Select Committee on Environment, Food and Rural Affairs Written Evidence

Memorandum submitted by C Thomas-Everard (BTB 34)


  1.  I write having heard, at 5.45 am yesterday, a report of some of the statements made to the Select Committee by members of the ISG—as I feel our experience and conclusions may assist the Committee. I hope very much that this comment is not yet too late for you to pass to members of the Select Committee.

  2.  We farm on Exmoor and have much experience of bovine TB. It is also apposite that I write when the results of TB incidences for the whole of 2005 have just been released showing that bovine TB has worsened in this one year—27% more cows have been compulsorily slaughtered as reactors (25,373) and that 27% of all herds in Gloucestershire, 21% of all herds in Devon and 20% of all herds in Hereford & Worcestershire have been under movement restrictions during the year (3,667 herds in the SW (and 5,242 herds nationally).

  3.  Several vets tell me that the rate of spread within the badger population, and from them to cattle, may increase much more in the coming years than the average of 18% in past years. Therefore, the quoted cost of £2 billion for the next ten years to continue dealing with, but not controlling bovine TB, may be an under-estimate.

  4.  I also believe that politicians and the public should treat the controlling of the spread of TB from infected social groups of badgers to the rest of the badger population as a matter of controlling a wildlife disease, as important as stopping the spread further into the cattle population. The photograph below shows the reason.

A badger badly affected by TB, after a bite from an infected badger. The huge neck abscesses have turned to puss. This badger would have suffered for a long time before dying. EXECUTIVE SUMMARY

  My family are engaged in hill-farming and beef production on Exmoor.

  A.  We have been affected by bovine TB in our herd of over 800 cattle on seven occasions since 1993 each time coming clear after repeated testing and removal of infected cattle.

  B.  There is strong evidence that our problems have been derived from an outside wildlife source—which I believe to be TB-infected badgers.

  C.  I consider that it is possible to differentiate between infected setts, less infected setts and uninfected setts using the PCR Enigma Field Lab within 20 minutes of taking samples.

  D.  I am sure that using only snaring and shooting as the only means of killing badgers will be infective and will spread bovine TB to more herds.

  E.  I believe that treating TB-infected setts with petrol exhaust gas (properly adjusted for maximum CO emission) is easy to administer and humane. Such treatment causes minimal amount of stress and can be carried out in the daytime at a cost lower than any of the alternatives while all the members of an infected social group of badgers are asleep underground.

  F.  I believe that wherever there is a widespread area of TB-infection in sentinel cattle most setts in such areas should be dealt with by engine exhaust gas, with coordination being administered by DEFRA and the work carried out by farmers, gamekeepers and DEFRA's wildlife team. Some healthy setts, identified by PCR analysis as being un-infected could be left if the PCR machine, referred to above, is as effective as the MOD developers at Porton Down state.

  G.  If this work (F above) is done thoroughly, I believe the immediate results of having far fewer herds with TB breakdowns will mean that the cost to DEFRA of administering a cull of infected badger social groups will be less than the cost of dealing with more and more herd breakdowns, even in the first year.

  H.  I believe that if such exhaust gas treatment of infected setts is carried out effectively, bovine TB could be eradicated within 4 years to the same low level of only 0.1% of herds being under TB restriction that existed in 1980.

  I.  In order to achieve that speedy improvement, and a rapid reduction in the cost to DEFRA of over £100 million in 2006 of dealing with bovine TB, it is essential to retain the skills and knowledge of the 2 DEFRA wild life teams; 52 at Polwhele, Truro and 48 trappers at Aston Down near Stroud.

A.   Background to our knowledge

  1.  A few of our herd of 350 suckler cows and their calves were first infected by bovine TB in 1993, after being clear of TB for 34 years. At first 3 out of 657 were found and slaughtered as TB reactors. At the two next tests in June and August a further 6 cattle had picked up infection.

  2.  I believe that this infection originated from TB-infected badgers introduced into the Exe Valley after being "rescued" from MAFF traps at Chagford on the edge of Dartmoor. I understand that the spoligotype of the TB in our cattle and the infected badgers in this valley was the same as that found at Chagford.

