Keratins as Sources of Protein for the Growing Chick

HAIR obtained from hogs at slaughter houses poses a problem of economic use and disposal. The returns on use, e.g., as an organic component of fertilizers, are usually low and when an outlet is not available, costly in terms of disposal. Hog hair, like feathers, is very high in protein which is almost exclusively keratin. The amino acid composition of hair and feathers is very similar (Block and Bolling, 1951); however, like feathers (Mangold and Dubski, 1930; Naber et al., 1961; Moran et al., 1966) and wool (Routh and Lewis, 1938; Greenwood and Speakman, 1964), the raw keratin from hog hair is most likely undigestible. By autoclaving, feathers can be efficiently converted into a friable meal (Binkley and Vasak, 1950) which is an effective dietary protein when properly balanced (Moran et al., 1966). The latter investigators implicated extensive molecular cross-linking by the large quantities of cystine as the reason for …