Stakeholders gather to share BVD eradication knowledge

More than 100 representatives from the farming industry, many of the European eradication programmes, tagging companies, testing laboratories, milk processors, retailers, veterinary organisations and farming unions attended the inaugural bovine viral diarrhoea (BVD) congress for the UK and Ireland, organised by Boehringer Ingelheim.

The BVDzero Congress marked the first anniversary of the launch of BVDFree in England, and aimed to allow policy makers and stakeholders to learn from each other, and share information on critically important aspects of their programmes. A follow-up meeting of all the BVD eradication schemes in the British Isles (England, Ireland, Northern Island, Isle of Man, Scotland and Wales), “Cattle Health and Welfare Group Aligning BVD Initiatives”, was held last month in Dublin.

Matt Yarnall presented the results of a BVD national survey. It revealed 97% of responders were keen to be involved in a national BVD scheme and that the importance of the whole industry being part of this was recognised. About half of the responders acknowledged current or past BVD and most farmers agreed a positive economic impact from being free of BVD.

Potential problems were noted in the definition of a closed herd being woolly: biosecurity was not properly understood; for example, closed herds do not graze elsewhere or buy in bulls. Vet recommendation on BVD control and vaccination were critical influencers of behaviour.

The opportunities and challenges in achieving BVD eradication in England were discussed in the context of what had been achieved elsewhere. The first herds that were part of BVDFree were achieving status by two years testing and progress was being made on the searchable national database at bvdfree.org.uk

The rules for BVDFree were similar to Scotland and compatible with Cattle Health Certification Standards (CHeCS)-accredited status; however, challenges compared to Scotland were the lack of Government commitment to legislation, the large area, no link to the Cattle Tracing System, lack of trust between different practice groups and the database provider, and confusion over local and regional schemes. Some practices had been very successful in getting nearly all their breeding herds to be part of BVDFree. Others were known to be doing regular BVD surveillance testing with their herds, but not yet registering herds to BVDFree.

In other parts of the British Isles progress was being made. As of 2018 the Isle of Man appeared to be free of active BVD, with the possible exception of one holding. Scotland had an industry-led, but Government-backed, scheme that was making steady progress, with herd prevalence falling.

Every breeding herd must declare status annually based on antibody check testing or testing every calf born for virus. BVD-positive status, where BVD persistently infected (PI) cattle existed live on farm, was introduced in May 2017 in addition to the previous negative and not-negative statuses. Phase five consultation had been completed, with measures to increase the pressure substantially on those herds not controlling BVD expected in 2019.

In Northern Ireland (NI) and the Republic of Ireland (ROI) a different strategy had been used, with the requirement to tag and test every calf born within 20 days of birth. Any animal born after 1 January 2013 must have a negative BVD virus result to move. Numbers of PIs have steadily fallen, from 11.3% in 2013 to 1.7% in 2017 in Ireland. It was noted PI retention has been a challenge, although this is reducing. Rural Development Programme-funded veterinary investigations of all herds with PIs had been available since 2017, plus restrictions on herds retaining PIs and notification of neighbours. Some financial support was available for PI removal, but reduced if this was delayed.

Finally, although Wales had been the last devolved nation to establish a BVD programme, an outline plan was presented and BVD was a priority of the Welsh Government’s Animal Health and Welfare board. Funded youngstock bleeds (antibody check test) were being performed at bTB tests. Results have been supported by local BVD advice, whether negative or not, and further support to eradicate BVD, if positive, was available.

Other European schemes were also considered. They all followed similar processes to one or more UK and Ireland schemes. It was agreed that, as well as testing, advice on BVD control in herds where initial testing indicated a problem – additional to biosecurity in all herds – was essential to prevent BVD maintaining or re-establishing itself in breeding herds.

Workshop tasks

The conference then moved on to a series of workshops where the issues of BVD control were reviewed. One of the breakout groups focused on the theme of PIs in a lively and animated discussion, with many ideas suggested by various representatives.

How can we stamp out persistent infectors?:

• Peer pressure – let neighbours know someone is keeping PIs.
• Name and shame.
• Bring in movement restrictions both to and from the unit.
• Continue to educate producers as to what can happen when a PI is kept.
• Strain test the PI to see if that strain of the BVD virus has been seen elsewhere.
• Helpdesk to telephone farmers.
• Restrict the time during which compensation is offered – reducing sliding scale the longer the PI is kept.

Another breakout session set out to consider the different approaches of youngstock antibody testing versus tag and testing of newborn calves. Again, this group had wide-ranging views and opinions.

Antibody testing (with relevance for England, Wales and Scotland):

• Youngstock antibody testing is a sensitive method to evaluate herd exposure to BVD. Meaningful interpretation can be challenging and appropriate sample selection from different management groups is critical.
• Antibody testing can be cost-effective – it may be cheaper than virus testing an entire herd.
• That said, it provides only a snapshot disease status for that moment and may be complicated for farmers to understand.

Ear notch testing newborn calves for BVD virus (relevant to NI and ROI):

• Straightforward to understand and explain.
• Gives a lifetime animal disease status.
• Can confer dam status from a calf result.
• Tagging is an essential management practice already carried out by every farmer.
• All calves may not be being tested currently, such as aborted or born dead, despite the legislation in place.
• More expensive for those herds already free of BVD; money could be spent on vaccination to reduce the risks of a BVD breakdown.

The group concluded both testing strategies have a role to play in BVD eradication and the decision should be taken in light of the regional programme and supporting legislation, if present, or, alternatively in conjunction with the herd’s vet.

Progress is being made throughout the UK and Ireland in BVD control, but continued effort is needed to achieve complete BVD freedom. The most chance of success would be if we could achieve absolute commitment from vets, farmers and the wider industry; an established national database of BVD-free herds and tested individual animals was likely to be a critical resource.

The Government has an essential role to play in the promise and delivery of legislation to ensure those who refused to engage in BVD control were not permitted to carry on harming neighbouring farms.