Story and Photography by Jennifer Denison

You’ve heard the proverbial saying “You are what you eat.”   The same adage is true for your horse. Whether you trail ride on weekends, compete at rodeos and horse shows, or breed and raise horses, if your horses’ nutritional needs aren’t being met, it could compromise their overall health, attitude, and ability to perform physically demanding feats.  Even worse, it could spiral into other more serious complications.

While it’s crucial to properly fuel your horse’s individual needs, figuring out which combination of feed and how much of each to give can be confusing and overwhelming.  To help simplify the process, we asked two equine nutritionists—Katie Young, PhD, Consulting Equine Nutritionist for Kentucky Equine Research, and Jyme Nichols, PhD, Director of Nutrition for Bluebonnet Feeds and Stride Animal Health, and creator of the “Feed Room Chemist” podcast—to break down the essential components of the equine diet and share strategies to develop a balanced ration that meets your horse’s needs.

Nutrient No. 1: Energy

One of the most misunderstood nutrients in a horse’s diet, energy is measured in calories, which are essential in supporting a horse’s bodily functions and activity.

“Horse people tend to think of the word energy as [a horse] being excitable or having lots of stamina, but in nutrition it means calories,” explains Nichols. “The other big misunderstanding is where the bulk of calories in the [horse’s] diet come from—people think of grain and supplements, but most calories are supplied by forage.  In fact, adding one extra flake of alfalfa hay provides more calories than any 2-ounce pump of oil or a half-cup of rice bran.”

As herbivores, or plant eaters, horses have digestive systems designed for fiber-rich diets that come from grazing hay and pasture.  And some easy-keepers or senior horses in maintenance (not being exercised regularly) thrive on high quality hay or pasture alone. 

“In nature, horses spend most of their time grazing grasses and other plants,” explains Young.  “So, it’s important when making feeding choices to start with forage.  All equines need forage to provide calories and other nutrients, plus forage provides fiber to help keep the digestive tract healthy.  Insufficient fiber can lead to digestive problems such as colic.” 

In general, Young recommends feeding at least 1 to 2 percent of a horse’s body weight in hay, and add more or less according to the horse’s body weight and body condition score (see sidebar on page 47 or visit https://ker.com/weight).

For example, a 1,000-pound horse requires a minimum of 10 to 20 pounds of hay (or dry matter) per day.  Pasture grasses have a higher water content than hay,  Young adds, so a horse requires more pasture than hay to fulfill its caloric needs.  Furthermore, hays tends to be deficient in other nutrients, such as some amino acids, vitamins, and minerals. 

That’s where adding a high quality grain-based, concentrated feed or ration balancer is necessary to fill the nutrient and caloric gaps. If your horse is in training or competition, performing heavy work, or is pregnant or in early lactation, there’s a good chance it needs additional calories. 

Nutrient No. 2: Protein

Protein is made up of amino acids, some of which a horse’s body naturally produces on its own and some that must be supplemented in its diet.

“Amino acids are ubiquitous in the equine body,” says Young, adding that there are several essential amino acids that must be provided in the horse’s diet, including lysine, methionine, and threonine. “Amino acids are the building blocks for all proteins, including muscle tissue, and are found in enzymes, blood, everywhere in the horse’s body.”

Photo courtesy of Kentucky Equine Research.

In Nichol’s experience, feeding a high quality hay often contains enough protein which, if fed at 2 percent of the horse’s body weight per day, the horse should get enough.  However, you must factor in some waste.

“If you’re losing 5 pounds of hay to wind, rain or trampling, you should increase how much you offer to offset the difference,” she says.  It’s always better to overfeed hay than to underfeed it.”

Young emphasizes the importance of feeding high quality hay for maximum nutrition.

“There are several factors that affect the quality of hay, therefore its nutrient content,” she explains.  “The higher the quality of hay, the better the horse’s digestive tract is able to digest and absorb the nutrients in the hay.”

When evaluating hay quality, she recommends looking for more leaves than stems (and small diameter stems), few seed heads or blooms, cleanliness (low dust) and a fresh, green appearance.

Nutrient No. 3: Vitamins & Minerals

“Once grass is cut, it fairly quickly loses its vitamin activity, particularly vitamins A and E,” says Young. 

Minerals are a bit more complex because they interact with each other and can create imbalances. For example, too much calcium in the diet will inhibit phosphorus absorption and vice versa. Nutritionists recommend at least a 2 to 1 ratio of calcium and phosphorus. Other mineral deficiencies and imbalances can cause developmental bone diseases in young horses.

Above: If your horse requires additional calories and nutrients, find a concentrated feed or ration balancer that fills the gaps. Below: High quality hay or pasture is the foundation of a horse’s diet. A horse should consume 1 to 2 percent of its body weight in forage per day.

“In growing horses you only get one chance to get it right,” says Young, explaining that you can’t undo growth disorders caused by nutritional deficiencies.

Rather than trying to balance dietary vitamins and minerals on your own, Young suggests feeding a high quality commercial feed or ration balancer from a reputable company, or consulting a state equine extension specialist, feed company nutritionist, or an independent nutritionist to help determine what your horse needs.

Photo courtesy of Kentucky Equine Research.

“I want to know the horse’s breed, age, body weight, body condition score, and everything it’s being fed,” she explains, adding that it’s important to physically weigh your horse’s hay and grain on a scale rather than measuring in terms of flakes or scoops, as flakes and scoops vary in size and weight. 

