Sporadic Copper Poisoning of Japanese Black Beef Calves During the Weaning Period

Abstract

Japanese Black calves on a farm died sporadically with jaundice and hemoglobinuria over a period of several years. Their symptoms suggested copper poisoning. The calves were fed multiple combined feeds. Most feeds contained copper, and the estimated copper levels in the combined feeds exceeded the required levels of the Japanese Feeding Standard for Beef Cattle. The calves might have been fed excessive copper continuously because the serum copper levels of the calves on the farm increased with age. We detected a high concentration of copper in the sera of the affected calves and in the liver of a dead calf. Under this high copper concentration, the calves ingested a large amount of feed and the calves that were in poor condition might have had severe poisoning.