Good quality hay is essential, since hay constitutes a large majority of the horse’s diet. Several factors influence the quality of hay. Any of the common hays can be fed to horses, but what’s most important is nutrient value in relation to the cost of the hay. To evaluate the quality of hay, the following questions should be considered:
- 1. At what stage was the hay harvested?
- Nutrient value largely depends on the age at which the hay was harvested. Early maturity hay is very leafy and has a high nutrient density and palatability. Late maturity hay contains coarse, thick stems and fewer leaves than early maturity hay. Hay type should be matched to the horse type. Early maturity hay would be perfect for growing horses and lactating mares, but it may not be the best choice for horses with low nutrient requirements. Mid- to late-maturity hays are best for horses with low nutrient requirements, because the horses can eat more to satisfy their appetites without overeating and becoming fat.
- 2. How many leaves and stems are present?
- Harvesting procedures can affect the leaf content. Excessive movement of the hay during the drying process can shatter the leaves. Overdried hay will lose its leaves when baled. Stem content is related to the age at which the plant was harvested. The ratio of stem to leaf increases as age increases so that the hay has a higher fiber content.
- 3. Is the hay free of dust, mold, and weeds?
- Clean hay is the best hay for horses. Mold and dust can inflame the respiratory tract and impair breathing. Many horses can develop permanent lung damage after consuming moldy or dusty hay. Heaves is a common respiratory problem that occurs when a horse consumes moldy or dusty hay. Mold can also cause digestive upsets in the horse. Weeds are undesirable in hays because they are low in digestibility and acceptability by the horse. In some cases they may also be poisonous. Many times, hay will not be consumed by the horse if weeds are present.
- 4. Is the hay free of insects?
- Alfalfa hay may be infected with blister beetles. When a horse eats a blister beetle, a chemical in the beetle causes colic, fever, and eventually death.
- 5. Is the hay weathered?
- Weather conditions affect field-cured hay–hay that is left out in the field to dry after it has been cut. Rain and excessive sunlight reduce the quality of hay by reducing the nutrient content. The ideal moisture content of hay when it is baled is 12 to 18 percent moisture. Excessive moisture due to rain can cause the hay to mold when it is baled or processed.
Ashley Griffin, University of Kentucky