Vitamin D Requirements of Ducklings

DURING the past few years a considerable interest has been expressed regarding the nutritional requirements of ducklings. The concentration of the duck industry in certain localities and the rapid growth of these birds introduce serious nutritional problems. Few other classes of livestock are fed with such little knowledge of the fundamental nutritional requirements. Because of the request for such information, studies were undertaken in this laboratory to establish the quantitative requirements of ducklings for some of the known nutritional factors. A report was recently presented on the riboflavin requirements (1939). The specific object of this investigation was to determine the minimum vitamin D intake which would permit satisfactory calcification. EXPERIMENTAL White Pekin ducklings hatched on Long Island were used in these investigations. The ducklings were two or three days old when received at the laboratory. They were immediately distributed as uniformly as possible and placed into electrically heated, thermostatically controlled . . .