Comparison of Response of Turkey Poults and of Chicks to Different Forms of Vitamin D

Turkey poults during the first 4 weeks of life were fed a vitamin D deficient diet supplemented with four levels of each of the following vitamin D sources: U.S.P. Reference Cod Liver Oil no. 2, another unfortified cod liver oil, irradiated 7-dehydrocholesterol, and irradiated animal provitamin. On the basis of per cent bone ash, a given number of A.O.A.C. chick units of vitamin D from irradiated 7-dehydrocholesterol and irradiated animal provitamin were, respectively, 2.29 and 1.83 times as effective for poults as the same number of A.O.A.C. chick units from Reference Cod Liver Oil. The other sample of cod liver oil was similar to the Reference Oil in relative efficacy for poults and chicks.