All About Alfalfa

What is Alfalfa?

If you own a horse, chances are you are familiar with alfalfa. When forage for horses is discussed, there are two broad categories: grasses and legumes. Alfalfa is a legume that is commonly included in hay. This forage plant tends to be nutritionally dense and can be a great addition to equine diets. In fact, if you have been to a feed store, you have likely been exposed to the vast variety of ways alfalfa can be fed. Of course, there is hay and pasture, but we also have processed forages (e.g., hay cubes and pellets) and it is a common ingredient in pelleted concentrates as well.

Nutritional Content of Alfalfa

There has been a variety of studies that compare alfalfa to other forages such as grass hay and the general trends are that it is higher in energy, protein, calcium, and potassium, while being lower in non-structural carbohydrates. It is regarded as a quality protein source for horses that supplies essential amino acids.

I often like to browse feed databases, as I find it incredibly interesting to look at the varying nutritional profiles. In the Equi-Analytical Feed Composition Library for the years 2021-2022 here is a comparison of legume hay vs. grass hay.

When to be Cautious?

Although alfalfa is a great feed ingredient for horses, it is not ideal for every situation. It is important to consider the high protein, additional energy and differing mineral content of this forage. Alfalfa often gets a bad reputation with easy keeper horses and those that have metabolic challenges. I commonly experience these owners thinking that this is due to a high non-structural carbohydrate content – however, that is not the case.

Alfalfa is not recommended for easy keepers or those that tend to be overweight as it is typically higher in digestible energy. Additionally, there is new research that shows that feeding metabolic horses a large protein meal can cause a spike in the blood insulin. Therefore, if your horse is overweight, it is unlikely that alfalfa is the optimal choice for them.

Another consideration with the higher protein content is hard-working horses. Horses that consume more protein than is required will often drink more and urinate more as protein cannot be stored in the body. For healthy horses this is not a concern, but for horses that are working to the point of dehydration or for horses with liver issues the protein intake should be calculated by a nutritionist. Alfalfa can also be a concern for horses that need to be maintained on a low potassium diet such as those suffering from hyperkalemic periodic paralysis (HYPP) however, please note that you must test the hay and these nutritional values cannot be assumed. There is a plethora of factors that impact the nutritional value of hay other than the species of grass or legume that is planted (e.g., soil nutrient content, weather conditions, time spent drying, etc.).

When to add Alfalfa?

Alfalfa can be a great addition to a nutrition program for horses that have higher nutritional requirements. This includes growing horses, broodmares, underweight horses, and horses with a heavy workload. Another situation that alfalfa is commonly a go-to for is when gastric ulcers are reoccurring.

For young and growing horses, additional protein and energy are required to support their growth. However, with growing horses, balance is crucial, and it is highly recommended to have a nutritionist balance the ration for you. When a young horse is growing too quickly the risk of developmental orthopedic disease increases, additionally when there are skewed mineral ratios or deficiencies it can be detrimental to healthy growth.

Broodmares towards the end of gestation and in early lactation have extremely high protein and energy requirements. To support these mares in producing milk for their growing foal alfalfa is often incorporated into the diet.

For working horses or those that struggle to maintain weight and topline, alfalfa is optimal. If these horses are being fed a forage that has a poor nutritional value, you may end up having to feed large quantities of concentrates to supplement their ration. Since horses have evolved to graze and consume forage this can negatively impact their gastrointestinal health. Therefore, sourcing a forage that is nutrient-dense like alfalfa can make all the difference in their nutrition program.

Even if a horse is not part of one of these groups they may benefit from the addition of alfalfa. Unfortunately, gastric ulcers are a common issue in the equine industry, and it is widely known that alfalfa can help to reduce this risk. The high calcium contact helps the forage to act as a buffering agent against stomach acid. Therefore, feeding alfalfa is a common preventative measure taken for horses’ recovery from gastric ulcers or those at a high risk of developing them.

Keep in mind, that everything needs to be balanced. A ration, even for a horse with high protein requirements, is not going to be 100% alfalfa. It is recommended that if you are including alfalfa in the ration, you include it at a rate of about 10-30%.

To conclude, alfalfa is a neat plant that plays an important role in equine nutrition. Due to its popularity, there are many misconceptions about the feed ingredient. This article has covered the basics, but if you have any questions on whether your horse would benefit from the inclusion of this high-quality forage simply send me a message, I would be happy to chat and ensure your horse is on the right track nutritionally.

By: Madeline Boast, MSc. Equine Nutrition

References:

DeBoer, M. L., Martinson, K. L., Kuhle, K. J., Sheaffer, C. C., & Hathaway, M. R. (2019). Plasma amino acid concentrations of horses grazing alfalfa, cool-season perennial grasses, and teff. Journal of equine veterinary science, 72, 72-78.

Equi-Analytical Feed Composition Library. Accessed October 10^th, 2023.

Grev, A. M., Hathaway, M. R., Sheaffer, C. C., Wells, M. S., Reiter, A. S., & Martinson, K. L. (2021). Apparent digestibility, fecal particle size, and mean retention time of reduced lignin alfalfa hay fed to horses. Journal of animal science, 99(7), skab158.

Loos, C. M. M., Dorsch, S. C., Elzinga, S. E., Brewster-Barnes, T., Vanzant, E. S., Adams, A. A., & Urschel, K. L. (2019). A high protein meal affects plasma insulin concentrations and amino acid metabolism in horses with equine metabolic syndrome. The Veterinary Journal, 251, 105341.

National Research Council. Nutrient Requirements of Horses. (2007). National Academy Press, Washington, D.C.