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“Bovine Tuberculosis (bTB) is a zoonotic disease which has persisted in cattle populations despite a stringent test and slaughter policy (Delahay et al., 2003). Britain must remain within EU guidelines on cattle TB incidence with implications for the meat trade between Britain and Europe for failure to do so (Wilkinson et al., 2004). The continued prevalence of the disease therefore has considerable scope for economic repercussions.

Badgers were first suspected as being reservoir hosts for the disease in the 1970s, with the first infected badger discovered in 1974 in Ireland (Aznar et al., 2011). Badgers are now considered to be the most significant wildlife reservoir of the disease and have been the subject of culling regimes since the 1970s (Delahay et al., 2003). Badgers are however a protected species under British law and have been since 1973 (Wilson, Carter & Delahay, 2011).

Studies into disease prevalence within the badger population have shown that 36 - 50% of badgers were infected with bTB. Badgers culled in response to bTB herd breakdown showed a higher disease prevalence than the wider population (Murphy et al., 2011).

The precise mechanics of bTB transmission between badgers and cattle is not fully understood but is considered to centre on environmental contamination with urine, faeces and sputum from infectious badgers (Delahay et al., 2003). Woodroffe et al., 2009 identified that most M. bovis strains were shared between badgers and associated cattle. This provides evidence for transmission between badgers and cattle.

Despite continued culling policies the incidence of bTB in cattle has continued to rise (Delahay et al, 2003). Field trials have shown only moderate decreases in the incidence of cattle bTB in badger cull areas with increases in neighbouring areas (Aznar et al., 2011). The Randomised Badger Culling Trial demonstrated that reactive culling completely failed to reduce TB in cattle and proactive culling was associated with”

By GlosResident1 Posted: October 09, 2012


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  • GlosResident1  |  October 09 2012, 3:18PM

    Grrr, here's the rest of what I was trying to say; a decrease in the focal areas but an increased incidence in neighbouring areas (Vicente et al., 2007). On a positive note the decrease in bTB seen in cattle during the proactive culling period also persisted one year post cessation of culling (Jenkins, Woodroffe & Donnelly, 2008). In a 2007 study by Donnelly et al. the incidence of TB outbreaks in cattle herds decreased by 23.2% in proactively culled areas, with TB breakdowns in cattle herds on the margins showing a 24.5% increase. They did however establish that successive culling increased the beneficial effect within the cull areas and decreased the negative impact in outlying areas. This form of focal culling has appeared to increase the prevalence of infection in badgers with postulations that this is due to the disruption of territorial behaviour resulting in increased transmission. Heightened prevalence in badger populations may offset the benefits of reductions in population density, potentially explaining the failure of previous focal culling strategies (Woodroffe et al., 2009). In 2007, Woodroffe et al. determined that the proportion of badgers captured close to cull boundaries increased on successive culls, providing evidence of badger movement into areas of badger removal by culling. They hypothesised that this increased movement increased badger to badger transmission thereby elevating disease prevalence, thus explaining the relatively low (19%) reduction in cattle TB. Further, Vicente et al., 2007 established that movement was directly related to the risk of individual badgers becoming infected, suggesting that higher levels of movement, for example in response to culling, increased the risk of badger infection. This is compounded by a study conducted in 2007 by Pope et al. in which genetic testing of 3450 badgers confirmed the wider dispersal of badgers captured following a second cull than those after the first cull. In particular movement exceeding 1km increased following culling. Badger culling is costly, labour intensive and unattractive to the public (Woodroffe et al., 2009). Bennet & Willis (2008) surveyed 402 households concerning badger control and, whilst 54% of respondents agreed with the statement "we should effectively manage the badger population", 73% also agreed with the statement that they "object to badgers being intentionally killed". In the face of differing statistics concerning the benefit of badger culling, with substantial evidence of increased incidence outside cull areas and heightened risk of individual badger to badger transmission increasing prevalence in the badger population it appears that randomised culling is not an effective strategy in the reduction of bTB. With strong public opinion and high costs it is unlikely that badger culling could be operated on a national scale and one could perhaps argue that ethically this would be a significantly undesirable step to take. What, then, of the alternatives? In terms of cattle controls compulsory testing and slaughter regimes for infected cattle exist. It is noteworthy that studies into the exclusion of badgers from cattle feed and housing were 100% effective when using badger-proof feed storage, gates, doors and electric fences, with the hampering factor to this being farmer compliance (Wilson et al., 2011). Given that transmission is thought to occur through the environmental contamination of cattle feed and pasture by infectious badgers, heightened biosecurity measures in these areas may contribute to significant improvement in reducing transmission rates. With 79% of farmers surveyed in Gloucestershire, Devon and Cheshire believing that whether their herds contracted TB was purely a matter of luck (Tasker, 2012) there is argument for concerted communication efforts with livestock owners. The only credible alternative to culling in the badger population is vaccination. Currently the BCG vac

