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

Abstract

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 (P values < 0.01). Improved growth and feed efficiency were consistently associated with lower emissions, but the magnitude of effects differed between steers and heifers and varied by season. Disease burden and mortality impacts also varied by season and arrival weight, with significant three-way interactions (P values < 0.01). Pens with poorer health consistently had higher emissions intensity, with the largest effects in lighter-weight pens during certain seasons. This study quantifies how improving health, G:F, and ADG can reduce emissions intensity. For example, reducing mortality from 5% to 0% lowers lifetime emissions by nearly 6%. Findings highlight the importance of health and performance in sustainability and help quantify potential impacts of strategies for improving health and performance to reduce GHG emissions intensity and improve production efficiency.