This is the third article in the “Fix It With Feed” series. Check back every Wednesday for more articles on nutrition and how it affects performance.

It’s green and leafy and horses love it, but alfalfa hay also has a bit of a bad-boy reputation in the horse world. It’s been blamed for colic and high spirits, but does alfalfa deserve the stigma?

The simple answer is “no,” since alfalfa hay is an excellent source of protein, calories, calcium and Vitamin A for horses. But alfalfa also isn’t for every horse—when making a decision about whether to incorporate alfalfa into your feeding program, it’s important to be informed about its strengths and weaknesses.

“Alfalfa is an excellent hay choice in many cases. I feed alfalfa to my own horses,” said Dr. Laurie Lawrence of the University of Kentucky’s Department of Animal Sciences. “I recommend it often, but not in every situation. It’s important for horse owners to remember that they should select the hay that best suits the nutrient requirements of their own horses.”

Let’s say you have a training-level event horse that competes five or six times a year, has access to good pasture, and is always on a diet because he’s a bit on the chunky side. Would alfalfa be a good choice for him? No. The same goes for an adult amateur hunter who shows once or twice a month and has no trouble keeping weight on.

But if you have a broodmare in foal, or a weanling growing up, alfalfa is an excellent forage choice. It’s an equally good option for a high-level athlete who can’t seem to maintain a healthy weight. In addition, alfalfa has been shown to have buffering effects on stomach acid, helping to reduce the incidence and severity of gastric ulcers.

“If he’s an easy keeper, and he maintains well on grain, grass hay and pasture, then you probably don’t need to add in any alfalfa,” said Tania Cubitt, Ph.D., a nutritionist with Performance Horse Nutrition LLC. “The harder keeper, or a higher performing athlete that needs to take in more calories to maintain condition, would be candidates for alfalfa. Broodmares and growing foals also have increased energy demands, and protein and mineral needs, and they benefit from alfalfa.”

It’s Packed Full Of Nutrients

While many people think of alfalfa hay as a kind of high-octane fuel for horses, the fact is that much spring pasture grass has more protein and calories than alfalfa hay.

Comparison of the nutrients in alfalfa with other forages

“In general, alfalfa has more energy than most grass hays, and that’s where its bad reputation comes from. Excess calories are energy. If you don’t exercise your horse enough, yes, it can alter his behavior and make him a little hyper. But if I fed him excess grain and didn’t exercise him, it would have the same effect,” said Cubitt.

Alfalfa is especially helpful for a hard keeper because of its high palatability—horses love to eat it. Feeding alfalfa is an excellent alternative to feeding excessive concentrates to get more calories into a horse’s diet.

“Alfalfa is usually lower in fiber, higher in energy, higher in protein and higher in calcium than grass hays. Because it is higher in energy and protein, using alfalfa makes it easier to meet those needs with minimal or at least lower levels of supplementation,” said Lawrence.

Because of its high calcium content, alfalfa needs to be fed with an eye to calcium-phosphorous ratio in the diet. Grass hay has low amounts of calcium and phosphorus, while feed concentrates (especially rice bran) have a lower amount of calcium and higher amounts of phosphorous. The ideal calcium to phosphorous ratio in the horse is a 2:1 ratio, but it can safely go as high as 5:1 in mature horses with no adverse effects. For more information on the calcium-phosphorous ratio, check out the website of Susan Evans Garlinghouse, DVM.

Which Alfalfa Is Right For My Horse?

Many farms on the West Coast of the United States feed exclusively alfalfa with no problems. But the ideal situation is to mix alfalfa with quality grass hay and good pasture forage.

There are alfalfa/grass hay mixes available in baled hay, but since alfalfa matures earlier in the spring than grass hays, it’s difficult to find mixed hay with excellent nutritional quality in both the alfalfa and grass.

If you’re adding alfalfa to your forage feeding, Cubitt advised feeding the best quality grass hay you can find and supplementing with alfalfa at meal times.

If good quality baled alfalfa isn’t available, substitute alfalfa pellets or cubes—1 pound of pellets or cubes is the equivalent of 1 pound of hay.

Early-cut alfalfa, when the plant is budding and before it blooms, is the most nutritious, since protein and total digestible nutrition levels fall as the plant matures. Early-cut alfalfa is leafy and has less fibrous stems than late-cute alfalfa, so it’s also more palatable.

If you want or need to feed alfalfa to a horse without a specific need for its high-protein and energy levels, feeding a late maturity cut of alfalfa is advisable. In any situation, planning your horse’s forage ration should be done with a careful eye to his whole ration, calculating his protein and energy needs and filling them with appropriate grain and forage.

It Soothes Stomachs Too

New research has shown that in addition to being an excellent energy and protein source, alfalfa hay also has the ability to buffer stomach acid and alleviate ulcer severity and formation.

A Texas A&M University study compared 12 horses eating a pelleted concentrate and Bermuda grass hay to 12 horses eating the same pelleted concentrate and alfalfa hay. Each horse in the study had been assigned a gastric ulcer score before the study began as a result of gastric endoscopy.

At the end of the study, the ulcer severity scores of the horses fed alfalfa had dropped overall, while the ulcer severity scores of the horses fed Bermuda grass hay had risen. “More than 80 percent of performance horses suffer from some varying degree of ulceration. Alfalfa is high in calcium, which has a buffering effect on the acid in the stomach,” Cubitt said.

“Adding a little alfalfa, especially prior to exercise, really helps buffer the stomach acid. If you’ve got a horse who wouldn’t otherwise need alfalfa in his diet—say, an easy keeper—but he has a history of ulcer problems, alfalfa can be beneficial. It doesn’t hurt before a stressful situation, whether it be trailering or competing, to add a little alfalfa to his hay net. Giving him some alfalfa half an hour or so before he’s ridden or trailered can help keep his stomach acid less acidic. If cubes or pellets are more convenient, that’s fine too,” continued Cubitt.

Alfalfa, The Myths

So why has alfalfa gotten such bad press with horse owners? Some worry that feeding alfalfa increases the risk of colic. Not so, says Lawrence. “Rapid diet changes are associated with colic, so it’s possible that if you change from grass hay to alfalfa hay all of a sudden, or you introduce alfalfa hay abruptly, you could increase the risk of colic,” she said. “Also, when good quality alfalfa is fed ad libitum [allowing the horse free access], horses may over-indulge, and that might increase colic risk as well.

“So if an owner wants to use alfalfa, two guidelines might be to: 1.) Change over to it gradually, and 2.) Limit or at least monitor intake to prevent overeating.”

There is also the misconception that alfalfa can cause kidney damage due to its high protein levels. That’s an old wives’ tale, probably inspired by the fact that horses with high protein intake tend to drink more water and therefore urinate more.

The body’s process for breaking down protein into calories results in nitrogen as a byproduct, which gets filtered out of the body in the horse’s kidneys. A horse that is converting excess protein to calories will drink more water to aid that filtering and will have urine with a strong ammonia smell, as the nitrogen is excreted as urea. But the excess protein does not harm the kidneys.

Some claim that alfalfa hay will make a horse hot or crazy. This isn’t true either. Alfalfa does provide a significant amount of calories, however, and excess calories in any form, whether from alfalfa, grain or oil, without the exercise to burn them, can result in an excessively energetic horse. Alfalfa fed with a careful eye to the proportions of the whole diet and the energy needs of the horse will not create excess energy.

Read Part 1: You Don’t Need A Ph.D. To Puzzle Out Protein
Read Part 2: Feeding A Hard Keeper Is All About Extra Calories And Patience