The present disclosure concerns embodiments of a combination and/or composition comprising bacillus, and yucca, quillaja or both. Embodiments of methods of making and using the combination and/or composition also are disclosed herein. In some embodiments, the combination and/or composition may be used to improve feed conversion rates in animals. In some embodiments the animals are avians; in other embodiments, the animals are non-avians. Embodiments of the disclosed combination can comprise a first composition comprising Quillaja saponaria, Yucca schidigera, or both, and Bacillus coagulans. Embodiments of the disclosed composition can comprise Quillaja saponaria, Yucca schidigera, or both, and Bacillus coagulans.