The Effect of High Dietary Calcium on the Performance of Laying Hens Fed Rations of Varying Energy Levels

Abstract

IT IS well established that egg shell strength can be increased by feeding a high-calcium diet to laying hens. However, there is considerable controversy with regard to the effects of high levels of dietary calcium on other production traits. Some investigators reported depressed egg production (Gutowska and Parkhurst, 1942; Hinners et al., 1963) and egg weight (Quisenberry, 1962; March and Biely, 1962; Hurwitz and Bornstein, 1963), whereas others found no effect on these parameters due to high calcium feeding (Titus, 1958; Petersen et al., 1960).In most of the experiments reported, the calcium supplement, usually limestone, was added to the expense of dietary grains. Thus, with the addition of the calcium, the dietary energy level was lowered. Furthermore, limestone supplementation also changes the physical appearance of the diet and its specific gravity, which may influence feed intake. Mehring (1965) tried to keep the experimental diets isocaloric by compensatory fat supplementation …