09/12/2026
Selenium. Small Mineral. Big Role.
Selenium works closely with vitamin E as part of the body’s antioxidant defense system, helping protect cells from oxidative stress. It is especially important for:
Normal muscle function — Supports proper muscle contraction and helps muscles function efficiently.
Recovery and cellular protection — Helps protect cells from damage and supports the body’s recovery after physical activity.
Immune system support — Contributes to a healthy immune response and helps the body defend itself.
Reproductive health — Supports normal reproductive function in both mares and stallions.
Healthy growth and development — Helps support normal development, particularly in growing horses.
A significant challenge with selenium is that the amount naturally present in forage depends heavily on where that forage was grown and the selenium availability of the soil.
Many areas of the eastern United States are known for selenium-deficient soils, meaning hay grown in those regions may contribute very little selenium to the horse’s diet. In contrast, some areas of the western United States contain soils naturally higher in selenium, and certain plants grown there may accumulate considerably more. However, selenium levels can vary greatly even within the same region, so geography alone should never be used to determine exactly how much selenium a horse is receiving.
This is one reason a forage-first approach is so important. Hay may be the largest part of the ration, but its trace-mineral contribution is not always predictable.
Selenium also has a relatively narrow margin between adequate intake and excess, so simply adding more is not better. The selenium coming from hay, grain, fortified feeds and supplements should all be considered when evaluating the total ration.
The Goal Is Balance. Know where your forage comes from. Understand the entire feeding program. Then provide selenium and other trace minerals in amounts designed to complement what the horse is already receiving.
Equi-Shine helps take the guesswork out of supplementation by providing carefully balanced vitamins and trace minerals to complement a forage-based diet.
