An Overview of Equine Feeds and Supplements

How much of a variety of feeds and supplements does a horse need?
How much of a variety of feeds and supplements does a horse need?

The important parts of your horse's diet are carbohydrates (energy), protein, fat, vitamins, minerals, fiber and plenty of fresh palatable water. Given scientific research and the work of equine nutritionists, many commercial products are available to meet the needs of horses when regular feeds don't meet a horse's requirements for a more specialized diet.

Just as with nutritional products for humans, many of these products do have merit, but others are a waste of time and money and may actually harm your horse's health.

Mainstay feeds and supplements

As you already know, hay or forage is the most important mainstay of the horse's diet. It contains most of the nutrients needed by the horse's body to sustain health and productivity.

Forages can vary greatly with maturity of grasses and hay, fertilization, management and environmental conditions. Because of their leaves, legumes are usually higher in protein, calcium and energy than grasses. Forages are high in fiber content making them an ideal source of roughage. They are the most natural feed for horses and frequently the least expensive feed available.

Concentrates have potential for overfeeding and may be associated with azoturia, laminitis, acute gastric dilation and developmental orthopedic disease.

Fortunate is the horse that has access to pasture grazing several hours or more each day. Horses at maintenance usually have more than adequate amounts of vitamins in their diet if they are eating fresh green forage on a regular basis.

Horses that are consuming fresh green pasture consisting of legumes and grasses also receive proper amounts of minerals in their diet with the exception of salt which should be available free choice at all times. Foals, pregnant and lactating mares and hard-working horses would be the exceptions and may require more dietary energy than a pasture can provide.


Horses and other equines love their grains making these the most overused supplements.

Equine candy

Horses and other equines love their grains making these the most overused supplements.

Concentrates are grains or combinations of grains that are high in energy and low in crude fiber. Growing or working horses often require more energy or protein than can be provided by hay or pasture. In these cases, it is necessary to provide horses with concentrates made up of the harvested seed portions of cereal crops that have a high nutrient store. Grains are palatable, dense, and usually low in fiber if processed correctly.

You can feed your horse either whole grain or grain that has been processed by cracking, rolling, flaking crimping or extruding the grains.

Oats have a high fiber content and are considered by many horse owners to be among the safest of grains to feed. However, oats are rather expensive when cost is compared to energy content.

Corn is a popular feed in many parts of the country due to its availability. Corn contains almost twice the amount of energy than an equal volume of oats. Corn is consistent in quality and is palatable. It also contains a significant amount of Vitamin A. Because of its high energy content, some horses may become more excitable if fed too much corn.

Wheat, rye, barley, and milo have hard kernels, making them more difficult to digest unless they are processed by being rolled, cracked, coarsely ground or steam-flaked. Wheat has a high gluten content and may cause stomach distress if fed in large amounts. Rye is susceptible to the toxin ergot so care has to be taken to make sure it is clean and toxin free.

Because of the hard kernels and the difficulty in digesting wheat, rye, barley and milo, it is recommended that they not make up more than 1/3 to 1/2 the total grain ration.

Wheat bran is a poorly digested cereal grain with a low energy content. Since it may lead to an impaction, it is best fed as a mash with plenty of water. It increases the volume of manure and is sometimes used for this reason.

Molasses is often used in concentrated feeds and is useful in increasing free-choice consumption and also it helps prevent minerals from sifting out of the grain mixture. Many veterinarians recommend its use as a vehicle for giving medications since most horses like it and eat it willingly.

Commercial combinations of grains are available and some of them are very good at meeting a horse's need for more energy. Care should be taken to read feed tags carefully when purchasing commercially made concentrates.

In addition, feeding of concentrates should be limited to no more than one-quarter of the total weight of the daily ration and should not be fed except as part of a carefully balanced feeding program.

Concentrates have the potential for overfeeding and have been associated with azoturia, laminitis, acute gastric dilation and developmental orthopedic disease. A veterinarian can determine which concentrates will work best for your horse and the quantity that should be fed on a daily basis.

Commercial horse feeds

Complete nutrition - easy to feed

Complete nutrition - easy to feed

The availability of "complete" feeds provide everything your horse needs in an easy to use product.

