Rolled bales of hay on a farm near Ames, Iowa
Hay is dried grass (and pasture flowers) used to feed domestic animals at places or times where there is not enough (fresh) grass or when fresh grass by itself is too rich in some qualities for easy digestion by the animal. It is normally produced at the end of the flush of the season after allowing excess pasture paddocks to grow until just before the grasses flower. The pasture is mowed and allowed to dry in the sun for two or three days. Drying can be hastened by "tedding" with a machine. When dry the hay is gathered, possibly into bales (in the U.S., traditionally rectangular ones, though rolled bales or "rolls" have become common in the late 20th-century) by a baler, and put into a stack or under shelter for storage until needed.
Up to the end of the nineteenth century grass and clover were not often grown together because crops were rotated. However, in the growing season, usually spring, farms produced more fodder than the animals could consume. Some paddocks were "shut up" for hay. Just as the leafy material was at a maximum in the pasture, immediately before the grasses flowered if judged correctly, the pasture was cut. Much of it was still being cut by scythe by teams of men. Later this would be done by horse-mower and, from the 1930s onward, by tractor. By the 1930s good pasture management meant that highly productive pastures were mainly ryegrass and clover so compromises were made when it was time to mow. Later still some farmers grew crops, like lucerne, specially for high quality or special-purpose hay.
During the drying period the process could be speeded, and the effects of rain accounted for, by turning the cut sward over. At first this was done by hand with a fork or rake; when machines were introduced this process was called tedding.
Subsequently the dried hay was "rowed up" by raking it into a linear heap by hand or by machine. As it was being rowed up the hay was gathered by another team. In early days, by forking it into a horsedrawn cart or dray or onto a truck, later by a sweep attached to a car, truck or tractor.
Later still the baling machine would gather and bale the hay in one process.
Loose hay was taken to an area designated for stacking—usually a slightly raised area for drainage—and built into a stack. The stack was made waterproof as it was built (a task of considerable skill) and the hay would compress under its own weight and cure by the release of heat from the residual moisture in the hay and from the compression forces. The stack was fenced from the rest of the paddock. When needed the haystack would be cut open, using a hay-knife, and some would be fed out to animals each day.
On some farms the loose hay was stored in a shed, normally in such a way that it would compress down and cure.
Baled hay was discharged from the rear of the baler onto the paddock. Bales were then picked up and taken for storage. As baling became more prevalent the bales were more often stored in a hayshed.
With the introduction of large round bales many dry-area farmers were able to leave the bales outside until they were consumed. Wet-area farmers later developed plastic bags to enclose the bales left outside.
From the 1881 Household Cyclopedia
Instead of allowing the hay to lie, as usual in most places, for some days in the swath after it is cut, never cut hay but when the grass is quite dry, and then make the gatherers follow close upon the cutters: put it up immediately into small cocks about three feet high each, and of as small a diameter as they can be made to stand with; always giving each of them a slight kind of thatching, by drawing a few handsful of the hay from the bottom of the cock all round and laying it lightly upon the top, with one of the ends hanging downwards. This is done with the utmost ease and expedition; and when once in that state the hay is, in a great measure, out of danger; for unless a violent wind should arise immediately after the cocks are put up, nothing else can hurt the hay; as no rain, however violent, can penetrate into these cocks but for a very little way; and if they are dry put up they never sit together so closely as to heat, although they acquire, in a day or two, such a degree of firmness as to be in no danger of being overturned by wind after that time, unless it blows a hurricane.
In these cocks allow the hay to remain until upon inspection, the farmer judges it will keep in pretty large tramp-cocks (which is usually in a week or two, according as the weather is more or less favorable), when two men, each with a long-pronged pitchfork, lift up one of these small cocks between them with the greatest ease, and carry them one after another to the place where the tramp cock is to be built, and in this manner proceed over the field till the whole is finished.
The clover is cut, and after it has lain four or five days in the swath, till it is sufficiently dry, the haymaker, with a rake, rolls up a sufficient quantity to form a ripple, which is set up in the form of a cone. Taking a few of the longest straws he twists them round the top, which forms the point of the cone, keeps the ripple compact, and shoots off the rain. In taking up the clover from the swath and forming the ripple, it is necessary to keep the upper or dry part inwards: by that means it is much sooner dry, and in a fit state for the stack. It is generally necessary for clover to remain five or six days in the ripple before it is put into the stack, but that depends on the state of the weather. There is no occasion to untie the ripples. The method of rippling is not so expensive as cocking; it is much superior both in wet and dry seasons—not so liable to be injured by the wet—much sooner dry, and of course of a better quality and more nourishing for cattle. Each ripple will weigh, when dry, about four or five pounds. They should not be made too large. Except where meadow grass is very long it would not be practicable to ripple it. The practice of rippling is simple, attended with little trouble or expense, and whenever tried will recommend itself:
Grass, when cut for hay, ought to be quickly raked, in order that its powers may neither be exhausted by the sun nor dissipated by the air. In the first stage small cocks are preferable, and on after days these may be gathered into large ones or hand-ricks, by which method the hay is equally made and properly sweetened. After standing eight or ten days in these ricks, according to the nature of the weather, hay may be carted home and built in stacks of sufficient size for standing through the winter months.
Material used for hay
The most common herbage used for quality hay is rye grass (Italian rye grass ( Lolium multiflorum ) and perennial, rye grass ( L. perenne )) with mixtures of other grasses and clovers (red, white and subterraneum). But alfalfa (lucerne) makes a superior hay for cattle and horses in many countries.
In hot-dry climates hay is made from very dry coarse grasses that have very low nutritional values, but that is the best that farmers in those areas can do.
It is the leaf material in the hay that makes for its quality. Farmers try to judge the point when the leaf in a paddock is at its maximum when the fodder is cut . The cut material is allowed to dry so that the bulk of the moisture is removed but the leafy material is still robust enough to be picked up from the ground by machinery and processed into storage—whatever that might be, bales, stacks or pits.