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Okay, here goes. The paper which landed on Robert’s desk the week of our TB test wasn’t a recent publication…in fact it was published in 2006. It never receive the coverage it should have at the time. Strangely its arrival had nothing whatsoever to do with the farm or our impending TB test. It was forwarded to Robert because of his involvement in all things hedge (being chair of the national hedgerow Biodiversity Action Plan group, Hedglink and co-chair of the Devon Hedge Group).
Robert popped his head around my office door “You should take a look at this.”
“What?” I looked up at him
“A paper on bovine TB linked to hedges”
“Hedges?”I scratched the top of my head and twiddled the hair “What…hedges decrease, increase the incidences?” As always when another study is published on bTB my reactions are mixed…hope, doubt, excitement, negativity and a kind of destructive inevitability.
“Oh something went wrong around here then!” I said wryly “Us being one of the most heavily hedged landscapes in Britain with some of the worst incidences of TB.”I leant back in my chair “So how do you mean? Good thick boundaries between contiguous farms?” I went on pre-empting his explanation “I didn’t know this…but the spread of disease from cattle to cattle out in the field is apparently quite unusual. The vet said a TB infected animal has to have developed lesions in the head and lungs and to hawk violently onto an area of grass just before it’s ingested by another animal to get cross contamination. Interesting…I always thought it was a much more tenuous encounter” I stretched “So, what’s its claim then? The paper? Where was the research carried out?” adding tongue-in-cheek “The hedgeless, stockless arable wastes in the east of the country?”
“No. Here. In North Devon. And on the Hereford/Gloucestershire boarder!” He grinned “I’ll send you a link. Have a look for yourself!”
So I did.
The study covered 120 dairy farms, 60 with recently infected herds and 60 without, and looked at the influence of various factors on the incidence of bovine TB. These factors were farmland habitat, topography (landform), badger density, proximity of farms with breakdowns, stocking density and herd size.
As expected bTB incidence was found to be linked to herd size and distance to nearest infected farms. In line with some other studies but not all, incidence was not found to be closely linked to badger density. It was also not closely linked to the extent or configuration of deciduous woodlands nor to the extent of pasture (both favoured badger habitats).
What was new was that hedgerow characteristics were found to be strong predictors of breakdown incidence. Hedgerow abundance, the number of hedgerow gaps, and the number of ungrazed field boundaries were all important. For example, a ‘hedge-poor’ farm (as defined in the paper) would be expected on average to have a 1.6 times greater risk of bTB than a ‘hedge-rich’ farm. Considering just total hedgerow length, an increase of 1 km per 100 ha was associated with a decrease in the risk of breakdowns by about 12.5%: in absolute terms this equates to the annual risk of bTB changing from 9.2% to 8.1% for herds in the West of England: an annual reduction of 251 infected herds (based on 2004 figures). These figures were controlled for herd size and distance to next bTB case: it is not simply the case that farms with plenty of good hedgerows have a lower stocking density.
The authors conclude that habitat management appears important to a farm’s bTB risk. ‘Nature friendly’ management practices – the presence of ungrazed wildlife strips, and the greater availability, width and continuity of hedgerow – are all associated with reduced bTB incidence.
They could only speculate on the mechanism through which hedgerows may reduce incidence of bTB, but suggest it could be due to one of two factors. The first is that hedge-rich farms are managed differently – for example they have different crop rotations which reduce the likelihood of cattle eating contaminated grass. The second (and more likely) is that the presence of hedges reduces badger-cattle transmission because a higher proportion of contaminated grass is kept out of the reach of cattle. Badgers preferentially use hedgerows as movement corridors and for their latrines, so where cattle are excluded from these areas by either hedge growth or fences, contact with the bacteria is reduced.
Given the practical difficulties associated with badger culling, and the fact that to be effective it has to be carried out over large areas (because of the perturbation effect), the authors suggest that improving habitat features such as hedgerows and ungrazed wildlife margins might be a more cost effective strategy to reduce infection.
