The Availability of Phytic Acid Phosphorus for Chicks

PREVIOUS reports (Harms el al., 1962; Waldroup el al., 1964) have indicated that phytic acid phosphorus and dicalcium phosphate were of equal availability to the chick. However, a widening of the calcium:phosphorus ratio decreased the relative availability of the phosphorus in phytic acid to a greater degree than phosphorus from dicalcium phosphate. The effect of Ca:P ratio on phytin phosphorus availability was previously reported by Vandepopuliere et al. (1961). They reported that plant source phosphorus was readily available to support growth in chicks when fed at a Ca:P ratio of 1:1 but did not permit increased bone ash as did dicalcium phosphate when the ratio narrowed from 4:1 to 1:1. The availability of phytic acid phosphorus to the rat has been reported to be markedly affected by the calcium and vitamin D content of the diet (Krieger and Steenbock, 1940). In view of these reports, experiments were conducted to further…