Studies in Mineral Nutrition of Laying Hens.

Abstract

IN RECENT years much research has been done to determine the qualitative and quantitative requirements of manganese in poultry nutrition. It seems to be an established fact that manganese is essential in the prevention of perosis as shown by Wilgus, Norris, and Heuser (1936), in normal embryonic development as shown by Lyons and Insko (1937), and by young chicks for maintenance and normal bone formation as shown by Van der Horn, Branion, and Graham (1938). But it is not yet quite clear what the role of manganese is in adult fowls, and what is the effect of some variations in the manganese content of the rations on laying hens, their production, and on the egg quality. Gallup and Norris (1939) reported that a deficiency of manganese in the diet of hens resulted in low egg production, high mortality of embryos, and decreased fertility, but this was observed when the ration . . .