So there you have it. A piece of research I had no idea existed. And the one thing we have on this farm? Exceptional density of hedges…with very few gaps; in fact we have many more hedges now than were present on the 1840 Tithe Map.
Could this be (and I hardly dare think it, let alone say it) a reason why we ‘continue’ (whispered very quietly) to go clear?
Those of you who follow me on Twitter or Facebook probably gathered my cattle had a bovine tuberculosis (bTB) test about ten days ago. Those of you familiar with farming and the countryside will have a pretty good understanding of the problems surrounding bTB and the distressing effect it has on farmers, farms and cattle industry. And those of you who aren’t that interested in farming, will, I’m sure, be aware of the debate that rages around badger culling, vaccination and the like.
Personally I feel every test brings us one step closer to the inevitable…bTB breakdown. Illogical? Probably. Or maybe not.
We’ve been ‘upgraded’ to six monthly testing, as the farm’s contiguous. I don’t know what’s changed; we’ve been contiguous to farms suffering breakdowns for a good many years. Anyhow this new status certainly makes me more jumpy.
I guess that it’s here that I should mention that in the twenty years I’ve been farming at Locks (and actually for the whole thirty-five years of my farming career) my cattle, first dairy, now beef, haven’t had a case of bTB. I say this with great trepidation; I really dislike mentioning it. I’m terrified of tempting fate.
Briefly, the bTB skin test takes place over a period of a few days. On day one tuberculin is administered at two sites – the first (or the top spot) is the control – avian tuberculin is used; and the bottom, the second site, is inoculated with bovine tuberculin. Three days later the test is read and a conclusion reached on the size of the reaction.
As we were getting ready on the first day I said to Polly, our vet, “Well, don’t suppose we’ll go clear. Bloody miracle if we do.” And somewhat to my surprise she said “Yes, it will be.” None of that nice reassuring talk… my fault for bringing it up, not hers for being honest!
I firmly resisted any temptation to check for reactions. On the Friday as we were sorting through the cattle before the vet came I mumbled to Olly “She doesn’t think we’ll get through you know.”
“Don’t be such a doom merchant” he snapped back at me. But I noticed he didn’t follow it up with “You’re daft. You always say that. Of course we will. We always do!” (I now know that he’d been checking the animals and had found some substantial lumps!)
Reading the test was heart in tongue stuff; Polly had the callipers (used for measuring the size of the lumps) out for practically every cow. Almost all the animals had sizable reactions to the avian tuberculin (indicating a high incidence of avian TB) but, thank god, no reactions to the bTB. We were clear! A surprise to all of us.
So why? Why did we go clear…?
Because I run a closed herd? Or that we’re organic? Maybe we practice exceptional welfare? Have a healthy badger set? Keep a native breed? Farm extensively? Don’t have tonnes of hard feed knocking around? Or that we are just too darn wet? But others are doing these things and more still suffer breakdowns. It is just luck?
Perhaps not…An intriguing paper arrived last week
Please log on tomorrow – I’ll be writing a post on this paper and would hugely value your reactions and comments
Friday 13th. Not that I’m superstitious. I just happened to be clasping onto pieces of wood, crossing my fingers (and toes) and nonchalantly chucking salt over my left shoulder.
Back in January Robert came into my office waving a piece of paper “Do you know anything about this?”
I looked up “No, don’t think so. What is it?”
“It’s a thing from Animal Health notifying us we’re to go onto six monthly TB testing because we’re contiguous.”
“Oh? Strange? We’ve been contiguous for ever.” Puzzled, I reached out for the piece of paper “I wonder why now?” I looked at the dates stipulated. “That’s a bugger – we’ll have just started calving. If that’s the case we’ll most probably throw up some inconclusives at the very least.” Inconclusive reactors are animals that develop lumps inbetween negative and positive; these animals have to be re-tested after six weeks.
A theory, not scientifically proven, is that animals who are suffering stress – such as those that are bulling, calving, carrying a burden of liver fluke or worms – are more likely to react unfavourably to the tuberculin skin test.
