Paratuberculosis affects cattle with long-term symptoms

Paratuberculosis is a chronic digestive disease in ruminants, such as cows and sheep, that causes long-term diarrhea, weight loss, and eventually death. The disease typically shows symptoms in animals over two years old, after a long period of infection without visible signs.

Early infection and difficulty in control

Calves are most vulnerable to infection in their first 30 days of life, though they can be exposed earlier. This long incubation period and the subtle nature of the disease make it challenging to detect and manage effectively. Researchers have long suspected that genetics may play a role in how animals respond to the disease.

Genetic research reveals resistance markers

In 2013, a study named Paradigm was launched by several research institutions to investigate whether a cow's genetic makeup influences its susceptibility to paratuberculosis. The study involved thousands of dairy cattle from two breeds, Prim'Holstein and Normande. Genetic analysis found significant differences between infected and uninfected animals, suggesting the presence of genetic markers that could indicate resistance.

Genetic tools offer new disease management strategies

The discovery of these genetic markers opens new possibilities for managing the disease. Farmers can now use genomic data to identify calves more resistant to paratuberculosis and adjust their health monitoring strategies accordingly. This approach could improve the overall health of dairy herds and reduce the spread of the disease.

Complementary strategies for disease control

Efforts to combat paratuberculosis include not only genetic tools but also biosecurity measures and management practices. These include maintaining clean housing, proper feeding to support rumen health, and careful selection of animals to prevent the spread of infection.

New national study expands research efforts

A new national research project, PRISSME, is currently underway. The study, which runs from 2025 to 2029, aims to explore genetic resistance to the disease, analyze the bacteria responsible, and study the microbiota of cattle. It involves several cattle breeds and includes collaboration with farmers to collect genetic and biological samples from their herds.