DEFECTIVE DOWN-SYNDROME IN CHICKS IS NOT CAUSED BY RIBOFLAVIN DEFICIENCY IN BREEDERS

1. Riboflavin-deficient practical and semi-purified diets were fed to broiler breeder hens. 2. Yolk and albumen riboflavin concentrations we re depressed by the deficient diets and cases of curled toes were seen in the chicks. 3. The few instances of defective down did not resembl e cases seen in field outbreaks of a condition involving depressed hat chability and a defective down syndrome. 4. It is concluded from obser vations in this experiment and in the field outbreaks that there is a condition in breeding chickens causing depressed hatchability and defe ctive down that is not attributable to riboflavin deficiency.