A shiver runs down my spine “But looking on the bright side” I say optimistically “I guess it means that we have sixty days to sell stock when it’s most wanted without doing a pre-movement test at our expense. If we go clear.”
To try and control the spread of TB you are allowed to move stock within sixty day of a test. If you want to move stock outside the sixty days of a routine TB surveillance test you have to pay yourself to have the animals tested.
I phoned the vets to arrange dates. It was decided – the 10th March for the test and the 13th to read the test.
So on Tuesday Sally, our vet, arrived to do the first round. Then we wait. We wait three sick-making days. I have to restrain myself from compulsively running my hands over the necks of the cattle. Then on Friday, Friday 13th, Sally returned to read the test. As always I feel ill. As always Olly says to me “I know we’ll go clear.” I wish I had his confidence.
It worked – all the touching of wood, throwing of salt and crossing of fingers – reprieve, reprieve, reprieve…we went clear. Not that I’m superstitious of course.
I began writing this in response to comments in ‘cull or not to cull’, but decided to publish it as a post in its own right. I have researched, read about and discussed the problem of bTB at length – with vets, farmers, scientists, ecologists, conservationists, people living, but not working in the countryside and those that do, city dwellers and politicians. I could give facts, figures, excellent examples and analogies for and against both sides of the argument. Personally I am, of course, subjective…I have a herd of cattle I care about hugely and are at risk; I also have a passion for wildlife. And I have to make a living from my work.
The question of whether or not to cull badgers is a complex one. It ain’t half as easy as many people make out. Quite simply, it’s not black and white. The science is uncertain, the risks are large, and we are dealing with emotions as well as facts. If we are going to find away forward, it will depend on us being open-minded, listening to each other and respecting each others’ values. Above all, we must be prepared to move our positions, to get off our high horses, to let our eyeballs settle back into their sockets. Far too many of us are entrenched: a position, for or against, has been taken, and that’s the end of it. If we are to get on top of this disease, for the benefit of all – people, cattle and badgers – we must start to pull together, use what evidence there is, consider the practicality of the various options open to us, and reach consensus on the way forward. It won’t be perfect and certainly won’t be easy, but it’ll be the best we can do.
I’ve had over a week to let Hilary Benn’s decision on a ‘no badger cull’ sink in. It’s coming around to my own herd’s bTB testing time again and I can feel the anxiety and worry beginning to build. This year there’s the added unknown of bluetongue vaccination and concerns that this could throw up more inconclusives or possible false positives. Oh happy times.
Maybe I’m a very simple soul or perhaps I’m missing the point altogether. But surely it’s staring us in the eyes – there is no perfect solution. There isn’t a ‘given success’ or some nice, easy erradicatrion programme. And there isn’t a course to be taken that will make everyone happy
bTB is out of control. A suitable vaccine is still years away (and only now they decide to throw extra money at it?), so forget that as an immediate solution. 28,000 cattle were killed last year, 14,000 have already been killed this year with the figure thought to rise to around 40,000 by the end of the year at an expected cost of £80 million to the taxpayer. Will the escalating killing and ever-increasing restrictions on cattle movements have an effect if it’s just one sided? Well of course it will, eventually, when all cattle have been culled. And yes, I am being facetious.
We need to do something.
‘Reducing the density of badgers over large areas (>100km2) where there are high levels of TB in cattle reduces the incidence’. ‘Removal of badgers is the best option at the moment to cut the reservoir of infection in wildlife, but vaccination will be vital in the longer term’. Sir David King’s main conclusions as reported by the Farmers Weekly.
Surely it’s high time all interested parties worked together and stopped this childish posturing? Here we are looking into the jaws of a recession, worried about food security, an energy crisis, possible wars and climate change. So, for pities sake, let’s get together; work out how we change certain farming behaviour and practises to minimise risk of bTB spread and have a sensible cull that will be effective at reducing bTB without causing nugatory destruction of badgers or unnecessary cruelty.