Comparative Growth-Promoting Values of the Proteins of Cereal Grains

Abstract

The growth-promoting values of the proteins of whole yellow corn, hard and soft wheat, pearled barley, brown and polished rice, rye and rolled oats were compared by means of ad libitum feeding experiments with young albino rats. As far as their N contents permitted, the materials were incorporated at 4.5, 7.5, 9.5 and 12% protein levels in diets approximately isocaloric and nutritionally adequate with respect to dietary factors other than protein. The results were evaluated on the basis of weight increases and gains per gram of protein consumed over 6-week periods. At the 4.5% protein level the values ranged in the following descending order: Oats, rye, polished rice, brown rice. Corn, barley, hard and soft wheat showed about the same value, which was lower than that of the other cereals. Brown rice surpassed all of the others at the 7.5% level. Rolled oats and rye gave much higher values than corn, wheat and barley. At the 9.5% level oats outranked wheat and rye. Hard and soft wheat gave practically the same values. A strikingly higher value was obtained for oats than for hard wheat at the 12% protein level — the only two that could be compared at this level. Oats, rice and rye proved superior to all of the other cereals at the protein levels at which they could be compared.