Monday, May 08, 2006

The iron has it - Mark Purdey on bTb

Mark Purdey, an organic farmer who plays a clarinet to his cows in Somerset had some interesting theories on the origins of BSE. While he was including organophosphates in the equation, our casualties fitted his thesis, but when he jumped to ley lines and the phases of the moon, Matt 5 got a bit lost. anyway, a comment on the previous thread reminded us of Mark's brush with bTb and his theories on that.

As we replied after the comment, if the facts don't fit our contributer's particular situation - and here they did not, then a theory it must remain.


"Despatches from behind the iron curtain of a British "biohazard" zone."By Mark Purdey, High Barn Farm, Elworthy, Taunton, Somerset, TA43PX,UK.

European livestock farmers dread the day when their cattle succumb to a tuberculosis breakdown. The implications are severe; a ruthless cull of infected cattle and badgers(not since 1997 Mark!), with all remaining healthy cattle impounded behind an iron curtain of government mandated movement restrictions and red tape. The knock on effects have virtually paralysed small farming businesses into a state of financial melt down. /**/But the official procedures of TB control are archaic and outmoded.They are founded upon the age old hypothesis that humans develop TB as a sole result of exposure to TB infected animals, whilst failing toaccommodate the more recent front line revelations in the multifactorial science surrounding mycobacterial disease. In this respect, we need to be questioning whether such cruel and costly strategies that are currently involved in TB control programmes are actually fulfilling their desired effect -- to protect the human population against the TBagent.

Earlier this summer , I was forced to come to terms with my own cattle joining the ever increasing ranks of TB infected herds that are currently blighting the UK.

TB Breakdown; a testing time.
At dawn I scaled the hill to collect the cattle from the furthest fields. The earth still held the heat of the previous day, and I was forced to coerce the cows a little, for they seemed more reluctant to rise and amble the few feet to the green lane than usual. Perhaps the cows were more perceptive than me, their sixth sense receptive to the fate that was about to befall them in a few hours time. As we reached the steeper gradients of the shillet track, the cattle accelerated a little, rutting up the dust with their hooves. The tailswish of a cow disturbed an early morning bee, that droned off beyond the bank of bluebells and into the haze of the dazzling sun. Gradually, the entire caravan of cattle snaked its way down the track to the valley bottom below. On the last stretch to the farm, a patch of giant foxgloves towered over us like an array of mauve lanterns, their luminescence still resonating the brilliance of first light. But I failed to heed their red alert, and just drove the cows on without a second thought. Back at the yard, the vet was ready and we led the cows straight down to the inspection pens. The procedure was simple - to measure the size of any lumps that had erupted on the cows' necks which served as a yardstick for gauging the extent of allergic response to the TB skintest - an intradermal injection of tubercle bacillus that had been administered by the vet three days earlier. After a few minutes I saw the vet stand back abruptly. "Oh" he said in a despondent, drawn out tone, popping on his spectacles slightly askew."We could have a problem here, Mark". I watched him fumbling through his pockets for the callipers, and now knew that he had to take a more precise measurement of what obviously looked like a colossal reaction lump on the cow's neck. I became anxious, and my mouth was beginning to parch up in anticipation of what was coming next.The air was heavy, like that period of suspense before a thunderstorm. Even the robins who had been busy in the yard a minute earlier rustling up the brittle leafs, seemed to have stopped in their tracks. The vet raised his glasses and wiped the sweat off his forehead. "You have a reactor, I'm afraid Mark". A few minutes later there was another reactor, and then several more. My mouth had parched up completely now and my stomach felt nauseaous.

I became angry at the thought of these fine young pedigree animals just into their prime, now condemned to slaughter under the government's animal health diktat. Furthermore, like many other cattle farmers in the UK, I was confused by the perfect condition of the TB reactor cows, since I had always assumed that TB was a debilitating disease. Although these cows had reacted tothe skin test and were therefore deemed to carry TB, I began to wonder whether they had successfully adapted to the infection by knocking out the greater majority of the invasive mycobacteria. In this respect, TheTB slaughter programme could actually be annihilating the resistant animals -- culling the genetically robust individuals that we really needed to be keeping as breeding stock for future generations.

