Lori K. Warren, PhD, PAS
Department of Animal Sciences, Institute of Food and Agricultural Sciences, University of Florida

Over the past 30 years, research has provided tremendous advances in feeding horses. Feed companies have taken this research knowledge and “put it in the bag” to help your horses grow up to their genetic potential, perform well, and live longer. Unfortunately, it has also generated a great deal of confusion about which feeds to select for your horses. As little as 10 years ago, a trip to the feed store involved a simple choice between oats or sweet feed. Today, you have hundreds of feed products to choose from, and that’s not counting the thousands of supplements that are also crowding the shelves!


Dr. Lori Warren

Dr. Lori Warren is an equine nutritionist and an Assistant Professor in the Equine Sciences program at the University of Florida. Her primary research interest includes studies with omega-3 fatty acids and Vitamin E supplementation and their effects on inflammation and immune system responses in horses. Dr. Warren received her M.S. and PhD in Equine Nutrition and Exercise Physiology from the University of Kentucky and her B.S. from the University of Wyoming. Prior to joining the faculty in Florida, she served as the Equine Extension Specialist in Colorado and the Provincial Horse Specialist in Alberta.

With the large number of feed products on the market, the task of picking the right feed for your horse can seem overwhelming. This article will provide you with the tools to decipher the type of feed products available, as well as the type of horse each feed is best suited for.

-Start With Good Quality Forage
Although the focus of this article is on the selection of grain-based feed products, it is important to recognize that the foundation of any horse’s diet is forage. Every horse, regardless of age or production level, should be consuming at least 1.5 – 2% of their body weight as good quality hay or pasture. Forage is an important source of calories and protein in your horse’s diet, and the fiber in forages is necessary to maintain gut health and motility.

Add Grain to the Diet, Only When Needed
Horses are not equipped to process large amounts of grain and, as a result, there are risks associated with adding grain to the horse’s diet. Large amounts of grain, particularly if consumed as one or two large meals, increases the risk of digestive upset and may result in diarrhea, gastric ulcers, colic, and laminitis. Ongoing research also suggests that adaptation to high grain diets may also put the horse at risk for metabolic disorders, including insulin resistance, which may cause or aggravate other medical conditions.

Grain products should be added to the diet only when forage cannot do the job alone. How do you know if your horse needs grain? Many horses, particularly mature horses that are not pregnant, not being ridden regularly, and are in good body condition, do not need grain at all. Such horses would be much healthier if they received an all-forage diet, whether it’s a suitable quality hay or access to pasture with adequate amounts of grass, and possibly a vitamin/mineral supplement. See Table 1 for estimations on daily intake.

Horses that typically need the added nutrition that grain provides include:
1) Growing horses less than 2 years of age
2) Lactating mares
3) Horses performing moderate to intense work
4) Horses in poor body condition that need to gain weight
5) Pregnant mares in the last 3 to 4 months of gestation (although some “easy keepers” may fare well with only good quality forage and additional vitamin/mineral supplementation).
6) Horses consuming poor quality hay or pasture

Because of the potential problems, the decision to feed grain should not be taken lightly. Careful consideration should also be given to the grain product selected. Fortunately, feed companies have attempted to provide you with a variety of feeds to choose from. Although the number of choices may seem daunting, matching the feed to your horse’s needs can be accomplished by reviewing the feed tag and applying a few basic guidelines.

Read Any Good Labels Lately?
In an effort to make better nutritional decisions, many of us routinely scan the nutrition labels that appear on all of our foods for the amount of fat, carbohydrates and sodium the product contains. However, this information is often ignored on the feeds we buy for our horses and other animals.

Each bag of horse feed contains nutritional information either on a feed tag or printed on the back of the bag that is similar to the labels we find on our own foods. The information includes a “Guaranteed Analysis,” which lists the concentration of nutrients in the feed. This differs from human food labels that provide this information as an amount per serving. (Note: if you want to know the amount per serving in your horse feed, all you have to do is multiply the concentration of the nutrient by the amount (lbs or kg) of product you intend to feed). The Guaranteed Analysis on horse feeds includes crude protein, crude fiber, crude fat, calcium, phosphorus, selenium, and vitamins A and D. Some feed tags also provide you with the concentration of other nutrients, such as copper, zinc and vitamin E.

