Northern Ireland steps up TB blood testing regime in cattle

Mandatory interferon-gamma blood testing will be introduced for some Northern Ireland cattle herds from 29 June as part of Daera’s efforts to improve bovine TB control.

NI agriculture minister Andrew Muir has confirmed the test will become compulsory for herds with 10 or more skin test reactors at a TB disclosure test, or those recording more than 40 reactors over a rolling 12-month period.

Mandatory gamma testing will also be introduced for cattle returning an inconclusive skin test result in non-breakdown or singleton reactor herds where bovine TB has not been confirmed.

See also: Joint Ireland-NI bovine TB project secures £9.6m

However, the measure will not apply to beef finishing herds.

The interferon-gamma blood test is used alongside the traditional bovine TB tuberculin skin test to identify infected animals at an earlier stage of disease.

Animals that test positive under gamma testing must be compulsorily slaughtered and are eligible for compensation, even if they have tested negative to the skin test.

However, while the blood test is more sensitive than the skin test and is less likely to miss infected cattle, it is also less specific. Daera estimates that about 3-4% of uninfected animals tested could return a false positive result.

Earlier disease detection

Mr Muir described mandatory gamma blood testing as a “long-standing policy objective” and said it would help identify infected animals earlier, reduce disease spread within and between herds, and shorten the duration of severe TB breakdowns.

The NI Department of Agriculture, Environment and Rural Affairs (Daera) said officials will work closely with farmers whose herds meet the new criteria to maximise the effectiveness of the testing programme.

The Ulster Farmers’ Union has been approached for comment.