Gerald Hauer, DVM
Bison Production Specialist
Alberta Agriculture, Food and Rural Development
Bison Centre of Excellence, Leduc, Alberta.
Phone: (780) 986-4100
Reprinted from The Tracker, volume3 issue 7, July 1999
Copper is a mineral that is important for the proper function of many tissues in the body. Deficiency of this mineral can lead to a variety of disease conditions. Deficiencies can be caused by lack of the mineral in the feed or by excesses of other minerals that bind to the copper and make it unavailable. Know the copper status of your herd and supplementing accordingly.
Copper deficiency is encountered in livestock throughout the world. It is a well known disease of farm animals in New Zealand and has been recognized in Canada as well. Elk and deer seem to be more susceptible than bison but under the right conditions all species be affected.
Copper is important for the proper function of many enzymes in the body. Deficiency leads to improper growth of bones, anemia, nervous tissue defects and many other abnormalities that can affect the health and productivity of your animals. There are two ways that deficiency can occur. Primary copper deficiency occurs when there are low levels of the mineral in the soil and therefore an inadequate amount in the feed. Secondary copper deficiency occurs when there are adequate levels of copper in the feed but there are high levels of other minerals such as molybdomen or sulfur which bind to the copper molecules and make them unavailable for absorption by the gut. Secondary copper deficiency is more common in Western Canada because of the high levels of molybdomen in certain soils and sulfur in the water. Peat and swampy land tend to have high levels of molybdomen and can cause copper deficiency.
The signs of copper deficiency in a herd are variable. The hair coat of affected animals tends to be lighter in color than healthy animals, and often lacks luster. Animals may have hind limb weakness as a result of degeneration of their spinal cord or there may be an increased incidence of fractures in the herd. Reproductive performance is often affected and diarrhea may be present in some animals.
The condition can show up in a herd in a number of different ways which makes the diagnosis difficult. Currently, the only test that gives a good indication of the copper status of an animal is liver analysis. Liver samples can be collected from animals that die on the farm or from slaughtered animals to assess the herd’s copper status. Blood copper levels are an unreliable measure the copper status of an individual animal but they may be of some use if a number of animals from a herd are tested. Feed and water analysis can give you some clues. Low copper or high molybdomen and sulfur would indicate that copper deficiency could be a possibility.
Treatment and prevention of the condition is based on oral supplementation. Copper can be supplemented in free choice minerals or fed as part of the ration in grain pellets. The choice of supplementation should be based on the requirements of your individual herd. If there has been not problem with copper deficiency in your animals in the past and you don’t pasture on soils that are prone to high levels of molybdomen, then the copper provided by free choice minerals is probably adequate. If you have had the condition diagnosed in your animals, then supplementing copper in the feed (grain pellets) is a generally recommended. Copper oxide boluses that are used in New Zealand and in the United States are not available in Canada.
Closely examine any health problems of your herd and consider the risk factors to determine if your elk of bison may be copper deficient. Analyze some liver, feed, and water samples if there is a concern and speak to your veterinarian or local feed representative to devise a plan to prevent this condition.