Commercial horse feed manufacturers have developed a number of feeds nutritionally formulated to meet specialized feeding requirements. Complete horse feeds containing alfalfa meal, soybean meal, and other cereal grains can be fed as the main source of daily nutrients.

Other combinations of cereal grains and protein supplements have been developed to provide extra energy for recreational activities and hard work. Commercial feeds are also available for feeding mares during late pregnancy and lactation and for the nursing and growing foal.

State and federal laws regulate the production, labeling, distribution and sale of animal feeds. The feed tag provides much useful information such as the minimum percentage of crude protein and fat, and the maximum percentage of crude fiber in the feed. Most feeds are designed to be fed with forage. Failure to provide the needed roughage can lead to digestive problems for your horse.

Commercial horse feeds come in the form of pellets, cubes, and loose mixes of grains that are often combined with molasses to increase palatability. These feeds are often referred to as sweet feeds and care has to be taken during hot humid weather to make sure they are properly stored to prevent spoilage.

Protein supplements

Since many feeds do not contain enough protein to meet the nutritional requirements of some classes of horses, a protein supplement such as soybean meal can be added to the grain or concentrate mix to supply sufficient protein.

Most protein supplements are the byproducts of the extraction of oil from soybeans, cottonseeds, flaxseeds and other oil seeds. These supplements usually contain 32 to 50 percent crude protein by weight.

Soybean meal is the most commonly used protein supplement. It is preferred for young, growing horses because it is high in lysine, the amino acid essential for growing foals. Given for 30 days at the end of winter, soybean meal aids in shedding and gives a gloss to the foal or horse's new spring coat.

TSpecialized supplements for the growing horse

Specialized supplements for the growing horse

Young horses often need more protein to support muscle growth. Grain or protein supplements can provide for this requirement.

Cottonseed meal is the second most popular protein supplement and is considered to be more palatable than soybean meal, but lower in protein quality and in lysine. For the mature horse, these attributes are not necessarily negative.

Linseed meal, rapeseed meal and canola meal are also considered to be palatable and good sources of protein. Peanut meal, safflower meal, sunflower meal, fish meals and various brewer's pellets and grains are other examples of protein sources that may be fed to horses. Again, it is important to read the feed tag and make sure that the product is the right one for your particular horse.

Dried milk products are also an excellent source of protein for growing horses because they are high in lysine. Although more expensive, they do meet the protein requirements of horses up to approximately 3 years of age. Horses that are older than 3 years often lack the enzyme lactase, making them susceptible to diarrhea.

Fat and oil supplements

Most horse feeds contain 2 to 4 percent fat, but some horses need more and will adapt to the consumption of diets containing 10 to 20 percent fat if sufficient time is allowed.

The purpose of adding fats to the horse's diet is to increase the energy density without incurring problems associated with use of large quantities of grain. Vegetable oils and animal fats are utilized for energy more efficiently than any other source of feed.

Lactating mares, racing and cutting horses, and other horses that have heavy work loads are prime candidates for fat and oil supplements. Fat supplements supply energy needs without increasing grain intake or reducing roughage intake which can result in problems with colic, diarrhea, founder and other health problems.

To prevent digestive upsets, fat or oil should be gradually added to the diet over at least 3 weeks until the desired amount is reached, usually 10 to 12 percent. The horse's weight, eating behavior and general well-being should be consistently monitored and the amounts of fat increased or decreased to arrive at the desired outcome.


At least 21 minerals are required in an adequate horse's diet, but the major concerns are calcium, phosphorus, salt, selenium, copper and zinc. A number of mineral deficiencies and toxicities can occur, but with the exception of selenium, calcium and phosphorus, they are uncommon, provided that average or better quality feeds are used and trace-mineralized salt is available.

In general, average or better forage and most feed stuffs provide adequate levels of necessary minerals. Problems are more likely to occur when minerals are supplemented in excessive amounts.


Vitamins play a role in regulating many physiological functions in the horse. Vitamin A is provided in sufficient quantities by green forages and is stored in the liver. Vitamin D synthesis is activated by sunlight. Vitamin E is present in sufficient quantities in most good quality diets, especially those that include grain. The microbes in the cecum and large intestine produce vitamin K.

