The Development of a Free Amino Acid Diet for the Growing Chick

GROWTH of chicks fed protein-free, amino acid diets was considered unsatisfactory until recently. Earlier investigators, Hegsted (1944), Almquist and Grau (1944), Grau and Peterson (1946), Grau (1947 Grau (1949), Luckey et al. (1947), Lewis (1953), Benton et al. (1955, 1957), reported growth rates of chicks that were considerably below those of chicks receiving intact proteins. Glista (1951) force-fed an amino acid diet that supported chick growth comparable to that obtained by feeding a diet containing intact protein. Fisher and Johnson (1957) reported growth of .5 chicks fed an amino acid diet for 7 days that was as good as the growth of control chicks fed a practical corn-soybean diet. Fox et al. (1958) found that day-old New Hampshire chicks fed a diet containing a modification of the mixture of Fisher and Johnson (1956) grew as well as chicks fed intact protein up to 2 weeks of age. Growth of chicks fed …