What is bovine TB?
Bovine tuberculosis (bTB) is an infectious disease of cattle.
It is caused by the bacterium Mycobacterium bovis (M. bovis), which can also infect and cause TB in badgers, deer, goats, pigs, camelids (llamas and alpacas), dogs and cats, as well as many other mammals.
This disease is one of the biggest challenges facing the cattle farming industry today, particularly in the West and South West of England.
How is bovine TB spread?
Bovine TB is spread from cattle to badgers and badgers to cattle.
This is known as the cycle of reinfection.
The links between badgers, cattle and TB infection were first suspected in the early 1970s and both experience and experimentation has subsequently proved them beyond doubt. Professor Sir John Krebs concluded in his 1997 report that there was “compelling evidence” that badgers transmit bTB to cattle.
In addition, both the Zuckerman and Dunnet reports to government came to the conclusion that the badger is the most important wildlife reservoir and it is involved in the maintenance and transmission of the disease to cattle.
There is still some uncertainty surrounding bovine TB and the way it is transmitted, but it is mainly a respiratory disease, caught by breathing in the M. bovis bacteria that cause bovine TB. This usually happens when animals are in close contact with each other, so animal density is a major factor in the transmission of M. bovis. Bacteria released into the air through coughing and sneezing can spread the disease to uninfected animals.
Direct transmission can happen, eg through nose to nose contact. There is also evidence that indirect transmission is possible, eg through contact with saliva, urine, droppings, pus from abscesses, etc. We know bovine TB is transmitted from cattle to cattle; from badgers to cattle and cattle to badgers; and badger to badger.
The programme of trials that followed the Krebs report were designed to identify the most effective strategy for preventing bTB in badgers spreading into cattle populations.
Cattle movements are also part of the problem and have been linked to taking the disease to previously TB-free areas. However, evidence shows that, providing the wildlife is not also harbouring the disease, this doesn’t lead to a long-term TB problem. For example, Northumberland has had pockets of bTB caused by cattle movements, but the outbreak has been stamped out and there is no evidence of any wildlife reservoir of the disease in this area.
The vast majority of bTB outbreaks occur in the 'hotspot' bTB areas of the South West and the West Midlands, and in these high-risk areas up to 50% can be attributed to localised transmission involving infected badgers.
What is the current situation?
The disease is spreading north and east across the country.
There are now areas where the incidence of TB in cattle is persistent and high; these are called 'hotspots'. These are mostly centred in the South West and the West Midlands. However, as the disease is spreading there are more and more hotspots in places such as Cheshire, and increased areas across the East Midlands.
There has been a four-fold increase in the number of cattle slaughtered because of TB in the last 17 years. According to Defra statistics, in 1998 there were 6,000 cows slaughtered due to bTB in England. In 2016, 29,227 cattle were killed.
Since January 1 2008, 246,819 cattle have been killed due to bovine TB in England (Defra, to January 2017).
When did bovine TB become a problem?
TB in humans became a significant problem in Victorian England as industrialisation crowded people together in insanitary conditions in large cities.
At this time, many of the dairy herds that were kept in and around the cities to provide fresh milk became infected with bovine tuberculosis (bTB). The milk was a potent source of infection and many people died.
A law was passed making it illegal to sell tuberculosis milk and the tuberculin test, which could identify infected cattle before they showed symptoms, was developed. It was seen to have the potential to eradicate the disease and so the Attested Herd Scheme was introduced in 1935.
By 1950, herds that tested positive for the disease were compulsory slaughtered. This scheme involved regular compulsory testing of all cattle herds and the slaughter of bTB reactors, just as happens today.
It was at the NFU Conference in 1958 that the government announced, wrongly, that TB had been eradicated.
By the mid-1970s, all cattle herds in the UK were thought to have been cleared of bovine TB. However farmers in two areas, Cornwall and Gloucestershire, continued to see individual cattle test positive, despite having their herds cleared of the disease.
It is believed badgers harboured a reservoir of the disease and had begun to re-infect herds in those areas.
This situation continued at a low level throughout the 1970s. Unfortunately during the 1980s the number of cases started to rise again. This increase in number and geographical area has continued ever since so that bTB in cattle is once again widespread in England and Wales.
How does bovine TB affect me?
This disease situation has the potential to affect everyone, from those living in rural areas seeing the impact on farming neighbours first-hand, to people who enjoy great British beef and dairy products and want to see a thriving sector.
Everyone will be paying for the costs of bTB via the public purse, with costs set to rise to £1billion in the next ten years unless action is taken.
There is also the potential for bTB to spill over into other species. While there are still very few cases of bTB found in dogs and cats, it is on the increase in other animals, and particularly in alpacas.
Unless bTB is reduced in the environment it is likely that these cases will continue to increase as the disease is forced to find new hosts.
How much does bTB cost?
According to Defra, the estimated average cost of a bovine TB breakdown on a farm is £34,000.
Of this, it is estimated £20,000 is borne by the Government, mainly as compensation for animals compulsorily slaughtered and the costs of testing, and £14,000 falls to the farmer as a result of the loss of animals, on-farm costs of testing, and business disruption because of movement restrictions.
