Copper (Cu) is an essential trace mineral that is required in the equine diet to support the proper function of many enzymes in the horse’s body.

Copper is important for iron metabolism, healthy connective tissue, energy production and antioxidant protection.

Horses might be low in copper due to low levels in their diet or because their diets have high levels of zinc (Zn) or iron (Fe). Excess intake of zinc or iron can interfere with copper absorption from the gut.

Copper and zinc levels need to be carefully balanced with each other to ensure proper absorption of both minerals from the digestive tract. A three-to-one (3:1) ratio of zinc to copper is recommended for most horses.

One of the most obvious signs of potential copper deficiency is a change in coat colour due to loss of pigmentation. The coat might appear dull, frizzy or discolored with a reddish tinge.

Copper deficiency can also cause anemia and weakened blood vessels, bones, or joints in adult horses. In young growing animals, low levels of copper can cause abnormal bone and cartilage formation. [1]

Copper toxicity in horses is extremely rare and requires very high intake of this mineral. However, high levels can reduce absorption of selenium and iron and interfere with how these are used by the body.

Mad Barn’s Omneity Premix is a fully balanced equine mineral and vitamin supplement that provides comprehensive nutritional coverage for your horse’s needs.

It contains 1000 mg/kg copper in the form of highly absorbable Bioplex copper, a source of copper proteinate that is organic and better used by the horse’s cells.

Our AminoTrace+ mineral and vitamin supplement provides higher copper content at 1500 mg/kg. It is designed for horses with metabolic issues and for horses that need to counteract high dietary iron intake.

We also carry bulk Bioplex copper powder for horses that require additional supplementation and a 3:1 Zinc Copper supplement.

The feeding rate for Bioplex copper depends on your horse’s condition and current feeding program. To determine the proper inclusion rate for your horse, submit your horse’s diet for analysis and our nutritionists can help.

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Benefits of Copper for Horses

All mammals require copper in their diet to act as a co-factor in the function of numerous enzymes. Enzymes are proteins that catalyze various chemical reactions in the body.

These enzymes are involved in important tasks throughout the horse’s physiology including metabolism, organ function, detoxification processes, growth and more.

Having adequate copper levels allows optimal function of the enzymes in all cells of the horse’s body. This can contribute to overall well-being, better coat and hoof quality, energy metabolism, and much more.

Below are the top 10 reasons why horses need adequate copper in their diet:

1. Coat Colour

Copper is required for the enzyme tyrosinase which makes melanin, the colour pigment in skin and hair. Horses with dull, faded hair might be low in copper and may not be able to make enough melanin.

Copper can support melanin production to protect against sun-bleaching and promote proper colouring, especially in chestnuts, bays, and blacks.

2. Hoof Health

Copper supports hoof health, not only when applied directly to hooves but also when levels within the body are optimized. Proper balance of copper and zinc supports the synthesis of keratin – a protein that contributes to the structural integrity of hooves.

Horses fed adequate levels of copper and zinc were shown to have lower incidence of white line disease (also known as seedy toe) with reduced risk of hoof wall separation. [2]

3. Hoof Growth

Copper has been shown to support hoof growth in yearlings and adult horses, especially when it is given in the form of copper proteinate instead of inorganic copper salts.

Supplementing the horse’s diet with copper and zinc proteinates increases the mineral content of the hoof horn which provides extra antioxidant protection and supports a strong hoof structure. [3][4]

4. Antioxidant Protection

Copper acts as an antioxidant by being part of the antioxidant enzyme copper/zinc superoxide dismutase. This enzyme exists in almost all cells of the body and protects against oxidant molecules that can cause damage to various parts of the cell.

Adequate antioxidant status protects against premature aging and helps cells and tissues/organs function properly.

Antioxidants are especially important for horses that are heavily exercised to help their tissues recover quickly. Older animals are also particularly vulnerable to low levels of antioxidants and might benefit from copper supplementation.

5. Immune Function

Low levels of the copper-containing antioxidant superoxide dismutase (SOD) can impair the function of the immune system.

Macrophages and neutrophils are immune cells that are found throughout the body. These immune cells rely on the SOD enzyme to generate hydrogen peroxide which is used to kill bacteria and prevent infection.

