Selenium is a key component in glutathione peroxidase, (anti-oxidant activity). It is involved in thyroid hormone conversion and binds heavy metals. Selenium is part of enzymes associated with immune support. It should be combined with vitamin E for maximum performance. Deficiency symptoms include weepy eyes, white muscle disease, retained placenta, zigzag pattern droppings, low tail carriage and therefore dirty rear-end. This mineral can limit sub-clinical mastitis. Sources include oil meals, Lucerne, oats, veterinary and commercial supplements which may contain 1.0-3.0 ppm
Finnish potato research reported a 30% increase in mean tuber weight of potatoes with selenium supplementation. This was linked to enhanced photo oxidative stress tolerance. Chinese researchers report an increase in rice yields. European research showed leaf levels as low as 10 ppm of selenium served to reduce aphid populations by 50%. Selenium is found in seafood, Brazil nuts, brewer's yeast, butter, garlic, kelp and molasses.
Weepy eyes is a sign of selenium deficiency.