It has cost the tax payer £500 million to control the disease in England in the last 10 years. It is estimated that the costs of bovine TB control will top £1 billion over the next decade, if no action is taken.
How do farmers pay for bovine TB?
Farmers pay a significant amount with regard to bovine TB and in a variety of ways.
First of all they pay for the cattle control measures. Farmers in endemic areas routinely test their cattle every year, and in a breakdown situation (when bTB is confirmed in a herd) they are testing every 60 days. Even for those without TB in their herds, pre-movement testing is required before any animal can be moved off farm.
It is estimated that the average cost of a routine bTB test for a farmer is around £350. Testing requires additional labour and causes significant stress, often leading to injuries to both stock and those people handling them, but also results in loss of income because cows don’t milk as well and beef animals don’t put on as much weight. It is widely recognised that the stress of handling can make animals more susceptible to other conditions and even cause pregnant cows to abort.
According to Defra figures, the estimated average cost of a bovine TB breakdown on farm is £34,000, although this figure can vary enormously from farm-to-farm. Of that, around £14,000 falls on the farm business itself as a result of the loss of animals, on-farm costs of testing, and business disruption due to movement restrictions.
An interim report published by the University of Exeter, looked at the costs of bTB breakdowns on eight case study farms from the South West of England.
One of the dairy farms used in the study, which lost 61 cows to bTB, estimated that the loss of these animals alone cost their farm £56,364 in milk sales. Consequential losses such as these are not recoverable by the affected farm business under the compensation scheme.
In addition, the money paid for animals which are slaughtered does not always truly reflect the value, particularly of breeding stock.
Herd restrictions put on trading animals after a breakdown can also be very expensive. Some farmers cannot sell animals and become overstocked, others cannot buy replacement stock to maintain their business and both situations can lead to big cash flow problems.
In addition, looking at the purely financial costs disregards the enormous emotional damage bTB does to farming families.
What impact does bTB have on a farmer?
In 2009 the Farm Crisis Network conducted interviews and found that ‘dealing with bTB causes considerable stress to both farmers and their families’.
Some 20% of those interviewed admitted that they were either 'panicked' or 'devastated' by the news of a new outbreak, and a further 50% were 'upset' or 'worried'. Farmers told the FCN:
"The worst thing was that cows very close to calving had to be shot on farm. We could see the calves kicking inside as they died."
“I feel there is a constant dark cloud of uncertainty over me, causing stress, anxiety and fear. I feel weary, mentally and physically which results in pain in my body.”
“Financially it is very stressful. Cash flow is a huge problem. Having to keep animals when I would normally sell them puts more pressure on me, on my family, animal accommodation and feed costs. I don’t know how long we can keep going.”
The study found that many farmers were suffering financial impacts to their businesses, including a reduction in sales of beef and milk as a result of culled animals, increased labour and extra costs of feed and bedding, as they had to keep animals for longer.
Some farmers have become so weary and frustrated by repeated bTB outbreaks that they have decided to go out of beef or dairy production altogether.
TB Free England video: Mervin's story
How does bTB affect cattle?
The stringent testing regime, and removal of cattle for compulsory slaughter if they test positive for bTB, means that on-farm welfare implications for cows with bTB are kept to a minimum.
However the number of cows being culled because of bovine TB has increased four-fold in the past 17 years and has resulted in 100,000s of cows being killed before the end of their productive life. Since the start of 2008, 299,098 cattle have been culled due to bTB in Great Britain, with 225,143 culled in England alone (Jan 2008 – April 2016).
TB Free England video: The calf
How does bTB affect badgers?
The major cause of badger deaths - 50,000 each year according to the Badger Trust - is road accidents.
However, in the hotspot areas, up to one in three badgers are estimated to have bovine TB (source: Independent Scientific Group on Cattle TB).
Badgers spend most of their life below ground sharing the same air space, tunnels and chambers, which provides the perfect environment for the disease to spread within a social group.
As in cattle, the disease affects the lungs, but also the kidneys. Infected badgers experience more extensive development of TB lesions than cattle, and infected animals will lose weight and body condition and experience severe breathing problems which limit their ability to forage normally.
However, it has been shown that badgers can go through a period of 'latency' when the disease is present but makes little progress and it is their ability to live with the disease and to pass it on readily within the confines of their setts to other badgers and to cattle at pasture and around farm buildings that makes the badger an almost perfect host for bTB.
How does bTB move between badgers and cattle?
A badger with bTB can infect cattle in several ways.
The primary route is inhalation, with cattle breathing in the bacteria from the air.
However, infection from cows eating contaminated material is also an important route.
Clinical sampling of live badgers has shown that bTB bacteria can be isolated from sputum, faeces, urine, bite wounds and draining abscesses. Badger latrine sites, where badgers urinate or defecate in fields, can contaminate grass with bacteria, which can then be transmitted to the cows when they graze.
Similarly, badgers mark their territory by urinating and this is often spread across cattle pastures.
If a badger has TB infection in its kidneys it will excrete a very high level of TB bacteria on to the grass. If an infected badger eats or drinks from cattle feed or water troughs, they can spread TB bacteria through their saliva, which infects the cows when they eat or drink from these contaminated sources.
