Feed = Fuel: 5 Tips for Your Horse’s Diet

Formulate a diet that’ll supply your horse with the nutrients he needs.

By William Rhodes, DVM, With Kaycie Timm, Photos by Kaycie Timm

Three horses eating from a hay feeder
Basing your horse’s diet on forage—such as grass, hay, or alfalfa—will help him maintain gastrointestinal health and can even aid in ulcer prevention.

With countless feed and supplement options, all of which claim to be the best for your horse, formulating a diet can be a daunting task. In my veterinary practice, I often see confused horse owners who have overcomplicated their horse’s eating plan in an effort to give him everything he needs to perform. Here, I’ve outlined five tips to help you put together a diet that will nourish your reiner and keep him healthy all season long.

Start With Forage

The basis of your horse’s diet, regardless of his performance level, should be good quality forage, such as grass, hay, or alfalfa. Your horse’s gastrointestinal tract was designed for digesting forage. I recommend investing in the best quality roughage you can, then basing the rest of your feed choices around that. 

Allowing your horse to graze on that forage source will also help your horse’s gastric health by stimulating the production of saliva. Saliva is a natural buffer of acid, and acid is what causes ulcers. The more time your horse spends working his jaw, the more saliva he’ll produce, which protects him from the acid that forms ulcers. For horses who don’t have access to pasture, I suggest using a slow-feeder method that simulates grazing. That slows down your horse’s intake and allows him to “graze” on that roughage. The longer he’s eating, the more saliva he’ll produce to buffer acid and prevent ulcers. 

The No. 1 issue I see in performance horses is gastric ulcers. If your horse is prone to ulcer problems due to the stress of his training regimen and hauling schedule, I suggest using alfalfa as your forage base. Alfalfa is high in calcium, which is another natural buffer for acid that’ll help prevent the formation of ulcers. This will in turn help your horse maintain a healthy weight, because the most common clinical sign of ulcers is reduced appetite, which often leads to undesirable weight loss. 

Balance Key Nutrients

With quality forage as the basis of your horse’s diet, a packaged feed can round out his nutritional program. You’ll find a variety of well-balanced, concentrated feeds that are optimized for performance horses, but it’s important to ensure that your horse will receive the right amount of protein and fat content.

Horses rely on amino acids from high-quality protein sources for targeted muscle growth. In most cases, a feed that provides about 12% to 14% protein should give your horse the amino acids necessary to build muscle. Most packaged feeds undergo thorough testing to ensure that the contents come from sources that’ll effectively nourish your horse, so you can trust he’s getting quality nutrition. 

Horse eating feed out of a bucket
Rely on nutritional sources proven to properly nourish your horse.

Fat content needs differ based on your horse’s body type as well as the type and intensity of exercise he’s doing. For a reining horse, you want a steady, quieter type of energy—not short, intense bursts like you’d need in a racehorse. Feeds with high fat and low starch content work best for a reiner, because you want his energy to burn longer, not hotter. 

The key with fat content is maintaining the proper ratio of omega fatty acids. While some fatty acids, such as fish oils, are anti-inflammatory, others actually promote inflammation. I’ve seen horses show clinical signs of muscle problems or recurring pain because they were supplemented with a
pro-inflammatory fat. Generally, cheaper fat sources, like vegetable and corn oils, promote inflammation that can be manifested as lameness and chronic inflammation.

It’s also important to keep in mind that the higher the fat content, the lower the palatability. If you supplement with a lot of fat, your horse might not want to eat his food. So, unless your horse has a known muscle problem, additional fat supplements likely won’t be beneficial.

Assess the Individual 

The portion of feed your horse needs depends largely on the intensity of his training and exercise. A young horse under a strenuous training program—such as a futurity- or derby-aged horse—needs more calories. An older, more mature horse might only need forage, not concentrated feed, especially during the off season.

Most feed companies provide a good baseline to help you determine how much your horse needs. Generally, you can find a chart on the feed bag listing recommended portions based on weight and workload (such as light, moderate, or intense). 

From there, you can adjust based on your horse’s individual needs after a few weeks of evaluation. Every horse is different, just like people, with different body and muscle types, so don’t be alarmed if your horse needs more or less feed than the other horses in your barn.

When you’re monitoring your horse’s weight, it’s important to differentiate if he’s losing fat or muscle mass. Horses generally lose fat, not muscle, when you limit their feed intake. If your horse loses muscle mass, such as over his topline, consult your veterinarian to rule out any underlying health problems. 

Horse looking over white fence
Your horse’s activity level and living environment, among other factors, play roles in determining his dietary needs.

Keep It Simple

Once you’ve ensured that your horse receives high-quality forage, sufficient protein, and an optimal amount of fat, don’t overcomplicate your horse’s diet. Although some supplements and additives may be beneficial, others can actually be harmful. The wrong combination of feeds and supplements can disturb the proper ratio of minerals in your horse’s system and result in a toxic reaction. Consult your veterinarian or a nutrition expert to ensure that everything in your horse’s diet plan works together. 

One supplement most horse owners want to use is something to protect their horse’s joints. First and foremost, it’s important to remember that nothing you feed, inject, or administer externally will replace good horsemanship when it comes to keeping your performance horse sound. However, a joint supplement can help your horse by supplying what he needs to withstand a rigorous schedule. Although it’s not absolutely necessary, a quality joint supplement from a reputable company can give your horse an added layer of protection.

Ask an Expert 

As you put together a diet for your reiner, it’s likely you’ll have questions. Take advantage of available resources and nutrition experts to address those concerns about your horse’s feed plan. Your veterinarian should be the first person you contact. Although we’re not “nutritionists,” we can often point you in the right direction. I know several experts in equine nutrition that I can call when I have questions, and we can work together to formulate the best diet for your horse.


Dr. Bill Rhoads

As founder and head veterinarian at Premier Equine Veterinary Services in Whitesboro, Texas, William Rhoads, DVM, provides cutting-edge veterinary care to equine athletes. Rhoads also offers continued care to many of his patients through his mobile equine clinic.