Over half of 25 herds test negative in IBR pilot programme
More than 50% of the tested herds in a pilot IBR Programme in suckler herds tested negative, indicating absence of, or a low number of Ibr-positive animals in the herd.
IBR is a highly infectious disease of cattle. Infected animals recover but become carriers and, despite appearing healthy, may start shedding virus when under stress.
About 75% of Irish herds contain animals that have been exposed to IBR, and are carriers, said Dr Maria Guelbenzu, Animal Health Ireland, at the recent Teagasc National Beef Conference. Cattle with IBR have a watery discharge from the nose and eyes.
They may present with red nose and eyes and lack of appetite.
Affected animals may be dull, off their feed and have a high temperature.
Bulls with antibodies to IBR (including those due to vaccination) are prohibited from entering semen collection centres. Although IBR is endemic in cattle populations across the world, seven European countries (Austria, Belgium, the Czech Republic, Denmark, Finland, Germany, Norway, Sweden and Switzerland) and regions in several other countries have control programmes, and are recognised by the EU as being ‘Ibr-free’. IBR status is important in the international trade of live animals and some animal products.
For example, the countries and regions mentioned above are granted additional guarantees by the EU when cattle are traded into these states or regions.
These include amongst other measures, that animals must come from holdings free from IBR for 12 months. The pilot IBR eradication programme was developed by Animal Health Ireland’s IBR Technical Working Group for herds participating in Phase Three of the Teagasc/irish Farmers Journal BETTER Farm Beef Programme. With 25 herds in 22 counties tested, and IBR on-farm veterinary risk assessment and management plans completed, results showed that 60% of the herds are likely to have a low prevalence of infection.
These herds would be the best positioned to progress towards an Ibr-free status, by testing the remainder of the herd, and either confirming freedom, or removing sero-positive animals.
In the 40% of herds with two or more sero-positive animals (which indicates herd prevalence greater than 15%), a large proportion of the seropositive results were from older animals, not homebred. These herds were generally bigger, and had more directly bought-in animals.
In an infected herd, complete and regular herd vaccination can be one of the measures to control IBR, as it makes it less likely that a latent carrier will reactivate and shed the virus, and less likely that a naïve animal will become infected and spread the virus after exposure. However, the whole breeding herd, and not just young stock, must be vaccinated. Information from the pilot IBR eradication programme will be used in development of options for an IBR eradication programme for Ireland.
It should be noted that the pilot programme results are not representative of the national herd.