Johnes monitoring in suckler herds

[Chae1]

I've not seen evidence to suggest they will shed more when stressed, but it is recognised that they are a lot more likely to break down with symptoms when stressed.

This seems to backup what he said. More antibodies produced. So more chance of picking it up in blood test.

Many people go on about the benefits of a closed herd, but with johnes it just manifests itself.

 

[M-J-G]

This seems to backup what he said. More antibodies produced. So more chance of picking it up in blood test.

Many people go on about the benefits of a closed herd, but with johnes it just manifests itself.

Do you know where that's from or who wrote it, it comes across quite vague?

The closed here is still the most effective way to get on top of the disease because there is background knowledge.

Buying in is simply putting on a blindfold.

 

[CharcoalWally]

Many people go on about the benefits of a closed herd, but with johnes it just manifests itself.

A closed herd should never be looked upon that it's a guarantee that cattle will never succumb to any disease , but as far as biosecurity goes , it's in a different league to buying in.

 

[Paul E]

A closed herd should never be looked upon that it's a guarantee that cattle will never succumb to any disease , but as far as biosecurity goes , it's in a different league to buying in.

........from a untested herd.
You can buy in safely from an accredited herd, especially if it has been clear for longer than the oldest cow there. If it has only been "clear" for 1 test, then it's still dubious, but better than nothing.

 

[Chae1]

Do you know where that's from or who wrote it, it comes across quite vague?

The closed here is still the most effective way to get on top of the disease because there is background knowledge.

Buying in is simply putting on a blindfold.

Its by NMR and herdwise. I can't find how to put a link to a pdf file. I just googled johnes shedding linked to stress to find if there was any evidence linked to what I'd been told and found that.

 

[Sir loin]

went to a talk given by our vets on iceberg diseases in sheep. Johnes disease and border disease(BVD) can pass between sheep and cattle especially in a naïve closed herd. when we used to sell pedigree we tested for 10 years and never found johnes in anything so we gave up testing and our vet said spend the money that you are saving by not testing on rabbit control as they can be carriers of the bacteria which can live out of host for 2 or 3 months.

 

[M-J-G]

went to a talk given by our vets on iceberg diseases in sheep. Johnes disease and border disease(BVD) can pass between sheep and cattle especially in a naïve closed herd. when we used to sell pedigree we tested for 10 years and never found johnes in anything so we gave up testing and our vet said spend the money that you are saving by not testing on rabbit control as they can be carriers of the bacteria which can live out of host for 2 or 3 months.

Like any wildlife vector, if you don't have the disease you're sometimes best to leave the wildlife alone, if you kill them off, other diseased animals might move in to take their place.

 

[CharcoalWally]

........from a untested herd.
You can buy in safely from an accredited herd, especially if it has been clear for longer than the oldest cow there. If it has only been "clear" for 1 test, then it's still dubious, but better than nothing.

Accredited for what? You can never be accredited for Johnes for a start. You just have to keep on testing.

You can buy in cattle that are tested for one thing ,but not another. Nothing's foolproof but a closed herd is in a different league for biosecurity.

 

[scholland]

The attached describes the various tests available and their sensitivity /specificity.

 

[M-J-G]

Accredited for what? You can never be accredited for Johnes for a start. You just have to keep on testing.

You can buy in cattle that are tested for one thing ,but not another. Nothing's foolproof but a closed herd is in a different league for biosecurity.

True about Johnes only being a monitored disease, there is no accredited or risk free status.
It's simply a case of looking at who has tested for longest without any cases.

But even then, how do you know there hasn't been a change in policy where other higher risk land has been taken on for grazing or a new flock of sheep have been taken onto the farm that could be infecting cattle.

At least when you home breed you have control of more variables.

 

[M-J-G]

Its by NMR and herdwise. I can't find how to put a link to a pdf file. I just googled johnes shedding linked to stress to find if there was any evidence linked to what I'd been told and found that.

The graph shows antibody levels which, which is really just an ability of the cow to fight infection combined with the level of disease challenge, which is dictated by numerous factors other than stress.

I have yet to find a link between antibody and levels of bacteria being shed.

I'd like to see the whole article, I'll have a look for it.

 

[CharcoalWally]

True about Johnes only being a monitored disease, there is no accredited or risk free status.
It's simply a case of looking at who has tested for longest without any cases.

But even then, how do you know there hasn't been a change in policy where other higher risk land has been taken on for grazing or a new flock of sheep have been taken onto the farm that could be infecting cattle.

At least when you home breed you have control of more variables.

Absolutely . This is what I always think when people airily tell you that they "know " the source. You know that they're testing for certain things if they can produce up to date documentation. You have no idea what else is going on on the farm. Some farmers are brilliant at taking a responsible overview of whole farm health. Other farmers are brilliant at telling you the bits they want you to hear.

As said already , closed status isn't foolproof , but it's in a different league.

 

[matthew]

The attached describes the various tests available and their sensitivity /specificity.

I'm wondering why PCR screening of dung is described as 'expensive'?
It's non invasive, fast turnaround and very good on specificity.
APHA advertise it at around £25 plus VAT for 5/6 pooled samples.

 

[Cowgirl]

How di

How do you know it’s a false positive ?

Post mortem examination.

 

[Hilly]

Post mortem examination.

After it’s died of Johnes lol

 

[Cripper]

If its bad in a closed herd i don't think test and cull is viable. It will take too long to get rid of it. Vaccination would be a better option if you can still do it. This worked for at least a couple of pedigree herds who had it in the past. They could not get rid of the disease without it. You were admitting that you had it if you vaccinated and it affects the tb test. I know of another herd who had a 'part' dispersal sale and got rid of all the cows They built back up with an embryo transplant programme with mainly NZ eggs. They were never as good as the original cows.

 

[Happy]

Oh,well. After 3 clear tests in a row to finally get to risk level 1 got results of test carried out last week today.
1 positive in 130 tested so back down to risk level 3.

Just goes to show it’s a never ending battle. Been testing 15+ years.

 

[M-J-G]

Oh,well. After 3 clear tests in a row to finally get to risk level 1 got results of test carried out last week today.
1 positive in 130 tested so back down to risk level 3.

Just goes to show it’s a never ending battle. Been testing 15+ years.

Does a clear PCR still get you back to RL1

 

[Happy]

Does a clear PCR still get you back to RL1

Not sure to be honest.
It’s a huge positive on bloods 226% OD so won’t even bother with dung culture prior to putting her away.
Next highest 14% with most 0% or below.
Cow is 7 years old so will be her 4 or 5th time of testing.

 

[AftonShepherd]

Not sure to be honest.
It’s a huge positive on bloods 226% OD so won’t even bother with dung culture prior to putting her away.
Next highest 14% with most 0% or below.
Cow is 7 years old so will be her 4 or 5th time of testing.

I had one either 139% or 149% last year that passed the dung sample test. Put her away anyway but at least it means another clear test (need one more to get to L1)