What is bovine TB?
Bovine Tuberculosis (bTB) is caused by the bacterium Mycobacterium bovis, which affects a range of mammal species. Over the last 20 years the incidence of bTB in cattle has increased substantially; not just in the south-west of England but also in Wales and the Midlands. This represents an economic burden on the taxpayer and the farming industry as infected cattle are culled.
Do badgers infect cattle with bTB?
The first badger to be found infected with bTB was a road casualty animal in Gloucestershire in 1971. The scientific evidence suggests that cattle can get bTB from direct or indirect contact with badgers, or other wild animals. It is not known what proportion of bTB in cattle arises from badgers, but estimates range from 20% to 50%.
There is evidence of cattle to badger transmission in parts of England to which cattle were moved from bTB infected areas during re-stocking following foot and mouth disease.
Where can I find links to the key scientific research?
Go to this page on our website which contains links to several of the key scientific papers on bovine TB and badgers.
What is the current conservation status of the badger in the UK?
Badgers are one of only a handful of large native mammals left in the UK. They are protected by national and international law and are an important part of the nation’s biodiversity.
The badger population had increased in the 1980s and 1990s following legislation to protect the species from persecution. The population is now thought to be stable at around 300,000 in the UK, although there are no up to date figures. One of the strongholds for the species is the south west of England. Here badgers may have reached carrying capacity, but in other areas, populations are at much lower densities.
Importantly, the UK has 25% of the global population of the Eurasian badger Meles meles. We therefore have an international responsibility to conserve the species, and that includes protecting the range of genetic variation within the UK population.
Isn’t the badger population out of control because there are no natural predators for badgers?
The UK badger population is thought to be around 300,000 although there are no up to date figures as the last national survey was undertaken in 1997. A new national badger population study commissioned by Defra is due to be published in the near future.
The population density of badgers is limited by the environment in which they live. The pastures, meadows, hedgerows and woodlands of England and Wales create rich habitat with abundant food and shelter. Badgers in the UK do not have any natural predators, though elsewhere in Europe cubs may be taken by mammals such as bears and wolves. The main ‘predator’ for the badger in the UK is currently the car. In 2006, 50,000 badgers were killed on our roads.
What is the impact of a badger cull on other wildlife species?
The final report of the Independent Scientific Group on Cattle TB (2007) states that:
‘In addition to its effects on badgers themselves, proactive culling in particular had impacts on other wildlife species. Numbers of foxes (Vulpes vulpes) increased in proactive areas, in comparison with survey-only areas and, perhaps as a result, numbers of hares (Lepus europaeus) declined (Trewby et al., in review). Before culling, hedgehogs (Erinaceus europaeus) were rare in parts of RBCT areas where badgers were abundant (Young et al., 2006), and badger culling increased their numbers (G. Wilson, personal communication).’
Who will pay for the culls and how much will they cost?
The badger control policy is based on a cost-sharing approach with the farming industry. The industry will be responsible for the operational costs of delivering culling and Defra will bear the costs of licensing, monitoring and policing the policy. The potential costs for a typical 350km2 area were outlined in an Impact Assessment published by Defra in November 2011 as follows:
Summary of costs
Licensing: £377,000 per area for two pilot areas (total over four years, highest in the first year)
Co-ordination: £20,000 per area (each year for 4 years)
Culling using cage trapping: £2,500 per km2 (each year for 4 years)
Culling using controlled shooting: £300 per km2 (each year for 4 years)
Culling using a combination of methods: £1,000 per km2 (each year for 4 years)
Vaccination: £2,250 per km2 (each year for 4 years)
Monitoring: £737,000 per area (for two pilot areas over 4 years)
Policing: £500,000 per area (each year for 4 years)
Are The Wildlife Trusts allowing culling on their land?
No. The Wildlife Trusts are against the culling of badgers and none of the 47 Trusts will allow culling on their land.
What will happen after the pilot culls?
An independent panel of experts will oversee and advise on the monitoring of the safety, humaneness and effectiveness of controlled shooting. If Ministers decide to extend the cull following the pilots, a maximum of ten licences will be granted to start each year. The exact timings of the process following the original pilots are unclear. However, the reporting process will need to be complete in order to allow time for new cull areas to be developed if the policy is to be rolled out. An Early Day Motion (EDM) is before Parliament proposing that the House of Commons debate the issue further before any wider cull be permitted http://www.parliament.uk/edm/2013-14/299.
Do other animals such as deer also get bTB?
Yes. Mycobacterium bovis can also infect and cause bTB in deer, goats, pigs, camelids (llamas and alpacas), dogs and cats, as well as many other mammals.
Do badgers die of TB?
Some badgers become infected with bTB but rarely die of the disease. The planned pilots aim to cull 70% of the badgers in these areas and most of those killed will not be infected with bTB. On balance most badgers will live for around 5 or 6 years in the wild. They rarely die of TB.
How can improved farm biosecurity measures help reduce TB in cattle?
Contact between cattle and badgers or their excretions may pose a risk of infection. Improving biosecurity on farms can reduce this risk.
The main transmission route between badgers and cattle has not yet been proven. Studies indicate direct contact between grazing cattle and badgers seems infrequent but transmission may occur via contaminated pasture or around farm buildings. Best practice videos and leaflets are available from the Defra website along with the following advice:
All general good practice helps to reduce the risk of animal diseases including bovine TB, for example: providing good ventilation in cattle housing, not overstocking cattle when housed (or at grass), following guidelines on cleansing and disinfecting and providing cattle with a balanced nutritional diet.
In addition, there are common sense, precautionary measures you can take to help protect your herd from possible TB infection from both badgers and cattle:
• Keep badgers away from stored cattle feed: badgers infected with TB can contaminate feed.
