Genetic profiling could breed cattle resistant to tuberculosis

Scientists are undertaking genetic profiling of thousands of cows as part of efforts to breed cattle herds which are more resistant to tuberculosis.

Hairy coos in Pollok Park in Glasgow
Hairy coos in Pollok Park in Glasgow

The disease is a major problem for dairy and beef farmers in some parts of the country, and efforts to curb TB in cattle include the controversial badger cull, as the wild animals can spread infection to livestock on farms.

Experts say that improving predictions for which cattle are more naturally resistant to TB will help farmers breed animals which are less likely to catch and pass on the disease.

The mass-profiling project by the Agriculture and Horticulture Development Board (AHDB), partnering with Scotland’s Rural College (SRUC), is one of two schemes by the organisations on genetic resistance to TB in cattle.

It builds on recent AHDB research which identified significant genetic variations between resistant and non-resistant individual animals.

Employing the same techniques used to establish if people have an inherited risk of cancer or certain diseases, the researchers will look for “genetic signatures” for TB resistance in 12,000 cows in affected herds.

Testing large numbers of animals will improve the accuracy of “genomic prediction” measures being developed to help farmers choose which cattle to breed and keep on the basis of TB resistance.

Although no cattle have complete resistance to TB, and a large proportion of the problem will remain from infection through the environment, breeding better inherited resistance into herds could make a “significant contribution”, Marco Winters, head of animal genetics for AHDB Dairy, said.

“If you think about humans, some people regularly get the flu and others go through the winter and never get problems. You see the same thing with cattle.

“There’s a genetic element, and we know from other traits with a similar level of heritability, it can make an improvement. We are breeding a better inherited resistance into the national dairy herd.”

He added: “It’s part of the solution, it certainly isn’t the only solution, because it’s not a complete resistance we can breed in.”

But as TB is such a “devastating disease”, anything that farmers can do to improve the situation would have an impact, he said.