Some Factors Influencing the Male Hormone Content of Cow Manure

Riley and Hammond (8) discovered that the feeding of dried cow manure to day-old chicks caused marked stimulation of the comb growth. Evidence was presented indicating that the factor present was an androgenic rather than a gonadotrophie substance. They reported that "feces from bulls were entirely without effect, whereas feces from pregn~int cows, as well as from unbred heifers, had marked androgenic effects."