A Growth Promoting Factor for Chicks in the Feces of Hens

Abstract

HAMMOND reported in 1942 that chickens grew well when dried cow manure was added to low grade growing diets. Whitson et al. (1945) showed that 8 percent of dried cow manure and 3 percent of sardine fish meal were about equally effective in improving the growth response of chicks fed an all-plant-protein basal diet containing 35 percent soybean oil meal. They concluded that the growth-promoting effect of cow manure was not due to a protein or to any of the chemically characterized vitamins. Rubin and Bird (1946a) presented evidence to show that the growth factor in cow manure was not identical with any of the chick growth factors previously described. In this report evidence will be presented to show that the feces of hens also contain a factor, probably synthesized in the digestive tract, which stimulates the growth of chicks in the same manner as does the growth factor of . . .