Why You Shouldn't Be Afraid of Feeding Alfalfa to Horses

As with a number of things in the horse world, many people have strong opinions about alfalfa hay and those opinions range from “it’s the best thing ever” to “there is no way I am ever feeding that to my horse.” The nutritional profile of alfalfa is neither good nor bad; however, we need to be aware of the unique attributes of alfalfa to ensure that it is incorporated into the diet in a way that is beneficial to the horse.

Isn't There Too Much Protein in Alfalfa for Horses?

On average, alfalfa is higher in protein compared to grass varieties of hay. An equine diet that incorporates a high proportion of alfalfa as the source of forage will supply crude protein in excess of the horse’s daily requirements. Excess protein in and of itself is not an issue for healthy horses. They will break down the excess dietary protein into ammonia which will be excreted in urine. Horses will create more urine in this process, so you may find that your horse will consume more water and their stall will be more wet on this type of diet. This increases your need for bedding and if stalls aren’t managed appropriately, the buildup of ammonia can contribute to respiratory issues.

High dietary protein does not lead to kidney dysfunction in horses; however, pre-existing kidney issues are exacerbated by excess protein intake. Because most of the horse’s diet is forage, an alfalfa hay wouldn’t be recommended for a horse with kidney disease; however, alfalfa meal as a small component of a commercial horse feed wouldn’t necessarily be a problem provided the total protein content of the product isn’t excessive.

Balancing the Mineral Profile of Alfalfa for Horses

The mineral profile of alfalfa differs significantly from grass hays; specifically, alfalfa is, on average, much higher in calcium. When balancing diets, the calcium to phosphorus ratio is something we look very closely at for certain classes of horses. The mature adult horse who is not used for breeding can tolerate a wide calcium to phosphorus balance (7:1) as long as the minimum phosphorus requirement is met. For these horses, we don’t necessarily need to feed a product specifically designed to complement a high alfalfa forage.

On the other hand, the diets of broodmares and growing horses must be very carefully balanced for a calcium to phosphorus ratio between 1:1 and 2:1. The risk of developmental orthopedic disorders increases significantly when the calcium to phosphorus ratio exceeds 2:1, which is often the case of grass/alfalfa blends and almost always the case in a straight alfalfa hay diet. Maintaining the proper balance of these minerals throughout gestation, lactation and through the growth of the young horse is key to supporting proper growth. Most horse feeds are not designed to supply enough phosphorus to offset a high calcium forage. Tribute® Superior Equine Nutrition has designed Alfa Essentials® and Alfa Growth® to supply a greater amount of phosphorus, compared to calcium, in order to complement a high alfalfa diet.

As a general rule of thumb, Alfa Essentials® and Alfa Growth® are designed to complement a diet that is 50% or greater alfalfa. We recommend using a hay analysis to confirm the exact calcium to phosphorus ratio of the diet used in breeding operations as visual inspection of hay cannot guarantee the correct ratio will be achieved.

Does Alfalfa Cause Hyperactivity in Horses?

One of the perceived issues commonly cited by the “there is no way I am ever feeding that to my horse” camp is that alfalfa makes horses hot. It was long thought that the protein content of feed drove hyperactivity in horses; however, we now know that sugars and starches drive hyperactive behavior. Alfalfa, on average, is lower in sugars and starches than grass hays, but it is also more energy dense, and the flakes are often heavier. Therefore, switching from 2 flakes of grass hay to 2 flakes of alfalfa would provide more total pounds of forage and that forage would provide more energy per pound. These two combined simply give the horse more available energy. This can be very helpful when you are working to put weight on a horse, but a horse that is already in good weight may use the additional energy for purposes that aren’t as desirable.

Benefits of Alfalfa for Horses

Alfalfa as a component of the horse's diet brings in high quality protein and highly digestible fiber that is translated to a good calorie source for weight gain or to support work. Alfalfa meal brings these attributes to commercial horse feed products and an alfalfa/grass blend hay or adding a few flakes of alfalfa to a grass-based diet can be beneficial. A 100% diet of alfalfa forage isn’t detrimental when additional steps are taken to ensure the total diet is balanced and the stable can be managed in a way that doesn’t result in ammonia buildup.

For questions about your horse's diet please contact us for a personalized equine feeding plan.

Article By: Nicole Rambo, Ph.D.
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