Are You Feeding Your Horse Enough Vitamin E?

sources of vitamin E but stored forages like hay or haylage lose their vitamin E activity quickly. Whole grains and some unsaturated fat sources are also good sources of the vitamin but again the vitamin deteriorates rapidly during storage. 
How much vitamin E do horses need?
The 2007 NRC Equine Nutritional Guidelines provide minimum recommendations for vitamin E intake for horses at different body weights and different metabolic states. It suggests that a mature 500 kg horse at maintenance doing no work needs a minimum daily intake about 500 IU international units of vitamin E. The requirement doubles to a minimum intake of 1000 IU for the same horse doing hard work. Research has shown that horses consuming diets higher in unsaturated fat sources such as corn soybean or canola oil may have reduced efficiency in utilizing dietary vitamin E sources. This could potentially increase the vitamin E requirement for hardworking horses that are consuming high fat feed supplements.
Most commercially available complete equine mineral supplements provide vitamin E at a minimum of 500 IU for a mature 500 kg horse thereby providing supplemental vitamin E at NRC recommended maintenance levels. This intake will provide an adequate level of the vitamin for most pleasure horses. The expectation is undoubtedly that any additional vitamin E required will be provided by the forages the horse eats or additional complete feed sources.
Unfortunately a reality of modern horse ownership is that few of our horses especially those in significant training or work have much access to fresh forage like pasture. Even semisedentary pleasure horses are likely to be limited in their access to pasture as we understand so much more now about the impact it has on horses with metabolic issues. Few pleasure horse are allowed unlimited access to rapidly growing spring pasture because of concerns such as insulin resistance and laminitis. Its too bad because fresh pasture is probably one of the best sources of vitamin E available for your horse.
Stored forages such as hay have reasonable levels of vitamin E at harvest but the levels decline rapidly after that. Most equine nutritionists assume that stored forages of any kind contribute no vitamin E to an equine diet.
An assessment of your horses diet may well show that you are providing your horse with vitamin E at a level that is adequate for maintenance. If however you have a horse that is in hard work senior
growing pregnant lactating or a breeding stallion its definitely worthwhile to consider supplementing hisher diet with additional vitamin E.
Horses have relatively limited stomach and small intestine capacity. For this reason it is important to feed small meals often when providing nutrients that must be absorbed in the foregut. For the best utilization of vitamin E by your horse the maxim for equine diets of small meals fed often is good advice. If your schedule will allow it consider dividing your vitamin E supplementation into at least two meals per day or more if it can be accommodated.
Remember that as a fat soluble vitamin a supplemental level of vitamin E in your horses diet will not necessarily result in consistent increased levels of alphatocopherol at the muscle or blood level overnight. Your plan for supplementation needs a long term commitment. The outcome though even for a pampered pasture pet can result in many tangible benefits