What assessment has the Cabinet Secretary made of the effectiveness of the badger culling method used in England as a means of controlling bovine TB?
The published analysis using the first two years of available data on the industry-led badger control in areas of Somerset and Gloucestershire, Brunton el al. (2017), showed that reductions in TB incidence were associated with culling in the first 2 years in both the Somerset and Gloucestershire intervention areas when compared to areas with no culling. An increase in incidence was associated with culling in the 2-km buffer surrounding the Somerset intervention area but not in Gloucestershire.
Defra’s latest report analysed the incidence of bovine tuberculosis in cattle in 2013 – 2016 for the three years follow-up in areas of Somerset and Gloucestershire and one year of follow-up in Dorset of industry-led badger control. This analysis revealed no statistically significant differences between the combined central areas of the intervention areas compared to comparison areas, or combined buffers of intervention areas compared to comparison areas buffers for years in isolation.
My assessment, in line with the author’s, is to urge caution in developing general inferences about the effectiveness of the policy at this stage. It should be noted a time lag of around 4 years was observed between culling in the Randomised Badger Culling Trial and a measurable significant effect on cattle TB incidence (Donnelly et al., 2007).