Egg Shells as a Source of Calcium for Laying Birds

The breaking of eggs necessitated by the overseas shipment of large quantities of dried egg powder has presented a problem in utilization of the waste product, dried egg shells. It has been assumed that, when suitably prepared, these shells would be of similar value to commonly used sources of calcium such as oyster shell and limestone as a source of calcium for laying birds. In order to test this assumption four pens of laying pullets were used. Since obviously the strength of the egg shells produced by these birds would be the most suitable criterion of the efficiency of the calcium source this was determined through the setting up of salt (NaCl) solutions for the determination of shell strength as was done by Olsson (1934) and at this institution by Munro (1940). Specific gravity readings of all eggs from two pens for a period of nine days from May 2nd . . .