Attitudes towards antimicrobial use and factors associated with antimicrobial use in western Canadian cow-calf herds.

One hundred cow-calf producers in western Canada were surveyed to determine their perceptions regarding antimicrobial use (AMU) and how these perceptions and other herd management factors were associated with AMU. Veterinarians were the most important source of AMU information. Half of the producers considered antimicrobial resistance (AMR) when choosing antimicrobials, while 24% considered the influence of AMU on AMR in human health. Younger producers < 30 y were most likely to consider AMR when choosing antimicrobials. Injectable products were used for disease prevention in 17% of herds; 5% used medically important antimicrobials in feed and 6% in water. Use of injectable antimicrobials of very high importance to human health was reported in 34% of herds. Producers with higher calf mortality were more likely to report AMU in feed or water. The use of Health Canada Category I antimicrobials was most common when calves were retained after weaning.