Hay is cured forage, typically grasses or legumes, cut and dried for animal feed when fresh pasture is unavailable. Making hay is a precise, multi-step process driven by weather and timing. Success requires significantly reducing the plant’s moisture content while retaining maximum nutritional value. This transformation involves careful attention to crop maturity, cutting, drying, and final packaging.
Field Assessment and Timing the Harvest
Determining the optimal time to cut the crop is the most important decision influencing hay quality. Forage quality, specifically digestible energy and protein, decreases as the plant matures and fiber content increases. Legumes like alfalfa should be cut in the late bud to one-tenth bloom stage to maximize nutrient density and ensure stand longevity.
Grasses, such as timothy or orchardgrass, are best harvested earlier, typically at the boot stage, just before the seed head emerges. Waiting past this point increases yield but lowers the hay’s overall digestibility. The entire process requires a window of at least three to five consecutive days of dry, sunny weather to allow the forage to cure properly in the field.
Mowing and Conditioning the Forage
Mowing is the first physical step, best done with modern equipment like disc mowers or a combination mower-conditioner. Disc mowers use rotating blades to cleanly slice the forage, which is faster and more efficient than older sickle bar mowers.
To accelerate drying, the forage must be conditioned immediately after cutting. Conditioning involves running the cut stems through rollers that crimp, crush, or flail the material to break the waxy cuticle on the stem’s surface. This mechanical treatment allows moisture to escape from thicker stems at a rate closer to that of thinner leaves, reducing the total field drying time. Proper cutting height is important; leaving a stubble of two to four inches allows for faster regrowth and prevents the mower from picking up soil that can contaminate the hay.
Curing, Tedding, and Raking the Hay
Curing is the field-drying phase where moisture content must be reduced from 75–80 percent down to a safe range of 15–20 percent for baling. Tedding is often necessary to speed this process, using a machine with spinning tines to gently lift and spread the cut material. This action promotes uniform drying, exposes the wet underside to the sun, and prevents moist clumps from harboring mold.
Once the moisture content drops to around 35–40 percent, the hay is ready for raking. Raking gathers the partially dried hay into continuous rows called windrows, which are sized for the baler and allow the hay to continue drying. Producers can estimate moisture using a twist test: if a handful of stems snaps cleanly, the hay is likely dry enough. A handheld electronic moisture meter provides a more precise measurement to confirm the target moisture level before baling. Baling hay above the recommended moisture level is a risk, as microbial respiration within the dense bale can generate enough heat to cause spoilage, mold growth, or spontaneous combustion.
Baling and Storing the Finished Product
Baling is the final step, packaging the cured forage into a dense, manageable unit for storage, handling, and transportation. Producers choose between large round bales, efficient for large operations and outdoor storage, and rectangular bales, preferred for feeding smaller livestock and stacking in confined spaces. Bale density is a significant factor in storage, as a tighter bale sheds water more effectively and maintains its shape.
Once baled, the hay must be stored to protect it from moisture, the primary cause of quality loss. Hay stored outside should be placed on a well-drained surface, such as gravel or pallets, to prevent wicking moisture from the ground. Round bales should be stored end-to-end in straight rows to minimize surface contact and allow air circulation.
Covering the bales with a tarp or plastic wrap provides the best protection from rain and sun. Storing hay inside a barn or shed offers the lowest loss rate, provided the bales are monitored for temperature and stacked for ventilation.