Badgering the true evidence.
The next stage of the so called 'crisis' procedure was to retire to the farmhouse for a tree's worth of form filling, where I was presented with several sheets of a TB questionnaire. I was amazed by the reductionist contents of the questions that followed. Each one had been designed on the assumption that the transmission of the TB agent from infected badgers to cattle was the sole cause of bovine TB. In this respect,*/baddie the badger/* had been dubbed the guilty culprit before the necessary detective work had even begun. ( If this was the TB 99 form, we found only one paragraph of the many sheets referred to badgers - ed) The exact same 'back to front' investigation was applicable to the questionnaire which the government presented to farms that had experienced a case of mad cow disease (BSE) where every question was based on the assumption of a meat and bone meal feed cause - despite the diversity of evidence which indicated that this theory was totally flawed.

The search for susceptibility factors -- the seeds of TB ?
The real question was why had my farm always boasted a TB-free status, despite being surrounded by TB affected cattle / badgers for many years. I began to wonder what changes had been integrated into our farming practises over recent years: changes that could be responsible for switching on the susceptibility of our cattle to the TB agent ? I felt that this was the relevant question that I should be asking right now.TB is virtually endemic in the soils, waters and atmospheres of themajority of ecosystems, where mycobacteria have co-existed with mammalian life for centuries. Despite its widespread prevalence, the TBagent has produced relatively few major outbreaks across the world. It seems that an epidemic of clinical TB can only erupt once some anti-TBcomponent of our immune defence has been disrupted. In this respect, the primary event is a disruption of immunity which enables the TB agent to breach the body's defences and opportunistically take a hold. A historical study of the epidemiology of TB demonstrates that epidemics of TB have occurred since the iron age, and that this disease has always been rife amongst specific population groups who are nutritionally impoverished in some way. For example, TB was rife amongst city slum dwellers who had no choice but to breath the industrially polluted air 24 hours a day, as well as the half starved Scottish / Irish crofterswho were evicted and forced onto boats bound for North America. Another more recent example involves AIDS victims whose immune systems are so severely compromised that they invariably develop TB as a secondarycomplication.

A Limey's view of TB cause.
So what is the key factor that has suddenly unleashed TB susceptibility amongst my cattle following so many years of TB-free status ? After much thought about the specific changes that I had integrated into my farming system over recent years, I began to wonder whether the TB breakdown in my herd could be connected to the drastic cost-cutting measures which I have been forced to adopt in order to survive the current agri-economiccrisis. Along with most other hard pressed livestock farmers across the UK, we had foolishly cut back on the use of the so called '*/non essential'/*lime / calcified seaweed based fertilisers. Furthermore, the trend in reduced usage of lime based fertilisers has been exacerbated by recent conservation measures that have debarred the harvesting of Cornish calcified seaweed altogether - thereby preventing future usage of this material on the farm. It is the general reduction in use of lime fertilisers, combined withthe recent increases in winter rainfall across the western UK, that has acidified the top soil as a result; whilst other eco-influences such as acid rain and the continued use of so called '*/essential'/* artificial fertilisers will undoubtably be playing their contributory roles in the acidification of Agricultural ecosystems. The pH alkaline/acidic value of the soils on our farm has dropped from an acceptable neutral pH 6 to an acidic pH 5 over the last three years -evidenced by the invasion of buttercups into our pastures where clover used to flourish. Research has shown that there is a correlation between areas of high mycobacteria incidence and regions where the soils are acid. This association is strengthened by the results of studies where lime was spread on farms in Michigan that were suffering from high rates of mycobacterium infection ( albeit the paratuberculosis strain of mycobacterium ). The study concluded that the lime treatment had produced a ten-fold reduction in the infection of cattle after a three year period had passed. [ Johnson-Ifearulundu and Kaneene 1997 ].