Infected badgers can also spread the bacteria through open cuts and wounds.
There is also the potential for direct transmission of bacteria through nose-to-nose contact between badgers and cattle.
This can occur when badgers visit farm yards and there is substantial evidence to show close contact in farm buildings as well as regular visits from badgers to cattle feed stores.
- Watch - NFU, Defra, Fera, Nadis and Welsh Assembly, Bovine TB and Biosecurity. Video 3. Biosecurity at pasture.
- Read more - Tolhurst, B. A.; Delahay, R. J.; Walker, N. J.; Ward, A. I.; Roper, T. J. Behaviour of badgers (Meles meles) in farm buildings: opportunities for the transmission of Mycobacterium bovis to cattle? Applied Animal Behaviour Science 2009 Vol. 117 No. 1/2 pp. 103-113
- Read more - Garnett, B.T. Delahay, R.J. Roper, T.J. Use of cattle farm resources by badgers and risk of bovine tuberculosis transmission to cattle.
Can pet cats catch or spread bovine TB?
The Animal Health and Veterinary Laboratories Agency (AHVLA) reported in March 2014 that nine cats had contracted bovine TB in Berkshire and Hampshire in 2013.
Following screening of the people who came into contact with the infected cats, Public Health England and the AHVLA announced two humans developed bovine TB. This was the first documented case of cat to human transmission.
It is believed that the cats were infected with the disease after contact with wildlife, such as badgers or rats, although other methods such as cat-to-cat transmission cannot be ruled out.
There have been no further cases of bovine TB reported in the Berkshire and Hampshire area since March 2013, the disease is still uncommon in cats.
How can the spread of bovine TB be reduced?
The evidence shows that bTB can be tackled successfully when the disease is tackled on all fronts at the same time.
This means using both cattle controls and badger controls in the hotspot areas -those areas where the disease is persistent and high.
Cattle herds in TB problem areas, and surrounding areas, are tested at least annually (the same testing frequency as Wales) and cows that react to the test are isolated and slaughtered.
The remainder of the herd is subject to strict movement restrictions, meaning cows cannot move off farm, unless it is for slaughter, until the whole herd passes two consecutive TB tests 60 days apart.
Despite these measures, huge numbers of farms are still closed down with bTB.
The number of cattle herds in England which were under restrictions because of a TB incident at some time during 2015 was 6,889. This is having a devastating impact on the British beef and dairy sectors.
Currently, TB infected badgers are not identified, treated or slaughtered, allowing the disease to build in this wildlife reservoir. It has developed to the extent that they can excrete vast numbers of bTB bacilli in their dung, urine and saliva which can then be ingested by cows.
The evidence demonstrates that badgers do spread bTB to cattle, and harbour a reservoir of the disease. In the TB eradication strategy published in April 2014 the Government recognises the role badgers play in spreading the disease in areas where bTB is rife and makes a clear commitment to controlling the disease in badgers in these areas as part of the strategy. There is no nationwide culling strategy.
What are farmers doing to limit bovine TB?
Farmers are working hard to prevent potential disease transmission although it is very difficult for a farmer to prevent a wild animal from coming into contact with his livestock out in a field.
|Repairs to a door to keep badgers out|
|Work to fencing to deter badgers|
|Drinking trough raised and wall-mounted|
|Badger-proof feed store (open)|
The measures that farmers take include raising feed and water troughs off the ground, ensuring doors to feed sheds fit well, and are kept shut at night, storing feed in covered bins and fencing off badger setts and latrines. They also do all they can to make their buildings 'badger proof' by ensuring there are no gaps in, or under, doors or walls that badgers could get through.
The only way of totally preventing infection would be to house cattle day and night, for 12 months of the year in secure premises and to sterilise all feed brought in.
The NFU, together with Defra, the Welsh Assembly Government and Food Environment and Research Agency (FERA), developed a Bovine TB and Badgers - Improving Farm Biosecurity DVD which is used to promote best practice.
In November 2015 a cross-industry biosecurity campaign designed to help farmers minimise the risk of their herds getting bovine TB was launched.
All advice on bovine TB from government, farming experts, leading vets and agricultural colleges was made available on one single website - www.tbhub.co.uk.
The campaign also features a Biosecurity Five Point Plan to improve disease prevention on farm and in the cattle trade.
In April 2016, further cattle measures were introduced, including compulsory post-movement testing of cattle moving into the low risk area of England from the rest of England and Wales, to help reduce the risk of disease spread.
Farmers also have access to independent advice from various events run by veterinary groups.
How is bTB testing delivered in England?
On February 16, 2015, the Animal and Plant Health Agency (APHA) confirmed the award of contracts for the delivery of bTB testing in England which changed the way bTB testing is delivered.
From May 1 2015, all new bTB testing and other Official Veterinarian work has been undertaken by five regional suppliers, who are responsible for allocating local vets and ensuring testing is carried out to a high standard. APHA said the change would help to drive up standards and ensure the ongoing quality of testing for animal disease.
Previously, on-farm bTB testing was done by vets working for private businesses (usually farmers’ own vets) who were trained, appointed and paid for by the APHA to do the work.
