THE INFLUENCE OF ESTROGENS IN EGG YOLK UPON AVIAN BLOOD CALCIUM

Abstract

Injs. of 50 to 100 cc. of egg yolk into the peritoneal cavities of immature [female] fowls and of capons induced a significant rise in the levels of blood Ca. Similar results were obtained by the use of progynon-B and theelin. Removal of 15 to 37 cc. of yolk from laying hens caused a drop of blood Ca of from 25 to 48%, being directly proportional to the amt. of yolk removed. Operated controls were unaffected, but in birds in which yolk was squeezed from the follicles and left in the body cavity the serum Ca dropped 23%. The thyro-tropic principle of the ant. pituitary depressed blood Ca and an extract of whole ant. pituitary had no effect.