Abstract
A bulk milk quality assurance programme for Mycobacterium avium subsp. paratuberculosis
(Map) in dairy herds was simulated. Herds were certified as `low-Map bulk milk¿ if, with a
certain probability, the concentration of Map in bulk milk did not exceed a maximum
acceptable concentration (MAC). The MAC was based on pasteurisation studies. The
programme starts with an intake procedure; test-negative herds enter a surveillance
procedure and test-positive herds enter a control procedure. The aim of this study was to
simulate different programmes to evaluate their epidemiological and economic effects in a
population of closed Dutch dairy herds.
Combinations of various herd examinations for the intake, surveillance and control
procedure were simulated with JohneSSim (a stochastic simulation model). For example,
intake was done by ELISA, surveillance by biennial ELISA and control by biennial faecal
culture. Test-positive animals were culled. All programmes were simulated with and without
preventive management measures taken by all participating herds. Sensitivity analyses
were performed for uncertain parameters.
The results show that herd examinations by ELISA for intake and surveillance effectively
ensure the quality of `low-Map bulk milk¿: >96% of simulated certified herds (increasing to
>99% after 10 years) were below the MAC. Preventive management measures hardly
influenced the Map bulk milk concentration of certified herds. However, preventive
measures were pivotal to enable herds in the control procedure to move to `low-Map bulk
milk¿ status. Culling based on biennial faecal culture was more effective than culling based
on annual ELISA. Average total discounted costs for 20-year participation in the programme
mentioned above were ¿6×103 per average Dutch dairy herd. On average, additional
preventive measures increased these costs to ¿40×103 per herd.
This study showed that a bulk milk quality assurance programme for closed Dutch dairy
herds is feasible and provided decision-makers with information on the cost-effectiveness of
different programmes.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 8th International Colloquium on Paratuberculosis |
| Editors | E.J.B. MPH, MBA, DVM Manning, S.S. DVM, PhD Nielsen |
| Place of Publication | Copenhagen, Denmark |
| Pages | 60-73 |
| Number of pages | 14 |
| Publication status | Published - 2005 |
| Event | A meeting of the International Association for Paratuberculosis, Inc. - Duration: 14 Aug 2005 → 18 Aug 2005 |
Conference
| Conference | A meeting of the International Association for Paratuberculosis, Inc. |
|---|---|
| Period | 14/08/05 → 18/08/05 |