Abstract: Embodiments of a composition comprising silica, mineral clay, mannans, or any combination thereof are disclosed. The composition may further comprise glucan. The composition is administered to an animal that will be administered, or has been administered, a growth promotant. The growth promotant may be a ?-agonist, antibiotic, steroid or hormone. The composition is fed to the animal for a period of time before administration of the growth promotant, during administration of the growth promotant, and/or after administration of the growth promotant. Administration of the composition to the animal ameliorates, or prevents development of, at least one deleterious symptom or sign, such as a deleterious symptom or sign potentially associated with administration of the growth promotant. Embodiments of a composition comprising (i) a growth promotant and (ii) glucan, silica, mineral clay, mannans, or any combination thereof also are disclosed.