Memorandum submitted by the National Federation
of Badger Groups
BOVINE TB
1. INTRODUCTION
The NFBG welcomes the EFRA Committee's continued
focus on the problem of bovine tuberculosis in cattle. This review
is particularly timely. It comes in the wake of a prolonged media
campaign driven by the farming unions, which aims to persuade
policy makers and the wider public that badger culling is vital
if bovine TB is to be controlled in the national herd.
Regrettably, many farming correspondents in
the media have lent weight to the farming unions' campaign by
reporting on badger issues alone. This extraordinary and inexplicable
bias has left many farmers feeling that there is no alternative
to badger culling. But there is an alternative—the gamma
interferon test—a highly advanced diagnostic test which
is already in use from Europe to Australasia, but which appears
to be poorly understood by farming unions, veterinary professionals
and DEFRA officials alike in the UK.
We hope that the Committee will take this opportunity
to tease out:
— Why DEFRA has failed to assess the
sensitivity and specificity of the gamma interferon test and wasted
time and tax payers' money, instead, on a flawed trial which its
own advisors warned would not provide adequate policy information.
— What the National Farmers Union and
its allies know about the gamma interferon test (particularly
with regard to its reliability), when they were provided with
key information about the test and what steps they have taken
to inform their members about the great opportunity offered by
the test.
— On what evidence DEFRA claims that
the gamma interferon test has a "lower specificity"
and is "more costly" than the intradermal skin test
(DEFRA, 2004), when DEFRA has not undertaken proper field trials
or, so far as we know, conducted an up to date analysis of the
cost benefits of implementing the test.
Seven years after the hugely expensive randomised
badger culling experiment began, we are still no closer to being
able to measure precisely the role that badgers do or do not play
in bovine TB in cattle. Indeed, after killing thousands of badgers
at a massive cost to the public, we are now advised that Professor
Sir John Krebs' grand trial will never provide the key answers
that it initially promised.
Instead, we find ourselves no further forwards
than in 1998 when the Krebs trial began: the Government still
has no coherent Plan B. Farmers and conservationists alike are
trapped in an endless cycle of consultations about TB control
strategies, in which DEFRA fails to provide an evidential basis
for any particular policy approach and, in the case of gamma interferon,
appears to be actively briefing against this test despite evidence
confirming its potential.
It is our view that DEFRA may have changed its
name since its reform in the wake of foot and mouth disease, but
it remains incapable of:
— implementing coherent, intelligent
research strategies;
— analysing scientific research and
advancing policy strategically; and
— communicating new information effectively
to farmers and other stakeholders.
The more that we have learned about the gamma
interferon test, the more we are persuaded that DEFRA has been
at the very least incompetent and perhaps, at worst, even negligent
in assessing its potential. Bovine TB is spinning out of control
whilst a likely control mechanism is available. We strongly urge
the Committee to do all it can to alert Ministers and farmers
alike to the potential of the gamma interferon test so that it
is implemented before bovine TB is so endemic in the national
herd that bringing it under control becomes prohibitively expensive.
2. THE GAMMA
INTERFERON TEST
The NFBG has previously outlined its concerns
over flaws in the tuberculin skin test and the lack of progress
being made by DEFRA with the gamma interferon test (NFBG, 2003a).
Whilst DEFRA has done little or nothing to report on the merits
of the gamma interferon test, the NFBG has extensively researched
the current research situation and the advantages of the test.
We make the following observations:
2.1 DEFRA's gamma interferon field trial will
not effectively inform future policy options
Contrary to advice from the Independent Scientific
Group (ISG), DEFRA's field trial is not assessing gamma interferon's
specificity and sensitivity. These two factors are essential if
DEFRA is to calculate the cost benefit of using the test in the
UK.
Sensitivity is the proportion of true positives
detected by a diagnostic procedure. For example, if 100 infected
cattle were tested and 90 detected, the test would have a sensitivity
of 90%. The remaining 10% of infected cattle would be false negatives.
Sensitivity needs to be high where bovine TB incidence is high,
as it is in the south west, parts of Wales and the west Midlands,
so as to remove as many infected animals as possible from the
population being tested.
Specificity is the proportion of true negatives
detected by a diagnostic procedure. For example, if 100 uninfected
cattle were tested and 90 were determined to be disease-free,
the test would have a specificity of 90%. The 10% misdiagnosed
by the test would be false positives. Specificity needs to be
high where bovine TB incidence is low, such as in much of Scotland,
northern, southern and eastern England, to avoid the needless
slaughter of uninfected cattle.
