Economy brands tend to use corn, wheat, gluten, soy and meal as major protein sources, which is not considered to be as healthy for the animal. (petbusiness.com)
Rice, wheat and corn, for example, are missing some of the nine essential amino acids, but grains combined with other foods are major protein sources in many countries. (uen.org)
• Is there enough protein in the broth to sustain you since you're cutting out all major protein sources? (eatrealstaysane.com)