Johne's Disease (Paratuberculosis)
Growing distribution and prevalence affecting farms across the globe
£2,600 ($3,438) typical losses in 100- head dairy herd
Reduces meat carcass value by up to 31%
No cost-effective treatments currently available
The disease is very difficult to diagnose without scientific techniques due to its symptomatic similarity to other diseases and its gradual progression.
Johne’s disease is currently under increased scrutiny due to concerns that Crohn’s disease in humans could result from the ingestion of milk contaminated with MAP bacteria. Although MAP has been shown to be capable of surviving pasteurisation and has been found in dairy products, research evaluating cause and effect between MAP bacteria and Crohn’s disease is inconclusive.
In the majority of cases Johne's disease is spread to a farm by the introduction of a new animal with a hidden infection (the so-called “Trojan cow”). From this individual the disease is then disseminated through the herd, particularly to young calves, via contaminated faeces. The progression of the disease is hidden at first and is difficult to notice before it has opportunities to spread. It is estimated that for every symptomatic animal in a herd there are already 15-25 other infected individuals.
Although the introduction of infected animals into the herd is the primary means of disease transmission between farms, many wild animals can also spread the disease. Foxes, deer and rabbits have all been shown able to spread MAP. The combination of hidden infections, animal reservoirs and the organism’s ability to survive in soil for up to a year means that eradication from infected herds is very challenging.
The cost of Johne’s disease to individual farmers is predicted to be £2,600 ($3,438 USD) for a 100 head dairy herd, although this figure is likely an undervaluation of the disease impact. At slaughter Johne's infected animals can be 15% lighter and have 31% lower carcass value.
Direct costs of Johne's disease come from via loss of milk production, lower carcass value and animal mortality. However, the majority of costs are due to the secondary results of infection, which include reduced fertility, replacement animal costs and infection by secondary diseases.
How Biotangents are tackling Johne's disease
Prevention of disease outbreaks is the first step in combating Johne's disease. Biotangents' Moduleic Sensing™ VET system will provide diagnosis of Johne's disease on site, allowing high risk animals to be prevented from entering the herd. This will minimise quarantine time, cost and the risk of Johne's outbreaks in herds.
In suspected clinical Johne's disease cases, fast diagnostic decisions are essential to contain the disease. By using Moduleic Sensing™ VET, results will be rapidly obtained on site, allowing the removal of contagious animals from the herd and preventing further disease spread.
For laboratory sample testing, Moduleic Sensing™ LAB allows PCR-quality testing to be conducted without the cost of equipment or technical complexities. This offers a more cost-effective, high throughput diagnostic solution regardless of laboratory complexity.
Herd management and eradication schemes
1. Fecteau M (2018) Paratuberculosis in Cattle. Veterinary Clinics of North America: Food Animal Practice 34: 209-222.
2. Radia D, Bond K, Limon G, van Winden S, Guitian J. Relationship between periparturient management, prevalence of MAP and preventable economic losses in UK dairy herds. Veterinary Record. 2013;173(14):343-343.
3. Phil Scott (2017) Available at: https://www.nadis.org.uk/disease-a-z/cattle/johnes-disease-paratuberculosis/ National Animal Disease Information Service.
4. Garcia A, Shalloo L (2015) Invited review: The economic impact and control of paratuberculosis in cattle. Journal of Dairy Science 98: 5019-5039.
5. Judge J, Kyriazakis I, Greig A, Davidson R, Hutchings M. Routes of Intraspecies Transmission of Mycobacterium avium subsp. paratuberculosis in Rabbits (Oryctolagus cuniculus): a Field Study. Applied and Environmental Microbiology. 2006;72(1):398-403.
6. Kudahl A, Nielsen S. Effect of paratuberculosis on slaughter weight and slaughter value of dairy cows. Journal of Dairy Science. 2009;92(9):4340-4346.
Johne's disease or paratuberculosis is one of the most important and challenging cattle diseases globally. The disease is caused by the bacterium Mycobacterium avium subsp. paratuberculosis (MAP), a relative of Mycobacterium bovis which causes bovine tuberculosis, though the infections and their symptoms differ greatly.
Johne’s disease is a gastrointestinal disease with a range of symptoms including:
Emaciation, preceding death