  3.  Shortly after that first outbreak in 1993, MAFF trapped and removed all badgers here and up the valley towards Mr Rawle's farm which first had a TB breakdown (a closed pedigree Devon herd). Of the first 47 badgers, 40 were found to be infected with TB (85%), 7 with open infectious lesions. When a further 100 badgers in setts on the edge of our property where trapped, killed, examined and samples cultured, all 100 were found to be free of TB. Unfortunately the data was then generalised so that it appeared that the 40 were infected out of 147, indicating that only 27% were infected. I suspect some of the Krebs trial results may be similarly over-generalised.

  4.  After that initial outbreak, we were clear of TB infection for over 3 years and I believe this to be because those infected badgers had been removed.

  5.  Only in 1997 did we have further TB infection in the herd. 10 invasive badgers were then trapped of which 4 were found to be suffering from TB. Each year since then we have found TB in the herd when tested in the early winter, a month or more after housing.

  6.  Although we are not totally self-contained, the only cattle brought onto the farm are about 30 bulling heifers a year and the occasional bull. We have never had a TB reaction in a bought-in animal within the first two years of arrival—which would happen if the infection came from bought-in animals.

  7.  With the exception of two years we have gone clear at repeated TB testing during each on the 9 winters since 1997. In all cases the incidence of infection has reduced during winter testing. If there had been any cow-to-cow transmission of infection the TB problem would have got worse instead of improving during the winter. I am advised that cow-to-cow transmission is potentially possible during winter housing but is very unlikely during extensive summer grazing.

  8.  We know from discussion with neighbours and others that this sequence of going clear during the winter and finding infection after summer and autumn grazing is a common situation.

  9.  Because we record where each animal has grazed each month and in which group, we can identify which part of the farm gives rise to TB infection during the summer. Often the infection is picked up by and identified in young stock which tend to be more curious graziers, reaching under gates and into hedges where badgers patrol and mark their territory by urination.

  10.  Last week our herd of 808 cattle tested clear of TB. Even on severe interpretation (a 3 mm lump in the skin instead 5 mm) there were no reactors and one animal only showed as an IR (inconclusive). Last week's result was the best (fewest IRs) we have ever had. We believe this to be because we are in the Krebs proactive area in which the DEFRA wildlife team have removed most badgers. If at the next test in 60 days time we remain clear we will again be allowed to sell live cattle.

  11.  To ensure we are protected from infection from bought-in replacement breeding heifers and the occasional bull, we always put such bought-in animals on another farm, farmed by this family, which has consistently remained clear of TB. Only after a post-movement test do we transfer such heifers onto Broford Farm where the main herd reside.

  12.  For all of the above reasons we conclude that we have not had any infection from bought-in cattle and that the source of our infection has been from the TB-infected badgers found on the farm or travelling up the heavily wooded Exe Valley.

B.   Other Outside Information

  1.  The current standard, EU enforced, intradermal herd test for TB is very reliable, particularly when two tests are carried out 60 days apart. Infection picked up within 8 weeks before a test is less likely to be identified, because the bovine animal has to have time to develop hypersensitivity to any TB bacteria encountered. (For this reason the proposed pre-movement test may give a dangerous false sense of security). It seems very strange that so little notice is taken of the remarkably low annual record of TB found in slaughterhouses where every bovine animal is purposely inspected for TB. This for 2005 was only 288 animals with TB lesions found in over 3.23 million adult cattle slaughtered at the 33 UK abattoirs (with another 1/2 million slaughtered as calves). The figures for 2004 was 201, for 2003: 161, and for 2002: 163. For 2005 the figure was equivalent to 1 in every 11,215 cattle (0.009%). This figure of only 288 cattle included animals from areas on a 2, 3 or 4 yearly TB-testing regime, and therefore many such cattle would never have been TB-tested in their lives. What this minimal number of TB cases found at slaughter also surely demonstrates is that there can be very little cow-to-cow transmission.

