The Relationship of Calcium-Phosphorus Ratios to the Utilization of Plant and Inorganic Phosphorus by the Chick

CONSIDERABLE interest has developed in the past 20 years in determining the availability of phosphorus from plant and inorganic sources. In order to properly evaluate results from such experiments it is necessary to understand some of the factors which may influence utilization of phosphorus such as calcium-phosphorus (Ca:P) ratio, levels of ascorbic acid and fat. Bethke et al. (1928) and Hart et al. (1930) reported that the optimum or near optimum Ca:P ratio for growing chicks was between 2:1 and 4:1. Wilgus (1931) stated that a 2.5:1 ratio was borderline and 3.3:1 was disastrous. Carver et al. (1946) found that a 1:1 or 2:1 ratio produced the most favorable growth in Leghorn cockerels. Briggs et al. (1944) reported that ascorbic acid fed to chicks receiving various purified diets promoted small but consistent increases in growth rate. They suggested that chicks fed a highly purified diet were not able to synthesize…