Copper

Copper (Cu) is another important mineral. It is used in the creation and maintenance of elastic structures such as connective tissue and other structures.

This is especially important in growing horses, as the bone collagen is one of these structures that relies on the presence of Cu to develop correctly.

Grass is one source of copper in the horse diet.

It is also important in moving stores of iron to areas where they are needed, as well as the creation of melanin.

Another important function of Cu is to help create red blood cells.

And lastly, it helps keep the central nervous system running correctly.

Cu is one mineral that can be highly influenced by other minerals. The following mineral forms can all reduce the absorption rate of Cu to varying degrees:

  • Calcium salts
  • Ferrous sulfide
  • Mercury
  • Molybdenum
  • Cadmium
  • Zinc

Dietary Sources

Common feedstuffs that are fed to horses vary widely in their Cu content. Can molasses has one of the highest concentrations of Cu. Due to this, its inclusion in feeds in a minimal amount can be beneficial. However, due to its high sugar content, if it is included in large amounts, the negatives outweigh the positives.

The table below lists the Cu concentrations of some common feedstuffs:

Feedstuff Cu Concentration
Cane Molasses 66 mg/kg
Flax Meal 19 mg/kg
Beet Pulp 11 mg/kg
Wheat Middlings 10 mg/kg
Grass Hay 9 mg/kg
Legume Hay 9 mg/kg
Oats 7 mg/kg
Corn 3 mg/kg

As mentioned above, Cu is one of the minerals that can be easily influenced by other minerals. The most notable of these is zinc When large amounts of zinc are fed along with small amounts of Cu, a secondary Cu deficiency can be created.

Copper Deficiency

Because Cu is associated with connective tissue and bone, a Cu deficiency usually causes bone problems.

Some common problems that have been linked to a deficiency include Developmental Orthopedic Disease.

Copper Toxicity

It appears that horses are fairly tolerant of high Cu concentrations. When horses were given large amounts of Cu orally, no adverse reactions were seen.

Thus, the maximum tolerable concentration for horses has been set at 250 mg/kg of ration. This level is way above the recommended intake level of 10 mg/kg dry matter.


Cu, like the other minerals is essential to your horse's health. Now you know how your horse obtains and uses this mineral, as well as deficiency and toxicity information.


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