Dr. Vanessa Corriher-Olson, Professor and Forage Extension Specialist
Texas A&M AgriLife Extension
Hay is the most common source of stored feed used in livestock operations. Because most of the harvested hay is used on the producer’s own farm, producers should be concerned with producing high quality hay to maximize animal performance.
The range of hay quality varies greatly, depending on climate, soil fertility, weed control, stage of maturity at harvest, harvest conditions, and storage. Most forage species, whether legumes or grasses, can produce high- or low-quality forage. Low quality hay requires extra supplementation to meet animal requirements. High-quality hay is dry, palatable, and a highly digestible forage that has enough nutrients to meet the livestock’s nutritional needs.
Hay quality is affected by such factors as maturity at harvest, soil fertility, nutritional status of the plant, available moisture during the growing season, season of the year, ratio of leaves to stems, stem size, weed control, foreign matter, harvesting, weather at harvest, and storage. Of all factors, the most important is stage of maturity or age of the plant at harvest.
As a plant matures towards heading, flowering and seed formation, its growth pattern changes from producing digestible leaves to producing indigestible hard stems and the ratio of digestible leaves to indigestible stems changes. This ratio determines the forage’s nutritive content and digestibility.
At each growth stage, the digestible part of the plant tissue decreases rapidly. To optimize both forage quality and forage yield it is commonly recommended that forages such as bermudagrass be harvested every 3 to 5 weeks and that forages such as sudangrass and sorghum x sudangrass hybrids be harvested before mature seed head production.
Harvested forage that is left to be rained on may exceed 40 percent moisture content for an extended period and lose substantial energy content due to leaching of non-structural carbohydrates. Rain can also shatter leaves off harvested forage and reduce both the crude protein and energy levels of the hay. It is better to wait for good curing conditions than to take a chance that rain will fall on mowed hay. At baling, the moisture content of hay for large round bales should not exceed 18 percent; for small square bales, moisture content should not exceed 20 percent. Tight windrows, moist soil and cloudy humid conditions all delay drying and promote valuable energy losses.
Close attention to all aspects of hay production will result in production of high quality and quantities of livestock feed.