Horses with low copper and zinc status might be more prone to mud fever or rain scald because their immune cells are unable to protect against overgrowth of skin bacteria in humid conditions. [5]

6. Iron Metabolism

This micromineral is important for iron metabolism and the production of red blood cells. Iron is a critical part of red blood cells which carry oxygen around the body. Several copper-containing enzymes are responsible for moving iron from where it is stored to where red blood cells are formed.

Anemia (low red blood cells) in horses can be caused by copper deficiency because they are not able to make enough red blood cells. Horses with anemia may be weak, have low energy, poor exercise performance and low appetite.

7. Counteract High Iron Diets

Copper supplementation can counteract high iron intake in horses with iron overload. High iron intake is common in horses because it is found in almost all plant material, water, and soil. Excess iron in the diet can contribute to insulin resistance, laminitis and liver damage. It can also slow down copper absorption from the gut.

Equine nutritionists aim for a ratio of approximately 4:3:1 of iron to zinc to copper in the horse’s diet to have optimal levels of these three interconnected minerals. Adding copper to the diet of horses with high iron intake can help improve their metabolic health and support healthy hooves and liver function.

8. Bone Development in Foals

Copper supplementation is recommended for pregnant mares to support adequate copper status in the foal. This trace mineral is required for the enzyme lysyl oxidase which helps form strong connective tissue.

In growing animals, copper helps support proper growth of cartilage, tendons, and ligaments. Osteochondrosis, in which the connection between bone and cartilage is weak, can be due to copper deficiency in foals and is often related to copper-deficient diets in their dams. [6]

9. Energy Production

Energy production by all cells of the body requires copper. This element is a component of cytochrome c oxidase, which is an enzyme within the mitochondria. The mitochondria is sometimes referred to as the power plant of the cell; it is the part of the cell that makes energy from carbohydrates, fats, and proteins.

All cells of the body are dependent on this enzyme to produce adenosine triphosphate (ATP), the molecule that acts as the main energy currency of the cell. Optimal copper levels ensure that cells metabolize nutrients properly and get enough energy from them.

10. Nervous System Function

The nervous system requires copper to function properly. Copper is involved in the production and maintenance of myelin. Myelin is a protective sheath that covers nerves to help them send signals around the body properly.

Copper is also involved in the production of the neurotransmitter norepinephrine which allows nerves to communicate with each other.

Copper is a trace mineral that is only required in miniscule amounts in the equine diet. Adding copper on a one-off basis might create imbalances with other minerals, especially with zinc and iron.

We recommend evaluating the whole diet before adding supplemental copper. You can submit your horse’s diet for analysis and one of our nutritionists will be happy to provide a complementary review.

Signs of Copper Deficiency

Severe copper deficiency is rare in horses. However, suboptimal levels are common and can be part of the reason for observing the following signs of a potential deficiency:

  • Faded coat colour; this is often one of the first signs of a possible copper deficiency
  • Horses with copper deficiency might appear sluggish and tired
  • Lower than normal appetite
  • Hooves that are more prone to splitting or cracking and may lose shoes often
  • Thin soles, thrush, abscesses, or soft and weak hoof walls
  • White line disease caused by cracks in the hooves which allow bacteria to overwhelm the tissue
  • Tendon and ligament weaknesses due to impaired production and maintenance of connective tissues
  • Allergies such as hives and sweet itch
  • Persistent mud fever or rain scald due to a weakened immune system
  • Yellowish eyes, skin, or gums which might be a sign of jaundice in horses with copper-deficiency anaemia

In more serious cases the following symptoms may be observed:

  • Developmental orthopedic diseases such as osteochondrosis or osteochondritis dissecans; these are more commonly observed in young, growing horses
  • Aortic rupture; copper deficiency can weaken blood vessels and cause aortic rupture which is often fatal
  • Uterine artery rupture; this potentially fatal condition is caused by heavy bleeding during or after delivery and is more common in mares that are low in copper [7]

Factors Leading to Copper Deficiency

Low levels of copper in forage can contribute to inadequate intake in horses. Copper content of forages is proportional to the availability of this mineral in the soil which i