Assimilation and Storage of Manganese in the Developing Embryo and Growing Chick

THE results of experiments reported by Gallup and Norris (1939) constitute additional evidence that perosis in chicks is due to a deficiency of manganese. The results support the contention that the deficiency is of dietary origin intimately related to the manganese requirements of the breed under investigation. Perosis consistently occurred in about 4 percent of the chicks in several experimental groups which were allowed adequate amounts of manganese. Since these cases developed soon after hatching the possibility of impaired manganese utilization induced by factors, dietary or otherwise, which operated during embryonic development and early growth was indicated. Accordingly, a study has been made of the assimilation and storage of manganese in the developing embryo, and in chicks receiving diets of medium and low-manganese content. The present paper reports the results of this investigation. EXPERIMENTAL Eggs from a selected group of New Hampshire hens were incubated weekly. The hens received an . . .