Utilization of Calcium from Calcium Sulfate by Chicks and Laying Hens

CALCIUM sulfate as a calcium source for poultry was evaluated over thirty years ago. Those early investigations indicated similar calcium availability from calcium sulfate and calcium carbonate, for chick growth and bone calcification (Buckner and Martin, 1928; Bethke et al., 1930; Deobald et al., 1936). On the other hand, calcium sulfate is considered to be a somewhat inferior calcium supplement for laying hens when compared to calcium carbonate (Titus, 1963). Since the early investigations, little research has been done on the utilization of calcium sulfate. It seems that, in practice, calcium carbonate in the form of oyster shells or limestone was preferred to calcium sulfate (gypsum) in chicks’ rations, due, mainly, to its higher calcium content and to economic considerations. With laying hens, which have a relatively high calcium requirement, it would seem difficult to supply all the calcium needed by calcium sulfate, due to excessive sulfate which may cause…