Johnes dilemma

Discussion in 'Livestock & Forage' started by NaeSure, Apr 15, 2019.

  1. NaeSure

    NaeSure New Member

    Location:
    Grampian
    I got the cows blood tested for johnes for the first time last autumn and had 2 positives out of 45. The first one is a 10 year old cow with no daughters in my herd (I’ve only had my suckler herd for 4 years) so she will be kept separate and culled once she has weaned her calf.

    The second one is a bit of a headache as she is one of my pedigree cows, she’s about 5 years old. I bought her (let’s call her cow A) and her heifer calf, along side her dam (cow B) and a number of others 18months ago.

    Scenario:

    Cow A - 5yo pedigree cow (still due to calve) tested positive for Johnes
    Cow B - 10yo pedigree cow, Cow A’s dam, recently calved a heifer calf, tested negative for Johnes
    Cow C - 2yo heifer just calved her first calf, daughter of Cow A. Tested negative for Johnes.

    I have ambitions of developing the pedigree herd and obviously tackling johnes is pretty important so the safest thing to do is to cull A,B&C and not keep any of their calves, but this family is one of my better families so I wonder if there’s a way I can keep maybe Cow B and her calf. Is it likely A might have caught it as a young calf and not from her mother? I think A&C will both have to be for the chop. The farm they were all from originally were a member of PCHS and this is my first year of being in myself. I plan to speak to my vet about it at some point but they’re flat out lambing and calving just now so they probably have better things to do right now!

    Thoughts??

    Thanks in advance
     
  2. JP1

    JP1 Moderator

    What does your own vet say?

    Are you in a health scheme like the SAC scheme? If so, call George and ask him for advice

    Me? I'd have them retested before I made a final decision
     
    Danllan, Tarw Coch, M-J-G and 4 others like this.
  3. Charolais cattle

    Location:
    Ireland
    Have you had a tb test in last 90days before johnes blood test?
     
    Cowgirl and juke like this.
  4. NaeSure

    NaeSure New Member

    Location:
    Grampian
    No tb test done in 90 days before johnes test but there was a routine TB4 6 months previous. I think retest the 3 generations is most likely and I’ll just have to figure out what to do then. If the results are exactly the same then the vet says to keep the oldest cow as there’s a fair chance the middle one caught it as a calf when she was born. If all three are negative then we should be ok...
     
  5. Charolais cattle

    Location:
    Ireland
    Dung samples only way to go... hope works out in ur favour... I had 3 turn down for johnes.. but had tb test week before.. send in the dung samples to get tested all clear.. but dung samples cost 30quid each..
     
    Last edited: Apr 15, 2019
  6. Chae1

    Chae1 Member

    Location:
    Aberdeenshire
    Retestings a waste of time in my opinion.

    If they test positive cull them.

    Keep testing B & C, if she's made it to ten years old doubtful she's got it.

    I'd wean cow As calf immediately after calving and put it on something else to reduce risk of infection.

    They generally only shed and test as positive when under stress, so that'll affect test results i was told.
     
    Milkingforfun and Matt like this.
  7. AftonShepherd

    AftonShepherd Member

    I'd say it's worth doing a dung sample.

    We had a positive this year at double the threshold (over 70 counts as positive, she was 141) but she passed the faecal test therefore preserving our Johnes 2 status.

    Having said that, I'm a great believer that there is no smoke without fire so she's isolated as if she was positive and her and her calf will be sold later in the year.
     
  8. juke

    juke Member

    Location:
    DURHAM
    First loss is the best lost with johnes .. doesn't take long to spread amongst a heard.
     
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  9. Chae1

    Chae1 Member

    Location:
    Aberdeenshire
    Do you think its right to sell the cow and calf to someone else, knowing its tested positive and possibly infecting there herd?
     
  10. AftonShepherd

    AftonShepherd Member

    The cow will be fattened and put through the fat ring. The calf will be Charolais and not sold for breeding.

    As I said, she has actually tested clear on faecal test anyway which is supposedly the reliable one, but the high reading in the blood test still concerns me.
     
