Energy and carbohydrate metabolism in magnesium deficient calves.

Magnesium participates in almost all phosphorylating enzyme systems of the animal body, and it is to be expected therefore that when animals are deprived of dietary magnesium abnormalities of intermediary energy transfer would result. Indeed, some of the signs of Mg deficiency are similar to those of thiamine deficiency, in which abnormalities of carbohydrate metabolism are known to occur. The present paper is concerned with the total energy exchange and certain aspects of carbohydrate metabolism of calves given rations deficient in Mg. The results show that the elevation of heat production and the abnormalities of carbohydrate metabolism that were observed were not due to failures of enzyme systems in which Mg acts as an activator, but to an increase in muscular activity.