Research is underway aimed at identifying the genes that make cattle more susceptible to a disease that costs farmers upwards of $80 million per year.
Johnes disease causes thickening of the intestinal wall, reducing the animal's ability to absorb nutrients and leading to wasting and ultimately death.
It is difficult to detect and also results in a loss of production in animals that appear to be healthy.
Similar gene-mapping work is already being carried out for the sheep and deer sectors and is part of a larger collaborative programme set up to tackle the disease.
The research into cattle is being carried out by the Livestock Improvement Company.
Project manager Dr Penny Back says although the research will initially focus on dairy cattle, the results could be used by beef farmers as well.