A report summarising the findings of a pilot study modelling "Cost Benefit
Analysis of Badger Control" has been published by Defra today. The Central
Science Laboratory and Reading University carried out the work for Defra.
The model used in the project aimed to estimate the overall effect on bovine TB in cattle of two different badger control strategies - trapping followed by shooting, and gassing.
The study found that:
- increasing the badger cull rate above 80% had little effect on the reduction of cattle herd breakdowns (CHBs) with only a small benefit observed if the cull rate was increased from 60% to 80%.
- culling badgers over a large area with one campaign might be more effective than culling small areas with repeated campaigns in terms of reducing CHBs, but not more cost-effective.
- culling badgers by trapping and shooting was more expensive than gassing, nevertheless, the overall economic benefit of this gassing would not be realised for more than 10 years.
- the time constraints of the project meant that the data used to assess the effects of cattle movement were least reliable. An early assessment suggested that between 26% and 85% of CHBs were not linked with new cattle being moved on to farms and thus might be associated with other reasons, e.g. badgers.
The pilot was a short preliminary study involving significant levels of uncertainty. The results of the study are not robust enough to provide evidence to support or reject methods of culling badgers. Defra has funded an additional 2 year project which will seek to build on the findings of the preliminary study, to refine the assumptions used and to validate the findings with independent models and existing data.