AFBI chief ‘cautious’ on new bovine TB test

The chief executive of the Agri-Food and Biosciences Institute (AFBI), Dr Stanley McDowell, has said he remains “cautious” on whether scientists in England will be able to come up with a new test for bovine TB.

Over the last 15 years, scientists at the Animal and Plant Health Agency (APHA) have been working on a test that can differentiate between TB infected cattle and those that have been vaccinated against the disease.

Field trials of a test capable of Detecting Infected among Vaccinated Animals (DIVA) began in 2021 and have now run for two phases. Earlier this year, the APHA announced that a third phase of on-farm trials will be completed in 2026-2027.

Hosting a meeting of the Stormont Agriculture committee at AFBI Hillsborough last Thursday, Dr McDowell said his concern relates to whether a TB vaccine would actually interfere with the results of a TB skin test in on-farm conditions.

“I hope that will get resolved, but I must remain in the cautious camp because of the interference with the skin test and the need to move to a differential skin test,” he said.

During his evidence session, the AFBI chief, who has a background in veterinary research, was also asked about the quality of current tests for TB in cattle.

He said the current skin test has good specificity (a reactor is highly likely to be infected), but moderate sensitivity, meaning it misses some TB infected cattle.

The gamma interferon (blood test) is more sensitive, but less specific, so there are a lot more false positives.

“There’s a need to constantly look at alternative testing techniques in terms of TB. And there’s been many things proposed.

“But many tests have been proposed that have not stood up to the test of time in terms of alternative. It’s not an easy space to be in,” the AFBI chief told committee members.

Unintended consequences from single focus on carbon

A continual focus on simply driving down carbon emissions from agriculture, can lead to some “unintended consequences”, AFBI director, Professor Elizabeth Magowan told the Stormont Agriculture committee last Thursday.

During the meeting, Professor Magowan was asked by committee chair, Robbie Butler MLA whether improved animal welfare results in lower carbon emissions on farms.

She pointed out that if the sole focus is on a lower carbon intensity per litre of milk or kg of liveweight gain, then year-round housed systems are potentially the best option – in these systems it is possible to maximise output from each animal.

“But that could have an unintended consequence on animal welfare, and certainly perception from the consumer. That’s stuff we have to bottom out,” said the AFBI Professor.

Legislation

While there are many different ways to assess performance on farms, there is NI climate change legislation in place since 2022, with DAERA planning to roll out carbon benchmarking of all farms.

That benchmarking project has been delayed by a legal challenge relating to the appointment by DAERA of a company to supply a farm carbon calculator.

“That is going through, hopefully, its final processes of award. I don’t think we’re privileged to say much more than that,” said Magowan.

She said DAERA hope to be in a position to roll out the carbon calculator on farms “towards the summer, into the autumn”.

“My colleagues across the UK – they’re very envious with regards to NI PLC and all farmers being on the one carbon calculator. I think it has huge benefits for us to all speak with one voice and have a common language and a common drive towards that goal of reducing our carbon footprint,” added Magowan.

MSS research

She also confirmed that AFBI will soon be starting a DAERA-funded project looking at multi-species swards and their ability to mitigate against droughts and perform without nitrogen fertiliser, thereby reducing carbon emissions on farms.