Introduction to Beta Agonists

Beta-adrenergic agonists (β-AAs) are synthetic compounds structurally related to catecholamines that activate β-adrenergic receptors (β-ARs), thereby stimulating intracellular signaling cascades, most notably the cAMP-PKA pathway. In livestock, β-AAs promote nutrient partitioning by shifting energy utilization from fat deposition to lean tissue accretion. Ractopamine and zilpaterol, which primarily act on β₁-and β₂-receptors, respectively, have been widely adopted in North American beef production to enhance growth efficiency. More recently, lubabegron (Experior), a β₃-selective agonist approved in 2018, has gained attention for its dual role in improving feedlot performance and reducing ammonia emissions.