The Effect of High Dietary Calcium on the Performance of Laying Hens

Hurwitz and Bornstein (1966) suggested that high levels of dietary limestone depressed feed intake. They further stated that this depression appeared to be more pronounced when the diet contained supplementary fat. In a subsequent paper (Hurwitz et al., 1969), it was found that calcium levels of 4.5 percent slightly reduced feed intake; however, it did not effect the performance of the laying hen. In contrast to the above findings Harms et al. (1961) found that a level of 5.5 percent calcium in the diet of hens for a period of ten months did not effect feed consumption nor performance as indicated by egg production, shell thickness, or mortality. The purpose of this study was to further investigate the influence of excessively high levels of calcium on the performance of laying hens. EXPERIMENTAL PROCEDURE Forty-eight groups, each containing five commercial egg production-type pullets maintained in individual cages, were used in this…