  2.  In addition to seeing that the standard skin herd test is very effective at not missing TB infection (as shown above), if anything it is hyper-sensitive. It should be noted that for 2004 (the latest results published) only 6,413 cattle were confirmed to have TB out of the 19,972 compulsorily slaughtered in the UK as TB reactors to the skin test, i.e. 68% of the 19,972 reactors did not appear to have TB and may have been "false positives". This bears out our own results when, in the one year we tested right through the summer, we had 25 reactors over 4 tests, none of which on post-mortem were found to have TB, either by visible lesions or by culture testing. We (and the SVS vets) suspect that there was a small amount of badger-originated TB infection at pasture which sensitised the 25 cattle to TB without incurring the disease.

C.   Potential huge advantage of using the MOD's Enigma Field Lab PCR machine

  1.  This Field Lab will give a reliable result as to whether a particular social group of badgers have TB within 20 minutes of samples of badger faeces (or urine or saliva) being put in it by any un-skilled person by matching the DNA of bovine TB. Thus the Field Lab can be used to identify where the edge of any proposed badger culling area should be to avoid the culling causing dispersal of infected badgers. Thus the 29% increase in herd TB breakdowns, identified as a problem during the Krebs trial, can by avoided or mitigated.

  2.  There may be also a role in identifying some social groups within a cull area which are not infected with TB so that these can be left to repopulate culled areas. This is a hypothesis which as yet is unproven, but work on using PCR machines to identify healthy social groups of badgers on the edge of culling areas will quickly indicate the approximate proportion of healthy setts to infected ones within a cull area. Thus if a number of healthy setts can be left alive, farmers and politicians can live with an easier conscience that they are not causing local disappearance of all badgers; there will be less chance of a ruling by the EU that Articles 7 and 8 of the Bern Convention have been breached and the culling is "not detrimental to the survival of the populations concerned" in such areas; and lastly the political task of reassuring the public that the culling of infected setts is necessary to save the health of the badger population will be more easily achievable.

  3.  I attach with this comment details of this Enigma Diagnostics machine.

  4.  This device requires no laboratory skill in preparing samples, all the preparation to draw out the DNA of the sample is automated in a series of treatments in the top half of the machine (the field lab), and gives a clear positive or negative answer within 20 minutes as to whether the DNA in the sample matches the bacteria being sought.

  5.  This Enigma Field Lab has been designed at Porton Down by the MOD to give a certain and definite answer to soldiers suffering a biological agent attack as to whether anthrax or other live organism is present, and what protection to don or utilise. It is therefore designed to be soldier-proof and to be sufficiently reliable because lives depend on its accuracy. [40]

  6.  I am assured by the Porton Down personnel who designed the Field Lab that there will be a reasonable degree of accuracy if a number of samples from a badger latrine are mixed and analysed as to whether the setts adjoining the latrine are infected by TB. If a more accurate result is required then samples of badger urine or saliva will give better results also with 20 minutes. Other live tests on badgers have been very unreliable and take about a minimum of three days for an answer. If mixed samples from badger latrines proves to be effective at identifying clean setts, then farmers could send such samples to a central point by post for immediate confirmation that their sett is healthy or infected.

  7.  Enigma Diagnostics is owned by the MOD and the Treasury so any payment by DEFRA to the MOD will make no difference to the tax payer, merely causing interdepartmental accounting. Enigma Diagnostics are willing to enter into a financing arrangement once DEFRA are satisfied as to the effectiveness of this machine.

  8.  Enigma Diagnostics have already drawn down an assay of BVD (Bovine Viral Diahorrea) from University work being carried out for DEFRA and used this in the Field Lab. In the same way much time can be saved by DEFRA asking Dr Mike Taylor of the Department Of Infectious Diseases and Micro-Biology, Imperial College, London, to make his bovine TB assay available to the Enigma team. Dr Taylor has been carrying out bovine TB work for DEFRA—principally on testing cows.

