Hay: The Basics
Aside from grass, hay (which is dried grass) is the horse's next most important foodstuff. The digestion of hay keeps the horse warm in winter, from the inside out, and provides the roughage to keep the digestive process moving along. Hay is complicated, especially during severe droughts, when hay shortages are common. Feeding hay involves finding a source, determining what type of hay you want, figuring out how much to buy, having a dry place with adequate ventilation to store it, and making sure the supply you get is good quality and free of mold. If you board your horse, of course, you don't need to worry about most of these details. That's part of what you pay for.
“Making hay” is not a matter of hacking down a field and scooping it up into bales — there is a fine art to timing the cutting and curing of it, and weather is a constant variable. Hay should be cut at the optimum growth period — late enough that it has leafed out and absorbed the maximum amount of nutrients but early enough that it doesn't go to seed.
After cutting, hay must stay on the ground long enough to “cure” (around three days), but the longer it sits in the field, the more the sun bleaches nutrients out of it. If hay gets rained on after it has been cut, precious nutrients are leached out. The hay will have to lay on the field longer to dry out again, and the farmer may drive around and fluff it up to prevent it from molding underneath.
Never lay a plastic tarp over your hay to protect it from rain and roof leaks. While the hay is curing, the plastic tarp will prevent moisture from escaping, and your hay will spoil.
Too much moisture in hay causes mold and mildew, which can be a source of chronic respiratory damage to your horse. It also presents a serious fire hazard. If hay is baled before its moisture content has lowered enough, the high moisture level in the tightly packed bale builds up heat, which can result in spontaneous combustion. Many a barn has burned to the ground from hot hay. You must be able to trust your suppliers and their haymaking abilities. Hay that gets wet after it is baled is not as likely to heat up, but it is definitely going to mold and spoil.
If you buy a few bales here and there from any number of different sources, it will not be effective to have your hay supply tested. But if you get your full year's supply of hay from one source, testing your hay for nutrient content can give you the basis on which to feed the right amounts of grain and supplements to your horse to balance the nutrition your horse is getting from his hay. Most grain stores have access to the sales representative of the particular kind of grain you buy, and they can often help you with testing your hay so that you can get a feeding plan for your horse. Some traits of good quality hay include the following:
Leafy: The leaf contains the nutrition, and by digesting leafy hay, the horse generates the heat she needs to keep warm in winter.
Green: Hay fades as it ages; don't feed last year's crop too long into the new haying season. Even if the edges of the bale have faded from being exposed to light, the inside should still be green.
A good smell: Although different grasses smell differently, good hay should basically smell sweet, fresh, and pleasing to your nose. If a bale smells musty when you open it, set it aside to use in the garden for mulch.
Dust free: Some dust on the outside of the bale is almost inevitable, but the hay should absolutely not be dusty inside. Likewise, hay should be free from mold, dust, and mildew. White mold can be commonly seen in hay; when it dries, it is simply white dust. Again, set it aside for garden mulch.
There are two basic kinds of hay that are commonly used with horses: grass and legume.
Most backyard horses that are being used for recreational riding will do best on grass hay. It can be fed in reasonable quantities without the consequences of overeating that rich legume hay such as alfalfa can cause. Timothy, brome, orchard grass, wheatgrass, bluegrass, and fescue are different kinds of grasses that are used in mixed grass hay. Some horses do have a preference, and there are some grasses that some horses don't like. You may want to keep track of which hay your horse ate voraciously and which he picked at and wasted.
Alfalfa and clover are legumes. The resulting hay contains more protein, essential amino acids, calcium, phosphorus, and beta-carotene than grass hays do. High performance horses do very well on alfalfa and need the extra energy it provides. Alfalfa may, however, provide a little too much energy for backyard horses that are ridden recreationally only a couple of times a week. Sometimes hay is part legume and part grass, which is a good compromise.
What are amino acids?
Amino acids are the group of organic compounds that form the structure of proteins. Hay from alfalfa and clover is rich in amino acids and gives horses extra energy.