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Age-dependent windows for cohort culling in BSE herds
1National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, DK-1790 Copenhagen, Denmark. anst@vet.dtu.dk
Preventive Veterinary Medicine
|September 15, 2009
Summary
To reduce Bovine spongiform encephalopathy (BSE) risk, a new method identifies high-risk animals for targeted culling. Age-dependent cohort culling is essential for older BSE cases, improving upon previous herd-wide practices.
Area of Science:
- Veterinary epidemiology
- Animal health management
- Bovine spongiform encephalopathy (BSE) research
Background:
- Traditional BSE control in Denmark involved culling entire herds.
- Dissatisfaction with whole-herd culling led to exploring targeted approaches.
- Cohort culling, targeting animals of similar age to the index case, was proposed.
Purpose of the Study:
- To develop a method for identifying animals most at risk in a BSE-infected herd.
- To evaluate the effectiveness of cohort culling for BSE risk mitigation.
- To propose age-dependent culling windows for improved accuracy.
Main Methods:
- Characterizing at-risk animals within BSE-infected herds.
- Modeling cohort culling effectiveness based on index case age.
- Developing formulas for age-dependent culling window calculations.
- Presenting age-dependent windows for Danish herd sizes.
Main Results:
- A +/- 1.5-year cohort cull is effective for index cases aged 6 years or less.
- Cohort culling is inadequate for older index cases, necessitating age-dependent windows.
- Formulas and graphical representations for age-dependent windows were provided.
Conclusions:
- Age-dependent cohort culling is crucial for effective BSE risk management in Denmark.
- The proposed method allows for targeted culling, reducing unnecessary herd losses.
- This approach enhances the precision of BSE control strategies.
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