Farmers and livestock keepers continue to be responsible for ensuring that TB testing is completed on time but now contact their regional delivery partner to make the arrangements. Delivery partners arel then be responsible for allocating the actual testing activity through their network of practices, and for assuring the quality of the work performed.
In recognition of the important relationship between farmers or livestock keepers and their vets in preventing and controlling disease and for ensuring the health and welfare of animals, the new contracts required delivery partners to offer testing work to eligible veterinary businesses operating within their geographical regions.
When making arrangements for tests, farmers and livestock keepers can express a preference to use a specific veterinary practice from within the delivery partners’ network to undertake their testing, and this preference will be honoured where possible. Farmers and livestock keepers who prefer to use a practice that is not part of the delivery partners’ network retain an option to pay for the testing privately.
Contract awards for two regions covering Wales were announced on January 27 2015 and came into force on April 1 2015. The changes do not apply in Scotland.
What is the government doing about bovine TB?
The Government published its Strategy for Achieving Officially TB Free Status for England on April 3 2014 in which it outlined its commitment to tackling TB using all the available options.
The then Secretary of State Owen Paterson re-emphasised that controlling the disease in wildlife is an essential part of the strategy.
During his statement to Parliament announcing the publication of the strategy, Mr Paterson also highlighted:
- A scheme for vaccination projects around the edge of the most badly affected parts of the country in an attempt to create a buffer zone of TB immunity to stop the disease spreading further;
- A comprehensive farm-level risk management programme throughout the cull areas which will be available to all cattle keepers and will provide bespoke assessments and advice for farmers on how to protect cattle;
- An investment of £24.6 million over the current Parliament in the development of effective TB vaccines for both cattle and badgers. Large scale field trials for a deployable cattle vaccine are currently being designed and work is also being carried out on an oral badger vaccine;
- The stepping up of investment in the development of improved diagnostic tests to enable the identification and removal of only TB-infected badgers.
Has this approach been tried elsewhere?
The UK coalition government has decided on this multi-faceted approach because the science shows it will work.
In addition, there is evidence from other countries which have significantly reduced TB by tackling all aspects of the infection cycle.
For example, the government in the Republic of Ireland has been conducting a badger control programme for the past 12 years. The number of cows testing positive to the TB test has fallen by nearly half in the past six years. In 2008 Ireland had just under 30,000 reactor cattle. By 2015, the figure had fallen to 15,317.
A reactive badger control strategy has been used, removing badgers in areas surrounding new TB herd breakdowns. This measure is partly credited for the 50% reduction in TB incidence that has been seen since 2000.
Is there evidence that proves the plan will work?
The government’s TB Eradication Plan, and the decision of successive farming ministers to include badger controls, is based on scientific experience from the Randomised Badger Culling Trial (1998-2007).
It demonstrated four keys areas which need to be achieved to ensure the badger culls are carried out safely, humanely and effectively.
- Controls need to cover a large enough area in order to reduce disease so the current Government TB Eradication plan has said that no area under 150KM² will be included. The most recent follow-up work published by members of the ISG (Independent Science Group) from the RBCT has shown that the size of area needed for an effective cull is not as large as initially thought and that the benefits can be sustained for a number of years after the cull has taken place.
- The RBCT said that bovine TB could increase outside of the cull area as badgers leave it, taking the disease with them. This is called the perturbation effect. So the current Government TB Eradication plan has focused on using hard boundaries such a major roads, rivers and coast lines to ensure perturbation is kept to an absolute minimum.
- The report authors called for strict conditions to deliver an effective cull. The culls are licensed by Natural England under the Badger Act for the purpose of disease control. Licences are only approved once the licence criteria have been met by those applying for a licence.
- The report questioned the cost-effectiveness of a cull and so the farming industry is working with Defra, Natural England and professional contractors to deliver the cull from the grassroots, using local knowledge and local networks. An industry led, funded and delivered method will save money.
I keep hearing about the 'RBCT'. What is it?
The Randomised Badger Culling Trial, or RBCT, is a large-scale field trial that was set up to quantify the impact of culling badgers on incidence of TB in cattle, and to determine the effectiveness of strategies to reduce the risk of a TB cattle herd breakdown.
The RBCT represents nearly ten years of work (1998-2007) and nearly £50 million of taxpayers' money. It was started after the Krebs Review on Bovine TB in Cattle and Badgers which reported in 1997. It concluded that despite there being 'compelling' evidence that badgers were involved in transmitting infection to cattle, the development of a control policy was made difficult because the effectiveness of badger culling could not be quantified with the data available.
It therefore recommended that a large-scale field trial - the Randomised Badger Culling Trial, or RBCT - be set up to quantify the impact of culling badgers on incidence of TB in cattle, and to determine the effectiveness of strategies to reduce the risk of a TB cattle herd breakdown.
The results of this robust experimental trial are fully published and peer-reviewed and represent the most substantial and coherent evidence base for the evaluation of badger culling. However, while the design of this experiment was exemplary, some have questioned how effectively it was carried out - in particular, all culling operations were suspended for a year in 2001 because of the Foot and Mouth Disease outbreak - and have raised doubts about the validity of the results on this basis.
