What is the difference between legume hay and grass hay?
The main difference is how legumes and grasses grow and make proteins. Legumes, such as alfalfa, clover, and peanut, use bacteria in their roots to grab nitrogen from the environment to make proteins. Grass hays, such as timothy, orchard, bermuda, and rye, don’t have this relationship and therefore have a much harder time making protein.
Legumes are higher in protein, which can be super for growing horses and pregnant mares. The increased protein, sometimes around 15%, can give your horse extra energy. The nitrogen and proteins are broken down and excreted in your horse’s urine, which might make him drink more water. This is definitely not good for the horse with kidney troubles, which is rare but does occur.
The lower protein levels and subsequent higher fiber content of grass hays mean your horse will be getting more fiber, thus requiring him to eat a bit more. Great for boredom busting!
At the feed store. Some of this hay has seen better days....
Legumes are also higher in calcium. This is both good and not so good. For the ulcer prone horse, the extra calcium acts as a buffer for stomach acids which have been linked to ulcers. However, the high calcium is not recommended for any horse at risk of enteroliths - big mineral balls in the gut. Some enteroliths are the size of soft balls or more - and obviously can create massive digestive system problems. Enteroliths are seen in Arabian and Quarter Horses, and sometimes in certain parts of the country. Your horse’s breeding, lifestyle, diet and overall health come into play here, your Veterinarian can help you decide if your horse is at risk.
The calcium is also a problem when compared to the amount of phosphorus. You may have heard of the calcium phosphorus ration, which is high in legumes and more normal and suited for horses in grasses. The high calcium can interfere with bone growth, so while the proteins and calories can be great for growing horses, you will likely need a phosphorus supplement to correct the ratio.
A batch of timothy hay!
Legumes are also delicious, which leads to much less wasted hay on the farm. The higher calories, combined with the deliciousness, are not always compatible with the easy keeper type of horse.
This is a second cutting of a grass and alfalfa blend, straight from the farmer.
At the end of the day - you can’t really say one is horrible and you should never feed it. Both have positives and negatives - just find the balance. Many hay growers also grow legume and grass blends, so that your horse has the benefits of both. Your Veterinarian and/or Equine Nutritionist can help you sort out the details so your horse has a balanced diet based on his needs.
Do you feed legumes, grass, or a combo?