Cultivating change: A study of Western Canadian dairy farmers' perspectives on mastitis-related antimicrobial stewardship and strategies for milk culturing adoption

Mastitis prevention and treatment decisions have been the focus of antimicrobial stewardship (AMS) in the dairy sector, as antimicrobials used for prevention and treatment of mastitis cases account for ∼65% of antimicrobials used on dairy farms. To improve on-farm AMS, a selective treatment approach to clinical mastitis (CM) is promoted, guided by pathogen identification through diagnostic techniques, such as milk culturing. To design effective interventions to support the adoption of pathogen identification, it is important to understand dairy farmers' perceptions regarding mastitis-related AMS and identify their barriers and motivators to the adoption of milk culturing as part of their CM treatment protocol. As such, interviews with 17 dairy farmers or farm personnel located in Western Canada were held and analyzed both inductively using thematic analysis and deductively using the COM-B framework, a part of the broader Behavior Change Wheel. The latter is a framework designed to assess factors that determine behavior and aid in the development of relevant interventions and was used to design potential interventions to mitigate the identified barriers and promote the facilitators (e.g., awareness that culturing is valuable, support of herd veterinarian, etc.) (Figure 1) that were identified in the interviews. Four themes were identified regarding AMS stewardship decisions: 1) Responsible in principle, unintentionally variable in practice, 2) Upstream solutions: Prevention, herd health, and good management as foundations of judicious AMS, 3) The need for consistent engagement of the veterinarian as an external advisor on AMS, and 4) Behavioral change around AMS: Generational differences, internal drive, external support. Based on the interview results, 10 interventions were suggested, including: encouragement of milk culturing through veterinarians and farm magazines, training to improve aseptic sampling, education to improve interpretation of test results and increase problem awareness, offering of comprehensive udder health packages that include milk sampling to enable farmers to send in samples, increasing familiarity of culturing through on-farm demonstrations and among peer groups, and, lastly, incentivizing farmers to adopt milk culturing through benchmarking. Implementing these interventions could lead to an increased uptake of selective CM treatment protocols, thereby contributing to AMS on dairy farms.