Types of Hay

Hay is the foundation of every horse's diet. A horse can live without grain. A horse cannot live without forage. Understanding hay means understanding the primary nutrition your horse consumes, which matters far more than grain selection or supplementation. Yet most horse owners give less thought to hay selection than to any other aspect of feeding. They take whatever hay is available, pay minimal attention to quality, and assume all hay is roughly equivalent. This assumption costs horses years of their lives through poor nutrition, health problems, and performance issues that would resolve with better hay selection.

The basic categories of hay available to horse owners are legume hay (primarily alfalfa), cool-season grass hay (timothy, orchard grass, bluegrass), and warm-season grass hay (bermuda, bahia, brome to varying degrees). Each category offers different nutritional profiles and serves different purposes in horse feeding. Timothy hay is considered the standard, the baseline against which other hays are compared. But timothy is absolutely the wrong choice for some horses and right choice for others. Making that determination requires understanding what each hay type offers and what your horse actually needs.

Hay quality varies dramatically even within the same type of hay. Two bales of timothy hay from the same field can have vastly different nutritional values depending on when the hay was cut, what weather it experienced, and how it was stored. Stage of maturity at cutting is perhaps the most important quality determinant. Hay cut at the right stage—bloom stage for legumes, boot stage for grasses—has far higher nutritional value than hay cut late when the plant has matured and lost nutritional density. Most hay farmers don't prioritize timing hay harvest for maximum nutrition. They harvest when weather allows and when they have equipment available, not necessarily when the plant is nutritionally optimal.

Understood correctly, hay selection becomes perhaps the single most important feeding decision you make. Better hay reduces the need for supplementation, reduces grain requirements, improves horse health and performance, and often costs less than feeding poor hay plus supplements. A horse eating excellent hay rarely needs supplements. The same horse on poor hay might need extensive supplementation to compensate for what the hay lacks. Understanding hay quality and selection matters more than understanding grain or supplements.

This guide covers the major hay types, their nutritional characteristics, appropriate uses for each, quality evaluation, and how to match hay type to your specific horse's needs. You'll learn to evaluate hay quality yourself, understand why certain horses need certain hay types, and make hay selections based on actual nutrition rather than convenience or habit.

Timothy hay represents the most common grass hay fed to horses and is considered a cool-season grass with moderate nutrition. Timothy contains roughly 8-12% protein depending on maturity at harvest, with higher protein early in growth and declining as the plant matures. The calcium-to-phosphorus ratio in timothy is roughly 2:1, which is acceptable for most horses. Timothy is relatively easy to digest and palatable to most horses. The energy content is moderate—timothy cut at boot stage is more nutritious than timothy cut at full bloom, but less energy-dense than alfalfa or earlier-cut timothy.

Orchard grass is slightly higher in energy than timothy and also contains more minerals, particularly calcium. Orchard grass cut early has nutritional value approaching that of alfalfa, though it's never quite as concentrated. Many horses prefer the taste of orchard grass to timothy, and some horse owners find orchard grass improves horse condition compared to timothy alone. The downside is that orchard grass is less commonly available in many regions and often costs more than timothy.

Alfalfa (legume hay) is significantly more nutrient-dense than grass hays. Alfalfa contains roughly 16-20% protein depending on stage of harvest and handling, which is 2-3 times higher than grass hay. Alfalfa contains roughly 1.5 times the energy content of timothy cut at boot stage. Calcium content in alfalfa is very high—roughly 1.3% compared to timothy at 0.3%. For horses with high nutritional demands (growing horses, performance horses, hard workers, or horses needing weight gain), alfalfa provides concentrated nutrition from forage alone. For horses prone to obesity or metabolic disease, alfalfa's concentrated nutrition can be excessive unless carefully managed.

Mixed legume hay—typically alfalfa mixed with small amounts of grass—offers middle-ground nutrition between pure grass and pure alfalfa. A 50/50 alfalfa-timothy mix provides more nutrition than pure timothy but less concentrated than pure alfalfa. Many horses thrive on mixed hay because it provides good nutrition without the excessive protein and calcium of pure alfalfa.

