Calcium, Phosphorus, and Vitamin D Interrelationships in Turkey Poult Nutrition

THE calcium and phosphorus requirements of growing chicks as influenced by the ratio of calcium to phosphorus and the level of vitamin D in the diet have been extensively studied. Although it is generally believed that a calcium to phosphorus ratio of 2:1 is optimum (Titus, 1939), Bethke et al. (1929) and Hart et al. (1930) showed the optimum ratio to be between 3:1 and 4:1 when low levels of vitamin D were fed. When more vitamin D was incorporated into the diet, less difference was observed between different calcium to phosphorus ratios and lower levels could be used (Hart et al., 1930). In the presence of high levels of calcium and phosphorus, less vitamin D was required (Nowatorski and Bird, 1943). Although the vitamin D requirements of turkey poults have been extensively studied, little has been reported on the calcium and phosphorus requirements. Mussehl and Ackerson (1935) found that . . .