[Anke]

Hi, I have just got my new tup in, but he hasn't got scrapie genotyped. I was wondering if it was worth doing, and have tried to find some relevant documents on the DEFRA website, but not finding anything that seems to give more detailed info. Is there some papers or similar anywhere on the we that explain it all a bit more detailed?

Does anyone know which combinations are safe? My older tup is ARR/ARQ and I have got also some ARR/ARR ewes. All my pedigree sheep are Shetlands (white) but I also have a number of crosses (not scrapie tested).

What does it usually cost per test? I am not going to join the scheme I think.

[Rosemary]

Don't think anyone bothers now, do they?

[Fleecewife]

The National Scrapie Plan was ended a couple of years ago, because the science behind it is shakey. No genotype is now considered to be more 'safe' than another.  Shetland Sheep are sometimes still scrapie tested because the disease itself has been a big problem on the Shetland Islands, so that is where the first testing was done.  The Shetland Sheep Soc uses a slightly different 'typing' system to the NSP, in that they talk of R1, R2 and so on, whereas the NSP refers to 'Type 1', Type 2' and so on.
As I said, the science behind it all is now outdated, but previously it was thought that sheep with an ARR in their genotype were resistant to developing scrapie, whereas those with a 'V' ie valine were very susceptible.  So ARR/ARR was type 1 and supposedly the most resistant, but type 5 VRQ/VRQ was extremely susceptible. Type 4 was I think ARR/VRQ - I wonder which one won out there - ARR or VRQ?  It was also found that most primitive sheep had type 3 genetics ie types such as AHQ and ARH.  Testing showed up some surprising results, when ARR appeared in some primitives, implying blood from other breeds where ARR is more typical.  An example of this was that Hebrideans were found to have about 20% of sheep with one or more ARR.  Not surprising as it is accepted that Hebs had close contact with Jacobs, which are predominantly ARR, in the old parkland flocks.  However, some Soays were also found to have ARR which definitely shouldn't have been there.
More worrying was that many good sheep were removed from the breeding flock, especially amongst coloured Shetlands, because of their genotype, and many second rate animals were bred from purely because they had ARR genotypes. 
To discuss whether or not to have your sheep scrapie genotype tested, please contact the Shetland Sheep Society for the latest advice. The SSS will also be able to put you in touch with the labs which do the work.  As well as paying the lab, you would also have to pay the vet to draw blood from each sheep.
The only time having your sheep scrapie genotype tested is worth the effort now is if you want to export to Europe or N Ireland and Eire.
The  NSP was based on the premise that scrapie in sheep could be passed on to cattle and humans, but this is now discounted.
For quality Shetland rams, you are better to go for an 'approved ram', which has been examined by the society inspectors and passed as of good breeding quality.

[kanisha]

Hi, fleecewife I have a couple of questions re hebredians. if I may.

is the reference to jacobs because of the prescence of dominant black in the breed or is there a known connection?

why are hebredians black? I understand the breed was ressurrected from park animals were they just kept as they were ornamental or was there another reason?

just curious

thanks

I do test for scrapie genotype. not because of any programme nor any particular need as I don't select on genotype but am interested to know.  heterozygous types are generally thought to be at greatest risk of scrapie this goes for ARR classic scrapie resistance and also for varient scrapie with other genotypes being more resistant

[Fleecewife]

Hi Kanisha.  Complicated question !  Hebs were first selcted, it is thought, as black individuals from the general Scottish multicoloured type back in the 1880s.  To breed true of course they had to be recessive black, although some people believe there may be a brown type carried under that.  It is known that Hebs and Jacobs were then present in some parkland flocks at the same time, in the late 19th and early 20th centuries.  There are no records of interbreeding, just an assumption that it probably happened. Now about 20% are dominant black - according to some estimations, but they are just that, estimations.  The scrapie testing with it's 20% or so of type 2 with the occasional type 1 seemed to support that theory.  Jacobs are dominant black, but so are Black Welsh Mountain (mainly), and there is a rumour that certain Heb breeders in the early years of the RBST may have used BWM to add size and horn strength to Hebs.  But who am I to spread rumours    So there is very little supporting evidence for anything, just assumptions and possibilities.  One thing which is certain though is that Hebrideans were not brought across to Britain by the Vikings as they were here long before that - or multihorned, (probably multi coloured) sheep were, from archaeological evidence. 

