How Much Hay a Horse Needs (and How to Choose It)

Author: Elliott Garber, DVM

Most horses need roughly 1.5 to 2 percent of their bodyweight per day in forage, which for a typical 1,000 lb horse works out to about 15 to 20 lb of hay when there is no pasture. That number is the starting point, not the final answer: you adjust it down for grass turnout and easy keepers, and up for hard keepers, cold weather, and heavy work. Just as important as the amount is that you weigh the hay rather than count flakes, because flake weight varies far more than most people expect.

How much hay a horse actually needs

The working rule from equine nutritionists is that a horse should eat between 1.5 and 2 percent of its bodyweight per day in forage, counting pasture, hay, hay cubes, and haylage together. The University of Minnesota Extension puts most horses at about 2 percent of bodyweight in hay daily, and notes that horses given free access will happily eat 2 to 2.5 percent. The Merck Veterinary Manual frames the same idea as 2 to 2.5 percent of bodyweight in total dry matter, with at least half of it coming from forage.

For a 1,000 lb horse, 1.5 to 2 percent is 15 to 20 lb of hay a day. If that horse is on good pasture for part of the day, the pasture covers a share of the forage and you feed less hay. If there is no grass at all, the full amount comes from the hay pile.

A few things push the number around:

• Easy keepers (the ones who get round on air) may need to sit near the low end, around 1.5 percent, to hold weight. In some weight-loss cases a vet or nutritionist will restrict forage further, but going too low has its own risks (more on that below).
• Hard keepers, growing horses, and lactating mares may need closer to 2.5 percent to keep condition.
• Cold weather raises the requirement. Forage fermentation in the hindgut generates heat, so a horse riding out a cold snap without a blanket can eat noticeably more hay than usual, sometimes up to about 3 percent of bodyweight.
• Work raises calorie needs, though a lot of that extra energy is better met by adjusting the ration with a professional than by piling on hay alone.

If you are not sure what your horse should weigh or whether it is at a healthy condition, our horse body condition guide and horse weight guide walk through scoring and estimating weight without a livestock scale. The broader picture of how hay fits with grain, ration balancers, and pasture lives in the horse feeding guide.

One firm floor: do not drop total forage much below about 1.5 percent of bodyweight without veterinary guidance. Feeding too little forage is linked to gastric ulcers, colic, and stereotypic habits like cribbing and wood chewing. Horses evolved to trickle-feed for most of the day, and long gaps with an empty stomach work against them.

Weigh the hay, do not count flakes

The single most common feeding mistake is measuring hay by the flake. A flake feels like a tidy unit, but its weight is anything but consistent. Kentucky Equine Research points out that some flakes are fluffy and light while others are densely packed, and that flake weight varies with forage type, moisture, flake thickness, and how the bale was made. Their example is stark: flakes from one style of grass bale can average under 4 lb each, while flakes from a bigger, denser bale can run close to 7 lb. Two horses fed “three flakes” could be eating wildly different amounts.

Penn State Extension makes the same case for weighing feed rather than eyeballing volume. The fix is cheap and takes five minutes: get a hanging scale (an inexpensive fishing or luggage scale works fine), weigh several flakes from a few different bales, and learn what your hay actually weighs per flake. Once you know that a flake of your current hay averages, say, 4.5 lb, you can portion by weight without weighing every single meal. Re-check when you open a new load of hay, because the next cutting or supplier will weigh out differently.

Grass hay versus legume hay

Hay falls into two broad families, and most horses do best on grass hay as the everyday base.

Grass hays (timothy, orchardgrass, brome, Bermuda, teff, and others) deliver moderate protein and calories that suit the majority of adult horses in light work or at maintenance. The Merck Veterinary Manual notes that grass hays give moderate protein, energy, and minerals, though a very mature, late-cut grass hay can drop below 8 percent protein. Some warm-season grasses like teff and Bermuda tend to run lower in sugar and starch, which matters for metabolic horses.

Legume hays, mainly alfalfa, are richer. The University of Minnesota Extension describes alfalfa as higher than grass in digestible energy, amino acids, and calcium, and Merck notes legumes carry more protein, minerals, and vitamins than grass hay alone. That richness is a tool, not a default. Alfalfa suits hard keepers, growing youngstock, and lactating mares, and its calcium content helps buffer stomach acid, which is one reason it comes up in ulcer management. But for an easy-keeping adult, a diet of straight alfalfa is usually more protein and calories than the horse needs.

A common practical approach is to feed grass hay as the bulk of the ration and add a portion of alfalfa where extra protein or calcium is genuinely useful. If you feed a lot of alfalfa to a young, growing horse, keep an eye on the calcium-to-phosphorus balance so it does not become inverted; this is a good conversation to have with your vet or an equine nutritionist.

Sugar, NSC, and hay for laminitis or metabolic horses

For horses prone to laminitis or diagnosed with Equine Metabolic Syndrome, Cushing’s disease (PPID), or insulin dysregulation, the sugar content of hay stops being a detail and becomes the whole game. The relevant number is NSC (nonstructural carbohydrates), the combined sugar, starch, and fructan in the forage. Oregon State University Extension explains that NSC varies widely even within the same grass or legume type depending on species, maturity, weather, and time of day at cutting, so you cannot tell it by looking.

For at-risk horses, the common target is hay under roughly 10 to 12 percent NSC. The only reliable way to know is a forage analysis: pull a core sample and send it to a lab. Buying a hay described as “low sugar” without a test is a guess.