How did it work?
The trial was conducted in thirty 100km2 areas of South West and central England, each located in a high-risk area for cattle TB.
The 30 areas were grouped into ten sets of three, each called a triplet.
Within each triplet, one area was subjected to repeated (approximately annual) culling across all accessible/consent land (proactive culling). In another area the badgers were culled on a single occasion locally, on and near farmland where recent outbreaks of TB had occurred in cattle (reactive culling).
The remaining area received no culling (survey only) and acted as an experimental control with which the culling areas could be compared. Participating farmers were aware of the treatment being applied to their area (i.e. they were not blinded).
Results showed that from one year after the last proactive cull to 25 February 2011, incidence of confirmed breakdowns in proactive culling areas was 16% lower than in survey-only areas.
What about vaccinating cattle - or badgers?
Vaccination will be an important tool to help control bovine TB in the future.
But the evidence suggests it will not work on its own – and where both cattle and badgers are concerned, a realistic programme remains a number of years away.
Vaccination won’t work on an animal that already has bovine TB, and no country in the world where wildlife carries the disease has eradicated it in cattle without tackling it in wildlife too.Vaccination and cows
There are calls for cows to be vaccinated against bTB.
However there is no legal vaccine available. Currently the only option is the BCG vaccine (Mycobacterium bovis Bacille Calmette-Guérin – ref 1,2,3,4,5).
The problem is that at present it is impossible to distinguish between a BCG-vaccinated and TB-infected cow. And for this reason it is currently illegal under EU law to vaccinate cattle with the BCG jab.
Work is underway to devise a DIVA test (ref 6,7,8) - a test that can Differentiate between Infected and Vaccinated Animals. But even when this has been fully developed, it will need to go through EU and international approval.
The upshot is that most estimates say it will be ten years before vaccinating cattle is a realistic possibility (9).
On top of that, there's evidence to suggest that the BCG vaccine and DIVA test will not eradicate bovine TB on their own. A recent scientific study (10) concluded that the efficacy of the BCG vaccine in cattle was between 56% and 68%.
We know the BCG vaccination reduces the progression, severity and excretion of TB, resulting in reduced transmission between animals, but it is not perfect. And for any vaccine to eradicate a disease it is necessary to ensure that 80% of the target population are immunised. The current BCG vaccine just does not does not shape up.
Scientists have said that vaccination has to be used in combination with other measures, which must include dealing with the disease in badgers. You can read more about bovine TB and cattle vaccination on the Defra website.
Vaccination and badgers
Most voices in the debate, including the NFU, support the use of badger vaccination in areas on the edge of the disease spread to help stop bTB spreading further.
Farmers are getting involved in badger vaccination projects in these areas because they recognise that vaccination could have a role to play in stopping disease spread.
The Government has also set up the Badger Edge Vaccination Scheme (BEVS) to support badger vaccination projects in areas on the edge of the disease spread that are thought to be most at risk of the disease spreading from the endemic areas of the South West and West Midlands. However, in December 2015 the Government announced that all badger vaccination projects in England were being suspended due to a global shortage of the BCG vaccine.
The only vaccine currently available for use on badgers is in injectable form – and that presents problems.
You need to cage-trap the badgers to vaccinate them. And you have to it annually for period of at least five years.
The process is costly and needs to be carried out by people who have been on accredited courses. Every trap has to be visited early in the morning, every day.
The Welsh Assembly Government is carrying out a five-year badger vaccination programme in the Pembrokeshire hotspot area. In December 2015 the Deputy Minister for Farming and Food, Rebecca Evans, announced that the badger vaccination project in Wales was being suspended due to a global shortage of the BCG vaccine.
In May 2015, the report on the third year of the programme was published and showed that 1,316 badgers had been vaccinated at a total cost of £929,540, or approximately £706 per badger. During the second year of the programme 1,352 badgers were vaccinated at a total cost of £926,784, or approximately £685 per badger. The first year of the programme saw 1,424 badgers vaccinated at a total cost of around £943,000, or approximately £662 per jab.
There are also question marks over the efficacy of the vaccine.
The science suggests the vaccine is most effective in very young animals, and less so in older subjects (12). Young badgers spend their early weeks in the sett, making it impossible to trap and vaccinate them and putting them at risk of infection before they emerge.
There is also no evidence as yet which shows that vaccinating a proportion of the badger population actually results in a reduced risk to cattle.
An oral bait vaccine is likely to offer the most successful route forwards. But this option is still some years away from becoming a part of any badger control plan, because there is no licensed or proven oral vaccine currently available. The Government's TB eradication strategy for England suggests 2019 as the earliest when an oral badger vaccine may be deployed, subject to research breakthrough and authorisation.
You can read more about bovine TB and badger vaccination here.
- Read more – A comprehensive range of references for this article can be found here.
Can badgers be vaccinated when cage trapped?
As part of the pilot cull, two methods are being used - controlled shooting and cage-trapping and shooting. Currently the only way to vaccinate a badger is via cage-trapping , using an injectable vaccine.