*/Branding the Iron on TB/*/cause/*
The relevant issue in respect of TB infection and soil acidity hinges on the fact that acidification of the topsoil leads to an excessive accumulation of available iron [ Pais and Benton Jones 1997] --particularly in the regions where soil iron is naturally elevated and rainfall is high. The iron is taken up by the pasture herbage (especially ryegrass, plantain [ McDonald and others 1973 ], bluebell tubers, etc) as well as percolating into the local water supplies as aresult; which, in turn, is taken up by any animals who thrive upon the local iron rich ecosystem -- particularly those individuals who are genetically predisposed to an increased uptake/retention of iron within their biosystems. Interestingly, the key hotspot zones of bovine TB across the UK are the Forest of Dean, Exmoor, Cornwall, Devon and the Mendip hills. These regions all correlate with the areas where iron has been mined in abundance [ Flett 1935 ] and rainfall is high. Preliminary pasture sampling from the specific fields on my own farm (June 2005) where the TB reactors had been pastured has consistently demonstrated an */excessive/* elevation of iron ( average 378 mg/kg), in relation to the levels of 143 mg/kg recorded three years previously.This research is being expanded to cover TB-free and TB farms across the key TB cluster areas of the UK .

*/What is the relationship between elevated iron and increasedsusceptibility to TB ?
Much research is published in the scientific literature which demonstrates that Iron represents an essential prerequisite in the pathogenesis of TB , enabling TB and other strains of mycobacterium to proliferate, metabolise and survive within the mammalian biosystem [Ratledge 2004 ]. In this respect, it is the supply of 'free' iron within the host which provides the TB agent with its 'fire power' capacity to unleash its deleterious pathogenicity, thereby invoking the often fatal, devastating consequences that result from TB infection. Although TB victims adapt to their parasitic attacks by stashing away their iron supplies in tissues that are inaccessible to the mycobacteria, the grand finale of the TB disease process usually culminates in the parasite getting the upper hand; whereby the host develops the classic iron deficient anaemic state that is a central clinical feature of TB. Mycobacteria acquire their iron from the host's own transferrin /ferritin molecules -- the iron binding transport / storage proteins thatare integral to the healthy metabolism of iron within the mammalian biosystem. The mycobacteria rob their host's iron by releasing a type of iron-capturing siderophore called an exochelin; which, in turn, transfers and donates the iron back to the mycobactins which exist inthe cell walls of the mycobacteria themselves [ Gobin and Horwitz1996 ].This hijaking of the host's iron supply is beneficial for the survivalof the TB mycobacteria in more ways than one. Not only does the TB agent utilise the host's iron for its own proliferation and survival, but it also utilises this metal to indemnify its own long term security within the host; by disabling the host's immune defence against itself. The parasite achieves this means of self protection by curtailing the viable synthesis of the iron binding beta-2-microglobulin molecules whose role is to activate the killer T lymphocytes [ Schaible and others 2002 ] -the host's main line of immune defence against mycobacteria infection.This could explain why individual humans whose T immune systems have become compromised through nutritional deprivation or AIDS toxicity areat a significantly greater risk of developing TB as a secondary complication. But TB is not the only pathogen that depends upon the host's iron for its maintenance and growth within the body. The infamous Clostridium Botulinum ( implicated in grass sickness of horses ), Leprosy, HIV,Candida , Listeria, Salmonella, Malaria etc, are all members of this insidious family of */ironmonger /*pathogens to which TB belongs[Weinberg 1999] Only last week, champion horsebreeder Gail Dunsbee had been in touch with me over the sudden death of one of her horses as a result of grass sickness -- a devastating paralysis of the autonomic nerve endings inthe horse's gut due to infection with clostridium botulinum. But much like TB, Botulinum is virtually endemic in the gastro tract of horses where it rarely produces any adverse health effects at all. So what environmental factor had suddenly switched on the susceptibility of her horse's gut to the infection ? Dissatisfied with the professional ignorance surrounding the root causes of grass sickness, Gail had taken matters into her own hands in order to safeguard the future of her surviving horses. And once again, it looks like the results of her preliminary soil analyses have provided the causal clues that might address this catastrophic problem for horsebreeders. Apart from the low potassium readings, the extremely excessive readings for Iron ( at 1344 ppm ) was the only other element of the twelve elements tested which had deviated from its respective reference range.This result could explain why grass sickness, like TB, has invariably remained confined to acid soil districts where iron levels are generally elevated.

