Trace Minerals for California Beef Cattle 

University of California, Cooperative Extension

Inyo County Mineral Data

Eleven herds were sampled as part of field trial work. The overall average for all cattle in all herds was 0.125 ppm whole blood selenium which is considered adequate. One herd average was deficient, 0.016 ppm whole blood selenium, which was located near Big Pine. These herds were receiving various trace mineral supplements, so it is difficult to precisely interpret blood values. Selenium deficiency is classified as variable and marginal to deficient based upon these limited values. Individual herds should be evaluated to determine their selenium status.

Copper values were highly variable ranging from frankly deficient to adequate in the same herds. Near Bishop the herd average serum copper was 0.4 ppm and a herd near, Independence was 0.2 ppm, both deficient. Marginal herds were found near Round Valley, Bishop, Deep Springs, Big Pine and Olancha. One herd was adequate, located near Round Valley. It is unclear if variability at the same location is due to management factors such as different supplements or forage levels. Ten of eleven herds were deficient or marginal in copper status, therefore copper supplementation is likely necessary at most locations.

The two herds sampled that were copper deficient had low molybdenum, suggesting primary copper deficiency. In contrast several herds with marginal copper levels had higher molybdenum levels (.09 to .36 ppm serum Mo). In those cases secondary copper deficiency may be a problem. Again, it is difficult to reach concrete conclusions due to variable trace mineral supplementation of the herds.

The same eleven herds all had adequate zinc serum levels. This suggests zinc is not a major problem in Inyo county.

The same eleven herds all had adequate phosphorus serum levels. This suggests phosphorus is not a major problem in Inyo county.