[Jacob-list] OPP and Johnes Testing

[Neal and Louise Grose]

Nedra and others,
    Your vet is giving excellent advice when he cautions to test for Johne's
disease as well as OPP. Johne's is a MUCH more serious disease because it
can be easily spread environmentally and can cross between species. It also
will result in chronic wasting disease and it is complicated to get a
definitive test on it. Intentionally orphaning lambs and bottle feeding them
to eradicate OPP is non-productive if you give them milk from a Johne's
animal, you are merely trading one disease for a worse one.
    OPP, on the other hand is NOT spread easily by contact unless you have a
strongly symptomatic sheep coughing up stuff in to a feeder. Commercial
stock is not overly effected by OPP because they are periodically replaced
as improved and more productive animals become available. I will
venture that we might not be concerned with OPP unless we are selling
breeding stock and "pet sheep", which of course, we are. Testing for OPP and
other similar diseases is mostly useful on a whole flock basis. Testing of
individual animals is fairly useless because of the erratic delay between
infection and the demonstration of a titer. Even infected animals transmit
infection only sporadically. OPP is, more than anything else, an especially
annoying disease.
    I realize that it sounds as though I am spouting off like usual, and I
would like to emphasize that I am going to be the last to advise anyone with
a OPP negative flock to blindly bring in animals without testing.
IF YOU ARE OPP NEGATIVE, TRY TO STAY THAT WAY!
    OK.
    I have experience. Our flock has been OPP positive since they were
purchased 15 to 17 years ago, though they did not show symptoms for a
number of years. 30% were tested positive in 1993, and that
ratio probably has changed little since then. The result since that time has
been...not much. We do not actively market breeding stock, and the
ones that we do sell are with full disclosure. We have sold sheep (many
before we tested) that have gone on to other flocks that have been tested
for years and are OPP negative. Some of these sheep as well as our oldest
ewe (12 years old) are from sheep that we lost to OPP early on. Our flock
has quickly grown to 80 breeding ewes, and is in excellent over-all health.
I cull 1 or 2 symptomatic sheep a year, and our involuntary cull rate is
less than 5%.  We do not test, because there is little purpose in doing so
unless we would make use of that in our culling decisions, and I am not
interested in having OPP as the only culling criterion. We lamb on pasture
(we do not even have a barn),
so it would  be very difficult to orphan lambs before they nurse. I do not
want to assist births, because that is not the reason we have Jacob Sheep.
Over the last 15 years, I have assisted less than 10 births, and 5 of those
were from a Finn ewe who tried to push 2 out at once. In ten years of
lambing 50 or more ewes a year, I have personally seen 20 or fewer lambs as
they were born, and normally only see them after they have nursed. I would
be happy to try to get our flock free of OPP, but it is not a practical
thing to
do with our limited resources at this time. And I am not about to sell
everything and start over.
    There are no hard and fast answers here. OPP will not bring on the
downfall of civilization, but it would be a lot nicer if we did not have it
to deal with. It is not as much of a threat to sheep husbandry as any number
of other problems, such as Johne's and Scrapie, and it seems to create
more of a stir than is warranted. It is perfectly rational to not want to
have it in your flock; and at the same time, while we may lose individual
sheep, we do not lose genetics from OPP.

Neal Grose
North Carolina

----- Original Message -----
From: "Nedra Darnell" <fibrefolds at sg23.com>
To: <jacob-list at jacobsheep.com>
Sent: Thursday, November 06, 2003 4:26 AM
Subject: [Jacob-list] OPP and Johnes Testing


> Betty, I haven't heard about the 8 to 10 years for symptoms, especially
for
> Jacobs.  Is there a study you know about or online reference?
>
> Our vet puts as much emphasis on eradicating Johnes as OPP and encouraged
> companion testing for it from the start.  It adds $2 per test to the cost.
> He may be more sensitive to Johnes because this is a dairy intensive area
> and as a Cornell graduate, he carefully follows their research and
> recommendations.  There is a web site for a Johnes organization at
> http://www.johnes.org.
>
> Nedra Darnell
> Fibre Folds Farm
> Bath, NY
>
>
>
> _______________________________________________
> Jacob-list mailing list, sponsored by Swallow Lane Farm & Fiberworks
> Jacob-list at jacobsheep.com
> http://www.pairlist.net/mailman/listinfo/jacob-list
>