Skip to Content

Is Alfalfa Hay Good for Horses? Benefits and What to Avoid

Is Alfalfa Hay Good for Horses? Benefits and What to Avoid

This post may contain affiliate links. We earn from qualifying purchases. Learn More

Getting your horse’s nutrition right is crucial to their health, well-being, and performance. However, with so many options out there, it can be difficult to determine which feeds to include in your horse’s diet.

It is important to know that horses have a primarily grass-based diet and consume around 1.5-2% of their body weight per day. They usually eat a combination of grasses that can include timothy, tall fescue, bermudagrass, perennial ryegrass, and legumes such as alfalfa or clover.

Alfalfa is a nutrient-dense perennial legume characterized by a high protein and low sugar content. It is also a rich source of many essential vitamins and minerals such as folic acid, nitrogen, and calcium.

Alfalfa is fed to horses around the world, usually in hay or pelleted form.

While there are clear benefits associated with this type of forage, many owners are put off feeding their horses alfalfa.

In this article, we aim to clear up common misconceptions and provide useful information about feeding alfalfa to your horse.

Is Alfalfa Hay Good for Horses?

Alfalfa hay is good for horses that struggle to keep on weight or require extra calories to perform well. Horses with metabolic disorders or insulin resistance, foals, and lactating mares can also benefit from alfalfa hay.

On the flip side, alfalfa hay can cause more harm than good if fed in excess quantities. Owners of good-doers and high-energy horses should refrain from feeding alfalfa as this will provide unnecessary calories.

Two dapple grey horses eating alfalfa hay
AZP Worldwide /

Introducing alfalfa hay to your horse’s diet requires careful consideration of your horse’s needs. If you’ve done your research and are still unsure whether this forage is right for your horse, consult your vet or equine nutritionist for advice.

Benefits of Feeding Alfalfa to Horses

Even though alfalfa is more pricey than most other types of forage, the benefits often outweigh the costs.

By adding quality protein and other nutrients to your horse’s diet, alfalfa can boost your horse’s immune system, muscle tone, and general health.

The main benefits of feeding your horse alfalfa include:

Nutritional Support

Compared to grass hay, alfalfa hay is more nutritious when cut at the same stage of maturity. It generally contains more crude protein, digestible energy and calcium, and less sugar and starch than other types of hay.

Feeding your horse alfalfa hay will provide them with an excellent source of protein, vitamins, and key minerals such as potassium, calcium, iron, phosphorus, and magnesium.

For example, foals that aren’t getting enough protein from their mother’s milk can be fed alfalfa to compensate for this deficiency.

Horses that are prone to tying-up (also known as Monday Morning Disease) should also be fed alfalfa to increase their protein levels.

What’s more, alfalfa contains amino acids that promote muscle regeneration, according to equine nutritionist Stephen Duren, PhD. Therefore, alfalfa hay is beneficial to horses that need to develop muscle along the topline and other areas.

Energy Source

A black, bay, and gray horses eating Alfalfa hay from a trough
Oleksandrum /

Alfalfa hay contains high-quality fiber that provides slow-release energy and is an excellent forage for maintaining weight and replacing lost calories.

Owners should consider feeding alfalfa to horses that work hard or expend a lot of energy. Examples are racehorses, sport horses, pregnant and lactating mares, and growing horses.

Weight Management

As mentioned above, alfalfa hay is ideal for horses that need to put on weight. Its low sugar content also means that horses prone to laminitis or metabolic disorders can benefit from alfalfa hay for healthy weight management.

Low Sugar Content

If your horse is sensitive to nonstructural carbohydrates (sugars and starches), feeding them alfalfa hay is a good way to reduce sugar intake.

A well-balanced diet is essential to managing conditions like Cushing’s Disease, insulin resistance, or Equine Metabolic Syndrome (EMS). As many grass hays have a higher than ideal sugar content, mixing or replacing them with legume hay will benefit these horses.

