve digestibility.
• Flatter, square ends.
• Beige brown colour
  
   

Maize

• Requires cooking to improve digestibility.
• Highest in starch of all cereals.

Legumes

Peas, beans and soya belong to a plant family known as legumes.  They are generally included in horse feed to provide protein, which is made up of individual amino acids.  Some of these can be synthesised by the horse whilst others have to be included in the diet and are known as “essential” – legumes are a particularly good source of essential amino acids.  Protein is required by the body to build tissues, including muscle, so is vital for the working horse.  It is rarely used by the body as an energy source so is not the cause of over excitable behaviour or laminitis!

Peas

• Harvested when they are more mature than those eaten by humans.
• Cooked and rolled and easily identified by their colour.
• Also a source of carbohydrate energy hence often only included in limited amounts.
  
   

Soya

• Sometimes added as a cooked, rolled flake but can also be incorporated into pellets as a finely ground meal.
• Flakes are thicker, smaller and rounder than maize flakes.
• Also an excellent source of oil (see below).

Other protein sources

• Grass is a natural source of protein for the horse and can be incorporated into pellets as grass meal.
• Distillers’ grains may also be used as a protein source as, although whole grains (cereals) do not contain much good quality protein, the distillery process removes all the sugars (starch) so the residue left is the protein in a much more concentrated form.  
• Milk proteins from whey are used to provide a source of protein that the foal can utilise.

Fibre

Fibre can be included in a compound feed in a variety of different forms and provides slower release energy as it takes longer for the horse to digest it in the hind gut.

Oat Feed & Wheat Feed

• These contain the outer parts of the cereal grains, including "bran" and the fibrous outer husks.
• Usually included as a pellet or incorporated into a pellet with other ingredients.
  
   

Straw

• A common source of fibre – oat straw is usually chosen for its palatability.

• Usually included as a pellet or incorporated into a pellet with other ingredients
• Sometimes it is “nutritionally improved” through a chemical and/or cooking process to improve digestibility.
• May also be present in a mix as a molassed chaff.
   

Alfalfa

• A legume, like peas and beans, but the leaves and stalk are dried and fed rather than the seeds.
• Contributes quality protein and calcium as well as fibre.
• May either be ground and combined into pellets or chopped and included in a mix as a chaff which is often lightly coated with an oil or molasses.

Grass

• May be dried and ground for inclusion in pellets or incorporated as a chaff.
• Also a source or protein.
  
  
   

Sugar Beet Pulp

• The dried remains of sugar beet after the sugar has been extracted, this is an excellent source of “super fibres”, which are more digestible than cellulose, the main fibre source in forages etc.
• Needs soaking before feeding but modern cooking processes have now reduced this soaking time and also allowed its inclusion in some mixes and cubes.

Oil

Although the horse’s natural diet does not contain much oil, he is able to utilise it surprisingly well and it’s a particularly useful source of non-heating, slow release energy.  It is utilised by the horse when performing low intensity work thus leaving valuable glycogen stores for use by the horse when the work intensity increases.  This is known as “glycogen sparing” and makes it ideal for horses requiring improved stamina.  Soya and linseed are the most common sources.

• Provides up to 2 ¼ times more energy than carbohydrate from cereals can increase the calorie content of a ration without a significant increase in volume.
• Comprised of different fatty acids and it is these that determine the quality and usefulness of the oil.  Some fatty acids, like Omega 3 and 6, are essential and need to be included in the daily diet, having benefits other than as an energy source. 
• A safe way to provide energy for horses who need to avoid starch eg. those prone to laminitis, or muscle disorders, such as ERS (Exertional Rhabdomyolysis Syndrome or “tying up”) or PSSM (Polysaccharide Storage Myopathy).
• The more oil included in the diet, the more the horse needs antioxidants to protect against free radicals produced during its utilisation.
• Generally included in a compound feed in a pellet or may be added as a light coating to a mix.

 Vitamins & Minerals 

These constitute only a very small fraction of the diet but are no less important as any deficiency or imbalance can affect performance and well-being.  Most pasture and forages are deficient in some vitamins and minerals so, even during time at grass, horses should be supplemented to help replenish body reserves or support healing. 

The quality of the vitamin and minerals included in a feed determines their availability to the horse; there is no point in having high levels if the body can’t use them and ends up excreting them!  Performance feeds should contain sources of chelated minerals which are attached to other molecules making them easier to absorb.  Some vitamins and minerals have “antioxidant” effects eg. vitamin E and selenium, and protect against the harmful effects of “free radicals” produced by normal metabolic function.

Vitamins

• Involved in many essential bodily functions.
• The horse can manufacture most vitamins except vitamins A and E which must be provided in the diet.  Demands for other vitamins vary according to a range of factors so most manufacturers include a broad spectrum to avoid deficiency.
• Requirement is increased when work load is higher or during pregnancy, lactation and growth.
• More is not necessarily best; it is the balance of vitamins and minerals which is important.

Minerals

• Also involved in body structure and function eg. calcium and phosphorus in bones, iron in red blood cells
• Can interact and affect the absorption of one another so a correct balance is vital eg. calcium to phosphorus

Added Extras

Molasses

A product of sugar extraction which provides carbohydrate energy.

• Often used to lightly coat a mix to prevent the components separating and avoid dustiness.
• May be mixed with the ingredients of pellets or cubes as a natural binder to help them stick together.

Herbs

Generally dried and included for palatability and their perceived health benefits.

It’s On the Bag

Feed ingredients (Composition) are listed on the bag in order of the greatest inclusion first.  If these and the nutrient analysis (Analytical Constituents) are printed on the sack rather than a sewn on tag, it shows that the manufacturer sticks to a constant recipe to produce a consistent product.  The choice and preparation of ingredients by reputable manufacturers is based on their belief that they will be the best for the horse and, as ever, you get what you pay for.  Having invested extensive time and money to produce a horse it is false economy to cut corners on feeding; maintenance of a fully balanced diet year round should be looked on as a nutritional investment with potential long term benefits for a healthy performance horse.