Abstract
Day-old White Leghorn male chicks were fed with the purified diets containing the graded levels of thiamine, nicotinic acid or choline. Content of the vitamin in the basal diet lacking one of these vitamins was determined microbiologically with L. fermenti 36,L. arabinosus and Neurospora crassa, respectively. From the body weight gain of chicks for 3 weeks, the requirements of thiamine, nicotinic acid and choline for the optimum growth were estimated as 2.5mg, 29 mg and 1.8 g per kg diet, respectively. All of these requirements are higher than those recommended by N.R.C. in U.S.A. Since the reassessment of the requirements of 11 vitamins has been completed, the results of this series of studies (I-IV) are summarized and given as the table of vitamin requirements for White Leghorn chicks on purified diet. The feeding experiment showed that chicks fed vitamins of the amount just given in Table 6 grew satisfactorilly.
