Mandatory interferon-gamma blood testing for bovine tuberculosis in Northern Ireland will begin on 29 June 2026, Agriculture Minister Andrew Muir has announced.

Initially, the requirement will apply to herds with 10 or more skin test reactor animals at a disclosure test, or to herds that have recorded more than 40 reactors within a 12-month rolling period. Beef fattening herds are excluded from the order.

A separate mandatory testing provision is being introduced for animals that have produced an inconclusive reaction to a skin test in non-breakdown or singleton reactor herds where bovine TB has not been confirmed.

The minister described the interferon-gamma test as an important diagnostic tool that aids early detection and removal of infected animals and said placing its use on a compulsory footing had been a long-standing policy goal.

The department intends to work closely with affected herd keepers to maximise the test’s effectiveness. Officials expect the measure to help curb disease spread within and between herds and to shorten the duration of herd breakdowns.