Subject: Information wanted about BSE in Sheep.

From: [email-masked]
Date: 23 Jul 1996 11:38:26 GMT

I have heard today that there is a possibility that the BSE agent was also
passed to sheep, but the symptoms may have been disguised by incidents of
scrapie. Can anyone give me more info on this ? I am also worried that BSE
may be present in other food sources, for example turkeys, which are fattened
and slaughtered so quickly that there is not time for the symptoms to develop.
Is there any meat that is ‘safe’ in the UK, or should I go vegetarian. I
am not a food-science expert, just a consumer who is very worried and does
not believe the UK government propaganda.

---

From: Oz <[email-masked]>
Date: Thu, 25 Jul 1996 10:36:32 +0100

In article <[email-masked]>,
[email-masked] writes
>not believe the UK government propaganda.

Well, nobody else has replied so .....

Well if you believe that all the UK govt says is propoganda that's a
problem for a start. They have funded most of the trial work too.

I suppose one needs to start by deciding what is a reasonable risk in
this situation. This is your choice. Would you fly on an aeroplane or
drive a car or be a pedestrian? Very different levels of risk. However
let us start with some facts.

1) Despite BSE entering the UK herd about 1980 (ie 16 years ago),
peaking in 1987 (nine years ago) and if you assume that V-CJD is caused
by BSE (currently unknown) then the incidence rate for V-CJD at present
in the UK is about 1:10,000,000 population per annum or about 1/10th the
rate of CJD. Did you ever seriously worry about getting CJD? Compare
this risk with other risks that you voluntarily take. Make a decision.

2) BSE infectivity has only ever been found in brain and upper spinal
chord in cattle. This has been out of the human food chain for ALL UK
cattle since Nov 1989.

3) Sheep, as ruminants, have been forbidden to be fed meat & bone meal
since July 1988. Ewes rarely (often never) get any compound
feedingstuffs anyway.

4) Sheep only live around 6 years. The economics of sheep breeding do
not allow the use of much (if any) bought in feed except possibly for
hitting a premium market such as easter lamb. Even then they are often
fed nothing but whole barley or maize gluten or other low cost vegetable
feed. 

5) Note that #(4) does not apply to the same extent in much of Europe.
The much higher price of lamb there and the climatic conditions reduces
the use of grass and increases the use of concentrate feed. They have
also not had a ban on feeding M&BM to ruminants (until recently?).

6) BSE has never been found in sheep so far. I have read (but I can't
find the reference) that the UK expected and looked for an increase of
scrapie in sheep because for a long time BSE was thought to be scrapie
(In cattle). They observed no such increase.

7) In the current food scare climate it is prudent to remove any
unnecessary public concern (we passed the necessary some decades ago)
and butchers on UK TV have said that sheep brain has never been used in
human food (except as a delicacy) anyway. A ban thus has little economic
effect except as an added disposal problem. However IMHO this has been
handled very badly indeed since it's not a matter of reducing risk
(since there really is no evidence whatsoever of there being a risk),
but as a cheap way to improve public confidence. The knowledge that BSE
is not scrapie has been known for a long time. Certainly nobody who has
followed this group's discussion would be remotely surprised that BSE
infects sheep, that scrapie infects cattle has been known for quite a
long time. However there has never been the slightest evidence that
sheep have ever infected cattle over the 200 years that scrapie has been
known, despite cattle and sheep sharing the same fields and often the
same buildings for much of that time.

8) So, personally, I don't worry in the slightest. I shall keep on
eating lamb, it's worth a 1:10,000,000 (probably zero) risk to be able
to see a new crop of lambs gambolling in the fields each year, and sheep
grazing on hillsides as they have for centuries. Incidentally I have no
sheep, none of my friends have sheep, none of my family have sheep and I
would only farm them if I was forced to.   :-)

Postscript: Gadjdusek, Science, 2 Sept 1977, Vol 197 No 4307 943-960.
[I bet Ralph will get this asap!]

