The Multiple Nature of the Deficiency of Unidentified Nutrients in Crude All-Vegetable Protein Chick Starter Rations

Abstract

THE necessity of adding small amounts of animal protein concentrates to chick starter rations deriving all of their protein from vegetable sources has been established by numerous investigations as reviewed by Heuser, Norris and McGinnis (1946). The properties of animal protein concentrates in promoting optimum growth and feed efficiency under such conditions are also contained in cow manure (Hammond, 1942, 1944; Rubin and Bird, 1946a, 1946b), hen feces (Rubin, Bird and Rothchild, 1946; McGinnis Stevens and Groves 1947a) and liver fractions (McGinnis, Stevens and Groves, 1947b, Nichol, Roblee, Cravens and Elvehjem, 1947). The effectiveness of small quantities of fractions of cow manure and liver is indicative that the response of chicks to animal protein supplements is not due to protein as such, but rather to a vitamin-like substance or substances carried by these materials. The experiments reported herein were a part of a series of studies of the distribution in . . .