The results of the fourth annual National BVD Survey are in and, once again, they reflect the different phases of the regional BVD programmes. “This is the
second year that questions have reflected the variations between the English, Scottish, Welsh and Northern Irish schemes,” says the brand manager for Boehringer Ingelheim’s BVD vaccine Bovela, Matt Yarnall.
“This ensures that the questions more relevant and that comparisons within the data are more meaningful.”
Improved health
He adds that one of the most encouraging trends picked up by the 2019 survey is an improvement in herd health, which is leading to a reduction in antibiotic use. “This is good news. Producers are moving towards a more preventative approach to herd health and this, in turn, is resulting in a decrease in antibiotic
use.”
This was most notable in Scotland, where the BVD eradication scheme has been running since 2011. “We know that BVD is one of the most complex diseases affecting cattle. The stage of pregnancy or age of livestock exposed to the virus has a huge effect on how the disease manifests in a herd,” he says.
“Improved calf health is one of the benefits highlighted by producers who are taking steps to control BVD. And this is one of the key target areas for reducing antibiotic use. Fewer cases of calf pneumonia means reduced antibiotic use. So there are positive improvements all round.”
Tagging calves
All eradication schemes – in Wales, Scotland, England and Northern Ireland – can make use of tag testing of all calves (born alive, dead or aborted) to identify BVD virus in herds. “The reason why a calf is born dead or is aborted could well be because it was exposed to the BVD virus in utero. Yet we know from
the survey that too many producers are failing to test all calves,” says Mr Yarnall.
“According to the Scottish results, almost half of producers do not tissue test calves born dead or stillborn, which is a huge concern. “The nature of the BVD virus, and the way that it is spread with an unborn calf being exposed during pregnancy, means it can easily go undetected in a herd,” he says.
“All too often we hear reports of herds with a devastating outbreak of calf pneumonia or an abortion storm, or even clinical BVD or mucosal disease signs, and it is only then that testing is carried out and active BVD infection is identified. Continuous and ongoing testing, coupled with vaccination and good biosecurity,
are at the heart of effective BVD control.”
BVD SURVEY information
A questionnaire was posted out, and also available on-line to complete. Using multiple- choice option, producers were able to give information about the BVD
situation in their herd, what experience, if any, they had of the disease, and how they work and plan to control it.
Throughout the UK, marginally more beef units than dairy units responded (58% compared to 42%), but this reflects the higher number of beef farms in the country.
BVD survey results show that schemes are tackling disease
Scotland
• Scheme started in 2011 – the first of the four regions to roll out such an eradication programme
• 65 dairy units responded with 290 beef units reflecting higher prevalence of beef farms
• 60% of producers stated they had never had a not-negative (positive or inconclusive) BVD test result
• 51% claimed herd health has improved since engaging in BVD eradication
• Ear tagging is popular – 44% do it, but 56% only tag and test calves that are born alive
• Majority of producers vaccinate against BVD, with 60% valuing it as an insurance policy
England
• 279 dairy units participated in the survey, and 199 beef units
• Despite BVDFree’s ‘Stamp it Out’ initiative, which offers free testing and vet support, 209 respondents were not aware of it
• Increasing numbers using Tag & Test – 33% up from 28% a year ago
• But only 42% are tagging all calves born, dead or alive, and this could lead to virus being undetected
• 62% of producers said that they run closed herds yet around a quarter of these buy in stock, or rear calves away from their main unit
• 10% of these ‘closed herds’ do not vaccinate, which leaves them vulnerable to BVD infection
Northern Ireland
• Compulsory phase of the eradication programme approaching end of its third year
• Roughly equal numbers of producers participated in the survey – 87 dairy and 95 beef – with above average herd size for the region
• 60% of herds described themselves as closed, yet 20% still brought bulls on to the farm
• 22% of respondents said that the incidence of calf disease has fallen and 12% claim a reduction in the use of antibiotics
• 26 producers have retained a PI
• Majority said they were happy with verbal assurance of BVD status
Wales
• 61 dairy producers responded with 102 beef units reflecting farm numbers in Wales
• Above average herd size at 171 cows for dairy and 53 for beef
• Gwaredu BVD rolled out in summer 2017 and more than 50% of Welsh herds have been tested, but 26% of respondents said they were unaware of the scheme
• 56% of herds described themselves as closed herds, yet 12% brought bulls on to the farm
• 44% of producers say they have identified a PI, yet almost half do not cull immediately
• Main impact of BVD was poor fertility (45 respondents), high levels of disease in calves (31) and poor weight gain (28)