Quality and stage of maturity matter more than hay type. Timothy cut at boot stage has better nutritional value than orchard grass cut in full bloom. Early alfalfa cut at late bloom stage has different nutrition than alfalfa cut weeks later when fully mature. The naming of the hay type tells you nothing about stage of maturity, so you have to evaluate the actual hay itself—the color, the amount of stems versus leaves, and the smell—to determine quality. Excellent timothy provides better nutrition than poor alfalfa.

The foundational guideline for hay feeding is that horses should eat primarily forage—roughly 80% of daily calories should come from hay or pasture. This means a 1,000-pound horse needs roughly 15-20 pounds of hay daily if not on pasture, regardless of other feeds. That baseline doesn't change based on hay type; the horse still needs that much forage. The difference between hay types is the nutritional density within that volume, not the volume required.

Evaluate your hay supply before bringing horses home. The hay you select determines your horse's baseline nutrition and health. A horse eating good hay most of the year is far healthier than a horse eating poor hay with supplements, even if the supplementation adds back some missing nutrients. Plan hay purchase around what will support your horses through seasons when fresh pasture isn't available. If you're buying hay from local sources, develop relationships with hay producers so you can select hay at optimal harvest timing rather than accepting whatever they have available.

Store hay properly to maintain quality. Hay stored in wet conditions develops mold and loses nutritional value. Ideal storage is in a dry shelter or under a tarp, with air circulation to prevent moisture accumulation. Hay stored inside a barn maintains quality best. Hay stored outside in the weather deteriorates, particularly if rain gets on it. Moldy hay is dangerous—horses eating moldy hay can develop serious health problems from mycotoxins in the mold. When in doubt about hay quality or moldiness, don't feed it.

Match hay type to your horse's specific needs. A performance horse needing significant nutrition benefits from legume hay or high-quality grass hay. A pleasure horse at risk of obesity benefits from lower-calorie grass hay fed in limited quantities. A metabolically sensitive horse needs to avoid excess protein and calories—timothy or grass hay works better than alfalfa. A growing horse benefits from legume hay or mixed hay for the protein and minerals needed for development. A senior horse benefits from soft, early-cut hay that's easier to chew and digest.

Introduce hay changes gradually if switching hay types. A horse switched abruptly from timothy to alfalfa can develop digestive upset or founder from the sudden mineral and energy changes. When introducing new hay, mix it gradually with previous hay over 10-14 days. This gives the horse's digestive system time to adapt to different nutrient profiles.

Different horses require different hay types because their nutritional needs, metabolism, and health status vary significantly. Matching hay type to your specific horse prevents many health and behavior problems.

Performance and working horses need high-quality, nutrient-dense hay because they have elevated energy requirements. These horses benefit from legume hay or excellent quality grass hay cut early. A jumping horse, barrel horse, or ranch horse needs the nutrition to sustain work, recover, and maintain weight. Poor hay forces the addition of extra grain to meet nutritional needs, which becomes expensive and creates metabolic complications. Better hay means efficient nutrition from forage with minimal grain supplementation.

Hard-keepers and horses struggling to maintain weight need the most nutrient-dense hay available—preferably legume-based hay or mixed legume-grass hay. These horses burn calories at high rates and need concentrated nutrition from every bite of forage. Alfalfa provides the nutrition to support weight gain in hard-keepers more efficiently than grass hay alone. The addition of grain to hard-keepers eating poor hay represents another inefficiency. Better hay reduces grain requirements and improves condition faster.

Easy keepers and horses prone to obesity need lower-nutrient-density hay to prevent excessive caloric intake. Pure timothy or oat hay—late-cut, stemmy hay—provides forage without excessive calories. The goal is to provide bulk and fiber for digestive health while limiting calories. A horse prone to laminitis or metabolic disease needs this type of hay-focused diet with minimal grain. Many easy keepers are overfed simply because they're fed the same quality hay as working horses; they should instead be fed lower-quality forage and given grazing control.

Metabolically sensitive horses and those prone to laminitis need specific hay selections. These horses should avoid excessive protein from legume hay and instead eat good-quality grass hay with protein content below 12%. Pure alfalfa is too high in protein and calcium for metabolic horses. A grass-legume mix can work if the ratio keeps overall protein moderated, but pure grass hay is usually the safest choice. Additionally, these horses benefit from hay with lower sugar content—later-cut hay when sugar content drops is safer than early spring hay when sugar content is highest.