D.   Reasons why snaring and shooting alone should not be adopted

  1.  I personally have a horror of snares having had a favourite terrier killed in someone else's snare. Whatever the intention, one size of "stop snare" cannot fit all size of badgers or dogs without causing very serious injury or death to larger animals.

  2.  I understand the law on snaring is that snares have to be inspected every 3 hours. In the case of badgers, which as a specie, are very wary, this requirement, although necessary for welfare reasons, is likely to reduce the number of badgers snared and will have a very high man-hour requirement. Once the method of culling badgers in the 1980's was changed DEFRA found that there was a fivefold increase in the number of personnel required to trap badgers compared to the previous regime. The earlier method of culling, when eradicating TB from the whole Thornbury area near Bristol and the Isle of Purbeck in Dorset, was by gassing with Cymag (made illegal under EU law from January 2005).

  3.  In reality if farmers have to do the snaring themselves, the pressure of other farming tasks is likely to mean that many snares will be set in the evening and only inspected in the morning. There is therefore a likelihood that dogs, cats and deer may be caught and die in extreme pain in such snares.

  4.  Having listened to many farmers about this subject I find that few want to take part in a campaign of snaring alone.

  5.  I understand that when badgers are caught but not killed in a "stop snare" they will demolish a bank, or undermine a small tree to try to free themselves. They also try every possibly way to get free including twisting the wire into a tight spiral or excessively tightly around and around themselves.

  6.  Setting snares on visible badger runs will merely weaken the social structure of a group of badgers by killing the healthy dominant males, which regularly patrol the boundaries of their territory, leaving sick TB-infected older badgers either in the sett or ejected to travel randomly. Removing the settled dominant male will cause fighting for territory.

  7.  Bites from infected badgers fighting hither-to uninfected badgers will cause the type of disease symptoms and wounds shown in the photograph at the beginning of this comment.

  8.  I believe that Appendix IV and Article 8 of the Bern Convention ban the use of indiscriminate means of killing badgers and prohibit the use of snares on badgers (unless exempted under Article 9 if "there is no other satisfactory solution").

  9.  If badgers are only to be snared or shot, then the current rule that a close season should be observed while badger cubs are reliant of a lactating sow is likely to apply. For the past 8 years of the Krebs trial, the DEFRA wildlife team has observed a close season from February to April in each year. However, it is now realised that, with milder weather, many badgers have far better winter feed and often make intensive use of crops of fodder maize. This has resulted in badger cubs being born outside of the normal late January / February season. If it is proper to avoid killing badgers when lactating sows may still be feeding their young then, by extension if sows are having two litters in a year or in eighteen months, the close season should match the period when neonatal cubs are suckling and there may therefore be almost no season when badgers should be snared or shot.

  10.  Relying on shooting badgers at night by rifle from a cross country vehicle in motor-able fields within 100 metres will be very piecemeal, and will cause dispersal of TB-infected badgers as the remaining ones fight for territory (so-called "perturbation"). I understand that badgers are much more shy at night than foxes and disappear when they see a light moving in a field.

  11.  I believe that only a minority of farmers own and have firearm certificates for rifles of sufficient size (.223) to kill badgers properly (ie a .22 rifle is too small). However well practised and competent the rifle user may be, the high rate of wounding in any mass attempt to cull sufficient badgers at night would cause far more suffering than treating badger setts with car engine exhaust in the daytime while the occupants sleep.

  12.  Snaring and shooting should only be used as a last resort where car exhaust cannot be used, such as dealing with a very sick badger which seeks shelter in farm buildings and has been thrown out of his old sett by his family. The fullest possible toolbox should be available to ensure a really complete cull of infected setts. For this reason cage trapping by the DEFRA Wildlife Teams may also be necessary (see page 10).

  13.  Very sadly, in the last 18 months, one teenager was accidentally shot by his stepfather while lamping foxes, and another person suffered a punctured lung (and nearly died) from a rifle shot while watching a badger sett at night in similar circumstances. Such accidents may be even more probable if large parts of the SW and West Midlands are peopled at night by farmers desperate to go clear of TB reinfection, or to prevent TB affecting their herd.

