Factors affecting management changes on farms participating in a Johne's disease control program

Area of Science:

• Veterinary Epidemiology
• Animal Health Management
• Dairy Science

Background:

• Johne's disease, caused by Mycobacterium avium ssp. paratuberculosis (MAP), poses a significant threat to dairy herds worldwide.
• Effective control programs rely on identifying and rectifying management weaknesses to prevent MAP introduction and transmission.
• Risk assessment (RA) tools are employed to evaluate on-farm biosecurity and management practices related to MAP.

Purpose of the Study:

• To evaluate if risk-assessment (RA) scores predict necessary management changes for Johne's disease control.
• To identify factors within RAs that motivate producers to implement management improvements.
• To determine if prior test results influence the adoption of management enhancements.

Main Methods:

• Annual RAs were conducted by veterinarians on 370 dairy farms in Alberta participating in a Johne's disease control program.
• Management changes were documented in a plan, with a maximum of three agreed-upon improvements recorded.
• Herd MAP infection status was assessed via environmental sample cultures; RA question scores were analyzed for prediction of management changes.

Main Results:

• Management changes were significantly more likely to be proposed for high-risk RA questions (19%) compared to low-risk ones (4%), with an odds ratio of 11.4.
• Improvements in RA scores were more probable between the first and second year of the program (OR=1.6).
• Farms with more than three positive environmental samples in the prior year were more likely to improve management (OR=1.3).

Conclusions:

• The RA process effectively identified management weaknesses, leading to targeted suggestions for improvement.
• Management improvements were not random, but influenced by herd MAP infection status, RA suggestions, and program participation duration.
• This study validates the use of RA in guiding practical, evidence-based management changes for Johne's disease control in dairy cattle.