Hay is a processed product derived from plants that can also be grazed by livestock, which often creates confusion about its classification as an agricultural crop. Unlike grains or vegetables, hay is not a species itself but a preserved form of various cultivated forage plants. This preservation step is a deliberate, managed process that transforms field-grown material into a storable commodity.
Hay: Definition and Classification as a Crop
Hay is defined as grasses, legumes, or other herbaceous plants that are purposefully cut, dried, and stored for use as animal fodder. The material is a preserved feed source intended for consumption during periods when fresh pasture is unavailable, such as winter or drought. Its classification as a crop is based on the fact that the forage plants are specifically cultivated, managed, and harvested for their economic value as a livestock feed.
The critical distinction between hay and other forages lies in the moisture content and preservation method. Fresh pasture is high-moisture forage consumed directly by grazing animals. Silage is chopped forage that is fermented and stored in an airtight environment at a high moisture level, typically between 40% and 60%. Hay is a dry roughage product that must be cured to a low moisture content, generally between 12% and 20%, to prevent spoilage.
The Agricultural Cycle of Hay Production
The creation of dry hay involves a precise, multi-stage agricultural cycle focused on rapid moisture reduction and nutrient preservation. The cycle begins with mowing or cutting, which must be timed to coincide with the forage plant’s peak vegetative stage, such as before the alfalfa plant begins to flower. Farmers often use mower-conditioners, which cut the forage and simultaneously crimp or crush the plant stems to accelerate the drying rate.
Following the initial cut, the curing phase is the most sensitive period. This is accomplished through the use of a tedder, a machine that gently fluffs and spreads the cut material. This action exposes more of the plant surface area to the sun and air, which is essential to quickly reduce the moisture content from the initial 80% or 90% down to the required 15% to 20% for safe storage. This process typically requires several consecutive days of dry, sunny weather to complete without rain damage.
The next step is raking, where the partially dried forage is swept into long, continuous rows known as windrows. Raking turns the hay one last time for final drying and gathers the material into a manageable line. The final step is baling, where a baler compresses the cured hay into dense, transportable units, ready for storage and eventual use as feed.
Major Types of Hay and Their Uses
The two broad categories of hay are grass hay and legume hay, each offering a distinct nutritional profile suited for different livestock needs. Legume hays, which include alfalfa and various clovers, are known for their high concentration of protein, calcium, and energy. Alfalfa hay, for example, can have a crude protein level ranging from 14% to 26% and is typically reserved for animals with high nutritional demands, such as lactating dairy cows, young growing stock, and performance horses.
Grass hays, such as timothy, orchardgrass, and fescue, generally contain lower levels of protein and energy but are richer in fiber. Timothy hay is a common choice for horses, as its balanced fiber content supports digestive health. This type of forage is also suitable for mature animals or those prone to easy weight gain. Farmers often select a mixed hay, which combines grass and legume species, to achieve a nutritional balance tailored to the specific requirements of their herd.