Effect of Various Prelaying Levels of Dietary Calcium Upon Subsequent Performance in Chickens

INTRODUCTION CONSIDERABLE research has been reported concerning the calcium requirements for growth and bone development of chicks (Hart et al, 1930; Twing et al., 1965; Itoh and Hatano, 1964) and the effect of dietary calcium upon the productive performance of laying hens (Deobald et al., 1936; Petersen et al., 1960; Mehring and Titus, 1964). However, relatively few and often very conflicting investigations have been reported concerning the calcium requirements of pullets from eight weeks to the onset of egg production and concerning the effect of calcium levels during the developing period upon the subsequent production. Berg et al. (1947) fed .7, .9, and 3.0% calcium levels for 50 days prior to laying and found no effect upon egg production for the first three months of production. Berg et al. (1964) fed levels as low as .4% Ca and .3% P and found no effect upon productive performance. Young et al.…