The Role of the Time Factor in Feeding Supplementary Proteins

Abstract

The question was investigated of whether supplementary proteins of low biological value promote the growth of infantile rats when fed individually at different times. It was found that yeast, blood and wheat gluten proteins do not promote growth when fed individually at a 9% level. Diets containing wheat gluten + blood protein, or yeast + blood protein, or yeast + wheat gluten protein, have satisfactory growth-promoting properties. If, however, these same pairs of proteins are fed separately with lapses of time between feedings, they do not supplement each other, as is indicated by the lack of resulting growth. These experiments show that delayed provision of the missing essential amino acids is ineffective, not only when fed as the amino acids themselves (Geiger, '47), but also when they are supplied in the form of proteins.