Studies in Duck Nutrition

THE protein requirements of ducklings have received relatively little attention. Horton (1932) found that a ration containing 19 percent protein produced definitely superior results when compared to the results obtained with a ration containing 12 percent protein. Hamlyn, Branion, and Cavers (1934) concluded from their experiments that the optimum protein level for growing Pekin ducklings is about 18 percent or less. Very little research work has been done on the requirements of the duck for unidentified vitamins. Hegsted and Stare (1945) reported that ducks grew poorly on purified diets unless a source of unidentified factors was supplied. They found, however, that the then unidentified “L. casei factor” (folic acid) was capable of replacing most of the activity of crude liver extract for ducks fed purified diets. In view of the lack of information on these subjects, an investigation was undertaken in this laboratory to determine, more precisely, the protein requirements . . .