Calcium and Phosphorus Requirements for Growing Chicks

In the preceding paper1 experiments were reported in which studies were made of the calcium-phosphorus requirements of growing chicks under rachitic conditions. The minerals consisted of salt mixtures in which the calcium-phosphorus ratio was varied as well as the levels of mineral in the ration. Since satisfactory growth was not attained with these salt mixtures, it seemed advisable to use natural minerals in these studies. EXPERIMENTAL The general plan of these experiments as regards the methods of selection, feeding, and management of the chicks and the records kept were the same as used in the preceeding experiments.1 In the four trials reported in this paper Barred Plymouth Rock chicks were used. As in the previous experiments, precautions were taken to prevent the exposure of the chicks to direct sunlight, or even direct skylight. The composition of the rations is given in Tables I and II. The results obtained are given . . .