Effect of the ingestion of heliotrope and copper on the concentration of zinc, selenium and molybdenum in the liver of sheep.

Merino wethers were used to examine the effect of feeding heliotrope, with and without additional copper (Cu), on the development of clinical signs, lesions in the liver and concentration in the liver of Cu, zinc (Zn), selenium (Se) and molybdenum (Mo). The feeding of heliotrope reduced liver concentrations of Zn (P < 0·05) and Mo (P < 0·01), but Cu ingestion had no effect on these parameters. The concentration of Se in the liver was only increased when heliotrope was given with copper (P < 0·01); it had previously been shown that Cu and heliotrope ingestion is followed by an interaction which results in a marked increase in the concentration of Cu and the production of extensive lesions in the liver, The increase in liver Se may therefore have represented a passive or active response to liver necrosis, whereas effects on Zn and Mo represented specific metabolic disturbances attributable to heliotrope feeding.