Soaking hay is the practical tactic when your available hay tests too high or when you cannot get tested low-NSC hay. Soaking leaches water-soluble sugars out of the hay. The University of Minnesota Extension reports that a fairly short soak of roughly 15 to 60 minutes dropped grass hay from around 13 to 14 percent NSC to about 9 to 10 percent in their testing, with diminishing returns past that. There are real trade-offs to know:

• Soaking also strips out beneficial minerals and can skew the calcium-to-phosphorus ratio, so a diet built on soaked hay may need a balancing supplement worked out with a nutritionist.
• Soaked hay spoils fast. Drain it and feed it promptly, and do not leave it sitting in warm weather.
• Long soaks (many hours) make both problems worse and hurt the hygienic quality of the hay.
• Soaking is a management aid, not a diagnosis or a cure. If your horse has foundered or you suspect laminitis, that is a veterinary emergency, and hay strategy is one piece of a plan your vet directs.

Our horse laminitis guide covers the warning signs and why fast veterinary involvement matters. Do not try to manage active or suspected laminitis by diet changes alone.

Judging hay quality

Lab testing tells you the nutrition; your eyes, hands, and nose tell you the quality. Both the University of Minnesota Extension and the Merck Veterinary Manual are blunt that hay must be free of mold, and mold is the non-negotiable line. When you open a bale, look and check for:

• Color and leafiness. Good hay is green and leafy rather than bleached, stemmy, and coarse. Leaves hold most of the nutrition; a bale that is mostly thick stems was cut too mature.
• Smell. It should smell clean and fresh, like a hayfield. A musty, sour, or moldy smell means do not feed it.
• Dust and mold. Break a few flakes open. A puff of visible dust or white or gray mold, and any warm or damp spots inside the bale, are all reasons to reject it. Dusty and moldy hay drives respiratory problems (heaves) and can cause colic.
• Weeds and foreign material. Scan for weeds, blister beetles (a serious risk in some alfalfa, especially from parts of the western US), baling twine, wire, and other debris.
• Moisture. Hay baled too wet heats, molds, and in bad cases can even combust in storage. Bales should feel dry and springy, not heavy and damp.

If in doubt, throw it out. The cost of a rejected bale is trivial next to a colic or a heaves flare. Store good hay off the ground, under cover, and with airflow so it stays that way.

Slow feeders and forage time

How the hay is presented matters almost as much as how much you feed. A horse that inhales its ration in an hour spends the rest of the day with an empty stomach, and that is exactly the pattern linked to gastric ulcers. The American Association of Equine Practitioners and equine researchers emphasize near-constant forage access because a steady trickle of hay keeps saliva flowing and buffers stomach acid; research has tied gaps of more than about six hours without forage to a higher risk of ulcers.

Slow feeders and small-mesh hay nets are the everyday tools for stretching a fixed amount of hay across more hours without overfeeding. They make the horse work for each bite, which mimics grazing, slows intake, and reduces boredom and waste. Spreading hay in several piles around a paddock or dry lot does the same thing and adds movement. For an easy keeper on a restricted amount, a slow feeder is often the difference between a horse that grazes contentedly all day and one that stands over an empty spot for hours.

A practical note: introduce slow feeders gradually, check that teeth and gums are not being caught by very small mesh, and pick net sizes suited to whether your horse is shod. Fold hay management into your horse’s routine care, and log condition and any diet changes on the profile tabs so you can see trends over a season.

Keeping hay and feeding on record

Hay is not a set-and-forget decision. Cuttings change, weight drifts with the seasons, and a metabolic diagnosis can rewrite the whole plan. Keeping notes turns guesswork into a pattern you can act on. On Creatures, you can build a profile for each horse and use it as the running record of its care. You can add a record for a forage analysis, a body condition score, or a diet change, keep health and medical records in one place for your vet, and set reminders for re-testing hay or rechecking weight. Over time that history is what lets you and your vet make good calls instead of guessing.

Frequently asked questions

How many flakes of hay is 20 lb?

It depends entirely on the bale, which is the whole point of weighing rather than counting. Flakes can range from under 4 lb to nearly 7 lb apiece. Weigh several flakes of your current hay on a hanging scale, then you can convert a weight target into a flake count for that specific hay.

Can a horse live on hay alone?

Many easy-keeping adult horses at maintenance do fine on good hay plus fresh water, salt, and a vitamin-mineral balancer to fill gaps hay does not cover. Hard keepers, working horses, growing youngstock, and broodmares often need more, which is where the full horse feeding guide and your vet or a nutritionist come in.

Is alfalfa bad for horses?

No, alfalfa is a useful feed for the right horse. It is richer in protein, calories, and calcium than grass hay, which suits hard keepers, growing horses, and lactating mares, and it can help buffer stomach acid. For an easy keeper it is often simply more than needed, so it is usually fed as part of the ration rather than the entire diet.

Does soaking hay remove all the sugar?

No. Soaking for roughly 15 to 60 minutes can meaningfully lower NSC, in one Extension test from around 13 to 14 percent down to about 9 to 10 percent, but it does not zero out sugar and results vary by hay. It also removes some minerals, so pair it with a balanced ration and, for a laminitis or metabolic horse, a plan your vet directs.

How do I know if my hay is low enough in sugar for a laminitic horse?

You test it. NSC cannot be judged by look or smell, so pull a core sample and send it to a forage lab. Aim for hay under about 10 to 12 percent NSC for at-risk horses, and soak it if the analysis comes back high.

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