Studies on the Calcium Requirements of Turkeys

COMMON et al. (1950) found that the increase of serum calcium and serum riboflavin, which follows the injection of estrogen, was enhanced when chlortetra-cycline1 was included in the diet of pullets. Migicovsky et al. (1951) fed chicks a low calcium diet and this same diet supplemented with penicillin. When the chicks were given an oral dose of Ca45 after 2 weeks of age, a greater percentage of the dose appeared in the tibiae 48 hours after administration in the case of the chicks receiving penicillin than in the controls. It was concluded that, under the conditions of the experiment, penicillin enhanced the absorption of calcium. In a previous report from this laboratory (Lindblad et al., 1954) it was noted that the more inadequate the diet with respect t o calcium and phosphorus the greater was the percentage increase in the weight of chicks and poults due to chlor-tetracycline. This was…