Also read: How Much Does a Bale of Hay Cost?

When to Avoid Feeding Alfalfa Hay

While alfalfa is rich in many essential nutrients, its high-calorie content is not suitable for all horses. Owners should be familiar with the risks of feeding this leafy green legume and evaluate whether its the rigth choice for their horses.

You should take extra care feeding alfalfa hay to certain types of horses, such as:

Young Horses

Always consult your vet before feeding alfalfa to a young horse. Due to its high protein content, there is a risk of young horses growing too fast and contracting developmental orthopedic disease (DOD).

Krishona Martinson, PhD, associate professor University of Minnesota’s Department of Animal Science advises caution in the amount of alfalfa hay fed to growing horses. If you decide to feed your foal or yearling alfalfa, monitor their growth closely and adjust the amount accordingly.

Horses in Rest or Light Work

Horses with only maintenance level energy requirements should be fed grass hay over alfalfa to avoid excess calorie intake.

“The biggest issue with alfalfa is weight gain in horses that don’t have adequate exercise,” Martinson says. Equine obesity is a major issue in many countries due to horses in light work being fed high-energy feeds.

If your horse is not burning the extra calories he receives from alfalfa hay, consider switching to a less caloric forage to avoid obesity-related issues.

Mature grass hay tends to be less energy-dense than legume hay and is a far better option for horses on a diet.

Horses Working in Hot Weather

Woman riding a black horse in a cross country competition

Because of the extra heat generated by protein metabolism, horses working in hot weather should stay away from alfalfa hay.

Protein-rich feeds can not only impair the horse’s cooling ability, but also increase the risk of dehydration.

Moreover, since the body can’t store excess protein like fat or sugars, it must be flushed from the system via sweating and urination. This will make the horse drink more and add to the risk of heat stress in lack of a sufficient water supply.

Endurance Horses

Along the same lines, alfalfa hay is not recommended for endurance horses that sweat extensively during a race.

The increased water requirements, body heat, and urination can further hinder the horses’ ability to perform over long distances.

With that being said, endurance horses can still benefit from small amounts of alfalfa, as long as it’s not their primary forage source.

Horses with Kidney/Liver Problems

The high protein content of alfalfa hay doesn’t affect a healthy horse. However, it can impair the processing and elimination of protein in horses with kidney or liver problems. Such horses should be fed a low-protein diet to prevent further metabolic issues.

Horses with HYPP

Horses suffering from hyperkalemic periodic paralysis (HYPP) have higher than normal blood potassium levels. This makes them prone to periodic muscle spasms that can escalate to paralysis in more severe cases.

Therefore, horses with HYPP should only be fed limited amounts of alfalfa as its high potassium concentration can make the symptoms worse.

Alfalfa Hay Feeding Guidance

Most horses in rest or light work will meet their nutritional needs being turned out onto pasture or eating grass hay.

To determine whether your horse needs the additional nutrients and energy in alfalfa hay, you should calculate their digestible energy, protein, and mineral requirements.

Alfalfa hay bales in a field
B Brown /

You can use data from the National Research Council to calculate your horse’s nutrient requirements at different life stages and exercise levels.

Alternatively, your veterinarian, nutritionist, or feed manufacturer can all advise you on creating a balanced feeding routine for your horse. They will also give you pointers as to whether or not to include alfalfa in your horse’s diet.

When making any kind of change to your horse’s diet, it’s important to do it gradually over a period of a few weeks. This will give the microbes in the horse’s hindgut time to adjust and avoid any potential digestive issues.

Alfalfa hay is frequently fed mixed with grass hay to balance the horse’s energy intake. This is a popular option for horses on a higher plane of nutrition, such as racehorses, endurance horses, and competition horses. Alfalfa can also be fed in pelleted form as a supplement.

You can use a laboratory testing service to work out the exact nutritional value of your alfalfa hay. Factors affecting a crop’s nutrient and energy levels include maturity, soil composition, and harvest conditions.

