The madness of “one size fits all “

[Private Pike]

If its so crap how did we get to bring bTB down to such a low level, through the 1960s & 1970s starting from very a high level of infection in the 1950s, using that test?
What is the principal change since then that turns a good, effective ,proven test to a crap test?

Took the boot off the neck of the badger, Four year testing was a bit too long ,Cattle moved after the last Foot and mouth without testing and general no testing in that period, Some slack testing when we thought we had it licked. . In hindsight the last few areas in the 70,s with T,B should have probably have had whole herd culls to finally 99% wipe it out.
Now it is firefighting with monetary support being reduced.

The test changed slightly in the 1970s with regards to the type of tuberculin and it's production, which some have attributed to the rise, although it was supposed to give superior performance there isn't any information about potency and quality of production at that time.

Maybe people tested better in those days too? What was the average herd size, how many vets would be doing 500+ whole herd tests? Do vets do a better, more careful job doing smaller tests when they feel less rushed/stressed about when they're going to finish?

 

[Private Pike]

Frequently, universities,usually holding hands with bio tech companies, launch a 'new test' for zTB.
Frequently that test has been trialled on humans first and frequently it has failed to live up to its promotional hype.
Also, taking blood samples and screening in a lab is more expensive way of screening for TB than the skin test and in all cases of which I'm aware, is very much less specific even if sensitivity is improved.

As a herd test, the skin test (SICCT ) is the best there is (for cattle), and repeated regularly any diagnostic test achieves a higher secificity / senstivety result than a one off on a single animal.

.

I'm not arguing with that, that's the case at the moment, but there's nothing to say that won't change in the future. The fact that it's the best there is now doesn't mean it's something we should be settling for or accepting as being good.

The theory of it is good, we can see that measuring CMI is generally a good way of detecting bTB exposure/infection, and that can produce good results, but in practice it still relies on a person to take the time and care to do it properly, to achieve optimum results, which IMO is its biggest failing. It can be a simple test to perform, it can also be difficult, potentially dangerous and is all too easy to take shortcuts in.

 

[Princess Pooper]

The test changed slightly in the 1970s with regards to the type of tuberculin and it's production, which some have attributed to the rise, although it was supposed to give superior performance there isn't any information about potency and quality of production at that time.

Maybe people tested better in those days too? What was the average herd size, how many vets would be doing 500+ whole herd tests? Do vets do a better, more careful job doing smaller tests when they feel less rushed/stressed about when they're going to finish?

No, it was only when almost the whole of England and Wales was TB free but they were unable to eradicate in a stubborn 'hotspot' in the SW that they started testing wildlife and discovered it in badgers in 1971. Whole herd culls would not have wiped it out because badgers would re-infect. Although badgers were protected from 1973, intensive badger culling for TB control was permitted (eg gassing with no re-colonisation of culled setts allowed for 12 months) and there were less than 600 reactor cattle in 1982, focused in the SW where annual testing was maintained. It was from the mid 1980's when there were much less stringent badger culls due to ''trials' of different strategies that control was lost, together with higher levels of protection for badgers and it's just got worse since then, yes aided by increases in cattle movements and poor biosecurity.

 

[matthew]

The test changed slightly in the 1970s with regards to the type of tuberculin and it's production, which some have attributed to the rise, although it was supposed to give superior performance there isn't any information about potency and quality of production at that time.

Maybe people tested better in those days too? What was the average herd size, how many vets would be doing 500+ whole herd tests? Do vets do a better, more careful job doing smaller tests when they feel less rushed/stressed about when they're going to finish?

Prior to the change of tuberculin antigen, vets used a human tuberculosis bacterial base. After the mid 1970s that changed to AN5 which is the bovine base.
The witches brew was made at .Weybridge until very recently, when U.K. purchased product from .Dutch company Lelystadt.
That company too use AN5 as their base.

What has been discovered by molecular geneticists is that the old AN5 cattle strain has gone from our cattle population. None left. Zilch. Test and slaughter worked. And what they suggest we have now, is badger adapted TB feeding back up.

And until we sort that out, no amount of different tests will solve our problems in GB’s tested sentinel cattle.

 

[Water Wheel]

Prior to the change of tuberculin antigen, vets used a human tuberculosis bacterial base. After the mid 1970s that changed to AN5 which is the bovine base.
The witches brew was made at .Weybridge until very recently, when U.K. purchased product from .Dutch company Lelystadt.
That company too use AN5 as their base.