[kanisha]

Hi Fleece wife thank you all makes sense to me except if jacobs were used there is the not insignificant problem of white spotting..............a recessive so even if it doesn't show in the first generation its likely to come back to bite you. I am intrigued you place so much importance on the scrapie genotype as supporting cross breeding with jacobs. I would have thought its entirely possible the varience in genotype could have taken place with the general scottish multicolours? Ouessants are getting on for as much as 60% ARR as opposed to ARQ ( ignore UK population of ouessants as these are of dutch origin and the dutch wiped out all their odd scrapie genotypes ( and still do) coz they don't like anything that isn't ARR/ARR) The main flock of reference to me goes back uninterupted and closed flock since the 1900's and this year just tested one of their ewes ARR/ARR

[Fleecewife]

White spots crop up every now and then and are not registerable.  This could be from Jacobs or it could be naturally present within the ancient Scottish multicoloureds (some of which would have been piebald).  There is much discussion about it but without getting the genome for the various breeds we can't resolve it.  Doesn't stop there being several different fiercely held opinions, as in every realm of human activity 
During the days of the NSP it was found that the northern shorttailed breeds (which is what I meant when I said primitives) were generally type 3 ie with neither ARR nor valine.  Hebs had no valine but did have ARR, so the assumption was that there was a recent mixing of blood with a breed or breeds which carry ARR naturally.  Oddly, Castlemilk Moorits were found to be exclusively type 3.  The other nst breeds were found to have varying percentages of ARR, and these were again assumed (by NSP) to be from recent admixtures of blood from other breeds.  Are Ouessants nst s or do they originate from longtailed sheep?

[kanisha]

Hi, fleece wife very interesting;  ouessants are Nsts they are classed on the age of index by geneticists as the oldest french breed. although the ouessant breed is a construct the origin of the sheep is the breton noir of which it would be impossible to find many if any that might not have been crossed out as the black sheep of the region is so indigenous everyone sees them knows them and doesn't think anything of them. the ouessants were kept  seperately as they long ago earned the title of worlds smallest sheep and curiosity of visitors to the region being so small. although it is widely acknowledged they are just the island population of the regions black sheep;
I am as certain as its possible to be that the roots of this breed in the region lie further back in the UK's populations of primitive sheep but at a time when the celtic regions ( cornish is understood by bretons and welsh has the same roots) were trading with each other. cornwall and brittany are very closely linked. it isn't by accident la grande bretagne is opposite la bretagne....

[Fleecewife]

I suppose that can only be determined by looking at the genomes of the various contenders, as with the Hebs.  One day it's going to have to be done, but probably not during a recession and when we are being told that the national diet will have to move increasingly towards a vegetarian one, because of all the greenhouse gasses our livestock produce.  All the more reason to preserve our rare breeds, whatever their origins.

[kanisha]

have you heard of the age of index? it was a very interesting study done by JJ lauvergne ( of his time one of the foremeost geneticists who worked alongside adalsteinsson who did the  work on determining the agouti patterns in shetlands.) it uses morphology to determine a breeds point of development along an evolutionary scale.like the definition of a short tail but uses  considerably more points of reference each one a determinant for a breeds point along an evolutionary scale;   it would be hard to breed back any breed from a longtailed sheep  to get a sheep meeting the definition of nst not to mention from the evolutionary scale there would be too much that was off for all the other criteria.    I would love to do a genome project just tell me where to get the testing done. I'm happy to fund a study in ouessants myself. in the meantime the age of index is a good starting point;

[Fleecewife]

Hi Kanisha.  I met Stefan Adelsteinsson 10 years ago (we talked about colour patterns in cats as well as Shetland sheep), but I don't recall hearing of JJ Lauvergne.  The immediate flaw that springs to mind would be that cross-breeding of longtailed sheep with shorttailed sheep can produce offspring with either long or short tails, and presumably the same holds for other features, so any admixture of 'alien' blood could skew the results. (Think of Hebs which are nsts, but they have fairly long tails, nearly to the hock, so morphologically they appear to be longtailed)  Also the example of, was it Merino sheep which have been isolated on a NZ island for many generations, and have reverted to being coloured rather than white, coloured being a primitive characteristic, shows that reverse evolution/adaptation can occur.  But now I come to think of it I have seen the age index you mention, can't remember the context.  I seem to remember it has some unexpected, or at least counter-intuitive, associations.  I'm going to have to find where I saw it now!!  I think rather weirdly that it was something to do with spinning.
I think they are working on sheep genomes somewhere, possibly Soay at Edinburgh, but I could be misremembering that. Also probably on OZ and NZ breeds, that being where the money and interest are.  It would be interesting to know which breeds' genomes have been mapped so far, and how close we are to being able to identify the different breeds accurately.  I would think that the points of difference between the various breeds would be minute, though hopefully significant.  But Ouessants, having been recognised as distinct, would seem to be ideal candidates  to work on - presumably they will be establishing base lines using very distinct breeds.  I'll see if I can find out more about how far sheep genome research has progressed, and which universities are doing it.

