| Popis: |
A PREVIOUS report from this laboratory (Willgeroth, Halpin, Halloran, and Fritz, 1944) suggested the use of turkey poults for the assay of vitamin D in poultry feed supplements. Using various samples, good agreement was obtained between assays using chicks and assays using poults. Reports by Bird (1944), Boucher (1944), and Sanford and Jukes (1944) indicated that not all sources of vitamin D were equally effective for poults when compared on the basis of A.O.A.C. chick units. Investigation of the diets used indicated that there were large differences in the mineral contents. This study was undertaken to determine the effect of the levels and ratio of calcium and phosphorus upon calcification in the poult. Special attention was given to the possibility that these elements might have an influence upon the relative effectiveness of vitamin D from different sources. MATERIALS AND METHODS The poults used in this study were hatched at the . . . |
