Studies of calcium and phosphorus metabolism in relation to the chemical structure of bone

Abstract

Ca and P balances of laying hens fed common basal rations plus different Ca supplements were struck. From the results, calculations of the daily changes in the Ca of Ca3(PO4)2 (called CaP) and residual Ca (called CaR) of bone were made. The values obtained showed that CaR is chiefly concerned in egg laying; there is a reciprocal relationship between the food Ca and the bone Ca for egg shell formation; and there is a highly significant negative correlation between CaP and CaR changes. The findings point to a fairly permanent real bone of Ca3(PO4)2 with a mobile deposit of residual Ca, possibly as carbonate.