Selecting Your Alfalfa Hay

When buying alfalfa hay for your horse, be sure to:

  • check that it’s free of dust and mold
  • aim for a good leaf-to-stem ratio as most nutrients are in the leaves
  • choose hay that’s a deep green color
  • buy from a reputable source so your hay is free of poisonous plants

What Happens if a Horse Eats too Much Alfalfa?

Letting a horse eat too much alfalfa can lead to colic due to excess gas production in the hindgut. The rich nutrients in alfalfa hay can also cause diarrhea, indigestion, and laminitis in overweight horses.

Five horses eating from a pile of hay in a field

On the longer term, keeping a horse exclusively on alfalfa hay would eventually lead to obesity and its associated issues.

The high protein content of this forage would also result in high levels of ammonia in the urine and poor air quality in enclosed spaces.

Frequently Asked Questions

Does alfalfa hay make horses hyper?

Alfalfa hay can make horses hyper if they don’t receive adequate exercise. Since alfalfa is more energy-dense than other types of forage, the unused calories will cause excitability just as concentrate feeds do.

Moreover, the high protein content of alfalfa will result in increased levels of acidity in the horse’s body, which can lead to inflammation in various areas. This can also make horses anxious, restless, or “hot”.

Does alfalfa cause laminitis?

Alfalfa can cause laminitis in horses due to its high protein content. Consuming more protein than needed can lead to excess glucose in the blood, raising insulin levels and potentially leading to inflammation in the feet.

Alfalfa hay is generally regarded as a suitable forage for horses prone to laminitis due to its low sugar levels.

However, its high protein and nutrient content can both trigger the condition in susceptible horses. Therefore, owners should counter the extra calories in alfalfa hay with regular exercise and a balanced diet.

According to the American Farriers Journal, consuming too much protein can overwhelm the horse’s body with amino acids. As these cannot be stored for later use, they must be degraded and eliminated from the body.

The metabolites from this degradation process will cause elevated glucose and insulin levels in the blood.

While insulin allows glucose to enter body cells and convert to glycogen for storage, it can also cause inflammation in the joints and feet, potentially resulting in laminitis.

Is alfalfa hard on horses kidneys?

Alfalfa itself won’t cause kidney problems in healthy horses. However, horses with existing kidney issues shouldn’t be fed alfalfa as they will struggle to process and excrete the extra protein.

“A normal, healthy horse can metabolize and excrete the extra protein in alfalfa just fine, if the horse has adequate water,” says forage extension specialist Ray Smith, PhD, from the University of Kentucky.

Horses with kidney dysfunction should be kept on a strict low-protein diet to avoid escalating the problem.

Does alfalfa cause ulcers in horses?

Alfalfa doesn’t cause ulcers in horses. In fact, the additional calcium in alfalfa acts as a buffer against acids in the stomach and can prevent the development of ulcers.

Some experts recommend offering horses alfalfa hay one to two hours prior to exercise to protect the stomach lining from splashing acids. The saliva produced from chewing will also act as a buffer and help prevent the formation of ulcers.

Is alfalfa good for senior horses?

Alfalfa alongside good-quality grass hay is an ideal forage choice for senior horses. Older horses often struggle to maintain their body weight and can benefit from the extra protein and calories in alfalfa hay.

Horses over a certain age will also have reduced fiber fermentation in the hindgut, meaning they can acquire fewer nutrients from the same amount of hay. As a result, they require higher quality forages in their diet, making alfalfa hay an excellent choice.

Many senior horse owners opt for a mixed legume-grass hay as a basis for their horses’ diet, such as alfalfa-timothy or alfalfa-orchard grass. Selecting less mature hay that’s easier to chew and digest is also recommended.

Older horses that have lost weight also require more proteins to help them build muscle.

Feeding alfalfa in chopped, pelleted, or cubed form will increase the quality and quantity of protein in their diet and provide much-needed calories.