Which mineral affects what? Horses need a versatile mineral supplement.
A horse’s basic forage is hay, so hay should be as high-quality and nutrient-dense as possible. However, quality and nutrient content vary depending on the year, weather, producer, and soil conditions. In addition to hay and/or pasture, horses also need mineral supplements.
Minerals and trace elements are important building blocks for the horse’s skeleton and connective tissues. They also take part in many chemical reactions in the body. The most important minerals for horses are calcium, phosphorus, magnesium, sodium, chloride, and potassium. The most important trace elements include iron, copper, zinc, and selenium. Mineral requirements vary from horse to horse depending on age, breed, size, and workload. General feeding recommendations can be checked here.
Iodine:
Horses need iodine to produce thyroid hormones. The thyroid gland regulates, among other things, metabolic rate, energy production, and body weight. Foals and adult horses need 1–2 mg/day, but pregnant and lactating mares require slightly more. Adequate iodine intake is important for breeding mares, as it affects the mare’s heat cycle, among other things. Seaweed contains especially high levels of iodine, so its use should be monitored and the dosage should not exceed about 30 grams per day. Iodine is also found in hay, oats, and mineral salt.
Potassium:
Potassium affects fluid balance and muscle metabolism. It is also needed for transmitting nerve impulses. Potassium and sodium are linked, and an incorrect ratio can cause muscle problems. Horses usually get enough potassium from basic forage. A deficiency may show as muscle weakness, fatigue, or constipation, but it is rare. Dandelion leaves and root are rich in potassium.
Calcium:
Calcium is a building block of the horse’s skeleton. It is also needed for coordinated muscle and nervous system function. Forage is the horse’s main source of calcium. Forage that contains clover and alfalfa contains more calcium than grass-only forage. Molasses is also a good source of calcium. Of all minerals, horses need calcium and phosphorus the most. Because calcium and phosphorus are key building blocks of bone, they are especially important for pregnant mares and growing foals. The calcium-to-phosphorus ratio should be about 1.8:1 for pregnant mares and foals, and 1.3–1.5:1 for other horses.
Cobalt:
A horse’s daily cobalt requirement is about 0.6–1 mg. Cobalt is needed for vitamin B12 synthesis in the horse’s body and is also important for the function of certain enzymes. Basic forages contain cobalt, but particularly high sources include molasses, flax, and brewer’s yeast. Deficiency signs can include anemia, reduced appetite, and licking behavior, but deficiencies are rare in horses.
Copper:
Copper is needed for enzymes involved in energy metabolism and supports the nervous system, skeleton, and connective tissues. It is also required for hemoglobin formation and red blood cell function. Copper affects iron absorption as well. Forages contain only small amounts of copper, so horses should receive it from mineral supplements. Copper deficiency signs typically include anemia, fading coat color, digestive disturbances, and licking behavior. In foals, copper deficiency can cause growth disturbances, which is why it is especially important to check copper and zinc intake for young horses. The ratio should also be correct, as excessive zinc reduces copper absorption. The copper-to-zinc ratio should be about 1:4. Copper intake should always be checked in anemic horses.
Manganese:
Manganese supports the growth of bone and connective tissue and is involved in nervous system function. It is needed for energy metabolism and for the synthesis of chondroitin sulfate, which is important for joint cartilage formation. Chondroitin sulfate is abundant in the extracellular matrix of bone, cartilage, and connective tissue. Pasture grass, straw, and bran contain manganese. Deficiency may cause skeletal defects, neurological issues, and loss of appetite. Horses need roughly the same amount of manganese as zinc and iron—about 300–400 mg/day.
Magnesium:
Magnesium is also a component of bone tissue. It plays an important role in muscle function, many enzymes, and overall metabolism. Horses need magnesium for muscle contraction and for transmitting nerve impulses. Its function is closely connected with calcium, and deficiency—or an incorrect balance—can cause muscle and nervous system issues. Deficiency signs include muscle tremors, neurological disturbances, and reduced appetite. On average, horses need about 10 g of magnesium per day. Competition horses need more—about 15–20 g. Over-supplementation may cause muscle stiffness. Magnesium is found especially in alfalfa, beet pulp with molasses, and molasses. Chia and flax are also good sources of magnesium.
