Nutritional Content of Five Equine Nutritional Supplements Relative to a 500-kg Working Horse

The nutritional content of supplement products fed to horses may contain widely ranging amounts of nutrients compared with established National Research Council (NRC) requirements for horses. This paper documents a wide range of individual nutrient dosages relative to the NRC requirements based on label information of five equine nutritional supplements. Some nutrient levels are in excess of NRC requirements for individual nutrients, whereas others are far below NRC. These variations were found in each of the five supplements studied. Practitioners may use this information to recommend whether or not a particular supplement is indicated. Authors’ addresses: PO Box 4768, Sunland, CA 91401-4768 (Ramey); and 967 Haas Road, Weiser, ID 83672 (Duren); e-mail: [email protected]. *Corresponding author. © 2011 AAEP.

1. Introduction

The supplement business in the United States is a hugely profitable enterprise. In 2006, it was estimated that the human dietary supplement industry in the United States directly produced $22.5 billion dollars, with another $38 billion dollars produced through indirect and induced effects.¹  Whereas dietary supplementation appears to be widespread in the equine industry, specific data on the economic impact was not available.

Although the selection of various supplement products may be largely driven by the horse-owning public and direct to consumer advertising, equine practitioners may sometimes be asked for advice on the best supplement to feed horses. The NRC guidelines may be used to compare equine nutritional requirements with labeled content of a supplment.

2. Materials and Methods

The daily requirements for 20 nutrients were obtained from a computer program developed from equations and other data presented in the sixth revised edition of the Nutrient Requirement of Horses (National Research Council [NRC]).² program performs some of the procedures necessary for the calculation of the requirements in the NRC. 

The program requires that the user give specific information (for example, the current body weight or the month of gestation for pregnant mares). For exercising horses, the user must choose from four levels of work load. The program calculates the requirements for various nutrients in amounts per day measured in milligrams or international units (for vitamins). For the purposes of this study, a 500-kg horse in light exercise was used to make the calculations. The requirements for each of 20 nutrients were tabulated (Tables 1–4).

The guaranteed analysis of various equine nutritional products intended to be complete supplements was then analyzed on a per dose basis appropriate for a 500-kg horse according to the manufacturer’s label. When reported in amounts of parts per million (ppm) or percentage, we converted those amounts to milligram per dose (ppm is milligrams per kilogram). No attempt was made to analyze the supplement products for content; rather, it was assumed that the label contents were accurate. The nutrients provided by a daily dose of the supplement were compared with established NRC requirements, with the results tabulated as percent of NRC requirements.
 

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