| Abstrakt: |
Experiments with growing rats were carried out to evaluate the egg replacement value and growth-promoting ability in relation to their amino acid content of by-products and a combination of by-products from wet milling of corn. In the first experiment, 8 diets containing 12.4% crude protein derived entirely from whole dried egg, corn steepwater solids, corn gluten, corn germ oilmeal, corn fine bran, zein, zein-extracted gluten, or reconstituted starch-free corn were fed to 170-g rats. Despite a superior chemical potential based on chemical score and essential amino acid index, the protein quality of corn germ oilmeal, as measured by egg replacement values, was lower than that of all of the other proteins except corn fine bran. Reconstituted starch-free corn protein was equal to corn gluten and zein-extracted gluten which were the best individual protein sources. In the second experiment protein from the same sources, excluding corn fine bran, was fed to weanling rats in diets containing 17% crude protein. Growth and efficiency of protein utilization confirmed the results of the first experiment in that corn germ oilmeal would not support growth and that reconstituted starch-free corn produced the most rapid and efficient gains of the corn proteins tested. However, growth and efficiency were appreciably poorer than when egg protein was fed. |
