High herd-level prevalence of Mycobacterium avium subspecies paratuberculosis in Western Canadian dairy farms, based on environmental sampling
| Autor: | Deb Haupstein, Karin Orsel, Herman W. Barkema, C. Pickel, J. De Buck, M. Slomp, Robert Wolf, J. Flaig |
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| Rok vydání: | 2014 |
| Předmět: |
Veterinary medicine
animal diseases education Cattle Diseases Dairy industry Sensitivity and Specificity Odds Alberta Animal science Paratuberculosis Genetics Environmental Microbiology Prevalence Animals biology Dairy herds Incidence (epidemiology) Sampling (statistics) Bayes Theorem biology.organism_classification Mycobacterium avium subspecies paratuberculosis Housing Animal Saskatchewan Manure Mycobacterium avium subsp. paratuberculosis Dairying Geography Logistic Models Herd Animal Science and Zoology Cattle Female Herd prevalence Food Science |
| Zdroj: | Journal of dairy science. 97(10) |
| ISSN: | 1525-3198 |
| Popis: | Mycobacterium avium subspecies paratuberculosis (MAP) causes chronic progressive enteritis in ruminants. The pathogen is present in most countries with modern dairy production, causing substantial economic losses for the industry. The objectives of this study were to estimate dairy herd prevalence of MAP in the Western Canadian provinces of Alberta and Saskatchewan, and to determine whether herd size and housing system (tie-stall versus freestall or loose housing) affected the risk of a herd testing positive for MAP. Six environmental samples were collected on 360 Alberta farms (60% of registered producers) and on 166 Saskatchewan dairy farms (99%). In total, 47% of the sampled farms in Alberta and 53% of the sampled farms in Saskatchewan had at least one environmental sample that was MAP culture positive and were, therefore, defined as infected. Sensitivity of environmental sampling was estimated using 3 subsequent annual tests performed on 82 farms. Because laboratory protocols were continuously improved throughout the project, the sensitivity increased over time. Therefore, a mean of the sensitivity estimates weighted on sampling year was constructed; this resulted in sensitivities of 68 and 69% for Alberta and Saskatchewan, respectively. Implementing those estimates in an approximate Bayesian computation model resulted in a true herd prevalence of 68% (95% probability interval: 60–80%) for Alberta and 76% (95% probability interval: 70–85%) for Saskatchewan. Herds with >200 cows had 3.54 times higher odds of being environmental sample positive and had more positive samples than herds with |
| Databáze: | OpenAIRE |
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