E Q U I N E AT H L E T E
Eating greens Benefits and drawbacks of alfalfa for horses By Heather Smith Thomas
Forage is the most natural feed for horses, as opposed to grain, and should make up the bulk of every horse’s diet. Forage (as hay or pasture) can be divided into two categories—grasses and legumes. Grass hay can be anything from orchard grass, timothy, bluegrass, bromegrass, etc. to fescue and coastal bermuda grass, or some of the cereal hays (oats, barley). Legumes for horses are generally alfalfa and various clovers. “Alfalfa is a perennial legume, grown in most regions of the U.S. for horses and other livestock,” says Krishona Martinson PhD (Equine Extension Specialist, University of Minnesota Department of Animal Science). Alfalfa grown in drier climates often makes better hay for horses than alfalfa grown in wet climates because the hay dries more readily, according to Martinson. It’s easier to get harvested without mold. Alfalfa also grows best in well-drained soils rather than wet soils, since it originated as a desert plant. Too much soil moisture will kill it. “Another important factor for growing alfalfa is to have the correct soil pH—within the recommended levels and soil types,” says Martinson. History of alfalfa Dr. Ray Smith, Professor and Forage Extension Specialist at University of Kentucky, says alfalfa was one of the first domesticated forages, planted and harvested by early people in what is now Iraq-Iran several thousand years ago. They had discovered its nutritional benefits for horses, especially for horses being worked hard. “The main feed for horses of early armies in those regions was alfalfa,” says Smith. “In its early development as a forage crop, much of it was grown under irrigation or partial irrigation in that dry region. In recent years, modern plant breeding has enabled this legume to adapt more readily to various conditions, including the more humid Eastern U.S., and alfalfa’s disease resistance has also been improved,” he says. “When alfalfa was first brought to the Eastern U.S. in the 1700s from Europe it didn’t survive well— partly because of wetter soils and lower pH. The nutrient content of soils in high-rainfall areas wasn’t 16 POLO P L A Y E R S E D I T I O N
good; much of the nutrients leaches out of wet soils.” By contrast, when alfalfa was brought to the Western U.S. in the 1800s during the Gold Rush in California, to grow feed for livestock, it did very well in that arid climate and soil types. “Use of alfalfa grew rapidly in the Western U.S. By the late 1800s and early 1900s, we began to learn more about adding lime to soils, to change the pH and make it more appropriate for growing alfalfa. Plant breeding was also beginning by the 1900s and plant scientists were able to develop alfalfa that could adapted to various soils in the U.S.” says Smith. Benefits of alfalfa “The biggest benefit of alfalfa for horses is that it tends to be more nutrient-dense than most grasses when harvested at the same stage of maturity,” says Martinson. Alfalfa tends to have more digestible energy, and more crude protein and calcium, and lower levels of non-structural carbohydrates. Alfalfa is a good feed for horses that are underweight (since it is nutrient dense), or horses prone to gastric ulcers (since the extra calcium acts as a buffer for acid in the stomach). “It can also be beneficial to horses with muscle problems that are prone to tying up, or horses with Equine Metabolic Syndrome (EMS) due to the lower amount of nonstructural carbohydrates,” she says. Horses with insulin resistance, Cushings, etc. can’t handle the high sugar content of some grass hays. Alfalfa is typically lower in sugar. For horses that are sensitive to the sugar content or carbohydrates in feed, a legume diet or mixed legume/grass diet will help lower the total sugar intake. Most owners of a sugar-sensitive horse realize the grain portion of the diet should be reduced or eliminated, since oats, corn and barley are 55 to 75% carbohydrates. But the forage component of the diet should also be evaluated. If hay is fed at 2% of body weight or more, that’s 20 or more pounds of hay. If the hay is 10% sugar, that’s a lot of sugar! It can be helpful to have hay tested, to see what the nutrient levels actually are. The biggest benefit of alfalfa is for horse owners who want to keep their horses on a higher plane of
