Targeted Herd Sampling for Disease Freedom in Cattle
Author Information
Author(s): Sarah Blickenstorfer, Heinzpeter Schwermer, Monika Engels, Martin Reist, Marcus G Doherr, Daniela C Hadorn
Primary Institution: Veterinary Public Health Institute, Vetsuisse Faculty, University of Berne, Switzerland
Hypothesis
Can targeted sampling of high-risk farms reduce the sample size needed to demonstrate freedom from infectious bovine rhinotracheitis (IBR) and enzootic bovine leucosis (EBL) in Switzerland?
Conclusion
Targeted sampling is more cost-effective and requires fewer farms to demonstrate disease freedom compared to conventional random sampling.
Supporting Evidence
- Targeted sampling reduced the required sample size for IBR from 2,259 to 1,241 farms.
- Targeted sampling reduced the required sample size for EBL from 2,243 to 1,750 farms.
- The cost for IBR surveillance using targeted sampling was €580,600 compared to €964,800 for random sampling.
- The cost for EBL surveillance using targeted sampling was €880,100 compared to €955,900 for random sampling.
Takeaway
This study shows that by focusing on farms at higher risk for disease, we can test fewer farms and still prove that the cattle are healthy.
Methodology
The study used scenario tree modelling to calculate sample sizes for targeted sampling based on identified risk factors for IBR and EBL.
Potential Biases
Potential bias from expert opinion in defining risk factors.
Limitations
The model relies on expert estimates and literature review, which introduces uncertainty.
Participant Demographics
Cattle farms in Switzerland.
Statistical Information
P-Value
0.002
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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