The Vitamin D Requirements of Ducklings

Abstract

Fritz, Archer and Barker (1940) fed groups of White Pekin ducklings on a starting ration with graded levels of U.S.P. Reference cod liver oil to supply 0, 20, 30, 40, 50, 60, 70 and 80 A.O.A:C. chick units of vitamin D per 100 grams of feed respectively. Thirty units produced maximum calcification as measured by the percentage of ash in the dry, fat-free tibiae at 3 weeks of age. This work was repeated using the A.O.A.C. chick test diet, with the vitamin A content of the diets equalized at a high level with a purified vitamin A ester. A fish oil concentrate was used to supply levels of 0, 20, 25, 30, 35, 40, 80 and 120 A.O.A.C. chick units of vitamin D per 100 grams of feed, respectively. Again, judging by bone ash determinations at 3 weeks of age, 30 units was stated to produce maximum calcification. These investigators .