What has been discovered by molecular geneticists is that the old AN5 cattle strain has gone from our cattle population. None left. Zilch. Test and slaughter worked. And what they suggest we have now, is badger adapted TB feeding back up.

And until we sort that out, no amount of different tests will solve our problems in GB’s tested sentinel cattle.

Is there a good reference to the strains of TB found in cattle in the 1960s.

 

[matthew]

No, it was only when almost the whole of England and Wales was TB free but they were unable to eradicate in a stubborn 'hotspot' in the SW that they started testing wildlife and discovered it in badgers in 1971. Whole herd culls would not have wiped it out because badgers would re-infect. Although badgers were protected from 1973, intensive badger culling for TB control was permitted (eg gassing with no re-colonisation of culled setts allowed for 12 months) and there were less than 600 reactor cattle in 1982, focused in the SW where annual testing was maintained. It was from the mid 1980's when there were much less stringent badger culls due to ''trials' of different strategies that control was lost, together with higher levels of protection for badgers and it's just got worse since then, yes aided by increases in cattle movements and poor biosecurity.

The whole sorry story is told here with clips from the CVO’s reports at the time.

https://bovinetb.blogspot.com/2007/07/condemned-to-repeat-past-mistakes.html

1988 - 1997 was basically standing still during the Interim Strategy.
Culling was difficult as the area allowed was reduced from 7km to just 1km and then only on land cattle had grazed. So if ancestral homes were in orchards or arable land, they were out of bounds.
Numbers and herd incidence gradually increased, but in 1997 on receipt of £1m bung from the Political Animal Lobby, a moratorium was put on all culling of badgers to ‘prevent the spread of disease’.
Section 10, 2 (a) of the Protection of Badgers Act.
And that saw incidence in our cattle herds doubling year on year,

 

[matthew]

Is there a good reference to the strains of TB found in cattle in the 1960s.

A lot on genome sequencing in this post, including Ian Boyd’s reference To AN5

https://bovinetb.blogspot.com/2018/02/its-all-in-genes.html

I think Noel Smith’s spoligotype database started a bit later than that, but it shows a geographical patch of predominately one type of zTB.
Spreading. Outwards.

 

[countryman765]

i was under the impression that inconclusive cows had to stay on farm to be retested at 60 days and not able to go straight to slaughter.

They won't allow you to cull irs as they are more interested in finding the disease than they are in getting a clean test. I made a mistake and culled one out of 39 irs last summer and animal health were not happy.

 

[countryman765]

As to the wildlife being clear in your area that's what they told me too. I asked how they knew that? They replied that Wales tested roadkill badgers.and those tested in my area were clear. Ohh what test do you use? I asked. Ohh the same as the post-mortem and culture test done on the cattle.. How is it then I asked is it that a reactor cow still has tb if nothing shows in abbatoir and culture but a badger is clear of tb if it can't be found in post-mortem and culture? Ohh was the only reply I got to that

 

[vantage]

They won't allow you to cull irs as they are more interested in finding the disease than they are in getting a clean test. I made a mistake and culled one out of 39 irs last summer and animal health were not happy.

I made that mistake,the sky fell down that day!

 

[Holsteinfriesian90]

I made that mistake,the sky fell down that day!

What happens if it drops dead? These things must happen with irs.

 

[vantage]

What happens if it drops dead? These things must happen with irs.

Lord knows!

 

[Beef farmer]

What happens if it drops dead? These things must happen with irs.

No, they are immune from that

 

[matthew]

I made that mistake,the sky fell down that day!

A hanging offence, no less.
You culled an IR, ahead of a notice that, assuming that
she’d passed a repeat test, confined her to barracks for the rest of her life. You could not have sold her except for direct slaughter .

And you would also have had to have a whole herd test (or two) before ‘they’ will release you from restriction.

We do live in a mad world. And it’s getting more mad. But rules is rules.

 

[countryman765]

I made that mistake,the sky fell down that day!

Lucky I had 38 irs left or not depending on how you look at it

 

[davidroberts30]

were these breeding stock IR's you guys sent to kill?

 

[vantage]

were these breeding stock IR's you guys sent to kill?

Milking barren cow here.

 

[davidroberts30]

i've sent fat IR's off under licence
i didn't want them getting a second test here

 

[countryman765]

Barrens. You have to ask for a license

 

[countryman765]

What happens if it drops dead? These things must happen with irs.

I'm quite happy for them to take fallen stock irs or not!