Alfalfa is a popular forage choice for horses and an ingredient in many equine feeds. This legume forage can be processed and preserved in many different ways to make it easier to incorporate into the diet.
Alfalfa is nutrient-dense and is an excellent source of energy, protein and minerals in the equine diet. It is also typically low in non-structural carbohydrate content.
This makes it a valuable roughage to include in the diets of pregnant and lactating mares, mature performance horses, or other horses requiring protein supplementation.
However, some horse owners hesitate to feed alfalfa due to concerns about its safety. If you are considering adding alfalfa to your horse’s diet, and want to know if it is a good choice, then this article is for you.
Alfalfa for Horses
Alfalfa (Medicago sativa) or lucerne is a perennial legume plant that is grown as a high-yield forage crop around the world.
Alfalfa originates from the Mediterranean and southwest Asia. It has since been developed into various cultivars that can withstand a range of growing conditions.
Due to its deep root structure, alfalfa is known to be drought tolerant and grows best in well-drained, loamy soil.
Optimal growing conditions are average day temperatures of 25oC (77oF), 600 – 1200 mm annual rainfall and soil pH of 6.5 – 7.5. 
Alfalfa is a high-yielding forage crop that can produce up to 27 tons of dry matter per hectare with a higher protein yield than soybeans. 
It can be seeded for pasture grazing but requires rotational grazing strategies because it is less tolerant to intensive grazing than grasses such as timothy or teff.
Nutritional Composition of Alfalfa
Alfalfa is known as the “Queen of Forages” because of its high protein and energy content, making it an important protein source for the livestock industry. 
Below are averages and reported ranges of nutritional profiles over 200,000 legume hay samples analyzed by Equi-Analytical from 2004 – 2022: 
- Crude Protein: 21% (18 – 24%)
- Acid Detergent Fibre: 30.5% (27 – 34%)
- Neutral Detergent Fibre: 38.5% (33.5 – 43.5%)
- Water-soluble carbohydrates: 8.8% (6.8 – 10.8%)
- Ethanol-soluble carbohydrates: 6.8% (5.2 – 8.4%)
- Starch: 1.3% (0.5 – 2.15%)
Grass hays such as timothy, teff, orchard grass, or brome tend to be lower in protein and higher in neutral detergent fibre (NDF) than alfalfa hay. NSC (starch and sugar) content is also higher in grass hay.
Nutritional values vary depending on growing conditions, soil nutrient levels and harvesting conditions. The only way to know the composition of the alfalfa hay you are feeding to your horse is to submit a sample for analysis.
The major factors that influence the nutritional composition of alfalfa include: 
- Growth stage
- Cut number
- Leaf-to-stem ratio
- Moisture conditions
- Processing methods
As the plant matures, the protein content decreases and the fibre (NDF and ADF) content increases. The protein content is densest in the leaves, whereas the stems are high in fibre.
The leaf-to-stem ratio is higher in earlier growth stages; at this stage, the stems are lower in fibre. The leaves are less abundant at later growth stages, and the stem becomes more rigid due to higher fibre and lignin content.
The nutritional content of alfalfa at different growth stages is: 
|Vegetative (30 cm)||No visible buds, flowers, or seed pods||24.6||20.1|
|Vegetative (60 cm)||May feel buds, no flowers or seed pods||22.5||24|
|Bud||Visible buds, no flowers or seed pods||19.3||30|
|Flowering||Visible flowers, no seed pods||17.8||31.5|
Alfalfa should be harvested between the late vegetative and early flowering stages to obtain the most nutritionally-dense and palatable hay while supporting plant regrowth.
Alfalfa is a high-yielding crop that can be cut several times through the growing season. In North America, three or four cuts of alfalfa hay are typically achieved in one season.
The first cut often contains weeds and other grasses, and the alfalfa may have a high stem content. Depending on growing conditions, the second cut may have a lower leaf-to-stem ratio than later cuts. 
The handling of alfalfa after cutting can significantly impact its nutritional profile. Baling at a lower moisture content increases the loss of leaves and therefore reduces the protein content.
In contrast, baling at a higher moisture level maintains a higher nutritional value but increases the risk of mold growth and may require applying preservatives. 
Processing methods, such as raking during hay curing, can also affect leaf loss and nutritional value. 
Forms of Alfalfa for Horses
As a feed for horses, alfalfa can come in many shapes and sizes, from pasture to chopped hay to processed pellets. While most forms of alfalfa provide the same nutrients on a dry weight basis, some forms may have unique nutritional qualities.
Below are some of the characteristics of different forms of alfalfa.
Alfalfa pasture is generally higher in protein and energy content than grass pasture. This makes it a good option for horses in heavy exercise, growing horses and lactating mares.
Alfalfa is also a palatable forage; horses often prefer it over grass. However, some research suggests that horses prefer clover over alfalfa pasture. 
