hops, beta acid, ruminal ammonia, ionophore


Hops (Humulus lupulus) have played an integral role in beer manufacturing and are widely known for their antimicrobial and preservative properties. α-acids of hops are extracted and utilized to enhance beer flavor, leaving residues largely composed of β-acids. Beta-acid extracts of hops are structurally similar to ionophores and may express ionophore-like traits. Ionophores, including Rumensin (Elanco Animal Health, Greenfield, IN), are used to improve feed efficiency and to decrease the incidence of digestive disturbances in feedlot cattle. A large portion of in vitro studies show benefits from feeding hops or hop acids with results similar to ionophores; however, live animal experiments are needed to confirm these observations. The objectives of this study were to assess the effects of β-acid extracts of hops on feedlot performance in cattle fed high-concentrate diets and determine a response to varied doses of β-acid extracts of hops.