Most countries that are now using the test as
a diagnostic tool first conducted their own trials to assess the
sensitivity and specificity of the test under their environmental
conditions. Such countries include Australia (Wood et al,
1991), New Zealand (Ryan et al, 1998), the US (Whipple
et al, 1995), Italy (Dondo et al, 1996) and the
Republic of Ireland (Neill et al, 1995; Monaghan et
al, 1997). Yet no field trial has been undertaken in the UK,
more than a decade after the test was first shown to be effective.
It has been suggested that the gamma interferon
test generates too many false positives and would lead to the
needless slaughter of many livestock. This is a false premise.
It assumes that the gamma interferon test is fixed in application.
On the contrary, specificity can be "turned up" and
sensitivity "turned down", and vice versa, according
to the circumstances in which the test is being used, by using
different antigens and different cut-off points.
It is also important to understand that "false
positives" may in fact be true positives, but technology
does not allow us to confirm them as such.
For example, false positives are defined as
cattle that test positive to the gamma interferon test but, when
slaughtered, are found to have no visible lesions on examination
post mortem and M bovis cannot be cultured from tissue samples.
However, the culture of bovine TB can be difficult and sometimes
impossible even when livestock have been intentionally infected
with large doses of bacteria.
Therefore, a classically defined false positive
result does not necessarily mean that the gamma interferon test
was wrong. It can instead be the case that culture is not capable
of confirming the result. This, in turn, causes specificity to
be underestimated and the number of false positive cattle to be
over estimated.
This problem can be circumvented by determining
the specificity of the test through field trials on uninfected
herds, in non-TB areas. The trial must include thorough post mortem
examinations. DEFRA's field trial, in stark contrast, is being
conducted in herds with bovine TB.
2.2 DEFRA is making misleading claims about
gamma interferon
2.2.1 DEFRA claims that the test "has
slightly lower specificity than the skin test used in the UK"
(DEFRA, 2004).
Since DEFRA is not conducting trials to assess
the specificity of the gamma interferon test in the UK, we fail
to see how DEFRA can justify its assertion.
2.2.2 DEFRA claims that "it may, in time,
be possible to increase the specificity of the gamma interferon
test by including recently identified antigens in the test"
(DEFRA, 2004).
DEFRA's consultation document was published
in February 2004, but research published as long ago as 2000 has
reported that significant progress has already been made in improving
the specificity of the gamma interferon test through the use of
M. bovis antigens (Pollock et al, 2000; Van Pinxteren et
al, 2000; Vordermeier et al, 2001; Buddle et al,
2003).
For example, four years ago, scientists reported
that the use of a specific M. bovis antigen (ESAT-6) increased
the sensitivity of the gamma interferon tuberculin test from 88.3%
to 99.2% (Pollock et al, 2000). Similarly, in November
2003, scientists (including two from the UK Government's Veterinary
Laboratories Agency) reported that a combination of two M bovis
antigens (ESAT-6 and CFP10) resulted in "significantly fewer
false positive reactors . . . than with the standard gamma interferon
test", but without reducing its sensitivity (Buddle et
al, 2003).
It therefore appears that DEFRA is either: (a)
not keeping abreast of current research, even when some of the
work is being conducted by its own scientists; (b) failing to
understand the research, resulting in a failure to allow scientific
progress to influence Government policy; or (c) intentionally
briefing against the gamma interferon test in order to avoid incurring
the cost of introducing the test.
2.2.3 DEFRA claims: "(the gamma interferon
test) is more costly than the skin test" (DEFRA, 2004).
The unit price of a single gamma interferon
test may be higher than a single skin test, although DEFRA has
not published up to date data to support this claim. However,
to focus on the cost of testing an individual animal is highly
misleading.
When all the costs associated with herd testing
are considered, the gamma interferon test can generate significant
cost savings by:
— Reducing the length of time a herd
is under movement restriction.
— Removing the need to visit stock
twice, as required for the skin test.
— Reducing veterinary and labour fees
by reducing the time spent on testing.
— Reducing the number of rounds of
testing required clearing up infection due to the test's increased
sensitivity (Wood and Jones, 1998).
Costs can be further reduced as the number of
tests increases economies of scale and by ensuring competition
between laboratories conducting the test.
