Genetic find might lead to cattle that are more resistant to TB

The study, which compared the genetic code of TB-infected animals with that of disease-free cattle, could help to impact on a disease that leads to major economic losses worldwide.

The research, led by the University of Edinburgh's Roslin Institute, has identified a number of genetic signatures associated with TB resistance in the cows that remained unaffected.

The study builds on previous research by The Roslin Institute, which showed that some cattle might be more resistant to bovine TB as a result of their genetic make-up.

Researchers at The Roslin Institute say the latest finding is significant as it sheds further light on whether it might be possible to improve TB control through selective breeding.

The team used the latest gene identification techniques to compare the genes of healthy and infected female Holstein-Friesians.

Bovine TB, caused by a bacterium called Mycobacterium bovis, not only infects cattle, but other livestock and wildlife. It also remains a risk to humans.

Despite intensive efforts over many decades, bovine TB continues to have a serious impact on livestock at home and abroad, affecting farm profitability and animal welfare. In 2010/2011, its effects cost the UK government £152 million.

This latest research, funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the EU, is published in the journal Heredity.

Researchers at The Roslin Institute worked on the study with colleagues from the Agri-Food and Biosciences Institute (AFBI) and Queen's University Belfast.

Refining genomic predictors of resistance will be the focus of a new BBSRC-funded study to be carried out by researchers at Roslin, the AFBI and Scotland's Rural College, the SRUC.

Lead researcher Professor Liz Glass said of the results: "Differences between cattle in their genes is not the only factor in determining whether the animal will get bovine TB or not; various environmental factors as well as differences in the TB bacteria may also affect susceptibility.

"If we can choose animals with better genotypes for TB resistance, then we can apply this information in new breeding programs alongside other control strategies. It is hoped that can help us to more effectively control TB in cattle."