Bovine TB is endemic in the badger populations in large areas of the South West and West Midlands. Scientific evidence has shown that in these areas up to one-in-three badgers will have bTB. This means that vaccinating badgers in these areas will have no impact on the levels of disease. A vaccine cannot cure a diseased animal.
Click here for more information about badger and cattle vaccination.
The badger culls
Pilot badger culls 2013 – what happened?
In February 2013, Natural England confirmed that all the criteria had been met to allow badger control operations to begin in the pilot areas of west Somerset and west Gloucestershire, for the purpose of preventing the spread of bovine TB.
Licences were granted for four years, with operations licensed to take place over a continuous six-week period between June 1 and November 30 for cage trapping and shooting and between June 1 and January 31 for controlled shooting. Both areas were overseen by independent experts who provided information for an Independent Expert Panel report on the two pilots.
In October 2013 the companies carrying out the pilot badger culls applied to Natural England for extensions to their six-week licences. A three-week licence extension was granted in Somerset and an eight-week licence extension in Gloucestershire after the Chief Vet advised the extensions would enhance disease control and achieve the earliest and greatest possible impact on bTB.
The three-week licence extension to the pilot badger cull in Somerset finished on November 1. The eight-week licence extension in Gloucestershire, granted by Natural England, was due to finish on December 18. However, after discussions between the cull company and Natural England, it was agreed that culling operations would stop on November 30 to coincide with the end of the cage trapping season.
Following the conclusion of the extensions, the then Secretary of State, Owen Paterson, advised Parliament that the extended culling operation in Somerset would deliver clear disease control benefits as part of a four-year cull in the area. He also told Parliament the extended culling operation in Gloucestershire had been successful in preparing the ground for a fully effective four-year cull.
The Independent Expert Panel report into the 2013 cull
On April 3, 2014 the then Secretary of State, Owen Paterson, published the Government’s 25-year TB Eradication Strategy together with the Independent Expert Panel’s report into the first year of the pilot badger culls in Somerset and Gloucestershire.
The Panel was appointed to assess whether the controlled shooting of badgers was safe, humane and effective. The panel made a number of recommendations regarding the operations of the pilot culls which Mr Paterson said would be implemented before culling restarted in 2014.
Pilot badger culls 2014
In a statement to Parliament on April 3 2014 the then Secretary of State, Owen Paterson, confirmed that the two pilot culls in Somerset and Gloucestershire would continue in 2014 but culling would not be rolled out to any other areas in 2014.
He also revealed the Government’s comprehensive 25-year strategy to eradicate bTB which included cattle movement restrictions and vaccination programmes in areas surrounding TB hotspots where TB is rife.
Pilot badger culls 2014 – what happened?
The second year of the pilot badger culls in Somerset and Gloucestershire were carried out in September and October 2014 over a six-week period.
On December 18 2014 the Secretary of State Liz Truss published the results of the second year of the pilot culls. The results showed that 341 badgers had been culled in Somerset against a target of 316, while 274 badgers had been culled in Gloucestershire against a target of 615.
In a Written Ministerial Statement the Secretary of State stated that the results in Somerset in 2014 showed the approach to culling worked, while the results in Gloucestershire reflected “the challenges of extensive unlawful protest and intimidation”.
The Chief Veterinary Officer advised that the results in Somerset showed that “industry-led culling can, in the right circumstances, deliver the level of effectiveness required to be confident of achieving disease control benefits”.
Badger culls 2015
On August 28 2015 Defra announced that Natural England had authorised the badger culls to continue for a third year in Somerset and Gloucestershire and had also issued a four-year licence to allow badger culling to take place in Dorset.
Badger culls 2015 – what happened
Badger culling was carried out for the third year in Gloucestershire and Somerset, and for the first year in Dorset, during September and October 2015.
On December 17 2015 the Secretary of State Liz Truss published the results of the 2015 culls. The results showed that all three areas had exceeded their minimum target but had not exceeded their maximum target. In Somerset, 279 badgers were culled against a minimum target of 55 and a maximum target of 524; in Gloucestershire, 432 badgers were culled against a minimum target of 265 and a maximum target of 679; and in Dorset, 756 badgers were culled against a minimum target of 615 and a maximum target of 835.
The Chief Veterinary Officer advised that the results indicated that “industry-led culling can deliver the level of effectiveness required to be confident of achieving disease control benefits”.
In a Written Ministerial Statement the Secretary of State said the Government wanted to see badger control over a wider number of areas in 2016 as part of its strategy to eradicate bovine TB in England.
Badger culls 2016
On August 30 2016 Natural England confirmed that culling would continue for a fourth year in Somerset and Gloucestershire and for a second year in Dorset. In addition, Natural England confirmed that all the criteria had been met to allow seven additional areas to be licensed for four-year badger culls in Devon, Cornwall, Dorset, Gloucestershire and Herefordshire.
Badger culls 2016 - what happened
The badger culls were carried out during August, September and October 2016.
On December 16 2016 the Secretary of State Andrea Leadsom published the results of the 2016 culls. The results showed all ten areas had achieved their minimum targets but not exceeded their maximum targets.
The Chief Veterinary Officer advised that the results in all areas again indicated that "industry-led culling can deliver the level of effectiveness required to be confident of achieving disease control benefits".
