Antibiotic use among beef cattle farmers in feedlots in Querétaro, Mexico.

The appropriate and rational use of antibiotics for the treatment and prevention of infectious diseases in animal, human, and environmental health contributes to reducing antimicrobial resistance within the framework of the "One Health" approach. Our aim was to identify the practices involved in the use and management of antibiotics on beef cattle farms in Querétaro, Mexico. A cross-sectional study involving 21 beef cattle farmers in feedlots surveyed in the municipality of Ezequiel Montes, Querétaro, was conducted between April and May 2025. Farmers were selected using respondent-driven sampling (RDS). The first participants of the target population were recruited on a convenience basis. A face-to-face survey was implemented, structured into five sections: (i) beef cattle farmers' profile, (ii) characteristics of the feedlot systems, (iii) antibiotic use, (iv) antibiotic prescription, and (v) inventory of stored antibiotic vials. The collected data were processed by performing a descriptive analysis of the variables. All surveyed beef cattle farmers were male, with an age range of 23-63 years (median 40; IQR 33-51.5). Forty-three percent of the beef cattle farmers had only a basic level of schooling. The animal census consisted of 30574 animals. In 19 of the 21 feedlot systems the veterinarian decided which antibiotics to buy, although all of them reported purchasing antibiotics without a prescription. Farmers recognized that pneumonia is the leading cause of morbidity and mortality in feedlot cattle. A total of 335 stored antibacterial products from 20 antibiotic classes were recorded: enrofloxacin (20.3%), penicillin (13.7%), florfenicol (11.0%), oxytetracycline (10.7%), tilmicosin (9.6%), tulathromycin (8.7%), and gentamicin (7.5%). Approximately 11% of the stored antibiotics have a "Watch" classification in the World Health Organization (WHO) AWaRe tool. However, in the World Organization for Animal Health (WOAH) classification, all registered antibiotics were in the "critically important antibiotic" category. Antibiotics used in intensive animal production systems can exert selective pressure, leading to the development of resistant strains of commensal or pathogenic microorganisms that affect both animal and human health. Research and communication on the rational use of antibiotics between human and veterinary medicine are essential to reducing antimicrobial resistance within the framework of the "One Health" approach.