E.   Petrol Engine Exhaust Gas

  1.  In contrast to snaring and shooting, petrol engine exhaust will kill an entire TB-infected social group at once. These means that any suckling cubs will be culled as they sleep beside their dam, so that there is no need for a close season. This means that setts can be culled concurrently across a whole infected area on the same day, minimising movement or dispersal of lone badgers and avoiding territorial fighting. If a number of the healthy setts are left entire, the social groups in them will not be weakened.

  2.  The sickest badgers tend to be ejected out of the main sett as soon as overcrowding occurs. These TB sufferers will be ejected by their progeny in the normal way, but because there will then be many empty badger setts to which such sick badgers can retire, they will move to such empty setts and drag out old carcases.

  3.  Twigs should be placed across the entrances of previously gassed setts after gassing and inspected regularly. As soon as fresh nomadic badgers are seen to have entered the sett it should be gassed again. This should thereby catch any TB-infected badgers which have been ejected from the healthy setts.

  4.  The DEFRA desk study records that normal petrol engine exhaust contains about 2% Carbon Monoxide (CO) when idling with adjustment to the carburettor to limit the air. American studies shown on the internet quote CO from an American petrol engine as being 12% and 24% if "detuned".

  5.  The DEFRA report states that petrol engines produce about 6% carbon Dioxide (CO2) and that CO2 increases the breathing rate and speeds absorption of CO. It concludes that 1 % CO in 1 hour is a lethal concentration.

  6.  Carbon Monoxide is odourless and colourless. If done quietly, a sett-full of badgers, which sleep by day, can be treated while they stay asleep. CO induces a deeper sleep followed by a painless death. I understand the main side effect, if any survive, is normally only a headache and nausea.

  7.  I understand from reading the DEFRA paper that, by computer modelling only, the authors concluded there would be a slower dispersal of exhaust gas into blind tunnels. In practise however exhaust gas can be seen on a cold day to mix rapidly with air. My very limited understanding of physics is that, by diffusion, gases and vapours mix and reach an equilibrium. Avogado's law, "that equal volumes of gases, at the same temperature and pressure, contain the same number of molecules" indicates this, unless the gas is particularly heavy, or very light e.g. hydrogen.

  8.  Because there are plenty of gas concentration measuring devices available commercially as gas alarms for domestic and marine use, the dispersal rate of exhaust gas in blind tunnels can rapidly be determined.

  9.  Most large badger setts have extensive links to a number of outlets and have, in addition, ventilation holes in the main accommodation. Treating a large and complex sett can therefore be done by watching for the exhaust gas to emerge and after sufficient time blocking each exit and ventilation hole. Any hole where exhaust gas does not emerge can then be treated separately. Adding an odourless colouring agent to the petrol to make it easier to see where exhaust gas emerges would be beneficial. I understand that most recent experience of engine exhaust gassing has been that of dealing with heavy infestations of rats or rabbits in banks.

  10.  The DEFRA report confirms that diesel exhaust contains at most 0.2% CO and should not be used.

F.   Selecting a widespread area of culling infected setts

  Where TB infection in the sentinel cattle indicate that TB is in some of the badgers within an area, the setts in that area should be dealt with by the most humane and effective manner. If possible PCR analysis should be used to identify uninfected social groups. It seems essential that coordination of such culling should be administered by DEFRA and the work carried out by farmers, gamekeepers and DEFRA's wildlife team. Such a cull should be carried out within a short time scale preferably, on the first occasion in an area, on the same day.

G.   Cost to DEFRA could be less than the cost of continuing to test increasing numbers of cattle and the other component costs in failing to control TB

  1.  If this work (F above) is done thoroughly, I believe the immediate results of having far fewer herds with TB breakdowns will mean that the cost to DEFRA of administering a cull of infected badger social groups will be less than the cost of dealing with more and more herd breakdowns, even in the first year. Our own experience has usually been that once the source of the TB infection, infected badgers, was removed, the following TB test of the cattle proved them to be free of TB. Where TB-infected badgers (85% with infection) lived, the cattle TB test at the end of the grazing season (when cow to cow transmission is highly unlikely) proved a few cattle in the herd were positive to fresh TB infection (less than half of one percent). However even those very few infected (usually young) cattle caused a period of further testing (testing being the main element, £36 million, in the costs to DEFRA of dealing with TB).

