The evolution of Mycobacterium bovis and the badger culling controversy
The Future for Control Methods
In the summer of 2013 pilot badger culls went ahead; Natural England issued cull licences for use in West Gloucestershire and West Somerset. These culls were carried out to further assess the effectiveness and ethics of culling. The pilot schemes were initially predicted to last for 6 weeks. However, on the 23rd October 2013 Natural England granted an 8 week licence extension with the pilot cull ending on the 30th November 2013. The original licenses issued by natural England allow the pilot culls to be repeated for four years in West Gloucestershire. It has yet to be seen how effective these culls were.
DEFRA plan to invest £9.3 million over the next four years to aid the development of an effective vaccination for cattle.
The Badger Cull Debate
Transmission of bovine TB can occur via cattle-to-cattle, badger-to-cattle, or badger-to-badger. Therefore we need control measures to prevent all various transmission routes. Measures to prevent cattle-
to-cattle transmission include: stringent testing, movement
restrictions and slaughter of infected animals. As already mentioned badger culling has been used historically to prevent badger-to-cattle transmission. Badger culling is an extremely controversial topic with people arguing for and against this control method.
Overall studies suggest the RBCT resulted in both positive and negative implications of badger culling... to see the arguments for and against the badger cull.
Year
1800s
1935
1950
Late 1960s
1971
1973
1975
1980
1981
1982-1986
1986
1986-1996
1996
1998-2006
A timeline for the history of bovine TB control methods:
Bovine TB Controls
Here is a brief history of the attempts to contol M. bovis and an outline for the badger cull debate
Significance
During the Victorian era industrialisation led to crowding of people in large cities which were supplied with fresh milk by outlying dairy herds. This milk was a source of infection of bovine TB.
Pasteurisation of milk introduced virtually eradicating bovine TB risk to humans.
Voluntary test and slaughter programme introduced for cattle herds in the UK.
Test and slaughter programme became compulsory.
Disease only found in South West England.
Bovine TB discovered in a dead badger recovered from a farm where an outbreak of TB had taken place. A reservoir of infectious badgers in the South West of England was thought to be the reason why bovine TB persisted in this area.
‘Badgers Act’ was passed allowing only the Minister of Agriculture, Fisheries and Food (MAFF) to issue badger culling licenses to individuals to stop the spread of bovine TB.
‘Conservation of Wild Creatures and Wild Plants Act’ authorised gassing as a method to cull badgers and prevent bovine TB spread. The MAFF decided that only people under their control would be allowed to cull badgers.
Increasing incidences of bovine TB in cattle. Evidently previous control measures weren’t effective enough at preventing bovine TB spread.
Lord Zuckerman’s review began and culling was temporarily halted.
Lord Zuckerman’s review concluded gassing was inhumane so trapping and shooting were introduced as cull methods.
Review introduced the ‘clean ring’ strategy. Infectious badgers near at risk farms were identified and removed. Cleared areas were kept badger free.
A further review by Professor Dunnet suggested that badger culling was essential for the eradication of bovine TB and put forward an interim strategy. This strategy involved culling badgers only from farms where badgers were the most likely cause of a cattle herd break out of disease.
Incidences of bovine TB in cattle continued to increase.
Professor John Krebs carried out a 3rd review. This led to the introduction of the Randomised Badger Culling Trial.
The Randomised Badger Culling Trial (RBCT) took place in parts of the UK that suffered from increased bovine TB risk. The main trial area was split into 30 smaller parts which were then grouped into 10 sets of 3 parts (‘triplets’).
Three types of treatment took place:
Reactive - badgers were culled locally on farms after a bovine TB outbreak
Proactive – attempted to eradicate all badgers in the whole area
Survey – no culling took place but badger activity was monitored in the area.
