Antibiotic and Vitamin B12 Supplements as Related to the Crude Protein Level of Bobwhite Quail Diets ,

THE beneficial effects of antibiotics and vitamin B12 supplements in all-vegetable starting rations for chickens are well known. Berry et al. (1945) and Mishler et al. (1948) demonstrated the supplementary action of condensed fish solubles in soybean oil meal rations for chickens and attributed the effects to unidentified factors. One of these factors has been shown to be vitamin B12 by Ott et al. (1948) and Nichol et al. (1949) in their reports that crystalline vitamin B12 would replace the animal protein factor activity of crude sources of vitamin B12, one of which is condensed fish solubles. Factors other than vitamin B12 were soon recognized as being present in these crude sources of vitamin B12 (Carlson et al. 1949; and Stokstad et al. 1949). These included, among others, antibiotics and an unknown growth factor believed to be present in condensed fish solubles. That vitamin B12 bears some relation to protein …