  2.  Thus the reduction to be brought about in the spread of TB to fresh healthy badgers and from them to healthy herds will give an immediate reduction in the biggest item in DEFRA's TB costs.

H.   Eradication of bovine TB within 4 years

  1.  To stop the suffering of badgers, the distress to farmers, the loss of productive animals and the escalating cost of over £100 million a year which has failed to control TB, the target surely must be to use all practical measures possible to eradicate (or at least to reduce bovine TB incidence back down to 0.1%. In only 20 years of procrastination bovine TB has worsened from less than a 100 herds affected to 5,634 herds in 2005 and from 686 cattle killed as reactors to 20,119 cattle. I believe that if all practicable steps are taken bovine TB can be brought down to a minimal level within 4 years.

  2.  The very removal of infected setts will cause a substantial reduction in the overcrowding and competition for territory that currently causes TB to spread from one badger social group to another and to cattle. Where older badgers are sick with TB they will be ejected by their progeny in the normal way, but, because there will then be many empty badger setts to which such sick badgers can move, they will move to such empty setts and drag out old carcases. Thus old TB sick badgers are much less likely to go into farm buildings looking for any form of shelter.

I. Retain the DEFRA wildlife team

  1.  In order to achieve a speedy improvement, and a rapid reduction in the cost to DEFRA of £ 90.5 million in 2005 (forecast to rise to over £120 million in 2006) of dealing with bovine TB, it is essential to retain the skills and knowledge of the 2 DEFRA wild life teams; 52 at Polwhele, Truro, and the 48 trappers at Aston Down, near Stroud.

  2.  This is not as great an immediate cost as may be supposed because only 20 of the skilled wildlife trappers have contracts which terminate shortly. The cost of the retention of these 100 highly skilled people should be borne by DEFRA until TB is brought under control.

  3.  The fact that bovine TB is out of control is essentially because successive Ministers have abrogated their governmental responsibilities by refusing to make a decision to control the infection in badgers before it got out of hand. Ministers have tolerated TB-infected badgers spreading infection to other healthy badgers, and to cattle, almost wholly for political reasons.

  4.  Until Ministers confirm their decision to control TB in infected badger setts, the skilled trappers should continue to be employed. They should use the time to identify healthy badger social groups at the edge of infected areas, while the ground is soft enough for tracking, and before the growth of leaves, shrubs and grass in the Spring obscure the badger setts.

  5.  A great advantage of retaining the 100 trappers is that they can, legally and with their specialist skills, trap badgers where it is desirable to do so. This will include live trapping within infected areas on the boundaries of properties where the owner will not allow anyone access, and in situations where it is helpful to take saliva or blood samples directly from live badgers to confirm that the spoligotype of the TB in the badgers matches that of TB in the adjoining cattle.

J.   Information source

  At present much veterinary advice is that cattle are acting as sentinel animals revealing a wildlife problem. I can only end by saying that coalminers would not have survived long if the mine-owners had merely killed all sentinel canaries and taken no other action to prevent fire-damp explosions.

  Much of the knowledge about the behaviour of families and social groups of badgers in this paper comes from Mr Bryan Hill. Mr Hill has made a very through study of the behaviour of many different social groups of badgers. I recommend very strongly that anyone who is in a position of responsibility as to the choice of methods of controlling bovine TB should talk to Mr Hill.

February 2006

40   You can also go to the Porton Capital website at the web address To enter the demonstration part of website, type in the username as porton and the password as down. There is a video entitled "Out of the lab" which you can view. For further information contact Dr Ian George, Business Development Director, Enigma Diagnostics Ltd, Building 224, Tetricus Science Park, DSTL, Porton Down, Salisbury, Wiltshire SP4 0JQ. Back

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