What Is Hay and How Is It Used?

Updated

Hay is dried, harvested forage—grasses or legumes cut and cured for use as animal feed. It is the standard stored feed for horses, cattle, sheep, goats, and other herbivores when pasture is unavailable, whether because of winter, drought, or confinement. The National Hay Association (NHA), the U.S. trade association for the hay industry, describes its members as producers, brokers, dealers, and consumers of forage products, which places hay squarely within the broader forage economy rather than as a separate category.

Hay, Forage, Straw, and Silage: What's the Difference

These terms overlap in everyday use, but they describe different things:

Term What it is Typical use
Forage The broad category: any plant material eaten by grazing or browsing animals, fresh or preserved Umbrella term covering pasture, hay, silage, and haylage
Hay Forage that has been cut and dried (cured) to a safe moisture level for storage Stored feed for livestock
Straw The dried stalks left after grain harvest (wheat, oats, barley, etc.) Bedding, erosion control, low-nutrition roughage
Silage Forage preserved by fermentation at high moisture, usually in a silo or wrapped bale Feed, especially for dairy and beef cattle

The practical distinction: hay is a feed, straw is largely a byproduct, and silage is preserved wet rather than dried. Forage is the category that contains all of them.

Common Hay Types and Their Uses

Hay is usually named for the plant it comes from, and the type determines both nutrition and price:

  • Grass hays — timothy, orchardgrass, bermudagrass, fescue, and similar. Widely used for maintenance feeding of horses and beef cattle.
  • Legume hays — alfalfa and clover. Higher in protein and calcium; common for dairy cattle, growing animals, and horses in hard work.
  • Mixed hays — grass-legume blends that balance nutrition and cost.
  • Cereal hays — oat, wheat, or barley cut before full grain maturity; used as palatable roughage.

Which type fits depends on the animal and its production stage. A mature, idle horse and a lactating dairy cow have very different protein and energy needs, and the hay should be matched accordingly.

Why Quality and Storage Matter

Hay quality is set largely at harvest and then protected—or lost—in storage.

  • Maturity at cutting drives nutritional value. Grasses cut early are leafier and more digestible; late-cut hay is stemmier and lower in energy and protein.
  • Curing and moisture determine whether hay stores safely. Baling too wet invites mold and, in severe cases, spontaneous heating and fire.
  • Storage conditions preserve what was harvested. Rain damage, ground moisture, and poor ventilation all reduce feed value.
  • Testing gives buyers and feeders actual numbers (protein, fiber, moisture) instead of relying on appearance alone.

For anyone buying or selling hay in commercial volume, these factors are the difference between feed that supports production and feed that merely fills a bunk.

Where the National Hay Association Fits

The NHA works within the hay industry, with federal agencies, and with Congress on issues affecting hay merchants and the people who depend on hay and straw in commerce. It is a non-profit funded entirely through membership dues, and its membership spans producers, brokers, dealers, and consumers of forage products, plus businesses that supply the industry.

If your interest in hay is commercial rather than just practical, the association's membership directory and events are the main points of contact. Note that the site shows a login area and an online membership application; access to member-only sections requires an account, so plan to join or log in rather than expecting open access to everything.

Quick Answers to Common Questions

Is hay the same as straw? No. Hay is harvested as feed; straw is the leftover stalk after grain harvest and is mainly used for bedding.

Can hay be replaced by silage? Sometimes, depending on the operation and equipment. Silage requires different storage infrastructure, so the choice is usually driven by facilities and climate rather than nutrition alone.

Does hay quality vary a lot? Yes—enough that testing is standard practice in commercial transactions.

Where can I find hay industry information or contacts? The National Hay Association at nationalhay.org publishes news and resources and maintains a membership directory.