Effect of Yolk Removal in Day-old Chicks on Early Nutritional Requirements.

Abstract

An operative technic for removal of the yolk from day-old chicks is descr. Observations on the growth rate of "deutectomized" chicks as compared with that of unoperated controls show that the operation had little or no effect on growth when an adequately supplemented diet was supplied. These results demonstrate that vitamin B12 activity is present in the yolk of the day-old chick and that its removal by deutectomy increases the dietary requirement for vitamin B12.