A Chick Growth Factor Found in Leafy Green Vegetation

DURING recent years much research has been directed toward identification and isolation of limiting growth factors for chicks fed diets based on the use of low cost protein and energy sources. These studies have led to the concept of “animal protein factor” (A.P.F.). Vitamin B12 is an important component of this apparently complex mixture of nutrients. (Ott et al., 1947; Hill, 1948; Carlson et al., 1949; Stokstad et al., 1949; Combs et al., 1950; Olcese et al., 1950; Hogan and Lance, 1948). The effects of dehydration on the water soluble nutrients of forage crops have been studied in this laboratory for several years. Data presented here demonstrate that the juice of freshly cut grass or alfalfa contains a growth factor which is largely destroyed by commercial dehydration of forage crops. A.P.F. sources such as fish meal, meat meal, fish solubles, and fermentation A.P.F. products fed at practical levels do not . . .