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Dr. Gray's Featured Article: Silica Supplementation in Horses Shown to be Safe and Effective

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While beer may be an excellent source of bioavailable silica for humans, a new round of dietary supplements may be a better way to provide horses with this essential trace mineral.

According to the sixth edition of the NRC Nutrient Requirement for Horses, a need for silica in the ration likely exists for the equine but determining a minimum requirement is difficult. That’s because silica is present in high levels in many of the things horses eat–such as cereal grains, alfalfa and beet pulp—but these environmental sources of silica are not as easily absorbed by the body as some others, such as orthosilicic acid.

The country’s leading research institution on silica supplementation in horses, the Department of Animal Science at Michigan State University, has recently published the paper “Mineral balance in horses fed two supplemental silicon sources.” While both sodium aluminium silicate (SA) and orthosilicic acid (OSA) were able to alter calcium retention and bone metabolism, only OSA was able to alter silica retention, digestibility and plasma concentration.

The bottom line: scientific studies have shown that certain types of silica are more bioavailable in the horse than others and that concerns over potential mineral imbalances are unfounded. Research in horses has proven the benefits of silica on bone growth and development while research in other species has shown that dietary deficiencies of silica can lead to deterioration of connective tissue strength and integrity.

O’Connor CI, Nielsen BD, Woodward AD, et al. Mineral balance in horses fed two supplemental silicon sources. J Anim Physiol Anim Nutr (Berl). 2008 Apr;92(2):173-81.

Spooner HA, Nielsen BD, Turner KK, et al. Mineral balance in horses fed sodium zeolite. 7th International Conference on Equine Exercise Physiology, 26-31 August 2006, Fontainebleau, France.

Nielsen BD, et al. Training distance to failure in young racing quarter horses fed sodium zeolite A. J. Equine Vet. Sci. 1993. 13(10):562-567. AND Proc. 13th ENPS p.5

Lydia F. Gray, DVM, MA SmartPak Staff Veterinarian and Medical Director Dr. Lydia Gray has earned a Bachelor of Science in agriculture, a Doctor of Veterinary Medicine (DVM), and a Master of Arts focusing on interpersonal and organizational communication. After “retiring” from private practice, she put her experience and education to work as the American Association of Equine Practitioner’s first-ever Director of Owner Education. Dr. Gray continues to provide health and nutrition information to horse owners through her position at SmartPak, through publication in more than a dozen general and trade publications, and through presentations around the country. She is the very proud owner of a Trakehner named Newman that she actively competes with in dressage and combined driving. In addition to memberships in the USDF and USEF, Dr. Gray is also a member of the Illinois Dressage and Combined Training Association (IDCTA). She is a USDF “L” Program Graduate and is currently working on her Bronze Medal. Find Dr. Gray on Google+

Posted in Ask the Vet, Nutrition

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4 comments on “Dr. Gray's Featured Article: Silica Supplementation in Horses Shown to be Safe and Effective
  1. Lisa Schroeder says:

    You keep speaking about silica when you must mean silicon! Silica is Silicon dioxide, or commonly known as sand (ground up quartz). Horses cannot absorb silica, and one would not want to feed sand to a horse anyway! Please get your chemistry straight.
    Lisa L. Schroeder, Ph.D.

    • SmartPak SmartPak says:

      Hi Lisa, thanks for sharing your concerns. We agree that feeding sand to a horse is not a good idea! We want to clarify that the silica used in our supplements comes from orthosilicic acid (a liquid source) and magnesium silicate. Both forms are widely used in both horse and human supplements to support connective tissue health.

  2. Shireen says:

    Can you provide a reliable source of obtaining orthosilicic acid and magnesium acid for a horse? Would feeding it have any benefits to hoof growth as well as bone and tendon/ligament strength?

    • SmartPak SmartPak says:

      Hi Shireen, thank you for asking! If you’re looking for a supplement with a source of bioavailable silica, you could consider supplements such as SmartFlex III Resilience, SmartFlex IV Ultimate, and SmartTendon. Each of these formulas contains bioavailable silica from orthosilicic acid, as well as magnesium silicate. Silica is thought to help support healthy connective tissues, so it may be nice to have on board for supporting tendons and ligaments, as well as hoof horn. – Dr. Lydia Gray

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