With so many kinds of hay from which to choose — grass, legume, a mixture of the two, and cereal grains (such as oat hay) — how do you choose?
Legume hay, such as alfalfa or clover, often has higher protein content than various grasses, but actual protein and nutrient content may depend more on stage of maturity when it's cut than on the type of hay. Late-cut alfalfa may have less protein than early-cut grass.
Nutritional value of any hay is related to maturity and leaf content. All plants have more nutrients and are more easily digested when the plant is young and growing, and contain more fiber and fewer nutrients when fully mature. About two-thirds of the energy content and three-fourths of the protein and other nutrients are in the leaves. Mature hay has coarse stems and a higher stem-to-leaf ratio.
Select hay that contains proper nutrient quality specifically for your animals. A mature, idle horse needs less nutrient-dense hay, for instance, than a growing foal, calf, kid, or lamb, and will do fine on low-protein mature grass hay.
The animals with highest needs for protein and other nutrients are lactating mothers and young ones that are still growing. They'll do best with nutrient-dense hay such as early-cut alfalfa or any hay that was cut before the grass made seed heads or the alfalfa bloomed.
For alfalfa hay, use the snap test to determine stage of maturity. As the plant matures, stems become coarser and more fibrous. If the stems bend easily in your hand, fiber content is still relatively low. If stems are coarse, thick, and snap like twigs, they contain more woody lignin, which is indigestible.
Avoid hay that contains dust, dirt, sticks, rocks, baling twines, wire, or weeds. Some weeds are deadly and others may cause indigestion. Certain grasses also are undesirable. Downy brome — also called cheat grass or June grass — and certain types of foxtail have sharp seed bristles that can poke into the animal's mouth and cause sores or infections.
Make sure the hay you buy will be safe to feed. Judge it by how the bales look, smell, and feel. Always break open a few bales to check, particularly with smaller bales. Large bales are harder to evaluate but you should check one or two, because they may have undergone more heating if baled too green, and might be moldy or dusty inside.
The outside of the bales may be bleached and no longer green but the hay inside should be green rather than brown or yellow. Hay should smell good — not dusty, musty, moldy, sour, fermented, or caramelized (from heat). It should be soft to the touch, with relatively small stems. Exceedingly coarse hay won't be palatable, even to a mature animal that doesn't need the fine, soft hay you'd select for young growing animals.
Don't buy hay that is excessively dry and sun-bleached, or baled too wet. If the hay is brown and stuck together, it's not safe.
Hay baled too wet or green (not yet cured and dry) will ferment and heat, destroying nutrients as well as causing ideal conditions for mold or even spontaneous combustion — which could burn down your barn or haystack.
Try to buy hay soon after harvest, or no older than the current year's crop. Hay more than a year old will have lost some of its nutrient value — especially vitamin A and some of the protein.
Heather Smith Thomas has authored several books on the care and feeding of livestock.