The Economic Impact of Alternative Antimicrobial Management Strategies in Western Beef Feedlots: An Agent-based Model

• Author / Creator

  Chen, Yunxuan

• There is growing evidence that antimicrobial use (AMU) in animal agriculture contributes to antimicrobial resistance (AMR), which has created global public threats that adversely affect health and welfare in society. This thesis explores the economic impact of antimicrobial use management strategies addressing Bovine Respiratory Disease (BRD) in the beef feedlot sector in western Canada. The research mainly examines the cost-effectiveness of alternative disease management strategies including an early diagnostic test compared to the currently used mass medication strategies as a common practice of feedlot managers. Externality costs of AMU, variability of frequency and expenditures of early diagnostic tests, and increasing impacts of AMR are further analyzed to compare the advantages and disadvantages of those strategies.
  
  A framework that integrates an agent-based model (ABM) and a modified susceptible-infected-recovered (SIR) model is developed to simulate the BRD disease dynamics and disease management strategies in a representative pen of cattle in a feedlot in western Canada. This integrated framework can incorporate individual heterogeneity which is important when modelling disease spread but is ignored by most of the studies that employ the population-based compartment models. An economic model of a feedlot manager who is assumed to maximize expected profits after finishing is constructed to assess the economic impacts of the different disease management strategies. Based on applying a single or combinations of these strategies over time, we designed nine representative disease management scenarios in this study.
  We find that the expected profits in the scenarios containing metaphylaxis strategy are higher than other disease management scenarios; however, the costs of required antimicrobial drugs are also higher. An early diagnostic test as a more accurate and rapid strategy could help to control BRD spread at an early stage and therefore reduce the unnecessary antimicrobials for those healthy calves that do not require AMU. Even though its expected profit is $8.61 per head lower than that under the “business as usual” scenario of arrival metaphylaxis, the total costs of antimicrobials are significantly reduced by $20.44 per head. Moreover, the advantages of early diagnostic tests are more evident when we consider the externality costs of antimicrobial use, the variability of early diagnostic tests, and the increased impacts of AMR in long-run practice. Findings from this study have implications not only for feedlot managers in advancing their antimicrobial management, but also for policymakers to choose appropriate mechanisms, such as providing subsidies to support the use of potential early diagnostic strategies or other regulations.

• Subjects / Keywords

  • Antimicrobial use
  • Agent-based model
  • Bioeconomic model
  • Bovine respiratory diseases
  • Disease management strategies

• Graduation date

  Spring 2021

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-yyqm-v483

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.