johnes

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justintime

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Good question Knabe.... this is a good question and I hope someone can give a definite answer. I certainly can not.

It has been proven that Trypsin washed embryos are sterile and disease free. This should lead one to think that the quickest way to clean up a herd full of Johne's carriers would be to flush the better cows in the herd and implant the embryos in tested Johne's free recips. This certainly seems to be one of the quickest, and may possibly be the cleapest way to clean up a herd when one considers the time it takes to test each year and eliminate carrier cattle as you find them. From this research it seems that washed embryos from Johne's carrier females should be free of all disease including Johne's, however....( and this to me is a real big However), there are a few research papers that indicate that Johne's seems to be able to jump a generation once in awhile. To me this indicates that Johne's has a genetic factor that is not understood yet. Some researchers have spent their entire careers researching this disease and gone to their graves not knowing much more about it than when they started.

The main problem with Johne's is that this disease doen't seem to act like other diseases. The tests for Johne's are suspect and there are numerous false positives. The test also takes a long time and thus is farly costly.

I can remember my grandfather talking about some herds that had Johne's in the 1920s and 30s.  Unfortunately, not much has changed since then.
This disease really concerns me simply because it has the possiblity of knocking the beef industry to it's knees. I hate to sound like an alarmist here, but there appears to be some links between Johne's and Chrone's disease in humans. This has not been proven yet but much research is being done on this. It this link is proven, hang onto you hat as the ride this industry takes could be pretty wild.

 

DL

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There are 8 information sheets on SP on JD somewhere that may address most or some of these issues but here is the Cliff notes version
1. JD infection is generally acquired before 6 months of age by ingestion of MPTb (Mycobacterium paratuberculosis - bug that causes JD) from manure of infected cows
2. It takes less than a cubic centimeter of manure to become infected - the more the cow is shedding the less manure it takes to become infected
3. Clinical disease or shedding of the bug takes years from initial infection/exposure
4. The older the animal when exposed, the less the risk of developing an infection
5. Repeated testing of the same cow over years decreases the chance (risk) that the cow has JD but there is really no such thing as a JD free cow (one could be fairly certain she was clean by doing an ileal lymph node biopsy - but that seems a bit excessive)
6. The risk of transmitting JD via either semen or embryos is minuscule
7. The risk of transmitting JD by using ET recipient of unknown status is NOT minuscule - in fact it is quite sizeable
8. Doing a JD risk assessment and annual testing is a reasonable way to assess the level of JD in your herd
9. The tests aren't perfect, but can be used with reasonable accuracy in a whole herd program
10. There appears to be a genetic susceptibility to JD but since there are so many environmental factors involved I think it is not accurate to say it "skips" a generation
11. JD is an under researched, incredibly fascinating, pathogenically different bacterial disease (of cattle, goats and other ruminants) AND YOU DO NOT WANT IT IN YOUR HERD
 

DL

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ROAD WARRIOR said:
DL - How long does the "Bug" stay alive and transmitable in the manure?

RW - waiting on a Red Angus baby (well the daddy is RA)

the bug is hearty and long lived - can live in water for a long time (months maybe??) - likes wet, damp conditions - does not like dry or sun.....bad bug...like I said very interesting disease that you do not want
 

ROAD WARRIOR

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DL said:
ROAD WARRIOR said:
DL - How long does the "Bug" stay alive and transmitable in the manure?

RW - waiting on a Red Angus baby (well the daddy is RA)

the bug is hearty and long lived - can live in water for a long time (months maybe??) - likes wet, damp conditions - does not like dry or sun.....bad bug...like I said very interesting disease that you do not want

Let me know what you think when it hits the ground DL !
 

knabe

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interesting

http://news.bbc.co.uk/2/hi/health/7240636.stm

With these genes out of action, the mouse cells produced much higher levels of interferon, which effectively blocked viruses from reproducing.

but did the virus remain dormant and viable?????????????????????

this might sound good, but could be dangerous, especially if that therapy or gene change stored dormant viruses and allowed them to mutate in vivo (in the body)

would be interesting to screen these genes in humans for snps, as well as cattle.

dl, any chance this is relevant for johnes, bvd etc?
 

DL

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knabe - I have always associated interferon with viruses - so yes to BVD but not so sure about JD (but I'm no expert here)

RW - heifer 72 lbs out of a Midas ET heifer - VIGOROUS - Midas is homo black and although I thought the dam was homo black because I thought her dam was homo black (that might not be true) - this calf may be red!! at least she appears to have red ears and she is not black (which is AOK with me - I like red) - I have high hopes for her - her mother is one of my favorites  ;)
 

Joe Boy

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Jan 31, 2007
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I heard a dairy man say that their baby calves are not allowed to nurse a know carrier and he listed a couple of other diseases with JD.  I cannot believe a Johnes cow can be in a dairy heard at all but like TB since many of the herds and all of the large herds are confined they are tested often.  After Mid-March no dairy cow of any kind can be sold in Texas without a permanent ID because of TB.
 
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