The Growth-Promoting Effect of Aureomycin on Various Types of Diet

AUREOMYCIN was found to produce growth responses in chicks on a variety of diets (Stokstad and Jukes, 1950), containing either soybean meal, peanut meal, cottonseed meal, or purified soybean protein as the protein source. Experiments with pigs (Burnside et al., 1949) showed that the response produced by crude aureomycin-B12 supplements was greater on a corn-peanut-meal diet than on a corn-soybean-meal diet. In the present investigation the effects of carbohydrates, yeast, and protein supplements on the response to aureomycin were examined. Chicks were obtained from eggs laid by hens which had been kept on a diet low in vitamin B12 (Stokstad et al., 1949). The chicks were Barred Rock × New Hampshire crosses. The compositions of the basal diets are shown in Table 1. The liver residue which contained 74 percent “crude protein” (NX 6.25) was prepared by drying the cake remaining after a hot water extraction of cooked liver… .