Inorganic Phosphorus of Horse Serum the Effect of Age and Nutrition by P. B. Pearson

Relatively little information is available on the phosphorus content of horse blood. Abderhalden (1)) in his pioneer investigations of 1898, analyzed the blood of two horses and reported 3.3 mg. of inorganic phosphorus per 100 ml. of serum. Robinson (2), using the method of Fiske and Subbarow, determined the inorganic phosphorus content of the blood of forty-four horses and found a range of 1.92 to 5.36 mg. per 100 ml. of serum with an average of 3.19, but did not indicate the age or breed of the animals from which the blood samples were obtained. The most complete work on the normal phosphorus values for mature horses is that of Kintner and Holt (3), who analyzed the blood of 69 horses and found a range of 2.63 to 5.00 mg. of inorganic phosphorus per 100ml. of serum with an average of 3.55 mg. In a recent paper Dimock and Healy (4) report an average of 4.9 mg. of inorganic phosphorus per 100 ml. of serum obtained from four thoroughbred yearling fillies. They observed no significant change in the phosphorus content of the serum from overfed fillies that received, in addition to the standard diet, haliver oil and ultra-violet ray treatments.