On the Effects of D₂ and D₃ Vitamins upon the Growth of Chicks

Abstract

1. The growth of baby chicks was accelerated by the administration of 500 I.U. of D₃ vitamin per day per head. Such effect was not clearly recognized when D₂ vitamin was given to day-old chicks.
2. When chicks were examined for roentgenogram of the hip-joint region and bone calcium content, the ossification of this region was in a more advanced stage in the D₃ vitamin administered flock than the untreated control and the D₂ vitamin administered flocks.