Infectious bovine rhinotracheitis (IBR) is present in just under half (48.8%) of suckler herds, results from testing show.

An animal-level prevalence of 11.4% was also evident from testing carried out as part of the Department of Agriculture's National Beef Welfare Scheme (NBWS) which was introduced in 2023.

Farmers in the scheme are required to engage a vet to blood sample and test up to 20 animals in the herd.

In total,10,650 suckler herds submitted one or more samples through the NBWS IBR testing programme and individual test results were available for 189,404 animals.

This constitutes approximately 20% of the entire Irish beef herd population.

To determine the herd-level IBR status, a ‘snapshot’ test was performed. The snapshot required the sampling of 20 randomly-selected animals over nine months old (to ensure there were no maternal antibodies remaining) and that were used, or intended, for breeding.

Animals of all ages and groups were tested to obtain a result that reflected the status of the herd.

Herds were classified as IBR-positive if at least one animal within the herd tested positive for IBR antibodies.

Age

For all positive herds (n = 3,150), the proportion of seropositive animals was higher in older animals.

IBR is a highly infectious respiratory disease caused by the bovine herpesvirus type 1 (BoHV-1) and while it remains endemic, it is at a lower prevalence than previously reported.