Blood calcium and magnesium of the cow in health and disease

Abstract

In 139 clinically normal dairy cows and heifers serum Ca was 8.65-11.65 mgm. % and serum Mg 1.85-3.17 mgm. %, but the common physiologic range as shown by distribution charts is closer than this. Infection with Brucella abortus had no effect on serum Ca or Mg; in advanced generalized tuberculosis slight hypocalcemia and definite hypomagnesemia were found in 32 of 35 cases. In lactation tetany the typical hypomagnesemia could be accompanied by normal serum Ca or by definite hypocalcemia, and in milk fever the typical hypocalcemia may be accompanied by normal or raised serum Mg. Mixed cases may occur. There is no evidence of interdependence between serum Ca and serum Mg in the blood of the cow.