Wednesday 25 November 2020

How to limit undesired traits in "breeding-back"?

Modern “breeding-back” projects such as Taurus cattle and the Auerrind project work with a breed selection that comprises all achievable morphologic aurochs traits. Size, proportions, colour, horn shape and size and body morphology to a certain degree. But the problem is that the sets of breeds also include a lot of undesired traits. Recessive colour variants, as well as alleles for very small horns (which might be recessive too, see here) and for different horn shapes. It requires a lot of breeding work to purge those unwanted traits from the population. Recessive alleles in particular are very difficult to breed out. While it is well-possible to achieve very good animals with the sets of breeds chosen, it will be difficult and longsome to truly stabilize the breed for the traits desired because of the high number of undesired traits. 
Therefore, I have been making some thoughts on a project that minimizes the amount of undesired traits but still is able to achieve all the aurochs traits that are achievable with domestic cattle. 
 
Such a project would have to chose breeds that already resemble the aurochs to a large degree and do not have any undesired recessive colour variants or different horn shapes or sizes. I think that a combination of wildtype-coloured Lidia, Maronesa and Sayaguesa would be suitable for this purpose. Lidia would contribute a very aurochs-like body morphology, Maronesa has the sexual dimorphism and horn shape (in good individuals) and Sayaguesa would contribute large size, long snouts (at least in cows) and long legs. The horn shape of this combination would be good to very good, n
o deviant colour variants would be present and since some Sayaguesa grow up to 170 cm withers height the right size would also be found in the gene pool. The bulls might end up a bit short-legged, however, and the horn size might not be that impressive, but overall it would be possible to breed a good result quite fast and would be a lot easier to stabilize. I would love to see Lidia x Maronesa, Lidia x Sayaguesa or Sayaguesa x (Lidia x Maronesa). 

 

9 comments:

  1. Look this bull.

    https://youtu.be/X1DeHh759XM

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    1. Looks like a pretty standard, unremarkable highland to me

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  2. I wrote an article a while back that addressed some of the same issues

    https://www.linkedin.com/pulse/too-many-cattle-breeds-enough-horse-back-breeding-effort-rhys-lemoine/?trackingId=gHwE5cz83sL9SaOQ5aj9rw%3D%3D

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  3. Horn found in Wales this year.

    https://www.bbc.com/news/uk-england-gloucestershire-52833791

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  4. https://www.youtube.com/watch?v=J_LnlJ7GUrg

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  5. A bit worried that the undesired trait of excessive aggressiveness could be too much present... Limia/ camargue bulls are so beautiful and aurochs like but often natural born killers...the video in the link explains that this poor guy treated his bull like a son for years but the bull one day killed him... https://www.google.it/amp/s/france3-regions.francetvinfo.fr/provence-alpes-cote-d-azur/2015/01/14/un-eleveur-tue-par-son-taureau-arles-632120.amp

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    1. I don’t understand the concern with aggression? In the wild this animal is expected to defend itself and its herd from predators. They auroch is not intended to be used for meat or dairy.

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    2. These animale will normally live in areas frequented also by people as it’s usual in Nederland. Same problem will concern the staff of the breeding programs. Personally I think that this Daniel proposal is the most interesting to obtain an auroch like new breed but you have to strong select Lidia bulls that are really really tame, Gent.le and it is not so easy... the risk of a bull as aggressive as a Lidia and as big as a sayaguesa is possible...

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