*/Ironing out the TB pathogen./*
Since elevated iron increases TB risk , it is easy to understand how the management of dietary iron can influence the outcome of TB [ Ratledge2004, Cronje and Bornman 2005 ]. For example. when TB infected mice weretreated with the iron chelating lactoferrin protein ( a natural ingredient of colostrum milk ) , there was a one hundred fold reduction in the number of pathogens present in the mice. [ Schaible and others 2002 ]. Likewise, TB diseased individuals used to be regularly treated with the iron-chelating compound p-aminosalicylate with some success [ Ratledge2004 ]. In this respect, it could prove beneficial from a preventativeas well as a curative perspective to introduce copper or zinc bicarbonate supplements into the diet of TB affected populations [ Paisand Benton Jones 1997 ]. Whilst these anionic compounds do not act as iron chelators as such, they will impair the absorption of iron across the gastrotract by competing for its uptake system of transport proteins. Furthermore, any foodstuffs containing phytic acids, such aslegumes ( alfalfa, clover, etc ) and grains [ McDonald and others 1973 ]will produce the same anti-iron effects. Use of inorganic phosphorus as an inclusion in fertilisers or mineral feed supplements would also assist in reducing the amount of free iron that is rendered 'available' in the soil or taken up into the animal respectively [ Underwood 1977 ]. The phosphorus competes for the ironbinding site on the transport proteins that normally convey iron acrossthe gut wall; thereby arresting the uptake of iron at its initial pointof entry into the body. It is also important to consider the knock-out effects that iron chelators might impact upon the */horror chamber/* of other pathogens which need to bite the */iron bullet/* before they can trigger disease.For instance, it has already been demonstrated that the iron chelating compounds, deferoxamine and 8-hydroxyquinoline-5-sulfonic acid have produced beneficial effects in the treatment of leprosy and clostridiumbotulinum respectively .[Weinberg 1999][ Bhattacharyya and Sugiyama 1989]

*/Iron in the Ecosystem. /*
It is proposed that badgers and cattle that co-exist within the same environments will both develop TB due to their separate co-exposure to the same iron-rich foodchain, and not necessarily due to across-infection from one animal to the other. Bluebell and other iron-rich tubers constitute a large part of thebadger's diet and these will gradually load up the badger's biosystem with a concentrated source of iron until threshold levels are exceeded - thereby providing any mycobacterial pathogens that are present with the sustenance to proliferate to pathogenic levels. Likewise, the high incidence rates of human TB that have been recorded amongst steelworkers and slum dwellers ( who lived beside their workplaces during theindustrial revolution ) could have been induced by the high levels ofiron in the atmospheres of their local environment.

*/The politics of TB. /*
I believe that government ministers in the UK have been correct in resisting pressures to re-enact wholesale slaughter of badgers as a means of controlling TB in the bovine / human populations. For the badger culls of bygone years have achieved nothing in terms of eradicating TB. (Thornbury? 100% eradication for 12 years? - ed)The disease has kept on re-occurring irrespective of the various slaughter measures that have been put in place. In this respect, we need to consider what is actually achieved each time that we re-enact this final farcical solution for TB control --eg; badger gassing and blanket cattle culls ?Furthermore, it is scientifically naïve to think that we will ever be able to eradicate a pathogen that is endemic in the environment at large. As long as optimum eco-conditions for the survival of TBmycobacterium are allowed to exist ( eg; high iron / soil acidity ),then TB epidemics will continue to rear their ugly head, as and when alterations in weather conditions and husbandry methods permit. In respect of consumers who are anxious about exposure to TB pathogens in their foods, they need to be aware that modern methods of foodprocessing safeguard consumers from exposure to the TB agent -- methods that did not exist half a century ago. For example, any milk that is taken from a TB affected animal today is automatically pasteurised in the modern dairy set up. (prohibited from the food chain including calves from January 2006- ed) Although pasteurisation produces some negative health effects -- by switching our immune response to TB and other pathogens into 'sleep mode' - this ultra efficient sterilisation process provides a guarantee of biosecurity for those who are concerned about TB exposure.