[kanisha]

Hi Fleecewife. If you haven't heard of JJ Lauvergne heres a bit of his work;

http://granit.jouy.inra.fr/productions-animales/1991/Prod_Anim_1991_4_4_06.pdf

http://www.biomedcentral.com/content/pdf/1297-9686-9-2-151.pdf

http://www.biomedcentral.com/content/pdf/1297-9686-8-2-153.pdf

http://www.gse-journal.org/index.php?Itemid=129&option=com_article&access=doi&doi=10.1051/gse:19810303

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2726201/pdf/1297-9686-2-3-249.pdf

just a taster he was quite prolific.

would be interested to hear of any  counter intuitive thinking .

maybe this is what you are thinking of?

http://wwwbibli.vet-nantes.fr/theses/2002/lallemand02_100/part1.pdf

yes the hebredians are interesting are you saying they are back bred from long tails?
as for merinos and their reversion to coloured  they still don't fulfil the criteria for primitive sheep by a loooong way; you would have had to sit there with a list of criteria ( assuming that those in the 17th/ 18th/19th century knew what those criteria were (not yet established) and then breed for them on all levels. if you read the study ( I have included it for you) they you will be able to see how these criteria came about. and that heterozygous types are not part of the criteria.

I knew that my theories of agouti grey had punctured the pride of some in the shetland world but I had no idea they would be this threatened by the theory wow I must be hitting close to the bone I hope as a result of my experiments this year to really get to grips with the colour theory love to have more details on any genome testing that can be done.

how do you explain hebredian tails?

[shetlandpaul]

strange if its not needed anymore. we had a really nice ram lamb this year a spotty shetland with a couple of colours and we even had difficulty giving him away. he was just to good to eat. people demanding that they want the scrapie results for him oh and wanting a list of parents. some people are really difficult. sorry im not spending 50 quid to give him away. next year any ram lambs will just be eaten. the scrapie testing did remove a lot of coloured shetlands and the more primitives shetlands thats why the multiple horned shetlands are very rare now.

[Fleecewife]

Hi Shetland Paul.  Most people who are breeding seriously do expect their stock to be registered, but there are also breeders around who have unreg stock, but more difficult to contact.  I think that in Shetland scrapie testing is still important in the effort to eradicate the disease because of its serious effect on the sheep.  The NSP was set up to try to eradicate the disease in mainland Britain for the sake of the supposed health of humans, not of sheep.
I had thought that the multi-horned Shetlands were rare before scrapie testing started, but perhaps not.  There is a chap down in England breeding multihorns, but he has a big problem with split eyelids.  If only there were more for him to introduce fresh blood, but finding the odd one in Shetland from such a distance then importing it is difficult.  But at least he's trying.

[Fleecewife]

Hi Kanisha. My, that's a lot of reading !  I will take a look when the sun isn't shining 

To try to explain the Heb tails look at the more primitive Shetlands (eg from Foula), which all come from the same nst stock as Hebs - they too have longer (but not 'long') tails.  The fluke shaped tails of the ideal Shetland might be the result of breeding selection since the 1927 standard was written.  Within Hebs there are those with shorter tails, although never fluke shaped.  On the other hand, Soays always have tiny short tails.  The actual length is I think less important than the number of vertebrae, which is 14 in nsts and more but variable in Longtailed sheep.  A bit like giraffes which have seven neck vertebra as do humans, but definitely not the same neck length     When grading Hebs, we look at tail length - tails must not reach the hock.  We don't however count vertebra in the tail, as that can only really be done post mortem. But no I'm not saying that Hebs have Long tails in their ancestry, although it's possible given the proximity of Jacobs, BWM etc in parklands.  (People also kept zebra in parklands at that time - there is a picture of one pulling a small trap  ) 
No, I mentioned that crossing long tailed sheep with short tailed sheep can result in either long or short tailed lambs to illustrate that the morphology of an individual animal might reflect previous cross breeding or an influx of alien blood.  However, I shall read all you have sent me and see if it is the same as I was dimly remembering before I comment any more, as I am perhaps thinking of a different thing.