A Beginners Guide to Selecting Hay
A Beginners Guide to Selecting Hay

A Beginner’s Guide to Selecting Hay

by Heather Smith Thomas of Salmon, ID

When buying hay for livestock, there are several factors that must be considered besides the price per ton/bale and type of hay (legume, grass or a mix of grass and legumes). Two of the most important considerations are quality (nutritional make-up) and whether the hay is healthy and safe for the animals. A certain batch of hay may have excellent protein levels, for instance, but is still a poor choice if it is dusty or contains patches of mold.

Different types of hay are grown in different parts of the country. Alfalfa grows best in a dry climate, with proper irrigation; too much water kills it. Some grasses do best in a cool climate while others do best in a hotter climate. In the north you will find more timothy (because it tolerates colder weather and grows early in the spring). In southern or humid eastern areas there will be more brome, ryegrass, orchardgrass, Sudan grass and Coastal Bermudagrass because these species tolerate heat and humidity better. Many different types of hay can work well for livestock, depending on the stage of maturity and nutrient levels when harvested. The condition and quality of a certain batch of hay is often more important than the type of grass or legume.

Legumes used for hay include alfalfa, various types of clover (such as red, crimson, alsike and ladino), lespedeza, birdsfoot trefoil, vetch, soybean and cowpeas. Good legume hay generally has a higher level of digestible energy, vitamin A, and calcium than grass hay. Alfalfa may have twice the protein and 3 times the level of calcium than grass hay. Thus alfalfa is often fed to animals that need more protein and minerals. Often they only need a little alfalfa added to a ration of grass hay.

A Beginners Guide to Selecting Hay


Horses can eat many kinds of hay as long as it meets their nutritional needs and is not dusty or moldy. Horses have more delicate respiratory and digestive systems than cattle. Dusty hay can lead to coughing and respiratory problems in horses, and mold might cause colic. Hay that is safe for cows may be disastrous for horses.

The term “horse quality hay” refers more to the nature of the hay rather than nutritional value. Regardless of whether it is nutrient-dense alfalfa, a mix of grass and legumes, an early-cut grass or a mature grass, it can be horse quality hay if it’s free of dust and mold. Beef cattle can tolerate some dustiness and most of the molds that are often present in hay, but horses cannot.

Choose hay that meets your horse’s needs. Hay that’s perfect for a backyard horse ridden on weekends may be inadequate for a mare and foal or a working horse. A mature, idle horse needs less nutrient-dense hay than a growing foal, weanling, yearling or lactating mare. The mature non-working horse can often do fine on low-protein mature grass hay.

A hard-working horse needs higher nutrient levels, but not much protein. Excess protein in the diet of a hard-working horse will be burned for energy and create additional body heat in the process – which is a disadvantage in summer. The animals with highest needs for protein and other nutrients are young growing horses and mares producing milk for their foals. These animals do best with nutrient-dense hay like alfalfa, whereas many other horses do best on grass hay. Different types of grass also have different nutrient levels, and these will also vary depending on stage of maturity at harvest. The optimum hay for different horses will be different.

Some horses (especially ponies) are “easy keepers” because of their efficient metabolism – staying fat on a much smaller amount of hay than a “hard keeper” or a fussy eater. If you overfeed with nutrient-dense hay they’ll be at risk for metabolic problems and founder. Some grasses are higher in sugars and create problems for these animals. Match the hay type/quality and amount with the needs of the animal.

A Beginners Guide to Selecting Hay


Beef cows can do well on almost any type of hay, but lactating cows and growing animals need a higher quality (more nutrients) than dry cows. Diary cows need the highest quality (more protein and minerals) to produce an optimum amount of milk. This generally means good legume hay, cut at the stage of growth when nutrient levels are highest.

For beef cattle, grass hay is often adequate. Some hayfields consist of “wild hay” or “meadow hay” rather than “tame” hay grasses that have been planted. Many of the native or volunteer plants that grow in uncultivated hayfields are good, nutritious grasses that make acceptable hay for beef cattle. As long as the plant mix is predominantly palatable types (rather than weeds or swamp grasses), meadow hay is adequate for mature cows that don’t need high levels of protein. Some native grasses, when cut before seed heads mature, are very palatable and high enough in protein content for calves and lactating cows, without needing to add a supplemental protein source. A mix of grass/alfalfa can be ideal for lactating cows or weanlings.

