A Chick Growth Factor in Cow Manure

Abstract

CONSIDERABLE interest in the feeding value of cow manure has developed since the initial papers by Hammond (1942 Hammond (1944). Whitson el al. (1945) demonstrated the effectiveness of cow manure as a substitute for animal protein in improving a diet in which soybean oil meal was the primary source of protein. They concluded that the active material in cow manure was neither a protein nor any of the chemically characterized vitamins. Rubin and Bird (1946a) reported on the non-identity of the chick growth factor in cow manure with chick growth factors previously described and (1946b) presented a procedure for the preparation of concentrates of the factor and described some of its properties. In addition to the growth factor, there is also an androgenic substance in cow manure (Riley and Hammond 1942) which stimulates comb growth. The scarcity of protein feedstuffs of animal origin and their relatively high cost, when available, accentuate . . .