Scottish scientists are behind a breakthrough which could allow farmers to breed cattle with increased resistance to a disease which in England and Wales now costs taxpayers nearly £160million a year to deal with.
Research led by Edinburgh University’s Roslin Institute has identified the genetic traits responsible for conferring resistance to bovine tuberculosis (bTB).
The disease, now endemic across parts of England and Wales, has significant economic con-sequences for farmers and the government. Infected cattle are compulsorily slaughtered and movement restrictions are imposed on herds until they test free from it.
Wild animals, such as badgers, are frequently blamed for spreading it. A recent pilot cull of badgers in Gloucestershire and Somerset provoked fury. Work remains ongoing on a vaccine which could be given to cattle to prevent them becoming infected.
The scientific study, led by the Roslin and also involving Northern Ireland’s Agri-Food and Biosciences Institute (AFBI) and Belfast’s Queen’s University, compared the genetic code of bTB-infected Holstein-Friesian cows with those of the same breed and which were disease-free. The work identified a number of genetic signatures associated with bTB resistance in the cows that remained unaffected.
The latest study builds on previous research by the Roslin, which showed that some cattle might be more resistant to bTB because of their genetic make-up.
The next phase of the research will be in refining genomic predictors of resistance and in finding out if these could then be used to selectively breed cattle resistant to bTB in the commercial herd.
BTB is caused by a bacterium called Mycobacterium bovis. It is a risk to humans.
Despite intensive efforts over many decades to tackle it, bTB continues to have a serious impact on livestock at home and abroad, affecting farm profitability and animal welfare.
The research, funded by the Biotechnology and Biological Sciences Research Council and the EU, is published in the journal Heredity.
Lead researcher Professor Liz Glass said: “If we can choose animals with better genotypes for TB resistance, then we can apply this information in new breeding programmes alongside other control strategies. It is hoped that can help us to more effectively control TB in cattle.”
NFU Scotland president Nigel Miller, a qualified vet, said the work did not provide an immediate solution to controlling bTB, but by pinpointing genetic signatures linked to higher levels of resistance, there was now an opportunity to identify sires which could increase resistance into the national herd.
He added: “If realised, that must be of real value. Resistance can limit the impacts of disease incursion and reduce losses in herds which come under the pressure of bTB infection.
“The bacterium responsible for bTB is closely related to the agent which causes Johne’s Disease and this genetic approach might be a route to solutions for other potentially devastating diseases. It is an exciting development, and good to see the work carried out in Scotland.”