Senior horses with dental issues benefit from softer, more digestible hay. Later-cut hay with more leaves and fewer coarse stems is easier to chew. Some senior horses do better on legume hay because the softer stems are easier to process than tough grass. Alfalfa hay is often fed to senior horses specifically because it's nutritious and the stems are softer than grass hay. Some seniors benefit from hay cubes or soaked hay that doesn't require extensive chewing.

Poor-quality hay represents the most common and most damaging hay-related problem. A horse eating moldy, stemmy, or nutrient-poor hay suffers silent nutritional deficiency. The impact isn't immediately obvious like acute illness, but the cumulative effect—poor coat, reduced performance, susceptibility to illness, slow wound healing—reflects underlying malnutrition. Horses eating poor hay for months or years develop health problems that resolve when hay quality improves. The tragedy is how many horses are maintained on genuinely poor hay because owners don't recognize quality problems or don't know better hay exists.

Mold and mycotoxins in hay create serious health problems ranging from subtle to fatal. A horse eating moldy hay might show reduced appetite, performance decline, or colic. More severely, moldy hay can cause serious illness or death depending on the type of mold and mycotoxin involved. Aspergillus mold produces mycotoxins that damage the liver. Other molds produce neurotoxins. When in doubt whether hay is moldy, trust your instinct and don't feed it. The risk isn't worth the savings of feeding questionable hay.

Founder (laminitis) can develop from inappropriate hay selection combined with metabolic sensitivity. Early spring hay rich in sugars fed to a metabolically sensitive horse creates the metabolic stress that manifests as laminitis. The same problem can develop from moldy hay or from excessive alfalfa fed to a horse prone to founder. Hay-related laminitis is entirely preventable through proper hay selection but difficult to treat once it occurs.

Weight gain and obesity develop from feeding high-quality nutrient-dense hay to easy-keeper horses that don't need it. A horse prone to obesity fed alfalfa or excellent timothy hay accumulates excess weight and metabolic stress. The solution isn't restricting hay volume—horses need forage for digestive health—but rather feeding lower-nutrient-density hay. This is almost never done because owners feed all horses the same hay regardless of whether it's appropriate.

Digestive problems and colic can result from moldy hay or abrupt hay changes. Additionally, hay with high dust content in poor storage conditions can contribute to respiratory disease and colic. Providing the best hay quality also reduces medical and health management complications.

The most practical tip is to invest in sampling and evaluating your hay supply before buying. If you're purchasing hay from a producer, inspect a bale before committing to purchase. Look at the color—good hay is green, not brown. Smell it—good hay smells pleasant and fresh, not musty or moldy. Feel it—good hay has visible leaves, not mostly stems. Ask the hay producer when the hay was cut and what the forage stage was. Early-cut hay is more nutritious than late-cut. Ask whether hay was rained on during curing, which damages quality significantly.

Get hay analysis if possible. Many universities and extension services offer forage analysis where they test hay for protein content, energy, minerals, and quality indicators. Knowing actual nutritional values allows intelligent selection rather than guessing. For valuable horses or performance horses, paying for hay analysis is worthwhile because it removes guesswork from feeding decisions.

Match hay selection to your horse. Don't feed all horses the same hay. A working horse benefits from excellent legume hay. An easy keeper benefits from lower-quality grass hay. A metabolic horse benefits from specific grass hay low in protein and sugar. This requires maintaining multiple hay supplies or at least recognizing that different horses shouldn't all eat the same forage.

Shift hay sources seasonally if needed to match seasonal forage changes. Spring pasture is different from midsummer pasture is different from fall pasture. Hay characteristics change with seasons and weather. Understanding these shifts and adjusting feeding helps maintain consistent nutrition throughout the year.

If you have a choice, pay slightly more for obviously better hay. The difference between feeding poor hay plus supplements versus feeding good hay with minimal supplements often costs less overall while producing better horse health. Better hay is an investment that repays itself through improved health, better performance, and reduced medical issues.