Abstract: The present invention relates to peptide-like compounds, eg aminocarboxylic acid amide derivatives, and to methods of using same in the field of general health care, for example, to improve resistance to stress, improve production of desired characteristics or useful products in animals, to increase weight gain, and to decrease feed efficiency. The invention has applications in the field of animal husbandry. It also relates to administering beta-alethine to improve feed efficiency in an animal, comprising administering to animal an amount of .beta.-alethine sufficient to reduce the amount of food required to increase a unit of weight in the animal.