Timothy hay is the most widely recommended all-around hay for horses, but the best choice depends on your horse’s workload, weight, and health. Grass hays like timothy and orchardgrass suit the majority of horses, while legume hays like alfalfa work better for growing foals, broodmares, and hard-working performance horses. Picking the right type comes down to matching the hay’s calorie and protein content to what your horse actually needs.
Grass Hay vs. Legume Hay
Horse hay falls into two broad categories: grass hay and legume hay. Grass hays (timothy, orchardgrass, bermudagrass, brome) are lower in calories, protein, and calcium. Legume hays (alfalfa, clover) pack significantly more of all three. Legume hay runs about 74% crude protein compared to roughly 54% for grass hay, and it delivers more digestible energy per pound. Legumes are also much richer in calcium, phosphorus, and magnesium.
For most adult horses at light to moderate work, grass hay provides everything they need without the excess calories that legume hay brings. Alfalfa isn’t “bad” for horses, but feeding it freely to a horse that doesn’t need the extra energy is a fast path to weight gain. Many owners use alfalfa strategically, mixing a flake or two into a grass hay diet for horses that need a calorie or protein boost.
Timothy Hay
Timothy is the gold standard for horse hay in much of the United States, particularly the Northeast and Midwest. It offers 7 to 11% crude protein and 0.7 to 1.0 Mcal of digestible energy per pound. Most horses find it very palatable, and its moderate nutrient profile makes it hard to overfeed. An average horse at maintenance needs roughly 18 to 20 pounds of early-cut timothy per day with no grain at all. Later-cut timothy drops in quality enough that some horses may need a few pounds of grain to make up the difference.
Timothy’s calcium-to-phosphorus ratio falls comfortably within the safe range for horses (the ideal is 2:1 calcium to phosphorus, with anything from 1:1 to 6:1 being acceptable). That natural balance means you’re unlikely to create mineral problems feeding timothy as the base of your horse’s diet.
Orchardgrass Hay
Orchardgrass has a nearly identical nutritional profile to timothy: 7 to 11% crude protein, similar digestible energy, and comparable fiber levels. It grows well in slightly warmer climates than timothy and produces multiple cuttings per season, which can make it easier to find and more affordable in some regions. Horses generally eat it readily.
One thing to watch: orchardgrass can have a calcium-to-phosphorus ratio that tips below the safe 1:1 minimum, especially when paired with grain. Oklahoma State University data shows that orchardgrass fed alongside oats can produce an inverted ratio of 0.68:1, which interferes with calcium absorption over time. If orchardgrass is your primary hay, a simple mineral supplement or adding a small amount of alfalfa to the diet corrects this easily.
Bermudagrass Hay
Bermudagrass is the dominant horse hay across the southern United States, where cool-season grasses like timothy struggle in the heat. Its protein (6 to 11%) and energy content are slightly lower than timothy or orchardgrass, and it tends to run lower in calcium (0.25 to 0.4%) and phosphorus (0.15 to 0.3%). Coastal bermudagrass, the most common variety fed to horses, is rarely available in northern states because it simply doesn’t grow there.
Like orchardgrass, bermudagrass can have a calcium-to-phosphorus ratio that inverts, sometimes landing around 0.71:1. A mineral supplement is worth adding if bermudagrass makes up the bulk of your horse’s forage.
Tall Fescue Hay
Tall fescue is abundant and inexpensive across the southeastern U.S., but it’s the least desirable common grass hay for horses. It delivers lower digestible energy (0.6 to 0.9 Mcal per pound) and lower protein (5 to 9%) than timothy or orchardgrass. Horses waste roughly twice as much fescue hay as alfalfa, largely because most fescue is harvested late when it’s stemmy and tough.
The bigger concern is that much of the tall fescue grown in the Southeast carries an endophytic fungus. This fungus produces compounds that can cause serious problems in pregnant mares, including prolonged gestation, thickened placentas, and reduced milk production. If you feed fescue, confirm it’s from endophyte-free or novel-endophyte varieties, and avoid it entirely for broodmares in the last trimester.
Alfalfa Hay
Alfalfa is the most nutrient-dense hay commonly fed to horses. Its high calcium content makes it an excellent choice for broodmares and growing foals, whose skeletal development demands extra minerals. The calcium-to-phosphorus ratio in alfalfa runs around 5.4:1, well within the safe range and far more favorable than most grass hays. Performance horses in heavy training also benefit from alfalfa’s extra protein and energy.
