Trace Minerals for California Beef Cattle 

University of California, Cooperative Extension

Lassen County Mineral Data

Selenium

Selenium deficiency is closely associated with soils of volcanic origin. East Lassen has not been found Se deficient. Samples from 6 herds (158 head total) had an overall average whole blood Se level of 0.117 ppm. The lowest herd average was 0.056. In contrast, the Honey Lake area is the most Se deficient area in Lassen County based on samples from 21 herds (311 head total) had an overall average whole blood Se level of 0.0295 ppm (below 0.04 ppm considered deficient and responsive). Several herds were extremely deficient, below 0.02 ppm. The Big Valley/Pittville area and Willow Creek area is Se variable and usually marginally deficient. At Big Valley/Pittville 15 herds (362 head total) had an overall average of 0.059 ppm. Herds were as low as 0.012 and as high as 0.188 ppm. For the Willow Creek area, 16 herds (402 head total) had an overall average of 0.072 ppm (lowest 0.026, highest 0.119 ppm).

The pattern based on available data indicates cattle in the Honey Lake area are usually deficient, while those in the East Lassen area usually are not Se deficient. Other areas of the county are more variable. In all cases, individual sampling would be best to determine specific Se status.

Copper

Random samples from 7 herds in Lassen county (35 head total) had an average overall serum Cu level of 0.67 ppm. This is marginally deficient.

Field trial work has sampled 815 head divided into four areas of the county. The Big Valley/Pittville area had an average serum copper level of 0.70 ppm (n=288). East Lassen ranches had an average of 0.55, the Honey Lake area was 0.66 with Willow Creek at 0.83 ppm. These values represent marginal copper status with Willow Creek approaching adequate levels. These samples were collected at various times of the year and no pattern was observed for monthly fluctuation. It is important to recognize that serum samples are not the best method of assessing copper status and thus absolute recommendations must be conditional. Based on historical data and observations, areas of the county with "white" alkaline soils tend to have high molybendum soils. These soils are usually associated with secondary Cu deficiency. Secondary Cu deficiency occurs with typically adequate forage and sometimes adequate serum Cu, but due to interference by molybendum, inadequate Cu is available. Thus, the apparent adequate or marginal copper status may be insufficient due to interferrring compounds such as molybdenum, and secondary copper deficiencies may exist.

Liver samples submitted to the California Veterinary Diagnostic Lab averaged 163 ppm (SD 123).  This supports a variable Cu status with deficiencies in isolated locations.  Individual testing is recommended.

Zinc

Samples (63) from the California Veterinary Diagnostic Lab suggest Zn is probably adequate in most locations.  Additional samples would be helpful in providing more confidence in that interpretation.

Phosphorus

No conclusions are available regarding phosphorus status due to lack of data.