He also said: "This year we have seen that badger control can be delivered successfully on a wider scale. Further expansion in the coming years, alongside our robust cattle movement and testing regime, will allow us to achieve and maintain long term reductions in the level of TB across the South West and Midlands where the disease is currently widespread."
Who is paying for the badger culls?
The pilot badger culls are being managed, organised and funded by farmers and landowners.
As these are pilots they are being carefully monitored to test effectiveness, safety and humaneness. These monitoring costs are borne by the government but would not recur if culling was rolled out to wider areas. These culls are part of a legal, licensed and lawful activity to reduce disease as part of a government policy.
Policing costs are associated with the threat of illegal action by anti-cull activists and are paid by government.
Will a badger cull really help to reduce bTB in cows?
Yes. The latest figures derived by experts from the RBCT demonstrate that five years after culling ceased, the rate of infection of herds in the area decreased by 16%.
This work has also shown that the effects of perturbation seen in the initial analysis of the RBCT have significantly reduced, and also that the incidence of bTB in herds surrounding the area of a cull have remained the same.
Is a 16% reduction in cattle TB worth it?
Yes. The figure of 16% is the one used by the government because it is the only verified scientific figure, obtained from the RBCT.
There are a number of reasons why this figure is likely to be very pessimistic. The RBCT concluded that culling should take place on an area of at least 150km2, whereas the trials where done over an area of 100km.
Moreover the trial areas were circles without hard boundaries. And there is plenty of evidence that the culling was not done effectively or systematically enough, and was totally suspended in 2001 during the Foot and Mouth crisis. But even if the 16% figure is correct this would mean 47 fewer farms would succumb to the disease within the trial area.
The alternative to a cull would either be to do nothing and wait, quite possibly for ten years, for another solution, by which time the incidence of the disease would be even more severe and take even longer to control, or to vaccinate badgers in heavily infected areas. This would be very ineffective and costly and there is absolutely no research data to indicate what the effect on the incidence of bTB in cattle would be.
How many badgers are infected?
In 2007, as part of its final report on the Randomised Badger Culling Trials, the Independent Scientific Group on Cattle TB reported a 40% infection rate among badgers in the hotspot areas where the RBCT ran.
The Badger Trust and anti-badger cull groups currently quote the ISG as saying there was a 16% TB infection rate in badgers. However, this figure is based on initial post-mortems, rather than the final full post-mortem examinations.
The latter examinations did indeed find that 40% of the 1,600 badgers culled had visible TB lesions.
Is the badger an endangered species?
No. Badgers first became protected in 1973 following the introduction of the Badger Act.
Badgers are protected not because they are in any way rare or endangered, but because of illegal badger baiting, which involves digging out setts and using dogs.
Subsequent laws have been introduced, such as the Wildlife and Countryside Act 1981, and have culminated in the Protection of Badgers Act 1992, protecting the sett as well as the badger.
A badger sett survey carried out by the Animal Health and Veterinary Laboratories Agency reported back in early 2014. It found that the number of badger colonies had doubled in the past 25 years.
There were at least 64,000 main setts in England in 2013, compared to 31,500 in 1988. The peer-reviewed study was published in Scientific Reports, a primary research publication from the publishers of Nature.
However, the researchers stressed that their remit had been setts and not badger numbers. Further research is expected in 2014.
If badgers have bTB, why is the population rising?
Bovine TB is a chronic, wasting infection.
Animals (and humans) can suffer from it for many years before succumbing.
The nature of this disease is such that if it reaches the stages of chronic infection it will cause a debilitating and painful death to those animals that succumb to it.
However, it has been shown that badgers can go through a period of 'latency' when the disease is present but makes little progress. It is this ability to live with bovine TB and to pass it on within the confines of their setts, and to cattle at pasture and around farm buildings, that makes the badger an almost perfect host for bTB.
How are badgers being culled?
Operators are required to follow best practice guidelines, undertake training and competence testing.Best practice guidance has been published for the two permitted methods of culling: cage trapping and shooting, and controlled shooting.
Independent monitoring is undertaken to assess the humaneness of controlled shooting during the pilots. The development of the monitoring protocols was overseen by a panel of independent experts. The monitoring includes field observations and post mortems.
A Defra spokesman said: “The design of the study to assess humaneness of the badger culling pilots has been overseen by an independent expert panel, which includes expertise in animal welfare, badger ecology and wildlife population management. All marksmen are required to pass a government training course and must adhere to best practice guidance to ensure they can carry out the cull in a humane way. The humaneness of the pilots will be monitored through field observations and post mortems.”
Culling 70% of the badgers seems unnecessary?
The requirement to cull 70% of badgers in a control area was established by independent scientists following results from the RBCT. These results showed that on average across the 10 trial areas if you removed 70% of badgers there would be a significant impact on disease reduction in cattle.
The UK is a signatory to the Bern Convention of the Council of Europe which prohibits the local extinction of endangered or protected species. The Standing Committee of the Convention is satisfied that the planned control in England does not breach the terms of the Convention.
Why can't only infected badgers be culled?
There is no simple way to determine whether a badger has bTB.
