title: Antimicrobial use on 24 beef farms in Ontario.
abstract: Understanding risk factors for antimicrobial resistance requires knowledge of antimicrobial selection pressure. The objectives of this research were to develop methodology for collecting quantitative antimicrobial use information from beef producers in Ontario, to document the types and quantities of antimicrobials reported (for a minimum of 12 mo), and to compare 2 metrics for injectable use reporting. Twenty-four volunteer beef producers were asked to complete a questionnaire, document drug use in a treatment diary, and retain empty medication containers. For injectable antimicrobials, producers recorded approximately 60% of the total use in the treatment diaries; oxytetracycline, penicillin, macrolides, florfenicol, and spectinomycin were used in the greatest quantities. Based on estimated weights of active ingredients (calculated according to number of animals exposed, duration, and average dose per day) the antimicrobials most commonly used in feed were monensin, tylosin, lasalocid, and tetracyclines. The antimicrobials most commonly used in water were lincomycin-spectinomycin, chlortetracycline, and oxytetracycline. Based on estimated weights and measured quantities, < 1% of antimicrobials used were in the Canadian category of highest importance to human medicine. A comparison of animal daily dosages to kilograms of active ingredient demonstrated that the relative ranking of use of antimicrobials varied with the chosen metric, and that further investigation into the best measure in relation to antimicrobial resistance is warranted.
authors.affiliation: Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, 160 Research Lane, Unit 103, Guelph, Ontario N1G 5B2. carolee_carson@phac-aspc.gc-ca
authors.forename: Carolee A
authors.initials: CA
authors.lastname: Carson
authors.forename: Richard
authors.initials: R
authors.lastname: Reid-Smith
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Irwin
authors.forename: Wayne S
authors.initials: WS
authors.lastname: Martin
authors.forename: Scott A
authors.initials: SA
authors.lastname: McEwen
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000600:supply & distribution; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D015169:Colony Count, Microbial / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D004363:Drug Utilization / Q000706:statistics & numerical data*; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology*; D005260:Female; D007267:Injections / Q000662:veterinary; D008297:Male; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D009864:Ontario; D015995:Prevalence; D012307:Risk Factors; D012621:Seasons; D012737:Sex Factors; D011795:Surveys and Questionnaires
chemical_list: D000900:Anti-Bacterial Agents