Whilst it is high time that governments should say farewell to their archaic strategy for TB control, some viable alternative will be needed to replace it. In this respect, governments should begin to examine the considerably cheaper / animal welfare friendly option of encouragingfarmers ( via subsidies) to adopt husbandry practices which prevent cattle from succumbing to TB infection in the first instance. Eg; by subsidising the spreading of lime fertilisers across the TB endemic/highiron regions, as well as promoting feeding / fertilising with iron-chelating/ anti-iron compounds on farms in the TB risk areas. This would reduce the amount of iron that is flowing up the farm foodchain, which, in turn, would reduce the levels of TB mycobacteria.Such a radical approach which curtails the susceptibility of cattle to the TB agent could produce some major advantages over the existing system which slaughters out the end results of TB infection. This would achieve a considerable reduction in the overall incidence rates of TB ,thereby reaping major savings for both human and animal life, farmers' livelihoods and the tax payer. Since the incidence of TB is increasing amongst the human population, it is high time that we adopted a more intelligent, civilised and updated strategy for dealing with the prevention of TB. In this respect, we need to be taking a closer look at the underlying causes of 'iron overload' in the human foodchain and ecosystem at large. This would entail looking at the impacts of acid rain and how it brings about a rise in the levels of available iron within the soil and water supplies. Issues surroundingthe industrial emission of iron particulates into the atmosphere, as well as the supplementation of our foods with iron additives representimportant areas that warrant investigation and the development of controls. Likewise, the indirect impact of various toxic or mutagenicenvironmental agents upon the metabolic processes that regulate iron homeostasis is an area that also needs to be considered. For a whole range of environmental chemicals /metals are recognised to disrupt or mutate the body's capacity to regulate the balanced uptake, storage and/or excretion of iron; thereby representing an alternative means through which iron levels could become elevated in the biosystem; which in turn, switches on an increased susceptibility to TB infection.

Meanwhile back on the farm, the knacker man had arrived to collect theTB reactors at nightfall. I lead the unsuspecting cows to the loading pen, feeling guilty that I had betrayed them by failing to mount any kind of resistance against the government's strategy of senseless slaughter. The cows waited, absorbing their final moments of life in the half light. Their backs were steaming and heads held low.The monster lorry rattled in like an aluminium alien, and then backed upto the loading pen. The ramps came down, and after a rapid fire of whelpings and whip lashings, the cattle reluctantly surrendered themselves to their fate; hooves sliding and clattering up the steely ramp into the dark hold of the lorry. As the truck turned the top corner, I caught my last glimpse of the cows, their noses frantically pressing through the six inch slats - a last ditch attempt to escape their premature and pointless execution.Tonight they will be sectioned to the post mortem bench, abattoired into oblivion..As I walked back to the farmhouse in the half light, I caught a glimpse of the patch of foxglove petals glowing like red hot irons on the hill, still resonating with the evening sun. It was a timely reminder that our TB problem had not been extinguished by the removal of our reactor cows from the farm, but was still very much alive and well, and rooted in the acidity of our soils. As I walked back to the farmhouse, I remembered that the presence of foxgloves indicates high iron and high manganeselevels in the soil. Mark Purdey 15/8/05

As we pointed out, Mark's withdrawal of lime from his land for monetry pressures and the subsequent increase in iron levels does not necessarily apply to all of us. And in our case, it did not. Ph levels were 5.8 - 6.2 at the last testing session. we would hope that Mark has rectified the acidity of his land since last August. Did it have any affect in subsequent tb tests I wonder? Conversly the 'cause' of his problem may have died or gone to pastures new.
A farmer in the north feeds 'his' badgers with selenium and reckons it protects them and his cattle. Time will tell.


Anonymous said...

The latest bovine TB figures would appear to be good news!
According to the Provisional TB statistics for Great Britain released on 5 May 2006

TB TESTS CARRIED OUT (in the year to 31st March) increased from
1,649,543 in 2005 to
1,807,805 in 2006

Despite this the number of cows slaughtered as reactors decreased from 7731 to 5455.

I reckon that is about 29% DECREASE

However 6099 herds were under movement restriction on 31 March 2006 (due to a TB incident, overdue TB test, etc), almost half of these
(2994) restricted due to overdue TB tests!

More cattle tested, loads less reactors than last year, and half of the herds under movement restrictions due only to late testing.

Am I missing something, or is this very good news?

Matthew said...

Thanks for this. See new thread.
We honestly don't know what is going on.