Sodium and chloride:
Sodium and chloride usually occur together in the body as sodium chloride—salt. Sodium regulates fluid balance and muscle metabolism. Daily requirement varies depending on workload. Competition horses are recommended 60–120 g per day; less active horses need less. Common deficiency signs include licking the ground, loss of appetite, fatigue, and muscle weakness. Forages typically contain low sodium and chloride levels, and salt requirements can be met with a salt block. Competition horses in heavy work may also need added salt mixed into feeds. Excess salt intake increases urination.
Selenium:
Selenium is essential for horses, but toxic in excessive amounts. It affects thyroid hormone production and also plays an important role in reproduction and fertility. Selenium supports muscle function together with vitamin E, and vitamin E as an antioxidant can partly compensate for selenium deficiency—and vice versa. Selenium levels in soil are low, so horses should receive selenium from concentrates and mineral feeds. Deficiency signs include muscle degeneration and general muscle fatigue. Daily requirement is about 0.9–1.5 mg.
Iron:
Iron deficiency is very rare in horses because basic forages contain relatively high iron levels. In addition, the horse’s body recycles and retains iron efficiently. Low iron values usually have another underlying cause, such as inappropriate intake of another trace element or digestive disturbances. However, sport horses may benefit from iron supplementation given as a course, partly because more iron is lost from the body during heavy exertion than during normal metabolism. For horses, nettle is an excellent iron supplement.
Over-supplementation of iron reduces the absorption of other minerals such as manganese and zinc—and especially copper—and can lead to deficiency signs. Excessive use of iron supplements can cause iron toxicity, particularly in foals. Iron is linked to oxygen uptake capacity and overall performance. Many mineral feeds contain added iron as well. Signs of iron deficiency include anemia, fatigue, poor coat quality, and diarrhea. A horse’s general daily iron requirement is about 350–450 mg. In the rare cases where a horse has iron deficiency, the cause is usually not low intake but poor utilization.
Sulfur:
Sulfur is important for protein formation in the horse’s body and also functions as a building block for vitamins. The horse’s body contains small amounts of sulfur naturally. The requirement is low, and horses generally get enough from forage. Sulfur is beneficial for joints, cartilage, and hooves. MSM is a natural form of sulfur.
Zinc:
Basic feed typically covers the horse’s zinc needs. Zinc affects enzyme and hormone function, immunity, coat condition, growth, skeleton, skin, mane and tail, and hooves. Deficiency may appear as skin lesions, poor appetite, or licking objects. According to research, eating soil, sand, or manure as well as wood chewing may be linked to iron or copper deficiency and an incorrect copper-to-zinc ratio in the diet (Aytekin et al. 2011). Excess zinc in the diet interferes with iron and copper utilization. Zinc deficiency is rare in horses. Zinc is found in yeast, bran, sprouts, nuts, and in the CdG Zinc product.
Silicon:
Silicon is needed for bone formation and for the development of cartilage tissue and tendons. It may also affect skin and coat. Basic forages contain only small amounts, so silicon is often added to mineral supplements. Nettle and diatomaceous earth are good sources of silicon.
Electrolytes:
A horse may sweat several tens of liters, and in doing so also loses a significant amount of salts and minerals—electrolytes (sodium, chloride, potassium, magnesium, calcium). Sweating uses up a lot of water from the body and can lead to dehydration, which also affects performance.
If lost substances are not replaced, deficiency signs can occur: decreased energy levels, fatigue, muscle cramps, neurological disturbances, trembling, and general muscle soreness. However, electrolytes should not be given unnecessarily, as imbalances caused by over-supplementation are also harmful. Electrolytes can be replaced with the Electrolyte Up product.
