The riboflavin requirement of the White Wyandotte chick

Abstract

1. Literature relevant to the elucidation of the role of riboflavin in chick nutrition is briefly reviewed.2. A series of experiments on the quantitative requirement of White Wyandotte chicks for riboflavin is described.3. The riboflavin requirement of White Wyandotte chicks for optimum growth to 6 weeks of age is the same as that for optimum efficiency of food utilization over the same period (3·0 μg. riboflavin per g. food).4. The riboflavin content for the prevention of curled-toe paralysis is 3·6 μg. per g. food, and is slightly greater than the requirement for optimum growth and food utilization.5. The curve relating the riboflavin content of the diet to the riboflavin content of the chick's liver has a sigmoid form, and in general tends to lie asymptotically to values of about 26 μg. riboflavin per g. fresh liver when the intake is grossly deficient, and 39 μg. riboflavin per g. fresh liver when the intake is fully adequate.6. It is suggested that the riboflavin content of the liver may be a more satisfactory criterion of the minimum riboflavin requirement for full well-being than the amounts necessary to secure optimum growth and prevention of curled-toe paralysis.