Fact sheet: Badgers and Bovine TB (bTB)

Bovine TB (bTB) is an infectious and contagious disease of cattle caused by the bacterium Mycobacterium bovis (M. bovis). Although the main reservoir and natural host of M. bovis is cattle, human beings and a wide range of mammals, including badgers and deer, are susceptible to the bacterium. In the 1930s, approximately 2000 people a year in the UK died from the disease, contracted either through infected milk or close contact with infected cows (1). The subsequent pasteurisation of milk and compulsory slaughter of infected cattle greatly reduced the incidences (1).

bTB is rarely fatal in cattle, with signs of infection usually only appearing in advanced cases, but it does lead to reduced milk yields, making it a particular concern for dairy farmers (2).

According to the Government, the number of cases is increasing in England and Wales, with 27,598 infected cattle slaughtered in 2007 (3). However, junior Defra minister Joan Ruddock has said that 91 per cent of cattle herds were free of it in 2008 (30). This compares to approximately 90,000 dairy cows culled annually due to mastitis (infection of the udder), 31,000 due to lameness and 125,000 due to infertility (4).

Bovine TB and Badgers 

There are less than 300,000 badgers in Britain. Protected by laws to prevent badger baiting, licences can be granted by the Government for ‘disease control’ and ‘research’ reasons. As of June 2007, there were around 10.3 million cattle in the UK (38). bTB cases have risen sharply since the 1980s and around one in six herds in Western England and Wales were put under restriction in 2007 (27).

Cattle farmers have long blamed badgers for the spread of bTB and since the mid-1970s tens of thousands of badgers have been killed in an attempt to control the disease. However, post mortem examinations revealed that more than 80 per cent of those badgers were disease free and in some infected areas no badgers were infected (5). A Defra survey from 2002 to 2004 found that six out of seven badgers killed on roads in areas of high infection were free of the disease (6).

In 1998, the Independent Scientific Group on bTB (ISG) was formed after a report by Sir John Krebs (Oxford University) claimed there may be a case for badger ‘culling.’ The ISG’s investigation included the Randomised Badger Culling Trial (RBCT), costing £34 million and taking 12,000 badgers’ lives (24). The report was published in 2007 (25) and ISG chairman, Professor John Bourne (Animal Health, University of Bristol), reported that “badger culling cannot meaningfully contribute to the control of bTB in Britain.”

The report also found that ‘culling’ would increase the spread of the disease as surviving badgers would wander outside of their normal range after their social group had been destroyed. TB infections in cattle increased by 27 per cent after the cull in areas where badgers were the main suspects (27).

Even the Government’s Agriculture Committee believe cattle movements and husbandry play a much greater role in the spread of the disease than infected wildlife (7, 8). The ISG also identified herd size and cattle movements as having “particular relevance” and that cattle-to-cattle transmission was the “main cause of disease spread to new areas”. Average herd size has more than doubled to 107 since bTB was at its lowest in the 1970s and the ISG recognised that infections increased with larger herds (25).

Bourne’s categorical findings were challenged by the Government’s Chief Scientific Advisor, Sir David King, who rushed out his own report within months, urging a ‘cull’. The King report was smaller, had fewer experts – and only met for a single day (41). Bourne and Nature, the leading science journal, heavily criticised the King report as “hastily written”, “superficial”, riddled with “small mistakes” and appeared to have been “written to please the farmers” (26). The result is that it gave the Government an excuse to instigate a cull to appease farmers should they want to.

Lords Krebs, who founded the original badger cull trials, was also highly critical of the King report. He has stated that improved cattle testing and keeping badgers and cattle separate would cost less than a ‘cull’ are “as likely to work”. He also expressed concern that a badger cull across the UK could kill at least 170,000 animals – more than half the UK population (41).

Any badger ‘cull’ will be an animal welfare disaster. Snaring and gassing are incredibly cruel but the main method is likely to be live cage traps and night shooting. With shooting, many badgers will simply be injured while traps cause huge distress. Both methods will leave cubs to starve to death in the setts, as the ISG acknowledges (25).

Until recently, Northern Ireland had the worst bTB incidence anywhere in Europe but has virtually halved it since 2002 through cattle controls and without killing badgers. It now has fewer cases per 1,000 cattle than either Wales or England (28). The Republic of Ireland has virtually eliminated badgers in most cattle farming areas yet the number of herds infected is still twice as high as in Britain (28).

