Mandatory blood tests to target severe bovine TB outbreaks in NI

Northern Ireland cattle herds facing serious bovine TB outbreaks will be forced to undergo additional blood testing from next week, under new rules aimed at speeding up disease detection.

Agriculture, Environment and Rural Affairs Minister Andrew Muir has published the criteria for the mandatory use of interferon-gamma blood tests, known as IFN-g, for bovine Tuberculosis in Northern Ireland.

The changes, which come into effect from 29 June 2026, will initially apply to herds with 10 or more skin test reactors at a disclosure TB test, or those with more than 40 reactors within a rolling 12-month period.

Beef fattening herds will not be included in the mandatory testing requirements.

Compulsory IFN-g testing is also being introduced for animals that have given an inconclusive reaction to a skin test in non-breakdown herds, or in singleton reactor herds where bovine TB has not been confirmed.

The test is used alongside the standard tuberculin skin test and can help identify infected animals at an earlier stage.

For affected farms, the move could mean additional testing, earlier detection of infected cattle and faster action to reduce the spread of disease within badly hit herds.

Mr Muir said he was pleased to confirm the criteria for using the supplementary blood test on a mandatory basis.

He said: “The IFN-g test is an important diagnostic tool which assists the bovine TB skin test in the early detection and removal of positive bovine TB reactor animals.”

He added that placing the test on a compulsory footing, where the criteria are met, had been a “long-standing policy objective”.

Northern Ireland's Department of Agriculture (DAERA) said the test has so far been used on a voluntary basis in Northern Ireland, with the department offering it to some herd owners affected by bovine TB outbreaks.

The department will now work directly with farmers whose herds are experiencing severe TB breakdowns to make best use of the test.

Mr Muir said: “Its use can reduce the further spread of this awful disease within a herd and to neighbouring herds and can also help shorten the length of time a herd is broken down.”

The interferon-gamma test is approved by the World Organisation for Animal Health and is recognised in European legislation as an official test for bovine TB.

The measure follows a 2021 consultation and forms part of Northern Ireland’s wider TB Eradication Strategy, published in 2022. It was also included in the 2025 Bovine TB in Northern Ireland: Blueprint for Eradication.

DAERA said the introduction of mandatory IFN-g testing does not require a legislative change.

The department said the policy will bring Northern Ireland into line with arrangements elsewhere in the UK and Ireland.