Zinc is an essential trace mineral that is required by horses for the immune system, tissue repair, growth, fertility and fetal development. It is involved in over 100 different enzymatic reactions in the body that affect hormone metabolism, energy synthesis, protein synthesis, collagen and keratin formation, blood clotting, insulin production and more.
Zinc is found most abundantly in the eyes and prostate gland followed by bone, skin and muscle tissue. Low levels of zinc in the diet can contribute to subnormal growth, fatigue, problems with hair, hoof and skin quality, impaired wound healing, loss of appetite, anemia and high frequency of colds and other diseases.
According to the NRC’s Nutrient Requirements of Horses, a 500 kg (1,100-pound) mature horse requires 400 mg per day of Zinc. Requirements are higher for horses that are lactating or undergoing heavy work. Many horses do not obtain optimal amounts of this mineral from their forage and could benefit from supplementation.
Zinc is commonly supplemented in balance with Copper because the two minerals compete for the same absorption pathway in the gastrointestinal tract.