Characteristics of Feedstuffs Fed to Horses

Balanced rations consist of a single feed or mixture of feeds to supply energy, protein, minerals, and vitamins for work, growth, lactation, pregnancy, and maintenance (idle horse). Balanced rations meet the equine's nutrient requirement for the day. The amount of nutrients needed depends on the equine's size and production status. Characteristics of feedstuffs are listed and described below.

Nutrient Composition of Feedstuffs Fed to Horses


Dry Matter, %

DE, Mcal/lb.

Crude Protein, %

Fat, %

Crude Fiber %

Calcium, %

Phosphorus, %

































Wheat Middlings    








Soybean Meal, 48%
















Flax seed meal








Vegetable Oil








Beet Pulp










Soybean hulls      








Rice bran








Brewers Grains








Photo Credits: Adobe Stock

Cereal Grains

Cereal grains are fed to horses as a forage supplement to increase the diet's energy and protein content. Grains are higher in energy than most forages and can be a valuable addition to horses' diets that cannot maintain body condition on forage alone.

  • Grains are usually fed to performance horses, pregnant and lactating mares, breeding stallions, and growing horses.
  • Grains are not necessary for mature, idle horses unless they do not have access to good quality hay or pasture or there are underlying health or teeth problems.

Many grains are fed to horses. The most common are oats, barley, and corn. Wheat and milo are other grains fed to horses. In general, cereal grains are:

  • palatable to horses
  • nutrient dense
  • low in fiber
  • high in starch
  • low in calcium with an inverted calcium-to-phosphorous ratio

Listed below are the characteristics of the grains. The table on Nutrient Composition of Feeds Fed to Horses lists the nutrients in the grains.


  • Oats are the most popular and safest grain to feed to horses. Oats are safe to feed due to their fiber content (10-13 percent). This means oats have more bulk per nutrient content, and horses must eat more to satisfy their nutrient requirements. Bulk makes it more difficult for the horses to overeat, colic, or founder.
  • Oats are a reasonable source of energy (1.52 Mcal DE per lb.) and protein (10-13 percent CP). DE = digestible energy, and CP = crude protein.
  • Oats are sold based on their weight per bushel. The heavier the oats, the more nutrients are contained per unit of weight. U.S. No. 1 oats weigh 36 lb. per bushel, whereas U.S. No. 4 oats weigh about 27 lb. per bushel.
  • Oats should be cleaned to remove dirt, weeds, other seeds, and broken kernels.
  • Oats can be bought as a whole or processed. Processing oats include crimping, rolling, or crushing the kernel. If oats are processed, crimping is sufficient to allow small intestine digestive juices better access to the kernel.

Whole Oats


  • Corn has about two times the amount of energy as oats. Corn is one of the most energy-dense feeds (approximately 1.76 Mcal of DE per lb.) and contains a high content of non-structural carbohydrates (starches and sugars).
  • Corn is a poor source of protein (generally lower than 10 percent CP).
  • Corn is commonly processed to increase the digestibility of the starch and reduce the chance of excess starch reaching the hindgut. It can be fed on the cob, shelled, cracked, steamrolled, and flaked. Generally, cracked and flaked corn is the most digestible.
  • Corn is prone to mold infestation and production of mycotoxins.

Cracked corn


  • Barley is lower in fiber than oats and more energy-dense compared to oats. Barley is high in energy (approximately 1.66 Mcal DE per lb.) and a reasonable source of protein (10-12 percent CP).
  • Barley weighs more per unit of volume (48 pounds per bushel) than oats.
  • Barley has a harder kernel than oats and should be processed before being used as horse feed.


Wheat (Wheat Bran and Wheat Middling’s)

  • Wheat is similar in energy compared to corn (1.74 Mcal DE per lb.) and higher in protein (11-14 percent CP). Because of the high energy density and gluten content, problems with over-consumption can lead to diarrhea, colic, and founder.
  • Wheat should be processed, as the kernel of wheat is quite complex.
  • Wheat bran is the coarse outer coating of wheat that is removed during milling and is commonly used to add bulk and fiber to the diet. As bran is very high in phosphorus, proper attention should be paid to ensure that the calcium-to-phosphorus ratio in the diet is still higher than 1:1.
  • Wheat middlings are fine particles of the wheat kernel obtained during milling. Wheat middlings are a common feed ingredient in commercial grain mixes.