• Make your farmyard less attractive to badgers: badgers are likely to be attracted to accessible feed and may spread disease to cattle.
• Be aware of main badger latrines and active setts at pasture: where possible keep cattle away from these high-risk areas.
• Keep cattle away from neighbouring cattle herds: disease can spread between cattle.
• Protect your herd: source bought in stock carefully and adhere to isolation procedures for any inconclusive or reactor animals.
A research study by the Food and Environment Research Agency (Fera) concluded that simple exclusion measures are 100% effective in preventing badgers entering farm buildings when deployed properly. The badger exclusion measures were individually tailored to fit the requirements of each farm and sought to secure every potential entrance point on each selected facility. The five main exclusion measures used were galvanised aluminium sheeted metal gates, adjustable galvanised aluminium sheeted panels (which could be moved up or down) on gates, galvanised aluminium sheeted fencing, aluminium feed bins and electric fencing.
Is it true that there are no benefits before five years in a badger vaccination programme?
No. Research has shown that vaccination of individual captive badgers reduced the progression, severity and excretion of bTB. Protection and benefits at the population level take time to achieve, with longer vaccinating programmes being more beneficial than shorter ones. It will take years of repeated vaccination before the disease declines in badgers - disease control benefits would be expected to accrue incrementally during a sustained vaccination campaign as numbers of successfully immunised badgers increase and previously infected animals die – more often from old age rather than the effects of TB.
A research paper published in 2012 by Stephen P Carter et al. states that:
"Vaccination of badgers with BCG appears to be beneficial in at least two ways: by directly reducing the TB burden in vaccinated individuals and by indirectly reducing the risk of unvaccinated cubs acquiring infection, most likely through a herd immunity effect on this susceptible component of the badger population. Indirect ‘protection’ bestowed upon juveniles before they become accessible for vaccination themselves could be an important contribution to the success of vaccinating wildlife."
In the Republic of Ireland is there a research study that proves that badger culling works?
The bTB situation in Ireland cannot be compared to England due to the differences in testing regimes applied (annual bTB testing in Ireland compared to the variable frequency of testing in England) as well as significant differences in badger population size and ecology; the average size of a badger clan in England is much larger than in Ireland, as is the overall density of badgers (3.2 badgers per km2 in England compared to 1.9 per km2 in Ireland).
The Irish cull has been undertaken on a reactive, rather than proactive basis – an approach that was discredited by the RBCT because it resulted in an increase in bTB incidence.
A number of other factors must also be considered: during the period of the Irish badger cull, the national herd decreased by more than 16% and the number of cattle herds by 6%; testing on individual animals increased by 13.5%; and the more sensitive gamma blood test was used more regularly from 2000, allowing more infected animals to be detected.
The decrease in bTB prevalence in Ireland cannot therefore be attributed to the badger cull. Indeed, the approach taken to date in neighbouring Northern Ireland has achieved a similar reduction in bTB by focusing on enhanced testing, biosecurity and cattle movement controls – and without culling badgers.
What about other countries? Haven’t they tackled the problem in the wildlife reservoir of TB?
Quotes about potential TB control in other countries often overlook key facts. In New Zealand, possums are culled to deal with bovine TB but, unlike badgers, they are non-native mammals and are also culled for conservation reasons to protect native bird species. This is therefore not a justified comparison to the situation in England. Moreover, in Australia and New Zealand there are much more rigorous programmes of local cattle herd depopulation, movement restriction and reintroduction when there has been a breakdown. This has not been accepted as part of bTB control in England.
What is the policy of the Welsh Government?
The Welsh Government announced in March 2012 it would undertake a badger vaccination project within the TB Intensive Action Area (IAA) in west Wales as part of its bTB eradication programme. According to the Welsh Government’s report of the project’s first year, a total of 1,424 badgers were vaccinated by the end of November 2012 by ten teams of two field operatives at a cost of £943,000.
What about the research study being undertaken in Northern Ireland on a test, vaccinate, remove approach?
The Northern Ireland Government announced in July 2012 that it would be undertaking a research study into a ‘test and vaccinate or remove (TVR)’ approach. This will involve testing live badgers; vaccinating and releasing the test negative badgers; and removing the test positive ones. The Northern Ireland Government has since commissioned badger sett surveys in two areas to help design and cost the research study. It has also published a public information leaflet.
What progress has been made on badger vaccines?
The Animal Health and Veterinary Laboratories Agency(AHVLA) has successfully licensed the injectable badger TB vaccine and is in the process of developing an oral badger vaccine that currently remains at the research stage and is not yet licensable. Once an oral vaccine candidate of suitable efficacy on captive badgers is identified, there would still be three to four years of further work to complete regulatory studies, transfer technology to a manufacturer and seek a licence for the product. The Wildlife Trusts continue to press for Government to develop and deploy the oral badger vaccine as a priority.
If The Wildlife Trusts support the killing of species such as grey squirrels and American mink for conservation, why do they oppose the cull of badgers?
The Wildlife Trusts regard killing wild animals (usually invasive non-native species such as American mink that are affecting the natural balance of ecosystems) as a “last resort” measure to deal with serious conservation management problems. There are examples where such action has led to local population increases in endangered species such as water voles and red squirrels. However, the majority of situations will involve allowing, and possibly encouraging, self-regulating natural processes to control numbers of the species concerned.
The badger cull does not address any nature conservation objectives. The Wildlife Trusts believe that badger vaccination can make a viable contribution to reducing the incidence of bTB in wildlife. However, it must be remembered that badgers are a spillover host and that bTB is primarily a disease of cattle. Efforts to eradicate bTB in England must therefore focus on cattle measures including better biosecurity, stricter movement restrictions, improved cattle testing, cattle vaccination and selective breeding to improve the genetic resistance of the national herd.