In July 2008, Environment Secretary Hilary Benn announced that licences would not be issued for killing badgers in England, as he believed that ‘culling’ could make the situation worse. While in Wales, the intention to kill badgers was announced in April 2008, with the intended areas not being identified until the autumn. The move in Wales was denounced by Viva! and groups as diverse as The National Trust and The Badger Trust, as a blatant move to appease farmers. Wales’ chief vet, Dr Christianne Glossop, has admitted that badgers could be wiped out in certain parts of Wales and the ‘cull’ could last into the 2030s (36).

This rush to slaughter ignores new, non-lethal solutions. An injectable badger vaccine is expected by 2010 and an oral version by 2014 while a cattle vaccine is expected in 2015 (30).
 

Cattle Movements and testing

In 1990, there were 173 recorded outbreaks of TB in cattle but by 2007, they had increased to 2,229 with 27,598 cattle slaughtered (3). This followed the rapid re-stocking of farms after the 2001 foot and mouth disease (FMD) epidemic. Under EU regulations cattle must be routinely tested for bTB, with infected animals slaughtered and movement restrictions placed on the farms. During the 2001 FMD outbreak, most TB testing was suspended and, in breach of EU regulations, Defra failed to impose movement restrictions on those herds not tested (10).

Despite several highly-contagious diseases in UK cattle, over 14 million movements take place every year as farmers buy and sell stock (11). Just as TB cases are increasing, so are the number of movements, with 619,107 more cattle moved in 2006 than 2005 (40). Cattle movements more than quadrupled between 1999 and 2006 and involved around 110 million animals (39). Movements dropped in 2007 but only because of FMD restrictions.

Movement of cattle in the periods between routine herd TB tests has long been recognised as a cause of new infections, even in relatively disease-free areas.

The ISG report also made clear that present methods of control - surveillance, testing and slaughter - are not working. The truth is, tests are highly inaccurate, missing around one third of all infected animals, leaving them to re-infect other cattle (35). It went on to say that better farming practices and not ‘culling’ were likely to reverse the increase in bTB (25). Even former Defra Minister, Ben Bradshaw, highlighted the near irrelevance of badger slaughter by admitting that 80 per cent of bTB outbreaks are caused by cattle (11).

Farmers are compensated for every animal that is slaughtered because of bTB - up to £1,924 for dairy cows and up to £3,755 for beef cattle (32).
 

Cattle Husbandry

The demand for badgers to be killed has diverted attention away from the many serious health problems faced by intensively-reared cattle - pneumonia, E. coli, coccidiosis (a fatal diarrhoea), salmonella and mastitis. They are all increasing and it is attributed to ‘poor nutrition’, ‘poor management’ and ‘poor welfare’ by the Government’s Animal Health Report, 1997 (12). Similar considerations must apply to the spread of bTB.

Disease does not solely result from contact with a pathogen but also from an animal’s inability to deal with that pathogen. Stress reduces the body’s ability to fight disease and intensive farming produces animals who are physically and mentally stressed – none more so than the modern dairy cow.

High stocking densities increase stress, as do high milk yields and both have increased dramatically over the last 30 years. Milk has gone up from an average of 3,700 litres annually to 8-10,000 in the modern, high-yield Holstein (16). Forced to give birth to a calf every year in order to keep this enormous milk supply going, dairy cows spend seven months out of every year simultaneously pregnant and producing large quantities of milk.

This crushing double burden results in a quarter of the national dairy herd being killed every year – physically exhausted at only four to five years old when they could naturally live to be at least 20 (17). On top of this immense physical stress, dairy cows also suffer the repeated emotional trauma of having their newborn calves torn away from them within 48 hours of birth. An unbearable anguish that would take its toll on any mother.

Although dairy cows graze outdoors from April to October, for the remaining six months of the year they are confined in indoor cubicles (18). The overcrowded, unsanitary conditions and high humidity lead to high levels of lameness and mastitis. It is also an ideal environment for transmission of bTB. The Irish bTB study confirms this (15).

Cows who once grazed mainly on grass are now also fed concentrated, high-protein feeds such as soya and maize to increase their milk yields, typically forming 30-50 per cent of their diet. This seems to affect their health as grain-fed cattle can have 100 times more E. coli 0157:H7 in their gut, for example (19). This, combined with a fall in the nutritional quality of animal feed, appears to have reduced their ability to fight disease. The lack of genetic diversity in modern farmed animals also plays a part (12). Also grazing has its problems as the common practice of slurry spreading can represent a potential source of bTB (15, 22).
 

The Vegan Solution

If, like us, you are outraged by this scapegoating of badgers as a cover for cruel, incompetent and unsustainable farming practises, there is one blindingly obvious solution – reject milk and other dairy products and switch to a vegan diet.
 

