In January, I talked about the importance of zinc and vaccine effectiveness (read it here). Today, I’d like to continue the immune function discussion, but focusing on copper.
Copper has several important functions in the body ranging from metabolism, to enzyme function, to reproductive performance. Most notably, copper is a key component to proper antioxidant enzyme function (passive immunity, happens in the background) as well as antibody production and phagocyte activity (both are active immunity, happens in response to a pathogen). Cattle with a low to deficient copper status respond poorly to vaccines and disease challenges. This is because copper deficient cattle have decreased immune system protector cells, decreased antibody response to pathogens, and increased susceptibility to infection, including parasites.
Copper status is especially important for gestating cows. Liver copper stores in the calf are essential as colostrum and milk are low in copper. As noted above, deficient copper levels lead to impaired immune function. Stress events (birth, weaning, and vaccination) cause the liver to dump copper in the circulatory system, depleting stores. Supplementing the dam with adequate to elevated levels of copper with high bioavailability from gestation thru weaning, not only helps ensure adequate calf liver copper, but helps the cow to rebuild her own liver copper stores. Research shows that cattle supplemented with copper did not lose as much liver copper, during a stressful event, as those who weren’t supplemented. There also appeared to be a positive effect of copper source with those supplemented with a chelated/organic copper source, in addition to inorganic forms, on liver copper levels.
What does it mean to your cattle? Copper deficiency is more common than you think and is a result of low copper in the soil, high level of antagonists (iron, molybdenum or sulfur), improperly balanced mineral supplements or a combination of the above. By the time you see an outward sign, such as a rough and discolored hair coat, your cows have already given up immunity and performance. Supplementing copper, in addition to other trace minerals, maintains proper immune function. Trace mineral deficiencies are costly, but they can be rather easy fix.