Recent studies of the copper-molybdenum antagonism.

The biological antagonism between copper and molybdenum was discovered when cattle grazing pastures high in Mo were found to develop a syndrome characterized by diarrhoea, growth retardation, anaemia and achromotrichia, which could be prevented by administering Cu. This syndrome was subsequently reproduced in non-ruminants, but further studies revealed important differences in the nature of the antagonism. In ruminants, dietary sulphate potentiated a Cu-Mo antagonism which decreased tissue Cu concentrations but, in non-ruminants, sulphate alleviated an antagonism, which increased tissue Cu (Dick, 1956; Miller & Engel, 1960; Underwood, 1962). The above studies generally involved Mo concentrations far in excess of those found in natural foodstuffs and the complex interrelationships were, therefore, considered to be of largely academic interest. Recent studies have, however, revealed evidence of a more widespread nutritional significance of the Cu-Mo antagonism for ruminants and non-ruminants and explanations for the contrasting responses of the two groups.