An investigation of bovine serum copper levels in Lincolnshire and South Humberside.

Analysis of more than 2000 bovine serum samples showed a large monthly variation in copper levels. There was also a difference in levels between beef and dairy cows although all showed the same monthly pattern. This monthly variation was correlated with rainfall; the higher the rainfall the lower the copper level. The interpretation of single herd blood copper values must be considered carefully in view of this variation.