Feed tags also provide a list of ingredients that were included in the mix. Again, it differs from a human food label in that the ingredients in a bag of horse feed may not be listed in the order of prevalence (i.e., on a human food label, the first ingredient listed is the one included in the greatest amounts, followed by those included in lesser amounts in descending order). Nonetheless, the list of ingredients on a bag of feed gives you an idea of what ingredients were used to generate the Guaranteed Analysis.

The information on the feed tag reveals a lot about what type of feed product it is, as well as what type of horse it is best suited for. Using a few simple guidelines, you can easily become adept at reading feed tags and deciphering what it is and who it should be fed to.

Hmmm…Which Grain to Chose?
Based on the Guaranteed Analysis and list of ingredients, grain-based feeds for horses can be placed into 6 categories:

1) Unfortified (plain) grains
All the bag contains is cereal grain—oats (rolled, whole), corn (cracked, steam flaked), or barley, or sometimes even a mixture of these three grains (3-way mix). Nothing else was added, meaning the grain has not been fortified with extra protein, vitamins or minerals. Unfortified grains may work well in some feeding programs, particularly if paired with a high quality grass or alfalfa forage, but if unfortified grains are fed to lactating mares or growing horses, additional protein, mineral and vitamin supplementation will be needed.

2) Traditional grain mixes
Until recently, traditional grain mixes were our only other choice besides a bag of plain grain. Traditional grain mixes contain several different types of grain (oats, barley, corn, and by-products of these grains), as well as additional protein, minerals and vitamins. They are typically sold based on their protein content (12%, 14%, 16%, etc) and may come in the form of a textured feed (where you can see the individual ingredients), a sweet feed (a textured feed with molasses added), or a pellet. Traditional grain mixes work reasonably well for most horses that require grain feeding. Traditional grain mixes also have an advantage over plain grains because of their additional fortification, which provides the horse with a balanced diet when fed in a reasonable quantity (typically 5 – 6 lbs minimum).

3) Fat-added grain mixes
The addition of fat to a traditional grain mix has become popular over the past 10 years. Feed companies increase the fat content through the addition of various vegetable oils (eg, corn oil, canola oil, soybean oil) or feed ingredients that naturally contain a high level of fat (eg, rice bran, flax, whole fat soybeans). Replacing some of the grain in the mixture with the higher-calorie oils often allows less total grain to be fed and, as a result, the risk of grain-associated digestive disorders may be reduced. Therefore, fat-added grain mixes work particularly well for horses that require a large amount of grain to maintain a healthy body condition, such as a high-level performance horse. One thing to keep in mind: fat only adds calories to the mixture, so the other nutrients should be included in the mix at higher levels to maintain a balanced ration for your horse. Depending on the level of fat added, this means you may need to select a fat-added grain mix with a higher protein content than you would normal use when feeding a traditional grain mix.

4) Fat-and-Fiber-added grain mixes
One of the newest trends in feeding horses are feed mixes that contain not only the components of a traditional grain mix, but also have added fat and added fiber sources. The fat sources added to these mixes are similar to those found in fat-added feeds. Additional fiber is often provided by highly digestible fiber from beet pulp and soybean hulls, but may also include alfalfa meal, wheat middlings and other fibrous by-products. The fat and fiber sources are included as energy (calorie) sources. Their addition replaces a portion of the cereal grain in the mixture. As a result, the calories are considered “safer” because the feed is lower in starch, which is a risk factor for digestive disorders. Many feed companies have capitalized on this concept by marketing their fat-and-fiber-added grain mixes as “low starch” or “low carbohydrate” feeds. Fat-and-fiber-added grain mixes are excellent alternatives to traditional grain mixes for any mature horse needing grain; however, more research is needed to determine the ideal fat-and-fiber formulation for growing horses.

