The best option for reducing its prevalence lay in changed and improved management of cattle, they were told.
While producers may have been disappointed that there did not seem to be a quick and easy solution to this bacterial disease, they were promised the suggested route towards tackling it would bring other benefits in animal welfare issues such as lameness and fertility.
Senior vet with the Scottish Agricultural College, George Caldow, thought that there was little prospect of any vaccination programme coming along that would solve their problems. "This is a disease that you will require to manage to reduce losses. You will not be able to vaccinate your way out."
Johne's affects both sheep and cattle but the problem is especially serious in the dairy sector, where it is estimated that 60 per cent of all herds in the UK have some degree of infection.
For producers with infected herds, the losses come from reduced yield, shorter lactations and general issues relating to animal welfare. Many of those cattle who carry the bug are also prone to other problems, such as lameness and poor fertility.
Caldow, who was speaking in Brechin at a meeting organised by the levy funded body DairyCo as part of the programme based on the dairy monitor farm at Carcary, Brechin, estimated that losses in severely affected herds could amount to an average of 94 per cow per year.
Even in moderately affected herds, the losses are calculated at more than 70 per cow.
The problem facing the vets and scientists in dealing with this disease, where the bug lies in the rumen, is that testing is far from 100 per cent accurate with most younger infected cattle not giving positive reactions.
Caldow advised that the best method of breaking the cycle of infection lay in changing management practices at both the dry cow stage and also at calving. At both points, infected cattle should be kept separate and calves should only be fed with their mother's milk.
But the most important point was they should also be kept in very clean surroundings as faecal contamination is reckoned to be by far the main method of transmission.
He said that the spreading of slurry on to grassland which would be subsequently grazed also provided a way of transmitting the disease.
But the biggest problem came not from within the herd but from importing heifers into the herds. Other aspects of the purchase such as potential milk yield are scrutinised but the testing of young animals for Johne's disease is remarkably unreliable.
"There was a big increase in recording the disease in the re-stocking period after the 2001 foot-and-mouth outbreak. Many of the heifers came across from Holland, where the disease is endemic."
Even in more normal times it is estimated that dairy herds require some 28 per cent of heifers to be brought into the milking herd every year as the normal lifespan of a milking cow is less than four lactations.
This makes the sourcing of new stock potentially dangerous from an importation of disease point of view, or as Caldow put it: "It is a real Achilles heel for the dairy sector."
While all the main dairying countries in Europe are badly affected, the disease is worst in the US, where four out of five herds are infected. For producers who have the disease within their milking herds, he said the decision on whether to cull had to be taken on pragmatic grounds. In heavily infected herds, it was often better to allow the cow to complete her lactation before disposing of her.
While some might want to see a complete elimination of the disease, Caldow said because it was found in other species, including sheep and rabbits, it would be very difficult to remove the disease altogether.