Alfalfa hay can be purchased alone or mixed with grass hay (i.e. Timothy/Alfalfa blends). Horses typically prefer alfalfa hay over grass hays, such as Bermuda or Brome hay. 
Alfalfa is easily digested and provides a good source of calories, protein, vitamins and minerals, making it ideal for horses that need a nutrient-dense diet. 
The hay is also rich in digestible fibre, which supports hindgut health and microbial fermentation. Microbes in the horse’s hindgut convert the fibre into volatile fatty acids, which are an excellent source of energy for horses. 
Alfalfa haylage is a fermented form of alfalfa that is commonly fed to dairy cattle. It provides a higher nutrient density when compared to alfalfa hay, but it must be processed and preserved properly so that mold and bacterial toxins do not form.
Haylage and silage are commonly fed to horses in Europe and other parts of the world, where frequent rainfall makes it hard to dry properly and bale hay.
Chopped alfalfa, also called green chop alfalfa, is cut and fed immediately before it has dried. This form of alfalfa is commonly fed to dairy cattle.
Green chop alfalfa has a nutritive value similar to alfalfa pasture, although its energy and protein content can vary depending on the plant’s maturity stage at the time of harvesting.
Chopped alfalfa can also be fed after it has dried, although the nutrient density is lower due to leaf fracture and loss.
Alfalfa cubes are made from dried, compressed alfalfa hay. These hay cubes can also be sold in a mix with other forages.
The cubes typically have a nutrient profile similar to alfalfa hay and are digested similarly. 
Alfalfa cubes are a good option for underweight horses with dental issues, as they can be soaked to form a mash that does not require extensive chewing.
Alfalfa pellets are made from ground alfalfa hay that is formed into a pellet. The pellets typically have a smaller particle size than alfalfa cubes.
The digestibility of pellets is similar to hay, although horses may voluntarily consume more pellets than hay. 
Alfalfa pellets can be an excellent energy and protein source for underweight horses with dental issues.
Cubes and pellets are also less dusty than hay and result in lower feed waste. However, diets that have much of the long-stem hay replaced by cubes or pellets can affect natural foraging behaviours and may increase stereotypical behaviours such as cribbing. 
Pellets may also increase the risk of choke because they can be consumed very quickly with minimal chewing required. 
Benefits of Alfalfa for Horses
Alfalfa is a nutritious forage that can benefit many classes of horses, including those with elevated energy, protein, or vitamin and mineral requirements.
Due to its high energy, protein, and calcium content, alfalfa must be carefully added to the diet to avoid dietary imbalances.
Growing horses require a carefully balanced diet to support healthy development. Alfalfa is a good forage source to meet young horses’ digestible energy and protein needs.
However, feeding alfalfa hay on its own may provide too much digestible energy, which can lead to a fast growth rate and increase the risk of developmental orthopedic disease. 
Since alfalfa is quite high in calcium relative to phosphorus, it must be added to the diet in an appropriate balance to avoid a high calcium to phosphorus ratio, which can impact growth and bone development.
Mares in the early stages of lactation have some of the highest energy and protein requirements of any class of horse. It is important to feed lactating mares an adequate diet to ensure they produce enough good quality milk to support the health of their growing foal.
Alfalfa hay is a particularly good option for lactating mares because it is nutrient-dense. Additionally, the higher voluntary intake compared to other hays makes it a good option if a mare’s appetite is limiting her intake.
Horses with Ulcers
Because of its high protein and calcium content, alfalfa is effective at buffering stomach acid. This can help increase the stomach’s pH and reduce the risk of gastric ulcers.
Gastric ulcers occur when stomach acid causes painful lesions or sores to form on the lining of the horse’s stomach. Ulcers are particularly prevalent in performance horses, affecting up to 100% of Thoroughbred racehorses. 
Feeding alfalfa may also decrease the secretion of gastric acid from stomach cells. Research in rats shows that a high-calcium diet inhibits the production of stomach acid, resulting in a higher pH. 
Researchers have found that diets containing alfalfa hay significantly decreased the number and severity of gastric lesions in horses. 
Additionally, alfalfa can be a good option to meet caloric needs while avoiding excessive concentrate intake. Grain-based feeds can exacerbate ulcers due to high non-structural carbohydrate (NSC) content. 
Horses in moderate to heavy work have higher energy and protein needs than those at maintenance. Alfalfa can be used as a portion of the forage supply to meet these needs.
Alfalfa can also benefit exercising horses at higher risk of gastric ulcers by helping buffer gastric acids. 
Keep these considerations in mind when adding alfalfa hay to the diet of an exercising horse: 
- Heat production: Protein generates more heat during digestion than fat. The high protein content of alfalfa may impact performance by increasing body temperature.