5) Complete Feeds
The first deviation from traditional grain mixes occurred 20 years ago with the formulation of complete feeds. Although complete feeds are one of the oldest additions to a feed company’s arsenal of products, they are also probably the most misunderstood. A true complete feed is one that contains both the forage (fiber) component and the grain component of the horse’s diet, and is designed to be the ONLY feed fed to the horse. Essentially, a complete feed is similar to a bag of dog food for your horse. Since this was a new concept for horse owners, it was often (and continues to be) fed incorrectly. Complete feeds are routinely fed in the same fashion as grain mixes (i.e., a few pounds along with hay), and not as they were intended (i.e., 15 – 20 lbs, no additional forage necessary). Consequently, the protein, mineral and vitamin fortification of these complete feeds was, in effect, being diluted by the hay or pasture portion of the diet and the horse was inadvertently not receiving the nutrients the owner intended. Interestingly, many horse owners liked the results they were seeing, despite feeding these products incorrectly. The higher fiber in the feed was said to keep the horse calmer and less “hot-headed” than traditional grain mixes that are high in starch. As a result, feed companies began developing fiber-added grain mixes (discussed below), as an alternative to true complete feeds. Today, there are still many complete feeds on the market, but a true complete feed (one that replaces the hay portion, as well as the grain portion of the diet) will have a minimum of 18% crude fiber. If the complete feed has less than 18% crude fiber, additional forage will be necessary. Complete feeds work well for older horses that are having trouble maintaining body condition, horses with heaves, and horses convalescing from surgery. Complete feeds are also handy during a drought when good forage is hard to find, as well as convenient for travel.

6) Fiber-added grain mixes
As stated above, one of the reasons fiber-added feeds were developed was because of the mis-feeding of complete feeds. However, fiber-added grain mixes have their own unique merits. The primary difference between a fiber-added feed and a complete feed is the fiber content: complete feeds have a minimum of 18% crude fiber, whereas the fiber in fiber-added feeds, although higher than a traditional grain mix, is only 8 – 14% crude fiber. Another difference between these products is the level of fortification: fiber-added feeds are designed to be fed in smaller amounts and paired with forage, similar to traditional grain mixes, so the level of protein, minerals and vitamins has been increased to ensure adequate supplementation. As a result, the horse owner can confidently feed a fiber-added grain mix in a manner they are accustomed to (i.e., as a supplement to forage). Similar to fat-added and fat-and-fiber added grain mixes, the replacement of some of the grain with fiber sources makes fiber-added feeds lower in starch. For some horses, less starch means a more tractable, calmer horse. Adding fiber to a grain mix will also decrease the calorie content compared to a traditional grain mix. By comparison, the extra fat in a fat-added feed increases the calories over a traditional grain mix, where as the addition of both fat and fiber will counter-balance each other yielding a calorie content similar to a traditional grain mix (depending on the proportion of fat and fiber in the mix). Therefore, fiber-added grain mixes are particularly useful for horses that need a reasonable amount of grain in their diet, but don’t necessarily have trouble maintaining their body weight. Horses that need much larger amounts of grain would be better off on a fat-added or fat-and-fiber added feed, due to the higher calorie content of those products.

Table 2 provides a summary of the features of each of the 6 categories of grain-based feeds and how to differentiate them from the Guaranteed Analysis on the feed tag. Table 3 provides a product selection guide based on the class of horse, crude protein content of the product, and the type of forage being fed.

Rules for Feeding Grain
Grain feeding is associated with a higher risk of digestive problems. While some of the products discussed above have gone to great lengths to reduce the amount of cereal grain (and, thus, starch) included in the mixture, they all still contain some level of cereal grain. To further reduce the risk of digestive problems associated with grain feeding, you must be conscientious about your feeding management. The following are some “rules” for feeding grain-based products:

Rule 1: Don’t feed grain if you horse doesn’t need it.

Rule 2: Feed by weight, not volume! This does not mean you have to weigh your grain at every feeding. But do have a general idea of what your scoop or can of grain weighs. That way, if you switch the type or form of grain you feed, you can make suitable adjustments in volume to avoid under- or overfeeding. Pellets are typically more dense than textured feeds or sweet feeds, so a scoop of pellets will weigh more (therefore providing more nutrients). By the same token, extruded feeds are usually less dense than textured feeds or sweet feeds.

Rule 3: Limit each meal of grain to less than 0.5% of your horse’s body weight (typically 5 – 6 lbs). If your horse needs more grain than this to maintain body condition, split the daily allotment of grain mix into two or more feedings spaced evenly throughout the day.

Rule 4: Whenever possible, give your horse at least 1 week to adjust for every additional 2 pounds of grain you add to his diet.

Rule 5: If you would like your horse to benefit from the extra nutrients that have been added to commercial grain products, do not combine these products with plain, unfortified grains like oats. Such a practice can dilute out the fortification, often requiring additional supplementation. It’s usually cheaper and more convenient to just feed the commercial grain mix.

