By Amy Burk, Ph.D., horse extension specialist at the University of Maryland (Full video: youtu.be/Wid5eW_0VlA)
From the January/February 2020 Paint Horse Journal
Fiber is essential for horses’ digestive health; a horse should consume 1–2 percent of its body weight every day in fiber, typically through hay or pasture. For a 1,000-pound horse, that’s approximately 10–20 pounds of fiber a day. Hay is generally fed to horses when pasture is not available. This includes during winter or drought conditions; when a horse is confined in a stall, dry lot or while being transported; or when a horse has special dietary needs.
Common types of hay include legumes, like alfalfa, and grass hays, like Bermuda or timothy. When assessing your horse’s diet, it’s important to consider hay quality because it can impact the available nutrients, fiber content and palatability. Evaluation is typically conducted through a visual inspection—the appearance, feel and smell of the hay—but a chemical analysis can also be a good tool and often provides a more accurate evaluation. Here’s how to get started:
- Determine stage of maturity at harvest. This is the No. 1 factor affecting hay quality. As the plant matures, its fiber content increases; this can cause a horse to feel full before its nutritional requirements are met—similar to when humans eat popcorn. Sugar, starch and protein contents also increase as the plant grows, but these decline after the plants produce seed heads. In general, leafy immature hay has greater nutritional value, and stemmier, more mature hay has lower nutritional quality. The ideal time to harvest hay is prior to “heading”—when the seed heads become visible.
- “Cuttings” don’t necessarily indicate quality. This simply refers to the number of times a hay field has been cut: first cutting, second cutting, etc. Depending on weather conditions, hay can be cut multiple times during the growing season, and quality can vary between cuts.
- Examine the leaves. The leaves contain most of hay’s nutritional content; select hay with an abundance of soft leaves, as opposed to stems.
- Consider color. Hay’s color indicates maturity, curing and storage. A bright green color often indicates good quality—hay that was harvested and cured properly, quickly and at an earlier stage of maturity—but make sure you consider the color of the entire bale. A sun-bleached outer layer doesn’t necessarily indicate poor quality within the bale. If entire bale is golden yellow throughout, however, the hay was overly mature at harvest and it’s of lower quality. Always avoid brown or black hay.
- Try the smell test. Hay should smell pleasant— like a freshly mowed field. Hay’s smell directly impacts palatability to horses, so avoid bales that smell musty.
- Check for debris. Hay should be free of dirt, dust, weeds, sticks, mold and other foreign materials. Blister beetles, sometimes found in alfalfa, are poisonous to horses.
- Lab test for deeper insight. A chemical analysis provides owners with the actual nutritional content of hay, including its levels of energy, fiber, sugar, starch and protein. If you opt for a chemical analysis, be sure to use a certified forage testing lab, take a representative sample of hay and ask for assistance interpreting the results to make accurate feeding decisions. Your state or county horse extension service can be a great resource.