2008-11-08

Genetic diversity in Alpine sheep breeds - emphasis on Slovenian breeds

Dalvit et al. have published a paper "Genetic diversity in Alpine sheep breeds" in Small Ruminant Research. They attempted to study the genetic diversity --> similarity via microsatellite molecular markers in breeds of sheep kept in the region of Alps. Their study involved animals of the following breeds:
  • Italy
    • Bergamasca (TIHO, SRR paper)
    • Biellese (TIHO)
    • Schwarzbraunes Bergschaf = Black-brown mountain sheep (TIHO)
    • Tiroler Bergschaf = Tiroler mountain sheep (TIHO)
    • Schnalserschaf = ??? sheep (???)
  • Germany
  • Slovenia
My interest in this article is of course due to the Slovenian breeds of sheep: the Bovec sheep and the Jezersko-Solčava sheep breed. The main result regarding these two breeds are that Bovec, Jezersko-Solčava and Carinthian were in the same cluster according to the Reynolds' genetic distance (e.g. see this lecture). This is partly an expected result, since to my knowledge Jezersko-Solčava and Carinthian are phenotypically very similar and the origin and history of these two breeds are similar. Sometimes a name Seeländerschaf was also used for Brillenschaf, which basically means Jezersko (~ lake land) sheep. The following Fst and mean molecular coancestry (MC) values were obtained:
  • Jezersko-Solčava - Carinthian, Fst = 0.053, MC = 0.188
  • Jezersko-Solčava - Bovec, Fst = 0.056 , MC = 0.201
  • Bovec - Carinthian, Fst = 0.084, MC = 0.176
Surprisingly, the molecular coancestry showed that Jezersko-Solčava breed has a bit more similarities with Bovec than with Carinthian breed, though Fst was lower for Jezersko-Solčava - Carinthian pair. The difference for mean molecular coancestry is not large, but I would say that Jezersko-Solčava and Carinthian are phenotypically much more similar. Bovec sheep is phenotypically quite different to Jezersko-Solčava. There surely have been different ways of selection of Bovec and Jezersko-Solčava breed since the former is today used for milk production, while the later is not milked at all and used as a meat type sheep i.e. only for rearing lambs. In study of Dalvit et al. Carinthian animals were sampled from Germany. I wonder if the same results would be obtained with animals from Austria. Additionally, TIHO site "states" that there has been some introgression of White mountain (Weisses Bergschaf) breed into Carinthian breed in Germany. However, this does not mean that Carinthian breed in Germany today still has any of the "genes" from White mountain. For example, in Slovenia Romanov rams were used in some flocks of Jezersko-Solčava sheep, but those animals were never treated as Jezersko-Solčava, but as a separate breed called improved Jezersko-Solčava or JSR in short. JSR breed is today a breed with the biggest population among sheep in Slovenia. Jezersko-Solčava breeds is maintained in its "original" environment, but also in some other parts of the Slovenia.

It was also interesting that Jezersko-Solčava and Carinthian were not clustered with Bergamasca. Historical records for both breeds say that at some time in the past breeders used Bergamasca and Paduaner rams. It seems that only some introgression of Bergamasca was done. The following Fst and molecular coancestries (MC) were obtained:
  • Jezersko-Solčava - Bergamasca, Fst = 0.050, MC = 0.185
  • Carinthian - Bergamasca, Fst = 0.077, MC = 0.160
  • Jezersko-Solčava - Carinthian, Fst = 0.053, MC = 0.188
The mean molecular coancestry for the Jezersko-Solčava - Bergamasca pair was practically of the same value as for the Jezersko-Solčava - Carinthian pair, while Carinthian - Bergamasca pair had a bit lower value. I again think this is not consistent with the history of Jezersko-Solčava and Carinthian breed. Bergamasca breed was involved in both populations, but that was some time ago. I would expect more similarities between animals of Jezersko-Solčava and Carinthian breed. These peculiarities could be due to the Germans vs Austrian Carinthian population, chosen set of microsatellites, substructures etc.

P.S. Slightly different results were obtained in "another version" as published in "Best Practices Manual for sheep and goat breeding". In that version, Jezersko-Solcava and Carinthian breed has greater similarity than Jezersko-Solcava (or Carinthian) and Bovec breed.

P.S. See also the "Atlas of Alpine sheep breeds" by Feldmann et al.

3 comments:

Gregor Gorjanc said...

For reference: sometimes Carinthian is writen with y Carynthian.

David Burbidge said...

This is very interesting - thankyou. We are planning to bring a Rough Fell sheep from Sedbergh in the Yorkshire Dales of England to Zrece in Slovenia, and I found it interesting to read about Slovenian sheep breeds. Lep pozdrav iz Sedbergha

Gregor Gorjanc said...

Nice breed! What is the litter size and daily gain?