Calcium and Phosphorus Requirements of Broiler Chickens

AFTER more than 35 years of investigation, there is considerable disagreement in the literature as to the levels of calcium and phosphorus required for optimum performance of growing chickens. A review of the more pertinent literature by Lillie et al. (1964) indicates that the range of discordant values is being narrowed to some extent and that the calcium level recommended by the National Research Council is higher than that which many investigators found to be adequate for optimum growth. The majority of the recent investigations (Formica et al., 1961, 1962; Vanderpopuliere, 1961; Waldroup et al. 1962a, b; Simco and Stephenson, 1961; Lillie et al., 1964) have been aimed at refinement of the requirement of the growing chick in the light of current nutritional knowledge. Such was the motive for the experiment reported herein. EXPERIMENTAL A 5×4×2 factorial arrangement was employed in the design of the experiment. The three-factor design included…