Selecting Hay of Good Quality

by Heather Smith Thomas of Salmon, ID

Hay quality can vary a great deal, depending upon growing conditions (wet or dry weather, hot or cool), stage of maturity when it is harvested, weather and moisture conditions at harvest, and so on. When buying hay, it is crucial to select hay of good quality. Poor hay will not provide adequate nutrition for your horses, and can also cause health problems if it is dusty or moldy.

Good grass hay will provide all the nutrient requirements (energy, protein, vitamins and minerals — and in proper balance) for the adult horse, and a mix of good grass and alfalfa hay will provide everything needed by the young growing horse or lactating broodmare, since the alfalfa has more protein, calcium and vitamin A than grass hay. Horses being fed high quality hay do not need expensive supplements and only a minimum of grain (most horses on good hay will not need any grain at all). But if hay is not good, its deficiencies must be made up with supplements and/or grain.

Some of the factors that can affect the nutritional value of hay are the species of plants (what types of grasses, whether there is a legume such as alfalfa or clover in the mix, etc.), fertility of the soil it was grown on (whether the farmer added manure or commercial fertilizer to his fields), age or stage of maturity when the hay was cut, the harvesting methods (whether hay was conditioned or crimped to dry faster and lose less leaves and nutrients during drying), curing time, and so forth.

The best way to check hay is to open a few bales and look closely at the hay inside. When checking hay, look at its maturity, texture, color, leafiness, and also look for possible problems such as weeds, mold, dustiness, discoloration due to weathering (if the swathed hay was rained on before it got baled and stacked), and foreign matter in the bales—such as baling twines or wire. And use your nose. The smell of the hay can give a good clue as to its quality. It should smell good — not musty or sour or moldy.

Stage of maturity is very crucial for all hay, if you are trying to buy hay that is high in nutritional value, but is especially important for alfalfa; it loses its food value much more rapidly than grass hay when overly mature. Mature plants have longer, coarser, and more fibrous stems, and may have already bloomed (or gone to seed, in the case of grass hay). Immature plants — whether grass or alfalfa — have smaller and more pliable stems and leaves, and will have more protein and total food value.

Stem size and pliability (texture) will greatly affect the palatability and digestibility of hay. Mature grass hay can be very adequate for adult horses that are not being worked hard, but if you are feeding young horses or hard working horses, their nutritional demands are greater and you will want more palatable and nutritious hay. Foals and weanlings, especially, will need very fine, palatable hay; they won’t eat coarse, stemmy hay very well, and will also not get much nutrition from it.

When looking closely at a bale, check the proportions of leaves to stems. Leaves are always higher in nutrients. Alfalfa hay must be leafy, especially if you are feeding it to young stock and broodmares, since most of its nutrition is in the leaves. If the alfalfa leaves have shattered (meaning the hay was too dry when it was baled), or are not attached to the stems, the hay will be dusty and there will also be a lot of waste when feeding it. The shattered leaves fall to the ground and may get tromped into the mud. Even on dry ground the horses may not be able to clean up all the leaves, or may eat dirt or sand trying to eat them. The only way the horses will get the full value of the leaves will be if they are fed in a manger or feed bunk. Even then, you risk having respiratory problems or development of coughing and heaves due to the dustiness (shattered leaves) of the hay. If the alfalfa hay is coarse and stemmy, its nutritional value can actually be less than grass hay, and many horses will not eat the coarse stems very well.

Hay color also gives a clue to quality. Bright green color indicates good harvest conditions (it did not spend a long time curing, becoming yellow or brown and bleached, losing nutrients) and good carotene content. Carotene is the substance in green growing plants that an animal converts into vitamin A. Protein content will also be higher in hay that is green instead of yellow or brown.

Be wary of any hay that has discolored or brown areas in the bale. This can indicate that it was baled too wet and heated. Damp or wet hay compacted in a tight bale will generate heat due to the chemical action of certain microbes. Under certain conditions the hay can become so hot that it will set the haystack on fire (spontaneous combustion). Damp hay can “heat” for several weeks; sometimes causing haystack or barn fires a month or more after it was baled and stacked. If you are buying hay that was recently harvested and feel any heat in a bale, do not buy the hay.

One of the major factors affecting quality of hay for horses is whether or not the hay is free of mold or dust. Hay that is dusty or moldy can cause respiratory problems, and moldy hay may cause colic. Some types of mold can cause abortion in pregnant mares. If there is any evidence of mold in any of the bales you check, do not buy the hay. Alfalfa hay is more apt to be moldy and dusty than grass hay, under the same harvest conditions, since alfalfa hay is higher in nutrients and if slightly damp provides an ideal environment for molds and fungi to grow. Be especially careful when buying alfalfa, to make sure it is free of mold and not too dusty for horses.