  • GlosResident1  |  October 09 2012, 3:19PM

    And the rest; vaccine is available as a safe and effective vaccination for administeration by intramuscular injection, involving capture, mark and vaccination processes (Wilson et al., 2011), with the efficacy of trapping estimated at approximately 80%, sometimes less (Delahay et al., 2003). Vaccination is unlikely to disrupt territorial groups since badgers are not removed and the integrity of existing groups are maintained. Further, whilst the current technique of capturing and parenterally administering the vaccine will undoubtedly cause some level of stress it is clearly ethically preferable to indiscriminately culling animals which may indeed be perfectly healthy. Advancements of oral vaccine techniques will further improve ethical considerations in this regard. Wilkinson et al., 2004 modeled various vaccination strategies, concluding that vaccination of some individuals in most social groups was more likely to have a positive effect on disease reduction than vaccinating most badgers in some groups. Hence they concluded the number of individuals was not the critical factor but rather the number of social groups in which some individuals are vaccinated. This is however based on computer modeling techniques and is therefore prone to the vagaries of ecological and field related variables. The Badger Vaccine Deployment Project began in July 2010 and will continue for 6 years to assess whether field vaccination of badgers is a credible measure (Wilson et al., 2011). Current studies are continuing into the potential for oral administration over a sufficient proportion of badger populations (Wilson et al., 2011). Education surrounding badger vaccination is critical given the recent study by the Countryside and Community Research Institute, which demonstrated that just 25% of farmers believed vaccination would have positive effects on bTB, 19% rejected vaccination entirely and 33% felt the government's current case for vaccination lacked credibility with less than 25% of farmers having any confidence in DEFRA's ability to competently manage a vaccination strategy (Tasker, 2012). Clearly "consumer confidence" is a large obstacle to addressed. With current evidence suggesting that badger culling may be ineffective arguably increasing focus should be given to vaccination strategies.

  • TimMessanger  |  October 09 2012, 3:30PM

    Why is the cull working in Ireland?

  • GlosResident1  |  October 09 2012, 4:04PM

    Because Tim the Ecology is vastly different. They have large swathes of open countryside with nothing like the population and farming density we have over here so large badger roaming means that they are still unlikley to stumble across high density farms in the same way as they do voer here. The topography and landscape between the two are not comparable at all.

  • eyeopener  |  October 09 2012, 11:16PM

    Well done GlosResident1 for making the narrative of Bovine Tuberculosis (bTB) and badgers, from the 1970's until now; reasonably accessible to the the public at large. The fact that your report covers a number of studies shows that there is an academic consensus on the futility of culling badgers.

  • GlosResident1  |  October 10 2012, 9:39AM

    Thanks eyeopener. Not everyone will want to read such a long narrative but for those who do want to know more about it I felt compelled to list the major previous studies and summarise their results. Even if just 1 person finds it useful and informative I will have achieved something. People are welcome to have opinions on any topic but I think the best opinions are always ones which are informed and not just off the cuff :-)

  • reactiv8  |  October 11 2012, 11:12AM

    TimMessanger - The cull is NOT working in the Republic of Ireland, however Northern Ireland is free from BTB and has no Badger hating bigots thankfully. Why do you always pop up with your ignorant posts? - You can accurately be described as a 'Troll'. Any Badger slaughter will only make the majority of the public hate dairy farmers and Tories. - You will likely say "So what?" - Just wait and see ...

