THE EFFECTIVENESS OF COPPER-OXIDE POWDER AS A COMPONENT OF A SUSTAINED-RELEASE MULTI-TRACE ELEMENT AND VITAMIN RUMEN POLLS SYSTEM FOR CATTLE

Copper oxide powder administered in the form of two experimentally pro duced sustained-release rumen boluses significantly increased blood an d liver copper concentrations in growing sheep. It was estimated that 7% of the copper released was stored in the liver. In two farm observa tion trials administration of two standard production boluses signific antly increased blood copper concentrations in out-wintered suckler co ws during late pregnancy and early lactation, and in growing cattle at grass in the summer over periods of at least 170 and 123 days, respec tively.