P958. "Scrapie has now been found to cause a disease clinically and
neuropathologically indistinguishable from experimental CJD in two
species of Old World Monkeys." 

Note that this is experimentally, and by injection into the brain. Some
indication at least that if scrapie was a problem, it might look like
CJD and thus would figure in higher levels of CJD in the UK, which is
*NOT* observed. Marmosets infected with scrapie succumbed to the disease
more quickly than they did to BSE.

------------------------------- 
'Oz     "When I knew little, all was certain. The more I learnt,
        the less sure I was. Is this the uncertainty principle?"

---

From: [email-masked] (J Ralph Blanchfield)
Date: Thu, 25 Jul 1996 20:12:34 GMT

>not believe the UK government propaganda.

Hello Chris,

If I were not a food scientist who is aware of the facts,  and I had
to rely for information solely on the garbled and often sensationalist
stories in the media, I expect I would be worried too. 

Perhaps I had better say at the outset that neither I nor the
Institute of Food Science & Technology (IFST) have any connection with
the UK Government or the agriculture or meat industries or any
lobbying or special interest groups.   IFST is the professional
qualifying body  for food scientists and technologists. It is totally
independent . It is controlled and run, by its professional members
who are elected to membership by virtue of their academic
qualifications and their relevant experience, and their signed
undertaking to comply with the Institute's ethical  Code of
Professional Conduct. They are elected solely in their personal
capacities and  in no way representing organisations where they may be
employed. They work in a variety of areas, including universities and
other centres of higher education, research institutions, food and
related industries, consultancy, food law enforcement authorities,
and in government departments and agencies.  

So here are the facts. I shall try my best to relate them for you
without using scientific jargon.  

BSE has not ever, not now been diagnosed in sheep "in the field". It
is very highly unlikely that it would be "masked by scrapie". The
people who would see it if it happened would be the vets. On Monday
(22 July) Francis Anthony, BSE adviser to the British Veterinary
Association, said: "We've been living with scrapie for more than 200
years and no scientist has been able to make a connection between
scrapie and man. It may be possible to transmit BSE to sheep
experimentally but there is no evidence in the field that BSE causes
damage to sheep. Otherwise we vets would be seeing it."

What he (and the UK Government and the EU Agriculture Commissioner)
are referring to is a research report published last month on
laboratory experiments at the Institute of Animal Health, where the
researchers fed six sheep with homogenised brain of confirmed BSE
infected cows, and one of the six developed an encephalopathy which
was different from scrapie, and was confirmed, by a special procedure
called strain-typing, to be BSE, not scrapie. They found the BSE
infectivity in the brain and the spleen, and one would expect it
therefore to have been in the spinal cord and the retina of that sheep
too, 

Even though BSE has not been diagnosed in sheep in "real life"
circumstances, the fact that it has been shown to be transmissible to
sheep under laboratory conditions when fed with infective cow brains,
says that it is possible to transmit, and therefore a prudent
precaution is not to eat sheep brains, spinal cord, eyes or certain
other sheep offals (probably spleen, tonsils, thymus and intestines).
So it looks as though these will be excluded from the food chain. 

In real life, moreover,  the lambs slaughtered for meat are not now
(if they ever were) fed on the infected meat and bonemeal that
originally caused BSE in cattle. There is anyway no evidence of
infectivity in the muscle meat of cows or sheep.

There is no known evidence to suggest that BSE can be transmitted to
poultry.

Finally, there is at present no direct scientific evidence
demonstrating that BSE is transmissible to humans.

For the benefit of those subscribers who would like to follow-up the
details of the research, they can be found in the paper is by Foster J
D et al (1996) "Detection of BSE infectivity in brain and spleen of
experimentally infected sheep", Veterinary Record, 1 June , 546-548.

Regards

Ralph

******************************************************************
J Ralph Blanchfield
Food Science, Food Technology & Food Law Consultant
Chair, IFST Member Relations & Services Committee
Web Editor, Institute of Food Science & Technology
IFST Web address: http://www.easynet.co.uk/ifst/ 
******************************************************************