Equine Supplements and Nutritional Requirements (AAEP 2011)

Equine Supplements and Nutritional Requirements (AAEP 2011)

Photo: The Horse Staff

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.

Based on the NRC guidelines, Ramey determined that most equine diets (approximately 7 kilograms [roughly 14.4 pounds] of alfalfa plus one pound of oats or 9 kilograms [19.8 pounds] of grass hay plus one pound of oats) more than adequately satisfy the nutritional needs of the 500-kg horse in light work. Substances that might be lacking are salt (sodium chloride) and possibly selenium in certain geographic areas, he noted.

Ramey found that according to the labels, and depending on the product, and the particular nutrient, levels within the analyzed products varied from 0.18% to 875% of daily nutritional requirements. In addition, he opined that formulations of each supplement "lacked balance." In general, Ramey concluded that with a few exceptions, these supplements didn't provide significant-enough amounts of required nutrients to make up for those a horse's diet might be lacking. He stressed, "A diet that is deficient in a particular nutrient is not going to be improved by feeding a supplement that doesn't contain sufficient amounts to correct the deficit."

Ramey noted that indiscriminate human vitamin supplementation is coming under fire, so he feels it is relevant to examine what supplements horses are being fed. He noted that, in human medicine, it's been shown that nutritional supplementation can sometimes cause harm. One example he cited is the previously accepted use of vitamin E to support the treatment of human prostate cancer; researchers recently found that vitamin E supplementation increased the risk of mortality.

To his clients, Ramey said he suggests "it may be that the best supplement is no supplement at all." He noted that avoiding spending money on supplements is particularly appropriate for horse owners who are struggling to simply maintain their horses in this difficult economy. He reported, "Human nutritionists contend that supplements don't make healthy people healthier." Similarly, if a horse is fed an adequate diet, then there might be no need for supplementation in the absence of a specific deficiency. He reminded everyone that "no benefit is achieved with hypernutrition."

About the Author

Nancy S. Loving, DVM

Nancy S. Loving, DVM, owns Loving Equine Clinic in Boulder, Colorado, and has a special interest in managing the care of sport horses. Her book, All Horse Systems Go, is a comprehensive veterinary care and conditioning resource in full color that covers all facets of horse care. She has also authored the books Go the Distance as a resource for endurance horse owners, Conformation and Performance, and First Aid for Horse and Rider in addition to many veterinary articles for both horse owner and professional audiences.

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