Pens of commercial feedlot cattle with better health and performance have lower estimated greenhouse gas emissions intensity.

With increasing emphasis on sustainability, beef producers are evaluating potential environmental impacts of production practices. However, gaps remain in understanding how cattle health and performance metrics align with environmental impacts and global protein needs. This study quantified how feedlot performance and health metrics for beef-breed steers and heifers are associated with total greenhouse gas (GHG) emissions and emissions per unit of production. Using data on 9,436 single-lot pens in nine U.S. commercial feedlots (2017 to 2021), we fit mixed-effects multivariable models, based on directed acyclic graphs, to evaluate four key explanatory variables: average daily gain (ADG), feed efficiency (G:F), medicine costs per pen (proxy for disease burden), and cumulative mortality. Sex, season of arrival, days on feed, and arrival body weight were assessed as potential confounders. The primary outcome was estimated carbon dioxide equivalent emissions per kg of final body weight (emissions intensity), derived from Uplook 1.0 (Elanco Animal Health). Across all study pens, 19.2% of estimated lifetime emissions occurred during the feedlot phase, while 41.8% of total body weight gain occurred at the feedlot; demonstrating how feedlots reduce emissions intensity and enhance production efficiency. Higher ADG and G:F were associated with lower emissions intensity, while higher mortality and disease burden were linked to increased emissions intensity. Significant interactions were observed in all models, with effects of ADG and G:F modified by sex and season (