The NFBG suspects that DEFRA's cost calculations
from 2001 (DEFRA, 2001) are now out of date and have limited value.
For example, a significant part of the economic cost of a TB outbreak
is the detection of false positive cattle (Pollock et al,
2000). If, in its calculations, DEFRA used specificity data that
were too low, the cost of an outbreak will be artificially raised.
We would therefore urge the Committee to investigate
why DEFRA has not conducted full and proper cost benefit analyses
of using the gamma interferon test. We would be particularly interested
to know whether DEFRA has calculated the cost of not implementing
the gamma interferon test, given the recent alarming rise in the
disease. How much money might have been saved already, had the
test been introduced years ago?
2.3 The gamma interferon test has key advantages
over the tuberculin skin test
The sensitivity of the tuberculin skin test—ie
its ability to detect infected cattle—can be relatively
low and varies from 68-95% (Monaghan et al, 1994). The
specificity of the test can also be low, resulting in false positive
reactions in cattle that have been exposed to mycobacteria other
than M. bovis (Snider, 1982). In Britain, specificity has been
slightly improved through using the comparative skin test, where
responses to M. bovis and M. avium are compared. However, the
test remains crude and unreliable.
Scientists have recognised for some years that
more specific and sensitive tests are needed, particularly in
countries where the incidence of bovine TB is low (Wood et
al, 1991). The gamma interferon blood test was therefore developed
in around 1990 (Wood et al, 1991). At that early stage,
some thirteen years ago, scientists identified key advantages
of the gamma interferon test over the tuberculin skin test. And
as the test has been researched, developed and refined, these
advantages have become clearer.
2.3.1 Key advantages of the gamma interferon
test
— Detects cattle in the early stages
of infection (Neill et al, 1994; Domingo et al,
1995);
— Detects infected cattle that fail
to respond to the skin test due to repeated testing (Wood et
al, 1991; Dr Chris Howard, unpublished data);
— Demonstrates higher specificity and
sensitivity in trials, resulting in fewer "false positive"
cattle, especially when using a cocktail of M bovis-specific antigens
(Vordermeier et al, 2001; Buddle et al, 2003);
— High sensitivity means that the test
is ideally suited to situations where bovine TB is spreading rapidly
and the detection of as many diseased cattle as possible is desired
(Wood and Jones, 1998);
— Can be used in parallel with the
skin test to detect almost all infected cattle (Wood and Jones,
1998);
— Designed to test for M bovis and
M avium at the same time (Wood and Jones, 1998);
— Cheaper in operation that the skin
test, due to factors such as enhanced specificity and sensitivity;
reduced length of time herds are under movement restrictions;
and reduced veterinary time and labour;
— Reduces the costly option of total
herd de-population (Wood et al, 1991);
— Distinguishes between cattle vaccinated
with BCG and cattle infected with M bovis;
— Effective for large-scale field testing
(Wood et al, 1991);
— Sensitivity and specificity can be
adjusted according to the purpose for which it is being used (Wood
et al, 1991);
— No second visit is required, reducing
stress on cattle difficult to handle;
— Analysis of results is more precise,
rather than a subjective assessment of a skin reaction by a veterinary
surgeon;
— Test is non-invasive and does not
compromise cattle immune system, so can be used repeatedly without
delays. In contrast at least 60 days must elapse between skin
tests due to its impact on the immune system;
— Test can be readily implemented by
lay testers, reducing the cost of test to the Government.
2.4 NFBG recommendations
The NFBG recommends that the Government:
— Conducts the current gamma interferon
trial according to the methodology proposed by the ISG (ISG, 2002).
This will ensure that data are collected on the specificity and
sensitivity of the test in the UK and will enable the consideration
of future policy options;
— Introduces the gamma interferon test
for herds: (a) with multiple reactors, inconclusive reactors or
persistent infection and (b) subject to pre-movement testing;
— Implements both measures above immediately,
while simultaneously accumulating further data.
3. THE BOVINE
TB EXPERIENCE IN
IRELAND
Interesting developments are being made in both
Northern Ireland and the Republic of Ireland, including the use
of the gamma interferon test. The NFBG would therefore welcome
an analysis of the experiences in both countries. In particular,
we hope that the Committee will be able to draw out the coherence
of the bovine TB control policy in the Republic of Ireland and
be able to determine the extent to which individual control strategies
are influencing the incidence of bovine TB in cattle.