References

1. Institute for Animal Health online: http://www.iah.bbsrc.ac.uk/public_info/topics/Mastitis.html

2. University of Oxford (2005). Press release: Cattle movements the most significant factor in spread of bovine TB, 26^th May. http://www.admin.ox.ac.uk/po/news/2004-05/may/26.shtml

3. Defra (2008) TB Incidences in Great Britain – Cattle. http://statistics.Defra.gov.uk/esg/statnot/tbpn.pdf

4. Sibley, R. (2003). Rethink health strategies. Farmers Weekly. February 28th 2003

5. Defra (2003). Update on Bovine statistics. TB Forum paper TBF 87, points 13-15 www.Defra.gov.uk/animalh/tb

6. Defra (2005) Road Traffic Accident Survey (RTA), 2002 – 2004.

7. Gilbert et al. (2005). Cattle movements and bovine tuberculosis in Great Britain. Nature 435, 491-496; 2005. 26 May 2005.

8. Phillips, C., Foster, C.,  Morris, P. and Teverson, R (2001). The role of cattle husbandry in the development of a sustainable policy to control M. bovis infection in cattle. Report to the Ministry of Agriculture, Fisheries and Food.

10. Wildlife and Countryside Link Statement on Bovine TB, May 2004.

http://www.badger.org.uk/tb/WCL-statement-2004.pdf

11. Badger Trust (2005) Bovine TB Strategy. Available from: www.badger.org.uk

12. Soil Association Policy Paper: Animal Health – The Prevention of Infectious Livestock Diseases (2002). Available from: www.soilassociation.org

15. Griffin, J. M., Hahesy, T., Lynch, K., Salman, M. D., McCarthy & Hurley, T (1993).  The association of cattle husbandry practices, environmental factors and farmer characteristics, with the occurrence of chronic bovine tuberculosis in dairy herds in the Republic of Ireland.  Preventive Veterinary Medicine, 17, 145-160.

16. Farm Animal Welfare Council (1997) Report on the Welfare of Dairy Cattle.

17. Roebuck (2005) Herd health and machinery integral to profitability. Farmers Guardian, May 6.

18. Defra (2002) Dairy cow welfare throughout the year. Papers presented at DEFRA/ADS meeting on 6 Nov. 2002. Easton College, Norwich.

19. Couzin J., 1998, ‘Cattle diet linked to bacterial growth’, Science 281 pp1578-1579.

20. Udris, G. A. (1983). Trace elements in the preventive treatment of bovine TB. Vet. Moscow, 2 17-20.

21. HMSO (1997). The Report of the Chief Veterinary Officer: Animal Health 1997. London: The Stationery Office.

22. Hahesy, T., Scanlon, M., Carton, O. T., Quinn, P. J. and Lenehan, J. J. (1992). Cattle manure and the spread of bovine tuberculosis. Tuberculosis Investigation Unit, University College Dublin. Selected Papers 1992, 1-6.

24. McCarthy, Michael (2008). The Big Question: Should badgers be culled to check the spread of bovine tuberculosis in cattle?. Independent. April 2006.

25. Independent Scientific Group on Cattle TB (2007). Bovine TB: The Scientific Evidence: A Science Base for a Sustainable Policy to Control TB in Cattle: An Epidemiological Investigation into Bovine Tuberculosis

26. In for the cull. Nature – International Weekly Journal of Science 450. November 2007.

27. Meikle, James (2008). Background: Badgers and bovine TB. Guardian. April 2008.

28. Badger Trust Cymru Report (2008). Facing the senseless slaughter: the fate of Wales’ badgers.

29. Gassing ruled out as a culling option. Farmer’s Guardian. 6 March 2008.

30. Bovine TB: DEFRA defends dithering government, Farmers Weekly, 21 March 2008

31. Badger culls spark tourism boycott ultimatum, Daily Post, 15 May 2008

32. Defra (2008) Compensation for Bovine TB, BSE, Brucellosis and Enzootic Bovine Leukosis

35. Lawson, Trevor (2008) Badger Trust Press release

36. Badger cull could be ‘hugely expensive’, Farmer’s Guardian, 30 May 2008

38. Defra (2007) Agriculture in the UK (2007), Chapter 3: The Structure of the Industry

39. Rural Payment Agency figures

40. Email from Kathryn Wood, Management Information Team, Rural Payment Agency, 6 June 2008

41. There are better ways to curb TB, says founder of badger cull trials, Western Mail, 24 June 2008