Grain and Concentrates for Horses: When They Help and When They Hurt

Horses are built to eat forage for most of the day. Hay and pasture support normal chewing, saliva production, and hindgut fermentation. Grain and other concentrates can be useful tools, but they are supplements to a forage-based diet, not the foundation for most horses. In practical terms, concentrates are most helpful when a horse has calorie or nutrient needs that forage alone cannot meet, such as heavy work, growth, late pregnancy, lactation, recovery, or trouble maintaining body condition.

The challenge is that starch and sugar from grain are digested very differently from fiber. When a horse gets too much starch in one meal, some can escape the small intestine and reach the hindgut. There, rapid fermentation can disrupt the microbial balance and increase the risk of gas, loose manure, colic, laminitis, and other metabolic problems. That risk is higher with large meals, abrupt diet changes, and in horses with insulin dysregulation, equine metabolic syndrome, or a history of ulcers or laminitis.

Not all concentrates are the same. Traditional sweet feeds and straight cereal grains tend to be higher in starch. Ration balancers, beet pulp, soy hull-based feeds, and some senior or low-starch complete feeds can provide calories or nutrients with less starch load per meal. Feed labels, guaranteed analysis, and the manufacturer’s feeding directions matter. So does the horse in front of you.

If you are wondering whether your horse needs grain, the best question is not "Is grain good or bad?" It is "What problem are we trying to solve?" Your vet can help match the feeding plan to body condition, workload, dental status, metabolic risk, and forage quality.

There is no one-size-fits-all amount. A horse’s safe intake depends on body weight, forage intake, exercise level, age, dental health, and medical history. As a starting point, many equine nutrition references advise keeping forage as the main part of the diet and using concentrates only as needed. Horses generally need at least about 1% to 1.5% of body weight in forage dry matter daily, and many do best with more forage access than that.

For cereal-grain concentrates, a practical benchmark for many healthy horses is to limit each meal to no more than about 0.5% of body weight. For a 500 kg horse, that works out to about 2.5 kg per meal, or roughly 5.5 lb for a 1,100 lb horse. Another commonly cited starch guideline is about 2 g starch per kg body weight per meal. Horses with insulin dysregulation, equine metabolic syndrome, or gastric ulcer concerns may need even smaller meals and lower-starch feed choices.

If your horse needs more calories than that limit allows in one feeding, the safer approach is usually to split concentrates into multiple smaller meals and increase calories with forage-friendly options when appropriate. Examples may include beet pulp, soy hull-based feeds, added fat products formulated for horses, or a complete senior feed if chewing hay is difficult. Any change should be made gradually over 7 to 14 days.

Weigh feed instead of scooping by volume. A coffee can or feed scoop can hold very different weights depending on the product. If your horse is easy-keeping, overweight, cresty, or has had laminitis, ask your vet whether grain should be reduced or avoided and whether a low-NSC plan would be safer.

Too much grain or the wrong concentrate plan can cause mild to severe digestive and metabolic trouble. Early warning signs may include leaving feed, eating too fast, loose manure, mild belly discomfort, pawing, flank watching, or a horse that seems dull after meals. Some horses show behavior changes first, especially if they are uncomfortable from ulcers, gas, or rapid diet shifts.

More serious signs can include diarrhea, repeated colic signs, marked depression, dehydration, sweating, increased heart rate, or reluctance to move. Laminitis is one of the most important complications to watch for after grain overload or major hindgut upset. A horse may look stiff, rock back onto the hind end, resist turning, or seem painful in the feet hours to a day or more after the digestive upset begins.

Feed-related problems are not always dramatic. Horses with insulin dysregulation or equine metabolic syndrome may gain weight, develop a cresty neck, or have recurrent foot soreness when starch and sugar intake are too high. Seniors with poor teeth may also struggle with whole grains or coarse feeds and can lose weight or quid feed instead of benefiting from the ration.

See your vet immediately if your horse gets into the feed room, breaks into grain, has colic, develops diarrhea, seems weak or depressed, or shows any signs of laminitis. Grain overload can become an emergency quickly, and early treatment may reduce the risk of severe colitis, endotoxemia, and founder.

If your horse needs nutrients but not a lot of starch, there are several options to discuss with your vet. A ration balancer can be a good fit for easy keepers on adequate hay or pasture because it provides concentrated vitamins, minerals, and protein in a small daily amount. Many 50 lb bags run about $30 to $40 in the U.S., but the daily feeding amount is small, so monthly cost can still be reasonable.

For horses that need extra calories with less starch than traditional grain, beet pulp and soy hull-based feeds are common choices. Beet pulp products often cost about $14 to $22 per 40 lb bag. They can help add fermentable fiber and are often useful for weight gain plans, though some products need soaking and all feeding changes should be gradual. Low-starch complete or senior feeds may also help horses with poor dentition or trouble chewing hay. These commonly run about $18 to $30 per 50 lb bag, depending on brand and region.

For horses at higher metabolic risk, the safest "alternative" may be less concentrate, not a different concentrate. That can mean tested low-NSC hay, slower feeding systems, more turnout if appropriate, and careful body condition monitoring. Cornell notes that horses with metabolic disease are often better managed with low-starch feeds, and hay can be tested for water-soluble carbohydrates and starch.

The best substitute depends on why grain was being fed in the first place. Weight gain, topline support, senior care, performance fueling, and mineral balancing are different goals. Your vet can help you choose a forage-first plan that fits your horse’s workload, teeth, body condition, and medical risks.