The NFBG is particularly interested in the extensive
references to Ireland's Four Areas Badger Study, made by both
farming unions and, more recently, the Godfray report. We were
surprised to see Professor Godfray make such clear statements
about research which is, as yet, unpublished in a peer-reviewed
journal.
We are also surprised at how others are apparently
well informed about the study, given that Professor Dan Collins
who heads it has refused to provide us even with the statistical
methodology, let alone the results. We hope that a head of steam
about the research is not being built up prior to its publication,
in order to be released so as to obscure any balanced assessment
of its possible deficiencies.
The NFBG has attempted to investigate the Four
Areas Badger Study and has obtained limited information from a
number of sources. Regrettably, the individuals who undertook
the research have declined to explain their methodology to us.
Our main observations are as follows:
(a)
On 31 May 2003, the BBC Radio 4's Farming Today programme
reported on the Irish study and quoted Dr Leigh Corner as follows:
"If you take the year of the study compared to the average
of the pre-study rate it (the reduction) is in the order of 70-80%.
I think in one area it was 90% reduction in reactors." The
NFBG was inevitably alarmed by these findings. They suggest that
if enough badgers are killed, bovine TB can be virtually eliminated
from cattle.
We contacted Professor John "Dan"
Collins and requested details about the scientific methodology
of the study. In particular, we wanted to know how the statistical
comparison was made between the "core" culling areas
and the control "reference" areas where, ostensibly,
no culling took place. Professor Collins refused to explain the
methodology to us and told us that the results were due to be
published in a peer-reviewed journal in June 2003. We understand
that no such paper has yet been published;
(b)
The NFBG contacted the Irish Government for clarification.
Margaret Good of the Department of Agriculture Food and Forestry
in the Irish Republic confirmed to us that "badger removal
operations" were also undertaken in the so-called "reference"
(control) areas of the Four Areas Badger Study, during the course
of the study (Margaret Good, pers com). The reference areas are
ostensibly similar to the scientific "controls" in the
no culling "survey only areas" in the Krebs trial. As
badger removal operations also took place in these reference areas,
they are not true scientific controls. It is unclear how the researchers
will draw meaningful conclusions from the results of the study,
unless they can accurately quantify the extent of culling in reference
areas and make a valid statistical assessment of its implications;
(c)
The NFBG has also been advised that badger removal
operations took place in some parts of some of the core areas
prior to the start of the Irish study. In some areas, these removals
were extensive. If these removals were similar to the reactive
culling operations undertaken in the Krebs trial, then the level
of bovine TB in those areas could have been artificially increased
before the Four Areas Badger Study began. By implication, any
subsequent reduction in bovine TB detected by the study would
be artificially exaggerated;
(d)
The Independent Scientific Group on Cattle TB (ISG)
also suggests that the Irish study may over-estimate the effectiveness
of culling. The ISG also points out that the Krebs trial is a
far larger-scale study than that undertaken in Ireland (Donelly
et al, 2003);
(e)
Farming unions and others have been keen to claim
that the Irish study reduced bovine TB by 90% through badger culling.
However, thus far, no data have been published to suggest that
the Irish have solved their bovine TB problem. Far from it: we
have obtained data from the Department of Agriculture and Food
on the number of herds under movement restrictions in each of
Ireland's 26 counties. The figures were provided to the Committee
last year (NFBG, 2003). At the time, we made two observations
on these limited data:
— In the counties where the Four
Areas Badger Study has been in progress, there has been no discernable
improvement in bovine TB vis a" vis other counties;
— Nationally, 6.5% of herds were
under movement restriction in 2002, compared to 3.3% of British
herds in 2002 and 3.2% in 2003 (DEFRA, 2004b);
(f)
The NFBG has seen little reference to the welfare
of badgers in published papers on the Four Areas Badger Study.
In particular, we have received reports of snares set on banks—where
badgers typically make their setts—with the results that
badgers can hang by the neck on a wire noose for many hours prior
to despatch. The Committee may wish to ask what independent assessment
of the welfare of badgers in the Four Areas Badger Study has been
undertaken and what are the implications for animal welfare if
snares were to be used in the UK.
4. BADGER CULLING
IS NOT
THE WAY
FORWARDS
Evidence is constantly accumulating to indicate
that a badger culling policy will not control bovine TB in cattle
or be cost effective (Delahay et al, 2003; Donelly, et
al, 2003; EFRA, 2003a; Bennett et al, 2004).
