Thursday, November 09, 2006

A new leaflet - farmers would prefer not to have...

... has been issued by Defra - don't they just love those fat green booklets? - printed on recycled paper of course. This one brings all the small pamphlets together in one 44 page A 4 issue entitled "Dealing with Tb in your Herd" - or something like that. Available in pdf format:

(Sorry folks, just checked this direct link, and it won't flag up this file. Go to Defra home page, type ' gamma-interferon' into the search box, and the file is near the bottom of first page of publication options. Best we can do until they get their 'link fairy' operative.)

Meanwhile as a top up to our posting ;
on the proposed introduction of gamma interferon, the Veterinary Times reports unamimous welcome from industry spokesman on its introduction - but with reservations as to specifics.

Its use will mainly be limited to new outbreaks in 3 or 4 year testing parishes, on skin test- negative animals, and with that we would agree. As would Trevor Lawson of the Badger Trust, and under those circumstances, many veterinary organisations and farming groups.

The test as envisaged for herds in annual and 2 year parishes is of more concern. In those areas Defra say they plan to use it :

*On inconclusive reactors that fail to resove their first tuberculin re test.

* On tuberculin-test negative animals in severe TB incidents to inform decisions on whole or partial herd slaughter.

*On tuberculin test-negative animals in herds with persistant, confirmed infection that fail to resolve through repeated short-interval tuberculin tests and have taken the basic herd biosecurity precautions.

Those criteria could apply to most of our contributers. IR's are historically given two chances to pass the skin re-test, which will now be reduced to a single strike. And Matt 5 lost over 40 animals through a 4 year breakdown, of which only three proved to have culturable confirmed disease. A g-IFN test at the height of this outbreak would no doubt have enabled Defra's best to "de-populate" Matt's herd, but it would not have addressed the source.

BCVA president Andrew Biggs is quoted in the Vet Times article :

"We have to remember that the RBCT showed, if nothing else that badgers give Tb to cattle. If we don't address that, I don't see any future for closed herds that go down with TB, when cattle movements onto the farm or even nose-to-nose contact [with neighbouring herds] are not significant factors".

Meurig Raymond, deputy president of the NFU supported the announcement of the introduction of another diagnostic tool aid "as far it goes". But he said that it still did not get to the root of the problem:

"The increased use of the gamma-interferon blood test will make it easier to stamp out isolated outbreaks of disease away from the main hotspot areas, - but additional testing will be of little value to the thousands of farmers whose herds are constantly exposed to infection from wildlife as a result of the Government's refusal, so far, to deal with the disease in badgers ... ..... Until we get to grips with that, Tb will remain a scourge to cattle, badgers and farmers alike".

We confidently expect Matt 5 to receive his own copy of Defra's new booklet any time soon. Yup, after eighteen months of freedom, the routine test revealed one reactor and 4 Inconclusives.

So our Matt is under restriction again. And this is where pre movement testing is such a comfort blanket. Not. Matt has tested 15 animals this year - and sold them. He has also purchased ( for the first time in 13 years) pre movement tested pedigree bloodstock to establish a new herd of beef cattle. In Spetember the herd consigning the new cows and their calves, went under restriction, involving Matt in cattle tracing and retests, and now all 15 animals sold from Matt's farm this year may have to be traced and tested. Defra don't have too much faith in the preMT do they?
And neither of course, do we. All Matt's new ladies passed their post movement re-test by the way, and that is a far better indication of their disease status.

Matt's Reactor is a cheeky angus yearling which tested clear last year after her purchase as a 3 week old calf. The inconclusives are home bred incalf heifers, both beef and dairy. The source is - well we'll leave that for you to fill in, but I think Defra would describe it as "non-bovine".

More on the gamma interferon blood test on the Defra website:

1 comment:

Anonymous said...

From Trevor Lawson, Badger Trust

Matt is right - the new gamma interferon test will involve many herds in TB hotspots. Take a look at our detailed report on the gamma test on the Badger Trust's website. It reveals the gross failure of the skin test, explaining in detail and with scientific back-up how the skin test leaves the disease to fester in herds.

It also reveals how Government vets and Ministers undermined the gamma interferon test, whilst other countries all over the world were busy taking advantage of it.

When infection re-emerges in "clear" herds, badgers are blamed by the SVS. But the unfortunate reality is that the infection may never have been removed in the first place because the skin test misses so much infection. Gamma interferon will address this loophole and is particularly good because it identifies infection early, when cattle are infectious but are readily missed by the skin test.

Also, ignore the implication from Matt that because TB cannot be cultured from some cattle slaughtered under the skin test, that they are not infected. An overwhelming body of scientific evidence shows that culture is not a reliable guide to infection because the disease is so difficult to culture. There are very, very few false positives to the skin test.

The Badger Trust welcomes the roll-out of gamma interferon, but we are concerned that for some farmers in marginal situations the loss of significant numbers of hidden, infected stock could push them into bankruptcy due to loss of milk production for 12 or more months.

Rather than fighting an no-win war for badger culling, surely it makes sense for the NFU to work with us and other organisations to push Defra into providing financial support for those farmers who lose all or a significant part of their herd when hidden infection is disclosed?

The farming and veterinary lobbies are completely isolated on badger culling, by the science and by the informed opinion of major landowning organisations like the National Trust and RSPB who are trusted by their millions of members. The farming and veterinary lobbyies' current position harms their credibility and damages public support for farmers.

Finally, the question raised by Matt and others is "Why test cattle more, when they will just get infected by badgers again?" First, the latest research from the RBCT shows that if you control TB in cattle, it rapidly diminishes in badgers too. That reduces what uncertain risk there is. This reduction of infection in badgers should be even greater if they are left alone, since the research also shows that culling badgers makes things worse. Second, we still don't understand the mechanism of what badger to cattle transmission there is. But Defra's recently published research project SE3029 found that:

Feed stores were the most frequently visited facility within farmyards although badgers entered every building type monitored. Whilst within farmyards, direct contact between badgers and cattle was rare, but physical contact was observed on four occasions. In contrast, during observations on 41 badgers at pasture, a minimum distance between badgers and cattle of 4m was maintained at all times and direct contact was not observed ... badger contamination of stored farm feeds was far more risky than badger urine at pasture.

Farmers who are concerned about the supposed risk from badgers would be wise to take steps to keep them out of farm buildings and feed stores. The evidence suggests that that might reduce the risk of infection and, more importantly, it is far more likely to be cost-effective, practical and sustainable than a badger cull. Again, we want to see Defra providing support to help farmers with this, but as long as the NFU focuses on culling, there is no pressure on Defra to do it.

If I was an NFU member, I would be asking where the NFU TB strategy is going and what benefit I could expect from it. We cannot see any benefit arising for farmers from the NFU's current position.