Copper plays an essential part in healthy equine nutrition. But unfortunately certain areas of the UK are particularly low in copper. These tend to be areas where the soil is light and sandy, such as south central, Hampshire/New Forest area and also parts of East Anglia. Devon also has areas low in copper, particularly around the moors.
Copper is an essential trace element for horses, especially youngstock. Copper is used for the production of elastic connective tissue, utilization of iron, energy metabolism and skin pigmentation. Osteochondrosis is also associated with copper deficiency and it plays a role in developmental orthopaedic disease in youngstock.
Copper absorption is very complex as it interacts with several other trace elements in the equine diet. Zinc, Iron and Molybdenum all effect copper absorption – so even if your horses diet provides adequate copper, high levels of iron or molybdenum could cause a copper deficiency by preventing copper absorption. High Molybdenum levels are a particular issue in the UK, especially for farmers. It is thought that molybdenum does not influence equine nutrition as much as it does ruminants, but is still a concern.
Trace Element interaction and ‘copper lock-up’ can be avoided by using chelated trace elements in the diet. This is where choosing the right equine supplement can really pay off. Chelated trace elements are usually made by combining the element with a protein, so that it is absorbed in the small intestine like any other protein, rather than competing for absorption sites with the other trace elements. Choosing supplements with chelated trace elements ensures that your horse is going to be able to absorb and utilise the essential ingredients much more efficiently than if the trace element is fed in its in-organic form (eg copper sulphate).
How do I know if my horse is copper deficient?
It is always a good idea to have your grazing and forage analysed for minerals and trace elements to ensure that your feed and supplements compliment the rest of your horse’s diet. It is also possible to carry out hair analysis to assess the actual copper status of the horse, but this is not always a reliable technique. Signs of copper deficiency in mature horses include loss of pigmentation, particularly around the eyes and an orangish tinge to the coat, particularly in darker coloured horses. A poor immune system and reduced stamina are also indications of a copper deficient diet. In foals and youngstock, an unexplained lameness or joint swelling can indicate Developmental Orthopaedic Disease so the diet should be evaluated to ensure the minerals are being fed in the correct balance.
Unlike sheep, horses can tolerate quite high levels of copper in their diets so it can usually be fed in the form of a supplement quite safely. As discussed, it is better to choose a supplement containing chelated (organic) copper to prevent any interactions which may prevent it from being absorbed. Copperite provides chelated copper along with Selenium, another trace element which is often deficient in soil.