Researchers in Northern Ireland have analyzed the responses to a Veterinary Risk Assessment and Management Plan (VRAMP) concerning Johne’s disease for 1,569 dairy herds. Their findings are reported in the recent issue of Veterinary Record and the article is Open Access.
Animal Health and Welfare Northern Ireland has been enrolling dairy herds across Northern Ireland (NI) in a voluntary Johne’s disease (JD) control programme since October 2020. A Veterinary Risk Assessment and Management Plan (VRAMP) questionnaire was completed for each herd enrolled and recommendations for improved farm management practices were provided to farmers. Herd JD testing was recommended but was not mandatory.
This study analysed VRAMP responses for 1569 dairy herds that had enrolled in the JD control programme up to October 2022. Univariate and multivariate regression models were applied to the data as appropriate.
Overall, 21.4% of the dairy herds had completed herd JD screening, with 13.7% of herds reporting a confirmed case of JD. A further 31.5% of herds reported suspected case(s) of JD. Eighty-nine percent of farms had introduced animals from outside the herd. Herds that utilise a mixed calving pen and hospital pen, and herds that do not separate JD-positive or sick animals within the calving pen, were significantly (p > 0.001) more likely to be a high-probability JD herd. Accidental mixing of neighbouring herds significantly (p = 0.01) increased the risk of a suspected or confirmed case of JD. Herds that utilise rented land (70%) were significantly (p > 0.001) more likely to be at a high risk for JD.
The VRAMP analysis identified areas of JD control that should be focused on in NI dairy herds, such as calving pen management and hygiene. The results highlight the importance of common JD recommendations in the management of on-farm disease risk.
This report yet again illustrates that purchase of animals from other herds is a common and risky practice for the introduction of infectious diseases like Johne’s disease. The second common and risky practice on dairy farms is housing sick cows and JD test-positive cows in pens where calves are being born which further facilitates infection spread to the most susceptible animals on the farm and animals likely to join the herd as replacements in the future. These risky practices have been associated with higher MAP-infection rates in dairy herds in multiple studies in other countries.
Many countries have standardized risk assessment tools for Johne’s disease in dairy cattle herds and for beef cattle herds in some countries. In the U.S. the risk assessments for both dairy and beef herd can be done using an App for iPads making completion of the task quicker and providing the option to share the result with regulatory veterinary agencies. While similar risk assessments may not be available for goats and sheep, the same basic principles apply, and veterinarians can use these concepts to help animal owners develop the most effective JD control programs for their specific situation. Contact your local veterinarian.