The only reliable method is by post-mortem examination. Failing that, as with cattle, by two tests separated by a number of days, which is completely impractical.
Badgers killed in the pilot culls are not be tested for bovine TB. The pilot culls are to test to see if the process is humane, safe and effective. That said, the two areas where culling is taking place are both areas where bTB is rife so a significant proportion of the population will be infected.
Disturbing badgers spreads bTB. Is this true?
Evidence from the Randomised Badger Culling Trials showed that bovine TB could increase outside of cull areas as badgers leave them, taking the disease with them.
This is called the perturbation effect. In response to the lessons learned from the RBCT, the current cull areas use hard boundaries such a major roads, rivers and coast lines to ensure perturbation is kept to an absolute minimum.
The size of the current cull areas is at least 150KM² which will help further reduce the risk of perturbation.
What is the current situation with bovine TB in Wales?
Decisions relating to bovine TB sit within the Welsh government natural resources minister's portfolio.
On March 20 2012, the Welsh Government announced a five-year badger vaccination programme in North Pembrokeshire.
During the fourth year of the programme 1,118 badgers were vaccinated at a total cost of £922,012, or around £825 per badger. The report on the third year of the programme was published and showed that 1,316 badgers had been vaccinated at a total cost of £929,540, or approximately £706 per badger. During the second year of the programme 1,352 badgers were vaccinated at a total cost of £926,784, or approximately £685 per badger. The first year of the programme saw 1,424 badgers vaccinated at a total cost of around £943,000, or approximately £662 per jab.
This could mean that, over the five-year period of the programme, vaccination could cost around £3,365 per vaccinated badger.
The Welsh government has not been able to determine the proportion of the population of badgers in the area that has been vaccinated.
In December 2015 the Deputy Minister for Farming and Food, Rebecca Evans, announced that the badger vaccination project in Wales was being suspended due to a global shortage of the BCG vaccine.
Welsh farmers adhere to strict cattle controls. Measures include annual testing and pre-movement testing across the whole of Wales, stringent rules for restricted herds with regards to buying in replacements to make up for lost animals, and even tighter testing for herds neighbouring a bovine TB breakdown.
Statistics from Defra show that the number of cattle slaughtered because of bTB in Wales increased from 8,086 in 2015 to 9,954 in 2016. The number of new herd incidents of bTB fell from 835 in 2015 to 710 in 2016.
As part of its drive to tackle bTB, the Welsh government is carrying out a Badger Found Dead survey. People are being asked to report sightings of dead badgers in Wales to the Animal and Plant Health Agency (APHA) who will then collect the carcases, wherever possible. The survey is aimed at improving the understanding of the distribution of bTB infection across Wales and will be carried out for at least the whole of 2015.
Click here to see the latest TB statistics.
What is the PCR test and how can it be used?
The Polymerase Chain Reaction (PCR) assay or test has the potential to be a rapid, inexpensive and very sensitive tool for identifying bTB infection.
PCR detects small amounts of DNA from mixed samples, and this method is often combined with immuno-magnetic separation (IMS), which increases the concentration of the samples resulting in increased test sensitivity.
There is potential to use PCR with faecal and environmental samples. However, there has been limited validation work on PCR in badger samples. Research assessing the sensitivity of PCR in badger faecal samples is currently being carried out in the Republic of Ireland and the results from this project will be available in 2014/5.
Defra has funded research into PCR since 2007 to detect the M. bovis bacteria from environmental samples such as badger setts and latrines. While PCR has been demonstrated to identify M. bovis in spiked samples in the laboratory with 100% specificity (100% reliable that a positive test result means disease is present) and 97% sensitivity (97% successful at correctly identifying diseased samples), it has been found to be less sensitive for samples in the field.
In a smaller environmental study, real-time PCR was able to identify the disease in all 12 infected setts and latrines sampled. However, there has been criticism of using samples from the environment in this context. Infected badgers shed M. bovis intermittently which makes the interpretation of environmental samples more difficult.
The next stage is to determine how to apply the PCR assay for bTB surveillance of wildlife on a large scale.
Is meat from cattle culled due to bTB fit to eat?
Yes. Cattle slaughtered by Defra that have tested positive for bovine TB are allowed into the food chain provided they do not show tuberculosis lesions in more than one organ or body part.
Defra applies strict guidelines for processing meat from animals which have tested positive for bovine tuberculosis. These EU-wide regulations are based upon internationally-agreed guidelines and are the same as those followed by many countries around the world, including Ireland.
The Food Standards Agency inspects this process and ensures these products are fit to eat.It states that there have been no documented cases where a person has caught bTB through eating meat and that careful safeguards surrounded the slaughtering and supply of meat to the food chain.
The European Food Safety Authority has described the threat of transmission through meat products as 'negligible'. And Defrahas categorised reports in the past that humans could be at risk of contracting TB from eating meat as "irresponsible scaremongering".
Across Britain only 0.5-1.0% of human TB cases, fewer than 40 people a year, are related to Mycobacterium bovis. The majority of these cases occur in people over the age of 45 and, according to the NHS, were probably recurrences of decades-old infections contracted before milk pasteurisation and meat inspection were common in the UK.