According to a statement from the BVD Technical Working Group of AHI, maintaining the current momentum and compliance levels of the programme will hasten successful eradication of BVD.
“The goal of the current programme is the eradication of BVD virus. The core element of the programme is testing to identify animals persistently infected with BVD virus and remove these from the cattle population. Associated with this, adequate bio-security measures to prevent the accidental introduction (bio-exclusion) and spread (bio-containment) of infection in herds is critical,” it said.
Maintaining the current momentum and compliance levels, and equally shorten the period when provision for vaccination is required is key, according to AHI.
“It is estimated that approximately 40 per cent of dairy herds and 10 per cent of beef herds currently vaccinate against BVD virus using one of the two vaccines (Bovidec and Bovilis BVD) currently licenced for use in Ireland. Once the national programme has been successfully completed and BVD eradicated there will no longer be a routine need for vaccination.”
In the meantime, AHI stressed the main purpose of BVD vaccination is to induce a protective immunity in breeding animals to avoid a range of negative outcomes of infection on reproduction, including failure to conceive, abortion, birth defects and most importantly the creation of calves that are persistently infected with BVD virus.
“As the programme progresses, the prevalence of PI animals will decrease, followed by a decrease in the prevalence of animals with natural immunity following exposure. On the one hand this means that the likelihood of pregnant cattle being exposed to virus will decrease but on the other hand the potential negative impact of such exposure would increase.”
However, it should be noted that the available BVD vaccines will not provide 100 per cent protection in all circumstances, even when stored and used correctly, particularly where pregnant cattle are exposed to high levels of BVD virus, cautioned AHI in its update.
Decisions on the use of BVD vaccine, including when to stop a vaccination programme, are herd-specific and should be taken by each farmer in discussion with their own veterinary practitioner, it added.
Further information on Animal Health Ierland BVD FAQ is available here. http://www.animalhealthireland.ie/page.php?id=115.