  • AmandaCCox  |  October 11 2012, 12:07PM

    At last some facts. Thanks for this. Hope people read it but they are probably too lazy and would rather look at pictures of cute calves like we had on the front of our local paper in the Forest...

  • GlosResident1  |  October 11 2012, 7:26PM

    Yes, I suspect many wont pass the time to read a summary of the previous work undertaken in this area but I felt it was important to allow those who did want some fact based information somewhere accessible to obtain it. I have worked on a dairy farm myself and have an interest but decisions should be reached on bias of feeling alone. The FACT is that previous and extensive culling trials have been conducted without any real meaningful impact.

  • GlosResident1  |  October 11 2012, 7:27PM

    Yes, I suspect many wont pass the time to read a summary of the previous work undertaken in this area but I felt it was important to allow those who did want some fact based information somewhere accessible to obtain it. I have worked on a dairy farm myself and have an interest but decisions should be reached on bias of feeling alone. The FACT is that previous and extensive culling trials have been conducted without any real meaningful impact.

  • GlosResident1  |  October 14 2012, 12:47PM

    A few more facts for you. In cases where badgers do subsequently contract bTB after being vaccinated the symptoms are much reduced and the animal survives. In addition, secretion of bacilli in sputum, urine and faeces is greatly reduced if not prevented altogether. In order to reduce the reproductive rate of the disease (R0) below levels at which the contagion is self sustaining it is not necessary to vaccinate EVERY badger, just a quantifiable proportion (the percentage figure of which I do not unfortunately have to hand). This is the basis for the research which concluded it is necessary to vaccinate SOME badgers in MOST groups. Hence oral vaccination techniques have a very real potential to be incredibly effective. Lets not forget that the scientists are all behind vaccination over culling.

  • nomossystone  |  November 16 2012, 10:35AM

    Thankyou for this information Glos Resident 1, this is very helpful, these details have given me a much clearer insight into the badger dilemma. I am totally against badger culls, and your information has eased my mind on the situation with these lovely creatures. Hopefully DEFRA is keeping a close eye on animal husbandry on farms in England,most of the general public have still not recovered from the shock of cattle being burned in the foot and mouth outbreak, I hope I never see another terrible outbreak like that in my lifetime!

  • Cueman  |  November 18 2012, 7:07PM

    How many badgers are there in the United Kingdom ?

  • rupertschum  |  November 18 2012, 7:59PM

    Whats the point of vaccinating badgers if they already have infection? The uninfected will need annual booster jab making an impossible task more so. In absence of vaccine disease control demands heavy culling of over populations.

  • dandypeople  |  November 02 2013, 11:47PM

    rupertschum, badgers do not need an annual booster jab, they only need to be vaccinated once. The reason for vaccinating for 4 or 5 years is to vaccinate cubs born that year and any adults that were not vaccinated the year before. You do not need to vaccinate every badger in a sett either, it has been found that vaccinating one third can produce positive effects. 'Data from the study also demonstrated that the risk of unvaccinated cubs testing positive for the disease was reduced by 79% when more than a third of the adults in their social group had been vaccinated.[60] This would suggest that not every badger need be vaccinated every year for a vaccination policy to be effective—the vaccine needs to be administered only to enough of the uninfected population to establish herd immunity.[61] What is clear is that the longer the vaccination programme was maintained, the greater would be the benefit realised.' (taken from a parliament paper). Most badgers that have btb are not infectious, vaccination will slow down the disease, so that many, if not most, will never become infectious. Those few infectious badgers, about 1.7%, will have died by the end of the vaccination period as badgers only live 4 to 5 years. Culling is required for 4 or 5 years and best reductions in btb in cattle are shown after 9 years from the start of culling so vaccination will achieve the same result in just 5 years. Badgers are not overpopulated. Predators breed according to the food and breeding site availability, if there is enough foo they will breed, if food is short they will not breed. Badger populations are higher in the west country than else where because there is more food and suitable ground for sett making. Ground suitable for cattle is also suitable for badgers. If farmers make sure that badgers cannot access cattle food, and make sure that maize crops are also inaccessible it is expected that badger populations may fall as food will be scarcer.

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