Cereal grain crops (especially oats) are sometimes cut while still green and growing, rather than waiting for seed heads to mature for grain. If harvested properly, this makes good hay for cattle, especially when it is grown with peas (a legume). There is always some risk of nitrate poisoning, however, if cereal grain hays are harvested after a spurt of growth following a drought. Hay can be tested for nitrate content, if you are considering using this type of hay.


Sheep prefer fine, leafy hay and will not eat coarse hay. Immature grass hay or leafy alfalfa is usually the best feed for sheep. Mature sheep can get by on good quality grass hay, but lactating ewes need a higher protein level and should be fed alfalfa, clover or some other type of legume hay. Lambs do well with any kind of legume hay – as long as it is harvested while still immature and growing so that it has finer stems. Second-cutting mixed (grass/alfalfa or grass/clover) hay often works well.

If rich alfalfa hay (very high in protein) is fed during gestation, this may be more protein than needed and can sometimes cause problems like vaginal prolapses and late term abortions in pregnant ewes, and milk fever after lambing. Sheep like high-quality alfalfa and may consume more than they need. If you are feeding legume hay to pregnant ewes it is safest to feed it as just a portion of the diet, using a fine, palatable grass hay to fill in the rest.

Sheep will often waste a lot of hay, especially if fed on wet or muddy ground. They waste less if the hay can be kept clean and dry in a feeder or feed bunk. For instance, feeding round bales out on the ground without a feeder may result in as much as 30-40% of the hay being wasted. Hay that has been walked on will not be eaten.

If you don’t have a feeder and you are putting hay out daily in a pasture, spreading it out on dry ground, sod, snow or frozen ground will result in less waste than feeding it on wet or muddy ground. Sheep will clean up fine hay better than cattle will, because of their smaller mouths and greater ability to pick up the leaves. Some farmers keep sheep and cattle together when feeding hay; the sheep can eat the finer leaves that cattle waste. A cow cannot pick the leaves with her larger mouth and tongue.


Goats are grazers and browsers and select a wide variety of plants. They need diversity in diet but can do well on various kinds of hay. There is no single type of hay that is best for goats, but they can be very picky eaters. Like sheep, they may waste a lot of hay unless you can put it in a feeder where the animals have to pull out just a little bit at a time. A feed rack slightly above shoulder height works well, with a trough or box below it to catch the leaves and finer particles that fall through.

Goats will often sort through hay and eat the most palatable portions; if hay is too coarse they will eat the leaves but not the stems. Mature grass hay is poor feed for goats. For instance, if the stems of Sorghum Sudangrass are larger than a pencil, goats will refuse to eat it.

Legumes (alfalfa, clover, vetch, soybean or lespedeza) are often higher in protein than grass hay and can be more appropriate for kids, and pregnant and lactating does. Mature goats can do well on a grass-legume mix and some types of grass hays, but generally do not like coarse grass hay. Goats and sheep have very small mouths and do not like coarse hay (and overly mature alfalfa can also be too coarse), though goats will often eat some types of hay that sheep won’t. Most good horse hays will work for goats, being palatable and free of dust and mold.

At pasture, goats eat some of the weeds (forbs) and other undesirable plants that other animals will not. Because of this factor, they will also eat weedy hay that might not be suitable for horses or sheep. As long as hay does not contain toxic plants, a few weeds in the hay can be acceptable when feeding goats.


For animals that need high levels of nutrients, choose hay that was cut before it bloomed—before the grass made seed heads or the alfalfa buds bloomed. Most of the nutrients are in the leaves, rather than the stems. Evaluate the leaf-to-stem ratio. When the plant is young and rapidly growing, it has more volume in the leaves; the stems are small and fine. As the plant matures and begins to bloom or create seeds, stems become bigger, taller and thicker, more fibrous, and a much higher percentage of the plant. Protein levels decrease as plants gets older, and drop even more drastically if the plant becomes mature and dry before it was cut.

