NAF Vitamin E, Selenium & Lysine. NAF Vitamin E, Selenium & Lysine supports muscle function in the performance horse and integrity and also supports fertility in breeding stock. NAF Vitamin E, Selenium & Lysine can also be fed to horses living in areas where the soil is deficient in Selenium. Vitamin E is a powerful antioxidant that helps to stabilse cell membranes, is essential to natural growth, fertility and muscle function and can also benefit the horse's performance as it supports oxygen delivery to the lungs. Read more… Lysine is an essential amino acid that is important for growth and development. Selenium yeast is safer to use than inorganic forms and is also important to natural growth, fertility and muscle function. Recommended Daily Amounts Horses - 45g per day = 3 scoops per day Ponies - 30g per day = 3 scoops per day A 1kg Refil Pack fed at the Horses Maintenance Rate will last approximately 22 days.