Horses that ingest large quantities of concentrates at one time (greater than 5 pounds) may exceed the capacity of the small intestine to undergo enzymatic digestion. The starch gets swept into the cecum and colon simply due to volume and rate of passage. The increased starch is rapidly fermented by amylolytic (starch-digesting) bacteria, causing a rapid release of volatile fatty acids and gases and decreasing the pH of the hindgut. The result is a horse can colic or laminitis may occur.

To reduce the risk of this occurring:

  • Maximize forage in the diet (>1.5% of the horse’s body weight per day)
  • Increase meal frequency by feeding grain throughout the day
  • Decrease feeding traditional types of concentrates and utilize low-starch (commercial) feed mixes
  • Replace with fiber-rich feedstuff or replace with the next-generation type of concentrate and vegetable oil in case of high energy requirements.


Fat Sources

Fats are highly concentrated sources of digestible energy allowing horse owners to provide more calories in a smaller meal. Listed below are characteristics of the vegetable oils and rice bran.

Vegetable Oils

Several types of vegetable oils may be used in horse feeds to increase the energy supplied by the diet and improve palatability. Plant or vegetable oils are the most common, and corn oil is the most palatable. Vegetable oil is:

  • highly digestible
  • very high in energy (100 percent fat)
  • 2.25 times more energy dense than carbohydrates
  • Horses can utilize up to 20 percent added fat in the total diet or 30 percent in the grain mix
  • Since there are no carbohydrates in vegetable oil, the problems associated with large amounts of sugars and starches in the diet, such as overactivity, or digestive upsets such as colic, will be avoided.

Rice Bran

  • Rice bran is high in fat (20 per cent) and a good source of essential fatty acids. It is very expensive, so if a source of fat is required, canola oil (100 per cent fat) is a more economical option.
  • Rice bran is very high in phosphorus, so when feeding it, one needs to ensure that the proper calcium to phosphorus ratio is maintained. Also, it is usually stabilized, meaning that due to the high fat content it is processed to prolong the shelf life of the product.
Protein Supplements

Equines that need protein are those young growing equines, milking mares, performance equines in high-stress situations, or equines being fed poor quality roughage like late-cut grass. Protein supplements provide amino acids. Protein quality refers to the amino acid balance of the protein supplement. Lysine is the first limiting amino acid, followed by methionine and tryptophan. These amino acids are very important for growth and milk production.

Soybean, canola, and linseed (flax) meals are all good sources of supplemental protein, but are not intended to be fed as the whole concentrate part of the ration. Other protein supplements include cottonseed meals, meat meals, milk protein, alfalfa meals, and commercial protein supplements. Listed below are characteristics of protein supplements.

Listed below are characteristics of protein supplements. The table on Nutrient Composition of Feeds Fed to Horses lists the nutrients in the feeds.

Soybeans or Soybean Meal is the most readily available source of protein.

  • Contains the highest protein (44 or 48 per cent CP) of any of the plant-based protein supplements. It is the preferred protein supplement for growing horses because it has a good amino acid profile. Soybean meal is high in lysine, which is the first limiting amino acid in horse diets.
  • Whole, roasted soybeans and soybean meal are both used as a protein supplement to increase the protein content of a concentrate mix. Whole, roasted soybeans are not as commonly fed to horses as soybean meal.

Soybean Meal

Linseed or Flaxseed meal

  • Linseed or flaxseed meal contains good protein levels (36 percent), but lower lysine compared to soybean meal.
  • Flax seed meal has been fed to improve the sheen of the horse's coat, however, the majority of the oil is extracted during solvent processing to make it into meal. To gain the sheen and fiber contributed by linseed meal, feed mechanically processed linseed meal, which will contain two to three per cent more oil.
    • Whole flaxseed, either ground or milled, can be fed to the horse instead of the flaxseed meal. The benefits of this feed are that the horse gets all of the oil from the seed as well as the higher protein.

Flaxseed Meal

Brewer's Dried Yeast

  • Brewer's yeast is an excellent source of protein (approximately 20 per cent CP) and an excellent source of vitamins. It may be beneficial in a diet for an aged or high-performance horse or horses in poor condition. Brewer's yeast should not comprise more than one per cent of the ration.

Animal-source Protein Supplements

  • Very few animal-based proteins are fed to horses because they have poor palatability and are more prone to spoilage than most grains.
  • Milk products are used in creep feeds and as milk replacers for foals because they are high quality proteins.
By-products from the Grain Harvest

Byproducts of wheat and corn grain processing are available for use at a lower cost, but inclusion in equine diets must be carefully considered because these products may vary in their nutrient content. Listed below are characteristics of by-products of the grain harvest. The table on Nutrient Composition of Feeds Fed to Horses lists the nutrients in the feeds.

