Sometimes hay just isn’t enough. Here’s how equine supplements can help horses get the nutrients they need to thrive.

Sometimes hay just isn’t enough. Here’s how equine supplements can help horses get the nutrients they need to thrive.

The majority of the horse’s digestive tract is dedicated to the microbial fermentation of forage. Therefore, the majority of his daily feed intake should consist of forage. Forage comes in many forms, from pasture to hay pellets to hydroponic fodder. At some point during the year, regardless of where you live, you will likely have to supplement your horse’s diet with a forage source other than pasture. Traditionally, this supplemental forage is in the form of hay.

Hay is thought of as a bulk commodity, and is commonly regarded as low in nutritional value. The truth is that good quality hay can provide a horse with the majority of his nutritional needs. Many horses can derive adequate calories and protein from hay, as well as many of their macro-mineral needs (calcium, phosphorous, magnesium and potassium). Keep in mind that hay is not perfect, trace mineral levels can be low (especially copper, zinc, and in some geographic areas, selenium), and the balance of minerals in the hay may not be optimal for the horse’s needs.

While good green hay provides more than adequate levels of vitamin A precursors, the sun drying process necessary to remove moisture will destroy much of the vitamin E and Omega-3 fatty acids that are typically abundant in fresh grass. For these reasons, even a horse that is seemingly doing well on hay alone should be given a source of additional trace minerals, Omega-3 fatty acids, and vitamin E. Other nutrients, especially nutraceuticals, may be necessary for horses with greater needs.

It is important to note that many supplement products contain a laundry list of minerals and other nutrients, but often in insignificant quantities. The product you choose should be formulated to provide what is generally lacking or out of balance in a forage/hay ration.

Look for products that provide at least 50% of the National Research Council (NRC) guidelines for copper and zinc (i.e. 50 mg of copper and 200 mg of zinc for a 1,100 pound horse) and 100% of the guidelines for vitamin E (500 IU). Note again that these amounts are for a 1,100 pound horse that is not in work, and that your horse’s nutritional needs increase with his work level. You may consider consulting with a qualified equine nutritionist if you’re concerned about getting your horse’s ration right.

Finally, be sure to look for the NASC Quality Seal on products you are considering. This tells you the product comes from a responsible supplier that has passed a comprehensive third-party facility audit, and maintains ongoing compliance with NASC’s rigorous quality standards, which includes passing random independent product testing to ensure products meet label claims. Visit for a complete list of NASC member companies that have earned the Quality Seal.

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Dr. Clair Thunes, PhD take the guesswork out of feeding horses by helping horse owners create personalized diet plans optimized for health and performance. As an independent equine nutritionist and owner of Summit Equine Nutrition LLC, an equine nutrition consulting company, she has clients across North America including breeders and performance horse owners. She is available for personal consultations either by phone, email or in person. You can find Dr. Thunes online at, or on Facebook by searching for "SummitEquineNutrition".