As farms struggle with virus, bovine TB has not gone away
ANDREW CRITCHLOW, Derbyshire NFU county advisor on a farming blight that has been around for too long
CORONAVIRUS is dominating the farming sector, as it is for everyone else. However, many other everyday concerns and issues are still there.
I make no apology of returning to one that has been around for a long time – bovine Tuberculosis (TB)
Bovine TB is predominantly found in the South West and Midlands, with Derbyshire sitting at the north-east corner of the region which is known as the High-risk Area.
That means there is a much higher prevalence than in counties to the north and east of the country.
Derbyshire is known as an ‘Edge’ county; we are very much at the frontline of the fight against TB.
Any mammal can be affected by Bovine TB but, in the UK, it is cattle and badgers that excrete the TB bacteria at sufficient levels to cause disease.
A recently-published study showed that TB spreads not only from cattle to cattle, but that badgers are an important source of infection to cattle and other badgers.
Badgers and cattle like the same environments and much of the same food, giving plenty of opportunity for infection to spread.
There are very strict legal controls on the movement of cattle, testing for TB before and after they are moved. Herds that test positive to TB are not allowed to trade so cattle cannot move off the farm unless for slaughter.
Unfortunately, scientific tests are not perfect – as we are learning in the coronavirus pandemic, so cattle can move that are healthy and test negative, but are actually carriers of TB.
In 2014 Defra produced a 25year strategy to eradicate TB which contained many measures to reduce TB in cattle and badgers. These included keeping farms under movement restrictions for longer, increasing frequency of testing
of cattle, and improving cattle and badger biosecurity on farms.
The government policy also includes badger culling in High Risk and Edge Areas and the use of badger vaccination where it is believed TB is not already endemic in badgers.
Defra confirmed a few months ago that culling would have to continue for the foreseeable future where it is necessary. Last year there were 43 cull areas in England. A recent document produced by Derbyshire Wildlife Trust questioned the accuracy of the Government’s Animal and Plant Health Agency epidemiological reports, which calculate 77% of TB in incidence in Derbyshire are attributable to badgers, by vets carrying out on farm visits.
Even if the true rate was half of that, TB could not be eradicated without tackling the badger source.
Culling is designed to reduce badger density to allow a healthier population to thrive, getting back a more natural balance to nature, which is not otherwise achieved as they have no predators.
A lower badger density will reduce the chance of spreading TB to other badgers and to cattle. It will also allow numbers of hedgehogs, ground nesting birds and bees among others to recover, as these are all predated by badgers.
Badger vaccination and culling follow very similar processes, if culling was allowed to happen without illegal disruption there would be no police costs, making them an equivalent cost per badger.
Culling costs reduce over the four years, vaccination costs do not.
We also have clear evidence that culling also reduces the cost for government (taxpayers) and farmers as we have peer-reviewed science that culling badgers reduces TB in CATTLE, unfortunately we do not have that evidence for vaccination.
The peer-reviewed Downs report published in scientific journal Nature in 2019, showed that after four years of culling there were reductions in TB incidence rates of 66% in Gloucestershire and 37% in Somerset relative to comparison areas.
Currently DEFRA pays for 50% of vaccination costs, it pays for culling and vaccination both to be licensed by Natural England but does not contribute to any other culling costs.
A vaccine for cattle is seen as the holy grail, this is dependent on trials for a test to differentiate between TB infected cattle and those vaccinated.
Vaccination also has to be accepted by other countries if we are to trade with them. A cattle vaccine has always been 10 years away as long as I have been farming and one that can be deployed on a wide scale will take time to become available.
The overall aim is to have healthy cattle and healthy badgers.
Vaccination has its place but we believe on the edge of the High-risk Area where TB is not yet endemic in badgers, which is probably in the north and east of Derbyshire, but unless we get on top of the disease NOW this area will get smaller and smaller.