Examine the leaves, stems, flowers or seed heads in the hay to determine the stage of maturity. For alfalfa hay, use the snap test. Mature stems are coarse and more fibrous. If the stems bend easily in your hand, the fiber content is still relatively low. If stems are thick and snap like twigs, they contain more woody lignin. Mature hay (either legume or grass) can be ideal for mature horses or cattle, but not the best for lactating animals, foals, calves, sheep or goats.

Try to buy hay soon after harvest, or no older than the current year’s crop. Hay that’s more than a year old has lost some of its nutrient value – especially vitamin A and some of the protein. Year-old hay may be fine for a mature, idle horse or a dry cow, sheep or goat but might not be adequate for a pregnant, lactating or young animal unless supplemented. The best way to assess nutrient quality is to have it tested. Your county extension agent can help you take samples to send for analysis. Then you’ll know if the nutrients are adequate or if your animals need a protein and/or mineral supplement.

A Beginners Guide to Selecting Hay


After choosing the type of hay you need for your animals, make sure the hay you buy will be safe to feed to them. Several clues can guide you when selecting hay, including how it looks, smells and feels. Examine texture, color, leafiness, etc. Always break open a few bales to check. Small bales are easiest to check, since you can open several bales to see what they are like inside. Large bales are harder to evaluate from the outside and it’s usually not practical to open several of them. If you are buying large bales you SHOULD check one or two, however, since they may have undergone some heating if baled too green (since the hay deep inside has no way to dry out), and might be moldy or dusty.

The outside of the bales may be bleached and yellow, and no longer green, especially if they sat in the field awhile or were on the outside edge of a stack. But the hay inside should be green, not brown or yellow.

Hay should smell good – not dusty, musty, moldy, sour, fermented, or “tobaccoed” (brown and stuck together) or caramelized from overheating. It should be soft to the touch, with relatively small stems. Exceedingly coarse hay may work for beef cows if they have another source of protein to balance their diet, but won’t be palatable for other animals. Don’t buy hay that is excessively dry and sun-bleached, or hay that was baled too green and wet. If the hay is brown and stuck together, it’s not safe.

To avoid the risk of blister beetles in alfalfa, choose immature hay that has not yet fully bloomed. These beetles fly in swarms to come feed on legume blossoms. If they were feeding on alfalfa at the time it got cut, some may be killed by the haying equipment, with their tiny bodies ending up in the hay. These beetles contain a deadly poison. It only takes a few beetles to kill a horse that consumes them in hay. Cattle and other ruminants are more resistant to this poison but it may still cause them discomfort and indigestion.

Avoid hay that contains dust, dirt, weeds, or foreign material – sticks, rocks, baling twines, wire, etc. Some weeds are deadly to certain animals and others may cause indigestion and colic. Even though grazing animals might avoid a certain poisonous weed in the pasture, they may not sort the weeds out of their hay, especially when they’re hungry and hay is the only food available. Sometimes the odor of a toxic plant is what keeps the animal from eating it, and some weeds lose their odor after being cut and dried in hay.

Some grasses are also undesirable. Downy brome – also called cheat grass or June grass – and certain types of foxtail, for instance, have sharp awns and seeds that can poke into the mouth tissues and cause sores or abscesses. Don’t buy hay that contains any of these grasses.

Fescue is a nutritious grass but often contains an endophyte fungus (inside the plant – you can’t see it) that can impair blood circulation to the extremities. This can be a problem when feeding it to livestock in cold weather (ears, tails or feet may freeze), or to pregnant mares. Blood flow to the uterus and fetus is impaired, leading to prolonged pregnancies and foaling problems.

Avoid bales that are excessively heavy for their size. They may contain too much moisture and mold. Always open a suspicious bale to see if it’s moist or molding, and whether there is heat from fermentation. Hay baled too wet or green (not yet cured and dry) will ferment and heat, destroying some of the nutrients as well as creating ideal conditions for mold or spontaneous combustion – which could burn down your barn or haystack.