Effect of Varying Dietary Calcium: Phosphorus Ratios on Tibia and Femur Composition of the Chick

Abstract

ALTHOUGH tibia ash has been the principal criterion of response in numerous mineral studies, recent data of Itoh and Hatano (1964) indicate that the femur is more representative of the total body skeleton. These investigators also reviewed the data of others on the use of tibia, toe, beak, humerus or sternum values as criteria in chick mineral or vitamin D studies. Tibia phosphorus has been proposed by Hurwitz (1964b) as a method of estimating net phosphorus utilization. Similarily, Hurwitz and Rand (1965) used tibia calcium in establishing net calcium retention values for calcium sulfate for the chick. Dickerson (1962) and Harshaw et al. (1934) reported femur calcium and phosphorus values for the chick which indicate the calcium: phosphorus (Ca:P) ratio of bone increases with age. It is also well known that the ash content of bone increases with age. Temperton and Cassidy (1964a, b) reported the Ca:P ratio of the tibia…