The water soluble vitamins are not required in large quantities in the horse's diet. Vitamin C, the B-complex vitamins such as thiamin, niacin, riboflavin, biotin are produced in the horse's digestive processes and are conserved by efficient recycling mechanisms in the horse's body.

Vitamin A is the only vitamin that may be inadequate in rations fed to most horses. Forage plants and grasses contain the carotene that is converted to vitamin A in the horse's body. Your veterinarian may recommend that your horse's diet should include a vitamin A supplement which is available at all feed stores.

A B-complex vitamin deficiency may occur in horses that are sick or not eating ample amounts of feed. B-complex vitamin supplements are also often given to hard-working and performance horses.

When a B-complex vitamin deficiency is suspected or when additional vitamins are desired, most veterinarians recommend that a 30gm dosage of a broad-spectrum commercial vitamin preparation be given each day. Brewers yeast is also a good source of the B vitamins and may be used to supplement your horse's diet.


Many by-products of grain production can be used in horse's diets if necessary for additional fiber or bulk. Sugar beet pulp is popular with some horse owners because it provides fiber similar to hay and has a digestible energy content similar to oats.

By-products made up of the fibrous stems or hulls of plants such as oat straw, soybean hulls, almond hulls and sunflower hulls are other examples of by-product feeds. Although they provide little nutritional value, they are good sources of additional fiber in the horse's diet and give the horse plenty of opportunities to satisfy its need to chew, along with helping keep the digestive tract healthy.


The hard working horse may require an electrolyte supplement

The hard working horse may require an electrolyte supplement

Heavy sweat can disturb the electrolyte balance of the horse, leading to serious conditions. Supplement with electrolytes helps the hard working horse cope.

Electrolytes play an important role in the working horse's diet. Work in high temperatures and humidity, a high level of competition, or a stressful environment will produce increased demands for nutrients in the horse. Muscle function, fluid balance and metabolism all rely on the balance of sodium, chloride, potassium, calcium, magnesium and other elements in the horse's body.

When a horse sweats, the body looses not only fluids, but also electrolytes. A vigorously exercising horse can lose up to 15 liters per hour with higher losses during more intense work or higher temperatures combined with high humidity. This means the body is loosing necessary minerals along with the fluids in the sweat.

When this happens, the functioning of the horse's bodily systems is compromised and in extreme cases can lead to colic or other serious conditions.

Electrolytes are best used at low levels before, during and after competitions or periods of hard work, especially on hot, humid days. Electrolytes will help the animal perform better and relieve some of the stress of the exercise.

In most cases, it is recommended that the electrolyte supplements be added to the horse's feed instead of to water. Some horses will not drink enough water at the time to get the full value of the electrolytes and some horses do not care for the taste and are reluctant to drink water containing electrolytes.


Probiotics are said to increase well-being, help metabolism and reduce stress in the body.  It is the fermentation in the horse's gut that provides the animal with the nutrients from digested feed. Probiotic supplements contain live bacteria such as lactobacilli that is given orally to restore beneficial bacteria to the horse's body.

Foals receive them from their dams and regular ingestion of various feeds allows these microorganisms to flourish in the horse's digestive system. Not every horse needs probiotic supplementation such as a healthy, mature horse that receives little exercise. However, a horse that travels and performs often needs supplementation to keep a healthy supply of bacteria in the digestive system.

Your veterinarian is your best source of information regarding any supplements, including the use of probiotics in your horse's diet.

Consider this

Many other supplements are available for horses including products similar to those used by humans such as Glucosamine and Chondroitin supplements in various formulations. Again, your veterinarian can advise you as to whether or not the use of these supplements would be beneficial for your horse.

About the Author

EquiMed Staff

EquiMed staff writers team up to provide articles that require periodic updates based on evolving methods of equine healthcare. Compendia articles, core healthcare topics and more are written and updated as a group effort. Our review process includes an important veterinarian review, helping to assure the content is consistent with the latest understanding from a medical professional.