Control of infectious bovine rhinotracheitis

Infectious bovine rhinotracheitis (IBR) is a highly infectious disease of domestic and wild ruminants caused by bovine alphaherpesvirus 1 (BoHV-1). IBR has worldwide distribution with the exception of a limited number of countries which have successfully eradicated it (Ackermann and Engels, 2006).

In the UK, IBR is thought to be endemic, with studies published in 1998 and 2017 finding the proportion of herds with positive bulk tank milk to be 69% and 62%, respectively (Paton et al, 1998; Velasova et al, 2017). Another survey of suckler herds found 83% of 107 unvaccinated herds with one or more seropositive animals (Woodbine et al, 2009).

There are multiple drivers for the control and eradication of IBR, highlighting its contribution to economic, environmental and social sustainability, as well as trade implications. IBR is known to be harmful to bovine health and productivity and this is reflected in a negative impact on the farm-level profitability of dairy and beef production. This effect has been better studied in dairy farms. In Ireland, the IBR status of a dairy herd was found to have a significant effect on the performance and profitability characteristics of dairy farms (Sayers, 2017). The study showed that multiparous cows in bulk tank IBR-positive herds produced an average of 250 kg/year less milk than cows from negative herds. Other studies have linked prolonged reduction in milk production with sub-clinical IBR (Statham et al, 2015) as well as increased youngstock and cow culling rates and longer calving intervals (Raaperi et al, 2015).