What proportion of herds in Ireland are positive for IBR?

Infectious Bovine Rhinotracheitis (IBR) is a virus that spreads between cattle and can cause a number of problems, including: coughing; loss of appetite; nasal discharge; weight loss; abortion; and reduced milk production.

The virus is spread mainly through direct contact with infected animals and can also be spread through the semen of infected bulls.

Speaking at the recent Irish Grassland Association (IGA) beef event in Co. Kildare, MSD Animal Health’s Bosco Cowley outlined that 75% of Irish herds are positive for IBR.

He said: “The first step with IBR is finding out where the farmer stands – finding out what the prevalence is like within the herd and the vet can help with this.

“There are some changes now whereby – after a time of primary course and six months vaccinations – farmers can go to annual vaccination. However, we would only advocate that in herds with low prevalence.”

Bosco also highlighted that an irradiation scheme will be implemented towards the end of next year. However, this will not be a complete eradication programme.

“We can’t actually go with a straight-forward test and eradication system because it would be too expensive and we would lose 75% of the herds in the country.

“We have to go to a middle ground which is classifying herds, vaccinating and – therefore – reducing the disease down to a point where we can kick the disease out of the country.

Continuing, he said: “This is a significant disease. This is one that hits production, but it also effects green house gas emissions; it is a significant contributor to green house gases.”

Bought-in animals and biosecurity

Animals that are bought off-farm – where the disease status is unknown – cause a major risk to production systems.

Touching on biosecurity, he said: “When farmers are buying in animals – be that breeding animals or growers – they increase the disease risk on the farm. In terms of management, it is very important that biosecurity comes front of mind.

“There are very few farms in Ireland that have quarantines to isolate animals when they arrive on the farm.

“We can implement disease programmes on our own farms; however, bought-in animals are by far the biggest risk to changing the disease profile on-farm.

“Farmers could have a clean or middle-prevalence herd with good vaccination programmes. Then, a bought-in prevalence jumps the disease up into a clinical entity, which can turn beefy animals into skeletons in the space of a few weeks.”

To minimise the risk, farmers – where possible – should purchase animals from one source where the disease status is good. This will not eliminate the risk, but it will lower the chances of an outbreak.

Bosco also highlighted that a very high proportion of herds in Ireland are positive for Leptospirosis (Lepto).