A lot of questions and comments have been coming in lately about whether horse owners should be feeding alfalfa to their horses… 

Is alfalfa a suitable choice for extra calories in the winter? Will it help their horses put on weight? Will it increase performance by providing more energy and building muscle? Can it be used as a replacement for hay?

Let’s take a look…

Because alfalfa is considered as a type of forage many people think it is also a type of grass. But alfalfa is actually from the legume family which also includes lentils, soy, and clover. 

Alfalfa contains anywhere from 14% protein on the low end to a whopping 25% or more protein for dairy grade. As well, it is largely made up of a form of fiber called lignin which is not digestible. This indigestible fibre combined with high protein means that it is not a very efficient source of energy, but it can be used for its nutritional benefits as well as a protein supplement. 

Now, let’s consider the risks and the benefits of feeding alfalfa…


  1. Feeding more protein than your horse requires can result in gastric indigestion as well as fermentation and putrefaction in the hindgut. This can contribute to leaky gut and will create too much ammonia which is toxic to the liver and kidneys if accumulated in excess amounts.
  2. Horses that are on high protein diets become overly acidic which can cause inflammation in various body systems including the joints and hooves. They may get “hot”, anxious or agitated, or show signs of liver or kidney stress. In fact, some horses are so sensitive to alfalfa they cannot tolerate even small amounts.
  3. Too much alfalfa requires a lot of calcium to buffer the acidic metabolites from protein metabolism. If there is not enough calcium available, the body will remove calcium from the bones, joints, and muscles. In addition, alfalfa can overstimulate the pituitary gland.


  1. Alfalfa is a high protein forage, so it makes an excellent supplement for horses that are protein deficient or for horses that have higher protein requirements such as senior horses or pregnant or lactating mares. Protein is essential for both the growth and repair of muscles, bone, cartilage, skin, hair, and blood. It is also necessary for the production of enzymes, hormones, and antibodies.
  2. Alfalfa is nutritionally dense. It contains high levels of calcium, as well as magnesium, potassium, iron, phosphorus, lysine, vitamin C, vitamin K, and folic acid. 
  3. Alfalfa helps slow down sugar absorption into the blood. This can make it a useful dietary addition to the feed for metabolic horses if they can tolerate it. It can also benefit performance horses whose blood sugar is fluctuating due to increased physical demands.

The bottom line is…

There are many benefits to feeding alfalfa to horses especially if they are protein deficient or they have higher requirements such as performance horses and seniors. 

However, you cannot replace fibre with protein! Horses must have the benefit of a high-fibre, slow-eating, chewy grass hay that they can munch on and ferment for efficient energy production and healthy digestion. 

High protein feeds, including alfalfa hay, should ONLY be fed when required as a supplement to improve protein levels; but should never be used as a primary staple or to replace grass hay.

However, horses are not anatomically designed to metabolize large amounts of protein. They are designed to ferment fibre!

Interested in learning more?

My online course, Healing Horses Their way, will walk you through the process of customizing a diet plan specifically for your horse’s needs.  Click here to learn more.

Meet Elisha

I am an animal lover, health consultant, scientist and educator. I am passionate about delivering safe and effective health care to all animals but horses and dogs have a special place in my heart. I believe that through education and awareness of natural animal health we can drastically improve their quality of life and longevity. I invite you to join me on my quest to make the world a better place for all of them.