Nutrient No. 4:  Water

“Water is the most important of all nutrients,” says Nichols. “A horse can drink up to three 5-gallon buckets of water a day. It is essential to all metabolic functions in the body, digestive health, and brain health.  “Horses who are not getting enough water each day will be more susceptible to impaction colic, will have a slower recovery time after exercise, and will have less stamina during performance.”

To evaluate your horse’s hydration level, Nichols recommends the simple “pinch test.”

“Pinch up a small fold of skin on the horse’s neck with your thumb and index finger and then release it,” she says. “If it snaps back to a flat position all is well, but if a ridge remains for two seconds or more, that’s a sign your horse may be dehydrated.”

Beside the amount of water your horse receives, the temperature and cleanliness are also important considerations. 

“If the water is too warm or too cold, a horse won’t drink as much,” observes Young.  “Water consumption directly affects feed intake. In the winter, a horse tends to not drink as much if the water is too cold, which leads to decreased feed intake and weight loss.  When the horse then gets cold and shivers, it requires even more calories to stay warm. It’s a downhill spiral that can be disastrous.”

On the road, horses sometimes refuse to drink water that smells and tastes different.  Some horse owners add sports drinks, electrolytes, and other flavorings at home and continue it when traveling to mask the smell and taste of the water.

“I generally recommend a metabolic pH balancer for horses that don’t drink well,” says Nichols, recommending TurboMag BCAA by Stride Animal Health.  “This ensures a specific cation-anion balance that improves cellular hydration, keeps a horse drinking and prevents things like impaction colic. I also include a tablespoon of loose salt in a horse’s feed every day of the year, no matter what.”

Before adding supplements to your horse’s diet, work with your veterinarian or an equine nutritionist to determine your horse’s specific needs.  

Young recommends the Hydration Hay Original Horse Hay Block, a blend of quality grass and alfalfa that has been compressed into small blocks.  Place the block in a bucket of water and it creates a moist hay.

“A two-pound hay block absorbs five times its weight in water,” says Young.  “You can place it in a bucket and hang it in the trailer and the horse will ‘eat’ its water while going down the road.”

Amounts & Adjustments

As a general guideline, Nichols and  Young recommend feeding a horse free-choice hay in a slow-feeding hay net or feeder.  This not only prevents boredom, which can lead to vices such as cribbing, wood chewing, and stall walking, but it also mimics the horse’s natural instincts to graze small amounts continuously. With horses, feeding small amounts several times a day is best for their digestive systems and mental well-being. 

“I break the grain portion up into two equal feedings, morning and night, being careful to never feed more than five pounds at one meal,” says Nichols. “Horses digest and absorb nutrition better when the meal size is small.  If I’m feeding a senior horse who cannot eat hay and must get the entire diet from pelleted feed or forage pellets, I will feed three times a day, if possible, because the volume is so large at each feeding.  If morning and evening feeding is the only option, I will feed in a large trough or big rubber tub so the feed is spread out in a single thin layer.  I may even throw in some large, smooth rocks or a small salt block, so the horse has to slow down and eat around these items.”

When changing the type or amount of feed in a horse’s diet, both nutritionists emphasize making gradual adjustments.

“The bigger the change, the more gradual,” says Young. “If you’re [transitioning] between similar feeds, make the change over three to four days.  Allow 10 to 14 days for more drastic changes.”

Nichols suggests a 12-day transition for grain, changing one-quarter of the ration every four days until you’re feeding a full ration of the new feed.  Both Young and Nichols also recommend gradually adding new hay to a horse’s diet to help prevent colic.

“Most people don’t think about transitioning between hay loads, but research shows that it takes up to three weeks for a horse’s digestive system to adjust to a new load of hay (even if both loads are the same general type of hay),” explains Nichols.  “Research also shows that horses are more likely to colic in the first 28 days after transitioning to a new load of hay. So, always blend the old load and the new load, and work your horses into it gradually as outlined above with the grain.  If you are going from grass to alfalfa or vice versa, this is ultra-critical.”

The foundation of every horse’s diet is forage, but as a responsible horse owner it’s your responsibility to assess whether your horse needs additional nutrients to support its activity level.  Adding the recommended amount of a concentrated feed or ration balancer can fill any nutritional gaps and keep your horse happy and healthy. 

Body Condition Score

Use these guidelines to determine if your horse is in good flesh or could use more nutrients in its diet. View the complete chart at https://ker.com/weight

1. Poor: Animal extremely emaciated; spine, ribs, tailhead, points of hip and buttock projecting prominently; bone structure of withers, shoulders and neck easily noticeable; no fatty tissue can be felt. 

3. Thin: Fat buildup about halfway on spine, slight fat cover over ribs; spine and ribs easily discernible; tailhead prominent but individual vertebrae cannot be identified visually; points of hip appear rounded but easily discernible; points of buttock not distinguishable; withers, shoulder and neck accentuated.

5. Moderate: Back is flat (no crease or ridge); ribs not visually distinguishable but easily felt; fat around tailhead beginning to feel spongy; withers appear rounded over spine; shoulders and neck blend smoothly into body. 

7. Fleshy: May have crease down back; individual ribs can be felt, but not noticeable filing between ribs with fat; fat around tailhead soft; fat deposited along withers, behind shoulders and along neck. 

8. Fat: Crease down back, difficult to feel ribs; fat around tailhead very soft; area along withers filled with fat; area behind shoulders filled with fat; noticeable thickening of neck; fat deposited along inner thighs.