Nutritional supplement use is widespread in the horse industry, with owners adding scoops of products to feed without necessarily understanding how these nutrients fit into a normal equine diet. A veterinarian and an equine nutritionist examined how five general equine dietary supplements stacked up in light of a horse’s daily nutrient requirements. David Ramey, DVM, presented the findings at the 2011 American Association of Equine Practitioners convention, held Nov. 18-22 in San Antonio.

Ramey started off his presentation remarking that supplement sales are often driven by direct-to-consumer advertising, with consumers being "educated" that nutritional supplements are necessary. He recognized that horse owners might ask their veterinarians for advice on the best supplements to feed horses, so he emphasized the importance of knowing what’s in supplements and how they might be used. He and Stephen Duren, PhD, an equine nutritionist with Performance Horse Nutrition in Weiser, Idaho, evaluated the following commonly used products in the context of the diet of a 500 kg horse in light work: Platinum Performance, Dynamite, Grand Meadows Grandvite, Farnam Vita-Plus, and Vita-Flex Accel.

To determine nutritional requirements for such a horse, Ramey and Duren used the National Research Council’s (NRC) Nutrient Requirements of Horses (6th Revised Edition, 2007). For the purposes of this evaluation, he assumed that the product label amounts were accurate. However, he did point out that actual levels of a product might vary from label content, in part due to lack of regulatory oversight.