Many horse owners struggle with grain selection for their horses. One of the biggest deciding factors regarding what to choose lies in the reason for feeding. Typically, grains or grain mixes are offered to horses to increase the calorie (energy) density of their diet. Usually this is because these horses have nutritional needs that are higher than what can be provided for from forage (hay, pasture, etc.), which is the foundation of an equine diet. In fact, grains and grain mixes are commonly referred to in the feed industry as “concentrates” because they are concentrated sources of energy.

One of the earliest known writings on equine feeding, the Kikkuli text (1350 BCE) on training the chariot horse, supported the feeding of oats and barely. Today, these remain two of the most commonly fed grains to horses, with oats being more commonly fed in Canada, and barley the grain of choice in much of Europe. Oats are often considered a “perfect” food for horses, in that they have a good amount of calories per unit weight (about 3 mcal of energy per kg of oats), 11% protein, lower starch than other grains (about 40% starch, compared to almost 70% in corn) and good palatability. However, while having a good amount of protein, oats are low in the essential amino acid lysine. Also, most grains are low in calcium (about 0.1%), and higher in phosphorus (about 0.35%), resulting in an inverted ratio of Ca:P that horses need (ideally it is 2:1). Therefore, while oats are still a great feed for horses, the overall diet would need to be supplemented to make up for any deficits and imbalances. For instance, feeding alfalfa hay would increase the calcium intake of the diet, or adding in a bit of soybean meal would bring up the lysine content. Some other additional vitamins or minerals might need to be supplemented to a hay and oat only diet, depending on the horse’s needs. Because oats tend to be economical, many horse owners prefer to feed oats and do some additional mixing of supplements to bring the overall nutritional content to what the horse needs.

It should be mentioned that oats are, in fact, highly digestible by horses with good teeth, and seeing the hulls in feces does not mean the horse doesn’t extract the nutrients out of them first. Oats do not require processing, so whole oats are fine, but feeding rolled or crimped oats might increase digestibility slightly.

Grain mixes, also referred to as fortified feeds or commercial mixes, essentially do the entire nutrient mixing for you. Companies that produce such feeds mix several cereal grains and byproduct feeds, along with protein, vitamin and mineral supplements, to formulate a diet that provides all of the nutrients required for the intended horse type, when fed at amounts recommended by the manufacturer. Companies may produce many different products for many different types of horses. The problem for owners, however, is that these feeds cannot take into account nutrients provided for in the hay, and, in fact, companies need to design the grain mix assuming the hay might be lower quality. Therefore, you might not need to feed the “manufacturer recommended amount” if you know what nutrients are provided for in the hay. If you feed good quality hay and the recommended amount of a grain mix, you might be feeding too much protein or minerals, or even too much energy. To this end, several companies have designed feeds to provide additional protein, vitamins and minerals, while not providing excessive energy; these are called “ration balancers.” However, when fed in amounts of 1 lb or higher, ration balancers can still contribute calories to a horse that might not need them!

Of course, to adequately balance a horse’s diet, it all comes down to the hay, which, again, is the most important component of a horse’s diet in terms of nutritional contributions, as well as its importance in digestive health. The only way to determine the nutrient content of the hay is to get it analyzed. From there, an owner can work with a nutritionist to calculate how many calories, grams of protein and lysine, calcium, phosphorus, etc. is coming from the hay, and determine what else needs to be provided in the diet, and those nutrients can be offered via either a commercially mixed feed or a cereal grain (such as oats) supplemented with some additional nutrients. While offering oats and supplemental calcium and lysine may be more cost effective, it does leave some room for error. Therefore, it is up to the owner to determine which type of feeding management best suits their facility.

Lastly, it should be noted that many commercial mixes offer different “forms” of the same product. Commercial grain mixes might be sold as “textured” form, which is also known as “sweet feed,” wherein the individual particles of ingredients are visible. These feeds do not necessarily contain added molasses. These same ingredients might then be processed and pelleted, to provide a “pelleted” form of the feed. These can contain the exact same ingredients and have the exact same nutritional profile, though, because they are processed, they might be slightly more digestible, and can prevent horses from “sorting” their food. Some companies also produce extruded feeds, which can use the same ingredients, but are further processed to result in the “puffy” type of feed that looks more similar to dog food. This form of feed can also have the same nutritional profile as other forms, but have the advantage of being more digestible, and are particularly good for older horses because water can be easily mixed with it to produce a nice slurry.

It is recommended to work with an independent nutritionist to help determine what feeding program best suits your horses.