- Hydration status: Excess protein consumption increases the need to eliminate nitrogen via urine which removes water from the body and can impact hydration during exercise.
- Electrolyte balance: The high calcium content can disrupt electrolyte balance during and after exercise.
These factors have less of an impact on horses performing short bursts of intense exercise (i.e. racehorses) and are more of an issue for horses performing prolonged exercise (i.e. endurance racing).
It is generally not recommended to feed a high level of alfalfa (more than 30% of forage) to endurance horses. 
Common Concerns with Alfalfa
Some horse owners express concerns about feeding alfalfa to their horses because they worry about contributing to hot behavior, effects on the calcium-to-phosphorus ratio of the diet, and whether alfalfa causes enterolith formation.
Some of these concerns are not supported by research, while others can be managed by properly balancing the diet with the inclusion of alfalfa.
Alfalfa has developed a reputation as a forage that is not appropriate for metabolic horses. Some horse owners believe it should not be fed to horses with Equine Metabolic Syndrome because it has NSC content.
Alfalfa is typically higher in energy density than grass hay, but the higher energy content does not come from non-structural carbohydrates.
Several studies have compared alfalfa hay with other hays such as Orchard, teff, wheat, and oat. In general, the NSC content of alfalfa is lower than grass or cereal hays. 
Other factors such as drought, cold stress, the stage of maturity and the time of day when the hay is cut have a greater impact on the NSC content of the hay than plant species.  Submitting your hay for forage analysis is recommended to determine NSC content.
Whether or not alfalfa causes more reactive behaviour than other types of forage has not been studied closely in horses.
However, evidence shows that feeding an alfalfa meal base in place of grain may reduce the incidence of stereotypies such as cribbing.  Other components of the diet fed in combination with alfalfa may impact the frequency of stereotypic behaviours. 
A properly balanced diet that includes alfalfa has not been shown to increase reactivity.
Calcium to Phosphorus Ratio
Alfalfa is higher in calcium relative to phosphorus content, leading to a high calcium-to-phosphorus ratio if the diet is not properly balanced.
Most mature horses tolerate a calcium to phosphorus ratio of up to 9:1, while growing horses tolerate a ratio of 6:1 as long as phosphorus requirements are met.
If you are feeding alfalfa, you may need to add other sources of phosphorus to your horse’s diet to ensure the calcium-to-phosphorus ratio remains within advisable limits. Feeds such as wheat or rice bran and supplements such as monosodium phosphate can be used to increase phosphorus intake and balance the diet.
High proportions of alfalfa in the diet (greater than 50 – 70% of dry matter) are associated with a risk of enterolith formation. Enteroliths are mineral-based stones that form in the intestines when a horse consumes an indigestible foreign object.
Horses fed high-alfalfa diets have higher colonic mineral concentrations and lower colonic pH, which may explain the heightened risk of enteroliths.
However, most horses fed a high alfalfa diet do not develop enteroliths, so the higher risk may not be due to alfalfa consumption alone.  Additional factors such as a lack of pasture access could lead to enterolith formation. 
If your horse needs alfalfa in their diet, a properly balanced feeding plan and good management practices can go a long way to preventing the development of enteroliths.
Anecdotal reports suggest some laminitis-prone horses may be sensitive to alfalfa inclusion in the diet. Alfalfa intake appears to trigger laminitis episodes in susceptible horses. 
It is unclear why this occurs but could be due to excess protein intake from alfalfa hay. High protein intake can alter hindgut function, which could influence gut health and inflammation.
In addition, elevated amino acids in the blood following alfalfa intake can stimulate insulin secretion, affecting laminitis risk. 
If your horse is prone to laminitis, it may be advisable to switch to grass hay if you notice increased hoof sensitivity when fed alfalfa.
Some horse owners express concerns that alfalfa hay makes their horse cough. 
However, it is not the alfalfa hay itself but rather the dust or mold content of any hay that can aggravate respiratory conditions such as heaves.
The dustiness of hay is related to the moisture content. Drier alfalfa hay will tend to be dustier as the leaves are more likely to shatter.
Alfalfa hay is generally baled at a higher moisture level than grass hays. This keeps a higher proportion of leaves intact, which ensures a high protein hay. However, if stored or handled incorrectly, the higher moisture content can lead to more mold and mycotoxins, which can irritate the respiratory tract. 
Regardless of the type of forage, always evaluate your hay for the presence of dust and mold. Dusty hay can be soaked or steamed to reduce respiratory irritants. Look out for brown or grey spots in the hay which can indicate mold and avoid feeding this hay.
Blister beetles are a pest commonly found in Midwestern states such as Kansas, Oklahoma and Colorado. They are attracted to blooming forages, such as alfalfa. These beetles produce a toxin called cantharidin which can be deadly for horses.
