Horsepower Vitamin E 4kgVitamin E destroys the dangerous free radicals formed as a by product of energy metabolism and assists in recovery from exercise by limiting free radical damage to cells. Studies have shown that horses without access to fresh pasture (even if provided with hay) often have a Vitamin E deficiency. A handy tip to remember is that if a horse is being fed a Vitamin E supplement and oil, then these should be given in separate feeds (ie oil in the morning,