Horse owners have strong opinions when it comes to whether alfalfa should be a part of the equine diet. Some say there’s nothing better. Others view it as a kind of poison. The truth, of course, lies somewhere in between.
While alfalfa isn’t a complete, “whole” food for your horse, you don’t have to avoid it either — if you balance his diet so he’s getting everything he needs in the right amounts.
Let’s look at the pros and cons of alfalfa.
6 Alfalfa Pros
Here are six advantages of alfalfa.
- Taste. Horses love it! No argument there. Give a horse the opportunity to choose among flakes of all-grass hay, grass-alfalfa mix, and all-alfalfa, chances are he’ll chow down the alfalfa flake first.
- Availability. Alfalfa is often readily available and reasonably priced. Expert tip: If you use alfalfa as your sole hay type, get advice from a nutrition professional on how to properly balance your feeding program.
Fiber. Alfalfa has lower indigestible fiber than grass hays.
- Calories. High-quality (“dairy”) alfalfa supplies 20 to 25 percent more calories per pound than grass hays, although the difference is much smaller for more mature cuts of alfalfa.
- Nutritional value. Heavily pregnant or lactating mares, and young rapidly growing horses, benefit from alfalfa’s high protein content. Alfalfa is also a rich source of calcium.
- Quality. Cubed and pelleted alfalfa tends to be very high quality. It is harvested before it becomes too mature so that the cubes and pellets hold together well. (Caveat: Watch for signs of overheating during processing, which damages the protein. Pellets and cubes should be green, not brown or black, on the outside.)
7 Alfalfa Cons
Now, here are seven downsides of alfalfa.
- Sensitivity. Insulin-resistant horses prone to laminitis may be sensitive to alfalfa. The cause isn’t entirely clear, but it may be related to alfalfa having more sugar in the form of glucose, and higher starch.
- High calcium content. The high calcium content of alfalfa causes an imbalanced calcium/phosphorus ratio if not corrected by other feeds or supplements. Most adult horses seem to tolerate this, but it’s not ideal for pregnant mares and growing horses. The high calcium also causes hormonal shifts that make it difficult for the horse to rapidly mobilize calcium from bone stores in times of need.
Waste. Due to alfalfa’s high protein content, excess protein will be burned as a fuel; the waste is eliminated in the urine as urea, which is converted to ammonia. Horses will drink more, leading to wetter, smellier stalls.
- Hard to cure/bale. Alfalfa can be trickier to cure and bale than grass hays. It needs a low enough moisture level so that it doesn’t mold, without being put up so dry that all its leaves shatter and fall off.
- Broken leaves. Alfalfa is prone to have more fines (broken, crumbled leaves). Since this is where the bulk of the nutrition is, this can be a considerable loss. Expert tip: Before opening a bale, put it on an empty feed bag. Feed your horse the small pieces that fall out.
- Grazing. Grazing on an alfalfa pasture requires the same precautions as feeding alfalfa hay, plus some additional considerations. For example, digestive upsets may be an even bigger problem, especially in the spring and fall when wide temperature swings can lead to rapid changes in plant composition. And unlimited access to such a highly palatable food as alfalfa may lead to significant weight gain.
- Intestinal stones. High-alfalfa/low-grain diets have been linked to the formation of enteroliths (“stones”) in the intestinal tract, which can cause colic and may need to be surgically removed.
Alfalfa Myths vs. Facts
Myth: The high protein in alfalfa causes osteochondritis dissecans (OCD), a joint disease of young horses.
Fact: High protein doesn’t cause OCD. Rather, low protein is a risk factor for OCD. What’s true, though, is that alfalfa’s unbalanced mineral profile could contribute to OCD.
Myth: The high calcium in alfalfa can prevent OCD and other bone problems in developing horses.
Fact: Calcium is important to developing bone, but so is phosphorus, magnesium, protein, and the trace minerals. Adequate mineral levels, in correct proportions, is the key.
Myth: Alfalfa’s high protein causes kidney problems.
Fact: High protein isn’t harmful to the kidneys. However, extra protein is metabolized to ammonia, which must be excreted by the kidneys. To handle this extra demand, your horse will drink more water and make more urine.
Myth: Alfalfa’s high protein makes a horse “hot.”
Fact: For reasons that really aren’t clear, some horses are more energetic when being fed alfalfa, but it isn’t the protein.
Myth: Alfalfa causes heaves or allergies.
Fact: Alfalfa is no more likely to cause an allergic reaction than any other type of hay. Molds growing in the bales can cause respiratory tract symptoms, but the same molds can –– and do ––grow in any type of hay.
Myth: Alfalfa can’t be fed to horses with hyperkalemic periodic paralysis (HYPP), because of the forage’s high potassium. (HYPP is a potentially fatal inherited disorder related to elevated potassium levels.)
Fact: Grass hays can be high in potassium too. In fact, depending on when they’re cut, they can be even higher.
Eleanor M. Kellon, VMD, currently works as a writer, teacher, and internal medicine/nutrition consultant. Prior to this, Dr. Kellon has had more than 10 years experience in private practice. She also has extensive experience with performance horses. She’s based in Pennsylvania, where she and her husband raise, train, and race Standardbreds. Her most recent book is Horse Journal Guide to Equine Supplements and Nutraceuticals (Globe Pequot Press).