Studies in Mineral Nutrition of Laying Hens

Abstract

THE progress and the bibliography of the investigations of the mineral metabolism in animals has been reported by Schmidt and Greenberg (1935), Greenberg (1939), Shohl (1939), and others. Schaible (1941) reviewed the results of research in minerals in poultry nutrition but the complexity of this problem and its great practical importance make it still a subject of further research. The calcium requirement of laying hens has been studied to some extent but the information on the optimum amount of calcium required by laying hens in diets, with known dietary levels of phosphorus and vitamin D, is still very scarce. According to Mitchell and McClure (1937) the minimum requirement of calcium is approximately 0.7 percent of the ration and by experience three times this amount must be consumed by high producing hens and one and a half to two times as much by growing chickens. It must be borne in mind . . .