Factors influencing dairy cattle farmer use of antimicrobials on farms in New South Wales, Australia

Abstract

Antimicrobial use (AMU) in the food chain is a potential driver of antimicrobial resistance. Despite Australia's strong regulation of AMU limited to veterinary prescriptions, a proportion of empirical antimicrobial treatments are administered by dairy farmers to manage common cattle health problems. This cross-sectional survey identified key influences on AMU by dairy cattle farmers within New South Wales, Australia, to detect opportunities for antimicrobial stewardship (AMS) engagement. The study identified existing relationships, resources and attitudes of the dairy farmers that could be optimised for on-farm AMS strategies. Farmers were most highly influenced by veterinary advice and clinical signs of the animal followed by the withholding period and the potential for antimicrobial resistance development. Farmers' high confidence regarding their own knowledge of antimicrobials (>90%), their high regard for veterinary advice (>90%) and high rate of veterinary health care plan use (69%) provides a strong framework to build the profile and practice of AMS on dairy farms. Positive engagement by dairy farmers (survey response of 20%), was achieved by working with the NSW Food Authority. Despite respondents reporting low reliance on formal (government and commercial) organisations for information about AMU, their engagement demonstrates an opportunity for groups with unparalleled access to dairy farmers to drive AMS. An association between frequent use of veterinary advice and respondents keeping ceftiofur on-farm requires further investigation. Quantitative and qualitative analysis of on-farm resources, decision-making, and practices is required to understand how practices relate to veterinary advice and accepted standards of appropriate AMU on dairy farms.

Keywords: Australia; antimicrobial stewardship; antimicrobial use; dairy cattle; dairy farmer.

Figure 1

Factors influencing whether an antimicrobial is used to treat an individual animal. Colours indicate the proportion of respondents reporting each factor as very strong, strong, moderate, slight, no or unknown influence.

Figure 2

Influences on which antimicrobial is given to an individual animal. Colours indicate the proportion of respondents reporting each factor as very strong, strong, moderate, slight, no or unknown influence.

Figure 3

Farmer confidence that antimicrobial use practices are done well on their farm. Colours indicate the proportion of respondents reporting their confidence that each practice is done well on their farm as very confident, moderately confident, somewhat, or not confident.

Figure 4

Percentage of respondents keeping different parenteral antimicrobial formulations kept on farm. Colours indicate rank according to the importance ratings and summary of antibacterial uses in human and animal health in Australia.

Figure 5

Percentage of respondents keeping different intramammary and intrauterine antimicrobial formulations on farm. Colours indicate rank according to the importance ratings and summary of antibacterial uses in human and animal health in Australia.

Figure 6

Usefulness of information sources for learning about antimicrobial use. Colours indicate the proportion of respondents reporting each source of information as always useful, quite useful, useful, somewhat useful or never useful.