Rule 6: For horses with tying up or a history of laminitis, it may be best to avoid grain altogether. If the horse needs additional calories to maintain body condition, switch to a higher quality hay or consider feeding a combination of beet pulp and vegetable oil or rice bran. Work with a nutritionist or veterinarian to come up with a suitable diet for horses that are overly sensitive to starch in cereal grains.

Does My Horse Need a Vitamin–Mineral Supplement?
Although the focus of this article is selection and feeding of grain-based products, a common question that parallels this topic is the need (or not) for vitamin and mineral supplementation.

One mineral that needs to be added to the diet of ALL horses is salt (sodium chloride). A source of salt should always be provided free-choice, either in the form of a salt block or as loose salt, wherever the horse is housed. You might also consider top-dressing loose salt on your horse’s grain to ensure he is meeting his requirement. Two ounces of salt meets the horse’s minimum salt requirement, but more should be added to cover salt lost in sweat during the summer months or when your horse is working (approximately 1 – 2 ounces per hour of heavy sweating). Make sure your horse also has a clean, fresh source of water available at all times.

Beyond salt, your horse might need additional mineral and vitamin supplementation if:
• You feed an all-forage diet
• You feed less than 5 lbs of a fortified grain mix per day
• You feed plain, unfortified grains

If you need a vitamin-mineral supplement, it is recommended that you choose a complete supplement that contains the major minerals (such as calcium and phosphorus), trace minerals (copper, zinc), and vitamins A, D and E.

Supplementing a single mineral or vitamin may result in dietary imbalances and adverse dietary interactions that reduce the availability of other nutrients. A complete vitamin-mineral supplement avoids these problems. There are two good options for supplementing vitamins and minerals:

1) Loose (or Livestock) Mineral
A loose mineral is a highly concentrated source of minerals or vitamins. Although a product designed for horses is best, you can also use a loose mineral formulated for cattle, but make sure it does not contain ionophores (eg, Rumensin) or excessive iodine (greater than 1500 ppm I; EDDI cattle minerals often contain too much iodine for horses). A product that contains at least 12% calcium and 12% phosphorus, along with relatively high copper and zinc levels is a suitable choice. Because the mineral and vitamins are provided in such a concentrated form, you will typically be feeding 1 – 3 ounces per day. Horses will have more consistent voluntary intake of mineral if it’s in a granular or crumble form, as opposed to a mineral block. Loose mineral can be top-dressed on the daily feed, or it can be offered free-choice in a weather-protected area (keep it fresh). A mixture of 1 part loose salt (NaCl) to 2 parts loose mineral makes a good mixture that will attract horses’ interest and meet both their salt and mineral needs.

2) Ration (or Oat) Balancing Pellet
Another recent addition to the product line of many feed companies is a ration balancing pellet containing concentrated levels of minerals and vitamins. Some companies also give you the option of including some additional protein by offering two products that differ in their protein content. If the ration balancing pellet contains less than 12% protein, it may not be contributing much protein to the total diet. The lower protein balancers are good to use with mature horses that are eating good quality hay, especially alfalfa hay. If the pellet contains more than 25% protein, this balancer may help meet your horse’s protein needs, as well as the mineral and vitamin requirements. The higher protein balancers are ideal for growing horses and feeding programs that utilize grass forages. Ration balancing pellets are not as potent as loose mineral supplements, typically containing 2 – 4% calcium and 1 – 2% phosphorus. As a result, they are designed to be fed at the rate of 1 – 3 pounds per head per day. They are typically tasty enough to be fed alone (good for those fat horses that don’t need grain, but need mineral), or they can be added to plain grains (eg, oats) to create a well-balanced, custom grain mix.

In an effort to meet the needs of their diverse equine customers, feed companies market a variety of products that are designed to offer a balanced diet with convenience. While it is a blessing to have so many choices for our horses, it is also a curse as we struggle to find the right feed. Luckily, each bag of feed comes with some guidance in the form of the Guaranteed Analysis, the list of ingredients, and (drum roll here) feeding directions! However, if you are somewhat mistrustful of your local feed company, or if you are the independent type, you can still be confident in your feed selection. The key to selecting the right feed is a basic understanding of the 6 categories of grain-based feed products, who they are suited for, and how to identify them from the feed tag. But do not forget, once you select the correct feed, judicious feeding practices are essential to maintain the health of your horse.