Effect of Addition of Penicillin to the Hen’s Ration on Biotin and Folic Acid Content of Eggs

OF THE theories that have been advanced to explain the mode of action of dietary antibiotics in promoting growth, the most plausible, on the basis of available evidence, is that the antibiotic modifies the intestinal microflora to provide the host with a more abundant supply of essential nutritive factors. Evidence in support of this theory, has been presented by Groschke et al. (1950), Linkswiler et al. (1951), and Sunde et al. (1951). Since the hen’s egg has been used previously as a means of studying the over-all effect of the balance between synthesis and utilization of vitamins in the intestinal tract resulting from different nutritional regimens (Couch, Cravens, Elvehjem and Halpin, 1948), it appeared that the same procedure might be applied in determining the effect of dietary antibiotics on vitamin availability to the animal. The effect of penicillin in the diet of the hen on the biotin and folic acid . . .