Estrogen and Serum Calcium Levels in the Bobwhite Quail ,

IT HAS been known for a long time that estrogens play an important role in calcium metabolism in the bird. Due to the enormous amount of calcium excreted during the period of egg shell formation it is likely that the hen requires a special mechanism to control calcium balance at that time. Riddle and Reinhart (1926) showed that the blood calcium rises in the pigeon prior to egg shell formation and is maintained until shell formation is completed. Similarly a hypercalcemia has been shown in the laying hen (Parhon, 1926; Hughes, Titus and Smits, 1927). Treatment with estrogens causes a marked rise in the blood calcium of the pigeon (Riddle and Dotti, 1936; Pfeiffer and Gardner, 1938), the chicken (Altman and Hutt, 1938; Zondek and Marx, 1939; Landauer et al., 1939) the duck (Landauer et al., 1941) and the sparrow (Pfeiffer et al., 1940). Similar results are obtained in the . . .