Antimicrobial use in 22 U.S. beef feedyards: 2016-2017

Area of Science:

• Veterinary Medicine
• Animal Science
• Agricultural Economics

Background:

• Antimicrobial use in livestock is a significant concern for public health and animal welfare.
• Standardized metrics for measuring antimicrobial consumption in beef feedyards are lacking.
• Understanding factors influencing antimicrobial use is crucial for responsible stewardship.

Purpose of the Study:

• To evaluate the feasibility of collecting antimicrobial use data in beef production systems.
• To identify feedyard-specific factors that may affect the interpretation of antimicrobial use data.
• To report antimicrobial use in U.S. beef feedyards using novel metrics.

Main Methods:

• Data collected from 22 U.S. beef feedyards.
• Antimicrobial use quantified using milligrams of antimicrobial per kilogram of liveweight sold (mg/kg-LW) and antimicrobial regimens per animal year (Reg/AY).
• Data standardized and quality-assured; analysis performed at study and feedyard levels, stratified by antimicrobial class and use category.

Main Results:

• Feasibility of data collection at the production system level was demonstrated.
• Antimicrobial use reported by class and use category (in-feed, bovine respiratory disease control, individual treatment).
• Medically important and non-medically important antimicrobials reported separately; regimen details provided.

Conclusions:

• Collecting and standardizing antimicrobial use data in beef feedyards is feasible.
• Transparent reporting of antimicrobial use metrics is essential for accurate interpretation.
• This study provides a foundation for future research on antimicrobial stewardship in cattle production.