We noted with interest that, when the Krebs
trial apparently showed that reactive badger culling increased
bovine TB in cattle by 27%, the NFU's animal disease spokesman
Anthony Gibson claimed that the NFU had long advocated a proactive
badger-culling policy (Western Morning News, 2003), when the NFU's
previous evidence to the EFRA Committee called for reactive culling
(EFRA, 2003b). It seems that, as the scientific evidence mounts
against their policies, the farming unions become more extreme
in their demands. This culminated in the outgoing NFU President,
Ben Gill, calling for the reintroduction of badger gassing. He
produced his own "scientific" report which lacked any
scientific justification for his proposals. Gill went so far as
to claim that gassing was "humane" (Gill, 2004).
We were even more surprised this month to see
the Conservative spokesman on agriculture, Owen Paterson, campaigning
for "targeted" badger culling in TB hotspots. We hope
that Mr Paterson will precisely outline the scientific justification
for his policy and its costs and benefits.
Those who have already called for badger culling
have been rather reluctant to justify the policy. In June 2003,
the NFU led a number of organisations in publishing a "statement
of recommendation" for the control of bovine TB, including
"reactive" badger culling (NFU et al, 2003).
We were surprised that professional veterinary bodies endorsed
the statement and we wrote to all the statement's signatories,
asking them to answer a number of key questions. These questions
remain just as valid today but, so far, none of the statement's
signatories have been prepared to answer the questions. The Committee
may be able to secure answers to some of these questions in the
course of its inquiry. A selection of the key questions can be
found at APPENDIX I.
5. BOVINE TB
VACCINES
The NFBG takes the view that TB vaccines must
be part of a long-term strategy to control bovine TB in cattle.
However, there are many questions that need to be addressed before
a vaccine for cattle or badgers can be introduced. We therefore
agree with the conclusions of the vaccine scooping study, published
in 2003, which concluded that research on both cattle and badger
vaccines should continue and that efforts be made to ensure that
the work is funded in full (Bourne et al, 2003). We also
agree that, in the meantime, other disease control measures should
be implemented. The NFBG has outlined its proposals elsewhere
(NFBG, 2003b).
We understand that scientists are currently
evaluating the use of two forms of BCG vaccine in cattle. The
first involves neonatal vaccination of calves. The second involves
"prime boosting"—vaccinating cattle with BCG then
boosting its effect with M bovis DNA. Both forms of vaccine have
shown promise in experimental trials but need to be further tested
in natural transmission studies, followed by full field trials
(Glyn Hewinson, pers com).
Further work also needs to be conducted in developing
a diagnostic test for TB in cattle that distinguishes between
(a) infected cattle and (b) vaccinated cattle that have been exposed
to M bovis. One reason for this being important is that a vaccine
is unlikely to provide protection to all vaccinated animals.
The vaccine scooping study also concluded that
there are "significant scientific hurdles" to consider
and overcome with a badger vaccine, even before it gets to the
point of field trials. An obvious unknown is the likely effectiveness
of a badger vaccine in controlling TB in cattle, when the role,
if any, of the badger is currently unclear. And as with a cattle
vaccine, a diagnostic test will be required. Progress is being
made in this area with an improved ELISA test but specificity
and sensitivity needs further improvement (Greenwald et al,
2003). We also believe that other factors such as ethical, economic
and practical issues will also need to be resolved.
6. ECONOMIC IMPACT
OF BOVINE
TB
DEFRA has commissioned a study of the economic
impact of bovine TB by researchers at Reading University (Bennett
et al 2004). We are extremely disappointed that DEFRA has
not widely publicised the results of the study and has not even
issued a press release on the subject.
We noted, with particular interest, that the study
concluded that a proactive badger culling strategy would be relatively
very costly (even without attaching any value to badgers themselves)
and such a strategy would have to result in very large reductions
in the incidence of TB in cattle to be considered worthwhile from
an economic (cost-benefit assessment) perspective.
7. REFERENCES
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policies. www.defra.gov.uk/animalh/tb/
Bourne et al (2003). Development of vaccines
for Bovine Tuberculosis. Report of the Independent Scientific
Group Vaccine Scoping Sub-Committee. July 2003. www.defra.gov.uk/animalh/tb/publications/index.htm
Buddle, B M, et al (2003). Use of mycobacterial
peptides and recombinant proteins for the diagnosis of bovine
tuberculosis in skin test positive cattle. Veterinary Record 153,
615-620.
