Many horse owners are curious about selenium, one of the most popular horse’s supplements. This nutrient is actually important for your horses, but it should be given in the right portion, or it will end up harming the horse. So what is actually selenium for the horse? What is the importance of it? What is the benefit of selenium for horses?   Selenium for Horses The Definition of Selenium Selenium works as the antioxidant in the horses’ body.  This is an essential trace mineral to guard the body’s cell membranes from free radicals. It works together with vitamin E, creating