Assay for the Unidentified Growth Factor in Dried Whey ,

BERRY et al. (1943), Hill et al. (1944), Reed et al. (1951) and others reported the existence of a chick growth factor in dried whey (DW) which has been termed the “Whey Factor” (WF). In 1948 the availability of crystalline vitamin B12 made it possible to look for additional unidentified nutritional factors in natural sources of B12. Apparently the first reports of another unidentified factor in fish products were made by Carlson et al. (1949), who used a purified diet, and by Sunde et al. (1950), who used a diet of commercial feedstuffs. Camp et al. (1954) reported that there were two distinct unidentified growth factors (UGF) required by the chick for maximal growth; FF found in fish solubles and WF found in dried whey, a distiller’s fermentation solubles and hydrolyzed whey. Combs et al. (1954) supported the idea of the “multiplicity of the unidentified growth factors.” However, Summers et…