DEFRA (2001). Gamma interferon feasibility trial.
Objective 4. To evaluate the feasibility of using the gamma interferon
test in reactor herds, as the basis for a larger field trial.
APPENDIX to TB Forum paper TBF 62, January 2002.
DEFRA (2004). Preparing for a new GB strategy
on bovine tuberculosis. Consultation document. February 2004.
DEFRA (2004b). TB statistics January-December
2003. www.defra.gov.uk/animalh/tb
Delahay, R J et al (2003). Bovine tuberculosis
in badgers: Can culling control the disease? Conservation and
Conflict, pp 165-171, Westbury Publishing.
Domingo, M, Liebana, E, Vilafranca, M, Aranaz,
A, Vidal, D, Prats, N, Mateos, A, Casal, J and Dominguez, L (1995).
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tuberculin test in dairy cattle in Spain. In: Griffin F and de
Lisle G (ed) Tuberculosis in Wildlife and Domestic Animals. Otago
Conference Series No 3. University of Otago Press, Dunedin, pp
304-306.
Dondo, A, Goria, M, Moda, G, Cesano, L, Garanzini,
A, Giammarino, M, Minola, G, Moriconi, E, Porta, G, Banchio, P
and Marmo, G (1996). Gamma interferon assay for the diagnosis
of bovine tuberculosis: field evaluation of sensitivity and specificity.
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cattle. Nature, 426, 834-837 Letters to Nature (18 Dec 2003).
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on Cattle TB.
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8. APPENDIX I
Questions asked by the NFBG of signatories to
the "statement of recommendations", June 2003 (NFU et
al, 2003).
1. You state that TB should be eradicated
in both "cattle and wildlife". Since bovine TB is found
in many wild animals other than badgers, how might TB be eradicated
in wood mice, shrews, stoats, deer and the other mammals in which
it is found?
2. Specifically, is it your view that the
only way to eradicate bovine TB is to eradicate all the mammals
which can harbour the disease?
3. You state that cattle movements should
be allowed on the basis of individual farm risk assessments. Since
you acknowledge that the TB test is not reliable, on what scientific
basis could the risk of TB transmission from a farm in a known
TB area be assessed?
4. You argue that counselling and financial
advice should be made available to farmers to reduce the stress
associated with a TB herd breakdown. Can you explain why this
should be the responsibility of the taxpayer and not the farmer's
union?
5. You call for reactive badger trapping
in TB hotspots outside [Krebs'] trial areas. Can you explain:
(a)
By what proportion would bovine TB in cattle be reduced
by such a reactive strategy, bearing in mind that claims lately
made in Ireland have not been published in a peer-reviewed scientific
journal?
(c)
What would be the financial benefit (to farmers and
to the taxpayer) of reactive badger culling in hotspots?
(d)
You state that TB is spreading in wild animals. What
scientific evidence do you have to support this claim?
(e)
Specifically, what scientific evidence do you have
that the disease is spreading between wild animals, rather than
being introduced to new areas by infected cattle movements?
(f)
You state that badgers are known to have a role in
the transmission of TB to cattle. What reliable scientific evidence
do you have to justify your claim?
(g)
Since there is no reliable method for testing for
TB in live badgers and you have consistently stated that you only
want to kill "unhealthy" badgers, how would you ensure
that only "infected" badgers were killed?
(h)
Since you have consistently stated that you do not
want to eradicate badgers, what proportion of badgers in a reactive
culling area should be culled and how would you know when the
target proportion had been reached?
(i)
Since you acknowledge that widespread badger culling
is politically unacceptable, why should the public purse rather
than the industry pay for a reactive culling strategy?
6. You say that biosecurity advice should
be based on proven scientific data. We agree. But how would volunteer
demonstration farms generate scientifically valid data? It is
already clear that the voluntary approach to the gamma interferon
trial may not yield sufficient or robust data because an insufficient
number of farmers are willing to take part.
7. You state that pre- or post-movement
testing of cattle should be "encouraged". Since post-FMD
breakdowns have confirmed the vital role that cattle play in transmitting
bovine TB, on what scientific basis should pre- and post-movement
testing not be compulsory? Any claim that it is "too expensive"
for the industry is invalid unless your cost benefit analysis
includes the cost to the tax payer of compensating farmers for
TB breakdowns and—were you demands to be heeded—the
cost of reactively culling badgers.
National Federation of Badger Groups
May 2004
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