The Use of Bone Mineral Mass as an Indicator of Vitamin D Status in Turkeys ,

The interrelationships of several parameters as indicators of vitamin D3 in turkeys were determined. Poults were fed a rachitogenic diet supplemented with 0, 300, 600, 900, or 1200 ICU vitamin D3 per kilogram diet to 4 weeks of age. Relative bone mineral mass determined by 125I photon absorptiometry, as well as percent ash, breaking strength, and weight of dried, defatted tibiae were elevated by increasing amounts of dietary vitamin D3. The simple correlation coefficients for relative bone mineral mass, percent ash, and breaking strength vs. log (dietary vitamin D3 [ICU/kg] + 10) were .97, .93, and .94, respectively, when data from all treatments were used, and were .80, .78, and .14, respectively, when data from the basal treatment were eliminated. Correlation coefficients for relative bone mineral mass vs. bone weight, percent ash, breaking strength, and calcium binding activity were .86, .92, .93, and .96, respectively, when data from all treatments were used. The results indicate that bone mineral mass measured by photon absorptiometry is a good indicator of vitamin D3 status in the young poult.