Serum Phosphatase in the Domestic Fowl

IT has been suggested that skeletal reserves of calcium may be available for eggshell formation in the domestic fowl 1 . If this suggestion is correct, alterations in the metabolic activity of the bony tissues might be expected in association with the laying period in the hen. Moreover, plasma phosphatase has been used to study alterations in calcium and phosphorus metabolism in sheep 2 , and the association of increased serum phosphatase with clinical disorders of bone is now fairly well established. As opportunity has arisen, therefore, serum phosphatase estimations have been made on birds at different stages of the reproductive cycle, using Bodansky's technique 3 and his definition of the unit of phosphatase. Some of the results secured so far are given: