The Influence of Calcium on Phosphorus Utilization by Chicks

STUDIES on calcium and phosphorus in animal nutrition have been conducted by scientists for half a century. Much of the emphasis of this has been on the optimum calcium to phosphorus ratio for the animal. The balance of these elements is especially important when either or both is present in the diet in deficient amounts. On the other hand, an imbalance of calcium and phosphorus will cause adverse effects when both of these elements are present in adequate amounts. This was shown in data published by Smith and Taylor (1961), Nugara and Edwards (1962) and Wadroup et al. (1963) where calcium to phosphorus ratios as wide as 4 to 1 depressed the weight gains of chicks. An optimum calcium to phosphorus ratio determined when both of these elements are deficient can be influenced by the level of vitamin D in the diet. Bethke et al. (1923) found that increased increments…