Distillery By-Products

Distillery by-products are high in fiber, protein and fat, and with energy values slightly lower than or comparable with the parent cereal grain source Distiller's Grains are the leftover from grains that are used in the distilling process. The sugars in the grains have been removed and fermented to produce alcohol, and what remains is a feed with relatively high protein and fiber. It is also a safe and useful feed for horses. Distillers grains, a by-product of the distilling process, are used for added protein and energy. It can be fed up to 20% of the total ration

Dried Distillers Grains

Beet Pulp

  • Beet pulp can be dehydrated and used as a source of fiber and energy.
  • Beet pulp is the pulp remaining after sugar is taken from the sugar beet. Beet pulp is very fibrous and has a similar nutrient profile to high quality grass hay, with:
    • 1.2 mcal per lb. DE
    • 9 to 10 per cent CP
    • higher calcium
    • lower phosphorus
  • It is relatively high in energy and calcium but low in protein, phosphorus, and B vitamins. It contains no carotene or vitamin D.

Beet Pulp Pellets

Citrus Pulp

  • Citrus pulps are similar to beet pulps as they are the pulp (peel, pith and seed) remaining from citrus fruits after the juices and sugars are extracted. The pulp is dried and pelleted after the addition of limestone to remove the acid. These pulps have a similar nutrient profile to beet pulp and other roughages. They provide energy to the horse in the form of fiber.

Soybean hulls are a by-product of the extraction of oil from soybean seeds. Soybean hulls are high in pectin and other soluble fibers. Because they are digested mostly in the cecum and contain relatively small amounts of starch, their use in equine diets does not pose a high risk for colic and laminitis.

Soybean Hulls

Dried Brewer's Grains

  • This is a by-product of the brewing industry, and mainly composed of the leftovers after the starches have been removed from barley. It is high in protein and fiber and low in sugars. It may be safe and useful in horse rations.

Molasses (Dried or Liquid)

  • Molasses is a popular component of mixed concentrate rations. It is a by-product of the sugar refining industry.
  • Molasses is an additive used to improve the palatability of feed, reduces dust and helps bind ingredients together. However, due to its high sugar content, it can be used an energy supplement as well. Molasses is very high in sugar (50-60 per cent), low in protein (three per cent) and high in mineral content (potassium, chloride, calcium and sulphates).
  • Molasses should not exceed 10 to 12 percent of ration. Five percent is the most common amount added to a ration.
Commercial Feeds

Many feed companies produce commercial concentrate grain mixes that are specially formulated for specific needs. These commercial feeds are balanced with added vitamins and minerals; feeding recommendations on the feed label should be followed to ensure proper nutrient intake.

The different feed types can be classified into different categories as outlined below.

  • Traditional Plain Grains or Mixed Grains are a bag of plain oats or barley, or a mix of oats and barley fits into this category. The grain mix is not fortified with added minerals and vitamins. Additional protein, mineral and vitamin supplementation will be needed for growing horses or pregnant and lactating mares.
  • Fortified Grain Mixes includes traditional sweet feeds and complete pelleted feeds. The mix can also be extruded. It is typically a grain mix with added protein, vitamins and minerals that is formulated for a specific type of horse. The grains may be whole, crimped, rolled, cracked, or flaked. Sweet feed is a grain, protein, mineral, or vitamin mix with added molasses to bind all of these components together. Molasses also improves palatability.
  • Fat and Fiber-added Grain Mixes
    • Fat can be beneficial as an energy source because it replaces some of the starchy grains reducing grain-associated digestive upsets. In these feeds, the fat source may be oil such as canola or soybean oil or a high fat feed such as rice bran or flaxseed. For performance horses, added fat can also improve athletic performance. These grain mixes have a higher crude fat (5-14 per cent) than traditional horse feeds.
    • Adding fiber sources, such as beet pulp or soybean hulls, to provide more of the calories in the feed makes grain mixes safer compared to regular grain mixes. These feeds are especially beneficial for horse’s sensitive to starches and sugars.
  • Complete Feeds are formulated as the only feed for the horse to replace both the grain and hay component of the diet. These feeds will have a substantial fiber component, and are typically over 18 per cent crude fiber. Some of these complete feeds have been specifically developed for the older horse that has trouble digesting fiber in the form of long hay, and for older horses having difficulties maintaining body condition.
  • Balancers are nutrient-dense complementary feeds, typically providing high-quality protein and delivering essential amino acids, such as lysine, and vitamins and minerals.  They are usually formulated to be fed at a much lower intake than conventional, complementary feeds.

Horse Grain Mix