The effectiveness of copper oxide powder as a component of a sustained-release multi-trace element and vitamin rumen bolus system for cattle

Copper oxide powder administered in the form of two experimentally produced sustained-release rumen boluses significantly increased blood and liver copper concentrations in growing sheep. It was estimated that 7% of the copper released was stored in the liver. In two farm observation trials administration of two standard production boluses significantly increased blood copper concentrations in out-wintered suckler cows during late pregnancy and early lactation, and in growing cattle at grass in the summer over periods of at least 170 and 123 days, respectively.