Divisions of Poultry Husbandry and Animal Husbandry, University of California, Davis
1. A method is described for the assay of thiamin with chicks,using a basal diet consisting principally of polished rice,fish meal and autoclaved yeast.
2. A response curve was constructedin which the level of thiaminadded to the diet is comparedwith the polyneuritic mortalityindex, the lattervalue being expressive of the degreeof protection affordedby a suboptimal level of thiamin fedduring the assay periodof 28 days.
3. The thiamin requirement of the chick was estimatedas beingbetween 130 and 150 micrograms of thiamin chloridehydrochlorideper 100 gm. of diet for prevention of polyneuritisunder theconditions studied.
4. The thiamin content of thepolished rice used in the basaldiet was found to be about 0.4micrograms per gram. A growthessential for the chick, absentfrom autoclaved yeast, was foundpresent in polished rice.