Hoof Nutrition Intelligence is a twice-a-month web segment that is designed to add to the education of footcare professionals when it comes to effectively feeding the hoof. The goal of this web-exclusive feature is to zero in on specific areas of hoof nutrition and avoid broad-based articles that simply look at the overall equine feeding situation.
This edition is sponsored by the W.F. Young Co. (Absorbine) of East Longmeadow, Mass.
Below you will find Part 2 of the latest question and answer installment that you can share with your footcare clients.
Q: How important is Vitamin E in hoof development?
By Kathleen Crandell, PhD
Vitamin E is one of only two important vitamins that the horse can’t produce that must be provided in the diet. This vitamin requires a small amount of fat in order to be properly absorbed, which is why it is considered a fat-soluble vitamin. However, grazing horses usually consume enough fat from green grass to satisfy this need.
The various roles of vitamin E in immune response, nerve and muscle function and antioxidant action make it vital to the health of young, growing horses. Together with selenium, vitamin E acts to maintain normal muscle function and aids in the prevention of muscular disease. It also provides antioxidant protection from damage induced by oxidation to body tissue, particularly cell membranes, enzymes and other intracellular substances.
A deficiency of vitamin E may cause a variety of symptoms and pathological changes, which may include nutritional muscular dystrophy (weak and poorly oxygenated muscles) and poor immunity to diseases (such as a recurrent cold and cough). Both vitamin E and selenium may help leukocytes and macrophages survive the negative effects of toxic products that are produced when invading bacteria are destroyed.
Vitamin E is found in fresh green forage, and horses consuming an adequate quantity of green forage have not been found to have a deficiency. However, vitamin E rapidly disappears during the harvesting of hay, with 30% to 85% being lost initially and further losses occurring during storage. The amount of vitamin E in hay is quite variable, depending on the type of forage and how it is harvested. Because of the large number of horses that have access only to hay as forage, manufacturers routinely add vitamin E to commercial feed mixes.
Vegetable oils are relatively high in vitamin E, but are generally not fed in sufficient quantities to have a big impact on the supply of this vitamin in the diet. The increasing popularity of high-fat feeds may have an impact on the fortification of vitamin E in feeds since these feeds require extra vitamin E to prevent oxidation of fat in the feed.
Horses are not very efficient in storing vitamin E, although their bodies can store sufficient amounts of vitamin E to cover 4 months of inadequate winter intake in a well-repleted adult. Foals born to mares depleted in vitamin E may have little or no reserves, which would make them more susceptible to infectious diseases.
Supplementing vitamin E is best achieved through the use of a natural, water-soluble product.
Kathleen Crandell, PhD, is an equine nutritionist with Kentucky Equine Research in Versailles, Ky.
Click here to read Part 1 of the November 15, 2017 installment: How well will my horses handle our area’s cold winter weather and will it have any impact on their feet?