TB reactor numbers finished last year at their highest level recorded since 1999, an Irish Farmers Journal analysis of Department of Agriculture bovine TB statistics has found.

Some 41,630 reactors were identified during TB tests in 2024, less than a decade after the number of cattle removed for TB hit an all-time low of 15,317 head in 2015.

The number of TB reactors recorded year-on-year fell in just three out of the last 10 years, with the approximately 12,000-head rise between 2023 and last year marking the single biggest annual jump in reactors since 1998.

Just shy of 600,000 cattle have been slaughtered for TB since 2000.

Reactor numbers are just one of three key TB metrics which have surged in recent years, less than a decade after disease trends had been pushed to historic lows.

TB’s 12-month herd incidence rate ended the year exactly 6%, meaning that around one in every 16 cattle herds nationwide deemed to have been free from the disease in the previous year experienced a breakdown.

This metric had been below 4% for the seven years after 2013, and had reached a historic low of 3.27% in 2016.

The jump between the herd incidence rates recorded between 2023 and 2024 was the highest witnessed since the increase between 1997 and 1998.

The number of new herds hit with a new restriction over the given calendar year also reached an all-time low point in the mid-2010s, as just 3,682 new herds were locked up in 2016.

A total of 6,142 herds had a new restriction imposed last year as this metric hit its highest level since 6,837 herds went down in 2008.