Horses that consume alfalfa contaminated with blister beetle fragments or oils from the beetle may show signs of gastrointestinal or urinary irritation, including: 
Talk to your hay provider about the presence of blister beetles in their fields, especially if your hay is from the mid-western US.
Black Blotch Disease
Alfalfa is prone to black blotch disease caused by the Cymodothea trifolii fungus.
This can lead to liver damage and secondary photosensitivity in horses, particularly those with light coloured coats. 
When to Avoid Alfalfa
While alfalfa offers many benefits, some horses do not need such a nutrient-dense forage and may not tolerate alfalfa well.
Feeding horses that do not require a high protein intake free-choice alfalfa can lead to excessive nitrogen excretion. 
Horses with kidney or liver issues should not be fed high-protein diets as these diets require increased urine production to eliminate excess amino acids.
Horses that require a calorie-restricted diet to maintain an optimal weight should be fed grass forage rather than alfalfa. Alternatives such as grass hay, cubes, or pellets will better meet the needs of easy-keepers.
In addition, horses with metabolic concerns (especially those that are overweight) may not tolerate large amounts of alfalfa. Recent research shows that very high protein meals cause a high insulinemic response in horses with metabolic syndrome. 
Alfalfa hay is typically higher in potassium than grass hays. It should be avoided by horses with hyperkalemic periodic paralysis (HYPP), who require diets low in potassium. 
Below are example diets for mature 500 kg (1100 lb) horses with alfalfa hay included at no more than 20% of the forage. These diets use typical alfalfa hay (20% crude protein, 40% NDF) and grass hay (10% crude protein, 67% NDF).
Note that every horse has unique needs and each feeding situation has practical limitations. For help with designing the right feeding plan for your horse, submit their information online to receive free guidance from our equine nutritionists.
Healthy 500 KG Horse in Light Work
Horses in light to moderate work likely do not need alfalfa hay to meet their energy requirements, but they can tolerate small amounts. Adding too much alfalfa hay can lead to weight gain.
Mad Barn’s Omneity vitamin and mineral supplement is added to the diet to ensure vitamin and mineral requirements are met.
|Feed||Light Work Diet|
|(Amount / Day)|
|Alfalfa Hay||1 kg (2.2 lb)|
|Grass Hay||10 kg (22 lb)|
|Salt||30 g (2 tbsps)|
|Omneity Pellets||200 g (2 scoops)|
|Digestible Energy (% of Req)||103%|
|Protein (% of Req)||155%|
|NSC (% Diet)||7.8%|
Healthy 500 KG Horse in Heavy Work
For horses in heavy work, forage may not be sufficient to meet their energy needs. Adding alfalfa cubes boosts the energy supply while serving as a carrier for calorie-dense oils.
In this diet, Mad Barn’s w-3 Oil is added as a palatable fat supplement enriched with the omega-3 fatty acid DHA and natural vitamin E.
|Feed||Heavy Work Diet|
|(Amount / Day)|
|Alfalfa Hay||2 kg (4.4 lb)|
|Grass Hay||11 kg (24 lb)|
|Alfalfa cubes||0.5 kg (1 lb)|
|Salt||30 g (2 tbsps)|
|Omneity Pellets||200 g (2 scoops)|
|w-3 oil||120 ml (4 oz)|
|Digestible Energy (% of Req)||101%|
|Protein (% of Req)||168%|
|NSC (% Diet)||8%|
500 KG Mare in Early Lactation (2 Months)
Alfalfa hay is a great way to add protein, energy and calcium to a mare’s diet while she is producing a high volume of milk. Oats and roasted soybeans are also good sources of calories.
After three months of lactation, the mare’s milk production will begin to decrease. At this time, the alfalfa hay and other calorie sources can be decreased depending on the broodmare’s body condition.
|Feed||Heavy Work Diet|
|(Amount / Day)|
|Alfalfa Hay||3 kg (6.6lb)|
|Grass Hay||7.4 kg (16 lb)|
|Alfalfa cubes||1.5 kg (3.3 lb)|
|Roasted Soybeans||0.75 kg (1.6 lb)|
|Oats||1 kg (2.2 lb)|
|Salt||30 g (2 tbsps)|
|Omneity Pellets||225 g (2.25 scoops)|
|w-3 oil||200 ml (6.5 oz)|
|Digestible Energy (% of Req)||100%|
|Protein (% of Req)||124%|
|NSC (% Diet)||11.6%|
Alfalfa is a staple in many horse diets and can be an excellent source of energy, protein, and minerals for horses that have higher nutritional requirements.
Mature horses in light exercise may not need the higher nutrient density of alfalfa, but this forage can be incorporated into most feeding plans in small to moderate amounts as long as the diet is balanced properly.
If you are interested in adding alfalfa to your horse’s diet but are unsure of how to balance it properly, you can submit your horse’s information for evaluation by one of our professional equine nutritionists.
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