The downside is that alfalfa provides more calories than many horses need. For easy keepers, pleasure horses, or any horse that gains weight on air, straight alfalfa is too rich. It’s also higher in protein than idle or lightly worked horses require, and excess protein increases water intake and urination, which makes stall management messier. A common approach is feeding alfalfa as 25 to 50% of the hay ration, with grass hay making up the rest.
Best Hay for Easy Keepers and Metabolic Horses
If your horse is overweight or has been diagnosed with a metabolic condition like insulin resistance or laminitis, hay selection becomes especially important. The general rule is to feed grass hay, not legumes, and aim for hay with a sugar and starch content (called nonstructural carbohydrates, or NSC) below 10 to 12%. You can’t determine NSC by looking at hay. It requires a laboratory forage test.
Feed at least 1.5% of your horse’s target body weight in good-quality grass hay daily. For a 1,100-pound horse that should weigh 1,000 pounds, that’s 15 pounds of hay per day. Limit or eliminate pasture access, since fresh grass is higher in calories and sugar than hay. If you cut grain entirely, a ration balancer provides the vitamins, minerals, and protein your horse needs in a low-calorie package.
Teff hay has gained popularity as a specialty forage for metabolic and overweight horses. It’s a warm-season grass that’s naturally higher in fiber and lower in sugar and starch than most cool-season grasses. Research from the University of Minnesota confirms that teff’s nutrient profile produces a smaller spike in blood glucose and insulin compared to other hays, which is exactly what metabolic horses need. The tradeoff: teff can have an inverted calcium-to-phosphorus ratio, so testing and calcium supplementation are important. Some horses also refuse to eat it because the high fiber and low sugar make it less palatable.
How Maturity Affects Hay Quality
The single biggest factor in hay quality isn’t the grass species. It’s when the hay was cut. Hay harvested early, before the plant heads out and goes to seed, has thinner stems, more leaves, and substantially more protein and digestible energy. Hay cut late is coarser, stemmier, and less nutritious. This is why a late-cut timothy bale can actually be lower in quality than an early-cut fescue bale.
Leaves contain far more nutrients than stems, so the leaf-to-stem ratio is one of the best quick indicators of quality. Good hay has abundant intact leaves, fine stems, and minimal leaf shatter (leaves falling off when you handle the bale). This matters more than species when you’re standing in front of a hay barn trying to decide what to buy.
How to Evaluate Hay Quality
Before you ever send hay to a lab, your eyes and nose tell you a lot. Good horse hay is green, which indicates it was cured properly without excessive sun bleaching or rain damage. It smells like fresh-cut grass. Hay that looks brown or black, or that smells musty, mildewy, or sour, has likely been baled too wet or stored poorly. Mold isn’t always visible, but that off smell is a reliable warning sign.
For storage, hay should be baled at 12 to 15% moisture. Anything above 20% on exposed surfaces encourages significant mold growth, and moisture above 30% can produce the kind of heavy black mold that covers entire bale surfaces. Excessively wet hay also generates heat internally, which in extreme cases creates a fire risk in hay barns.
A laboratory forage analysis gives you the numbers that matter. The key values to look at on a hay test report are crude protein, digestible energy, and fiber measurements (ADF and NDF, which tell you how digestible the hay is, with lower numbers meaning better digestibility). For metabolic horses, NSC is the critical number. Testing costs roughly $15 to $30 per sample and is available through most state university extension labs. If you’re buying hay by the ton from a single source, one test tells you exactly what you’re feeding for months.
Matching Hay to Your Horse
The simplest way to think about hay selection is to match calorie density to workload. Idle and lightly worked horses do best on moderate-quality grass hay. Horses in heavy work, lactating mares, and growing youngsters benefit from higher-quality grass hay or a grass-alfalfa mix. Metabolic horses need tested, low-sugar grass hay, potentially teff if it’s available in your area.
- Idle or lightly worked adults: Timothy, orchardgrass, or bermudagrass hay. No grain needed for most horses if hay quality is decent.
- Performance horses in moderate to heavy work: High-quality grass hay supplemented with alfalfa, or a grass-alfalfa mix.
- Broodmares and foals: Alfalfa or alfalfa-grass mix for the extra calcium, protein, and calories that support fetal growth and lactation.
- Overweight or metabolic horses: Tested grass hay with NSC below 10 to 12%. Teff hay if available. No alfalfa, limited or no grain, restricted pasture.
Regional availability shapes your options as much as nutrition does. If you’re in the South, bermudagrass will be your most affordable and accessible choice. In the Northeast and upper Midwest, timothy and orchardgrass dominate. Work with what grows well in your area, test it if you can, and adjust with supplements or small amounts of alfalfa when the numbers call for it.