    Angus77 and Chae1 like this.
  11. Half Pipe

    Half Pipe Member

    This is just my view
    The test results show that cow A is less likely to have gotten jhonnes from its dam, so the risk to cow C depends if the source for cow A was still in the both herd
    When cow C was a calf (highest risk of infection)
    I would kill cow A as soon as possible.
    Preferably straight to abbatoir.
    Like @Chae1 said, not fair spreading it thru market etc (someone might think it's a nice cow to add to there herd)
    The longer it's on farm, the more contaminated muck produced and they can loose condition fairly quick.
    Have another source of colostrum available for cow A's calf and don't let it feed from her.
    Colostrum and muck from positive cows are main source
     
    le bon paysan likes this.
  12. choochter

    choochter Member

    Location:
    aberdeenshire
    Two tales to tell…

    Tale 1
    The first cow I ever bought came with a lovely heifer calf at foot. That heifer calf tested positive when in calf for the second time and was culled after rearing the calf. I still have that first cow, now aged 17 and in calf with her 14th calf. Presumably, the heifer calf must’ve picked up Johnes from some other cow’s infected dung before I bought them

    So, by that reckoning, CowB should be fine.

    Tale 2
    I bought 2 heifers a couple of years ago, quarantined them and tested for Johnes. One tested low antibody positive for Johnes and negative in the dung. We waited a couple of months and retested the heifer but this time took two blood samples and sent them to two different labs.

    The result on the second test was antibody negative and dung negative from the original lab and low antibody positive from the second lab.

    So, that was unhelpfully unclear to say the least.

    Therefore, I think that if CowA’s result was high then she probably has it and should be culled. And in that case keeping her daughters might be too big a risk. If CowA’s result is a low positive, then I’d be keeping her and retesting in a year.
     
    AftonShepherd likes this.
  13. Danllan

    Danllan Member

    Location:
    Sir Gar / Carms
    Luckily we've never - knowingly, anyway - had it, but family and friends have. Some good advice already given, even though conflicting on parts, but it is a personal decision, although there is the greater good to be considered in making it.

    For myself, I think you just have to weigh a doubt against a certainty, swallow your losses and cull hard. Such is life... :(
     
    Johngee likes this.
  14. Cowgirl

    Cowgirl Member

    Location:
    Ayrshire
    Dung samples an absolute must - false positives (and negatives) are common with blood testing.
     
    Charolais cattle likes this.
  15. Chae1

    Chae1 Member

    Location:
    Aberdeenshire
    Don't know if it will affect beef herd but its only a matter of time before someone makes link between johnes and crohns disease in humans.

    How many cull cows with it are going into food chain. Milk from infected cows must be more dangerous.

    Its frightening in my opinion.
     
  16. Cowgirl

    Cowgirl Member

    Location:
    Ayrshire
    Still no definitive proof yet, despite it being a tempting theory.
     
  17. Whitepeak

    Whitepeak Member

    Location:
    Buxton, Derbyshire
    We’ve just entered a health scheme, and did our first Johnes screen about a month ago. I spoke to one of the vets and he explained to me that the initial screen is testing for antibody, in other words an immune response from the cow, if she tests positive she has been exposed to Johnes but is potentially not infectious hence the need to retest. The retest (bloods and dung) tests for for antigen, ie. presence of infection. So a cow could test positive on the 1st test but then go clear on retest as she isn’t infectious/excreting disease. Although there is a high likelihood of her becoming infectious so at some point particularly if she has a very high initial test result. Therefore they recommend to isolate all positive animals and consider culling.
    TB testing can interfere with blood testing due to TB and Johnes being from the same bacteria family. Dung samples aren’t effected by TB testing however.
     
  18. dowcow

    dowcow Member

    Location:
    Lancashire
    Don't cull anything off a single test. Vets told us labs are known to mix up samples, and the test isn't very good, and that a single high result should only count as a 'maybe' and only if another test on another day comes back as high it should become 'probably'.
     
  19. Keep calving pens strawed up well to reduce risk of transmission to calves.

    We had one or two go down with johnes a few years back but always bought in stock and have culled hard with all cows now home bred and a fast turn over of home bred replacements.

    It’s about 5 years since the last one was culled with johnes so I am pretty confident we’ve got rid of it.

    Buying stock in is the biggest risk.
     
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  20. dowcow

    dowcow Member

    Location:
    Lancashire
    One of the ways suggested to dairy farmers to deal with Johnes is to breed medium risk cows to beef bulls. If you are buying in dairy beef heifers to expand a beef herd, there's a higher than ever chance of bringing it in.
     
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