A study published in the journal Scientific Reports has confirmed statistically significant reductions in the incidence of bovine TB in two badger cull areas in England.
Co-authored by scientists from a number of universities alongside the Animal and Plant Health Agency (an agency of Defra), the study compared TB incidence rates in cull areas within Gloucestershire, Somerset and Dorset, with similar areas outside a cull zone.
Gloucestershire and Somerset were among the first to introduce a badger cull in 2013, while the area in Dorset started culling badgers in 2015.
Analysis of data by the group of scientists pointed to a 66% and 37% reduction in TB incidence after four years of culling in Gloucestershire and Somerset respectively, when compared to areas outside the cull zone.
No change in Dorset
However, there was no change in incidence rates after two years of culling in the area within Dorset.
The report authors note that Dorset has larger dairy herds than the other two counties, and possibly also a higher density of badgers, so the proportion removed in the first year of culling is lower than elsewhere. “A reduction in the incidence of TB in cattle may take longer to emerge in Dorset,” states the report.
Implementing culling may lead to greater focus on cattle controls, TB testing quality and implementation of biosecurity
One result that was unexpected is the reduction in TB incidence rates found in the 2km wide buffer zones around the Gloucestershire and Dorset cull areas. The theory (established in a UK Randomised Badger Culling Trial (RBCT) in 2003) is that culling causes remaining badgers to roam, leading to different groups of badgers mixing, resulting in an increased spread of the disease. It was one of the main reasons why a previous Labour government decided not to proceed with badger culling in 2008.
The latest study is at odds with that conclusion, leading the authors to acknowledge that there might be compounding issues not yet fully understood.
“The current analysis suggests that there are other mechanisms at play that amplify effects associated with badger controls. Implementing culling may lead to greater focus on cattle controls, TB testing quality and implementation of biosecurity,” reads the report.
Despite that, they are clear that culling can bring “statistically significant reductions” in bovine TB, but also clear that it is not the “entire solution” to the cattle TB problem in Britain.
Reaction
Commenting on the results of the study, National Farmers Union (NFU) vice president Stuart Roberts said it is clear that culling badgers is a crucial element in tackling the disease.
“There should now be no doubt in anyone’s mind that this policy works,” said Roberts.
Over 67,000 badgers culled
Licences to shoot badgers are issued by Natural England in TB hotspot zones, with the cost of control mostly borne by farmers. Since badger control began in 2013, over 67,000 badgers have been killed across 32 areas. Culling has begun in a further 11 areas this year.
Scotland still TB free
Since 2009 Scotland has been the only part of the UK to achieve official TB-free status.
To maintain that status no more than 0.1% of herds must be infected with TB over the last six years.
A Scottish Government spokesperson said: “The incidence of bovine TB in Scotland remains stable and within the threshold for retaining Officially TB Free (OTF) status, with only a small number of cases each year.
Confirmed breakdowns
“Last year, there were 12 new confirmed breakdowns in Scotland.
“There is no evidence in Scotland that badgers or other wildlife play a significant role in the spread of bovine tuberculosis for cattle.”
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