tag:blogger.com,1999:blog-1222590081823739642.post7390648638337726590..comments2024-03-28T07:28:58.459-07:00Comments on The Breeding-back Blog: The genetic and developmental background of visible traitsDaniel Foidlhttp://www.blogger.com/profile/02924677790606716751noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-1222590081823739642.post-48702762305704710522017-08-07T04:18:21.213-07:002017-08-07T04:18:21.213-07:00Well, just wanted to say that in Navarra the dichr...Well, just wanted to say that in Navarra the dichromatism is already unmasked...<br />Yes, i think i basically mean the Y-chromosome. <br />If this is the case maybe it could make a breeding-strategy to build two pools, and finally take only the cows from the one and the bulls from the other and mix these up.<br /><br />Well, if it would be completly unpredictable it would hardly be possible to make any decisions about selection.<br />I think if two breeds are combined that are much different then one could expect more surprises in future generations, and if there are certain similarities then it's likely that these could be kept up.<br />So in general i would expect that the result of an Pajuna-Maremmana-cross is more predictable than the result of an Watussi-Chianina-cross, for example.<br />(my comments tend to disappear, is thias due to moderation ?)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1222590081823739642.post-13034497501520030762017-08-06T07:32:08.244-07:002017-08-06T07:32:08.244-07:00Well, just wanted to say that in Navarra the dichr...Well, just wanted to say that in Navarra the dichromatism is already unmasked...<br />Yes, i think i basically mean the Y-chromosome. <br />If this is the case maybe it could make a breeding-strategy to build two pools, and finally take only the cows from the one and the bulls from the other and mix these up.<br /><br />Well, if it would be completly unpredictable it would hardly be possible to make any decisions about selection.<br />I think if two breeds are combined that are much different then one could expect more surprises in future generations, and if there are certain similarities then it's likely that these could be kept up.<br />So in general i would expect that the result of an Pajuna-Maremmana-cross is more predictable than the result of an Watussi-Chianina-cross, for example.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1222590081823739642.post-87730460781827258502017-08-06T03:13:22.087-07:002017-08-06T03:13:22.087-07:00The black allele E^d carried by Camargue is not pr...The black allele E^d carried by Camargue is not problematic, as it is dominant and therefore easy to select out. I would not worry about that. <br /><br />Why should some breeds be "better at passing on the male part"? What's that supposed to mean, are you talking about the Y chromosome? <br />I think the looks of Manolo Uno are ok, but the looks of an F1 are completely irrelevant as it is solely the product of heterozygosity - it does not tell you what to expect for later generations (except for dominant-recessive traits). F1 do not give an accurate idea of the potential for a breed combination. So if you cross two breeds and the result seems to be disappointing in F1, it does not mean anything for further breeding. Daniel Foidlhttps://www.blogger.com/profile/02924677790606716751noreply@blogger.comtag:blogger.com,1999:blog-1222590081823739642.post-39487881645720460612017-08-06T01:34:25.302-07:002017-08-06T01:34:25.302-07:00Thanks for reply.
Interesting.
You mean Maronesa i...Thanks for reply.<br />Interesting.<br />You mean Maronesa is the only breed with a clearly expressed sexual diChromatism, don't you ?<br />From the Lidia-strains at least some individuals of the the Casta Navarra have some degree of dichromatism. This breed is on the smaller side, but maybe due to the colour it would be less tricky to cross with this than with Camargue...<br /><br />To that XY-dimorhism-question, may it be that some breeds are better in passing on the male part of it than others ? Could it make sense to focus on certain bull-lines, Maremmana and Pajuna for example ? Because there is at least one very good cross of these...Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1222590081823739642.post-10789334284706025152017-08-05T07:08:26.874-07:002017-08-05T07:08:26.874-07:00To your first question: No, both males and females...To your first question: No, both males and females pass on dimorphic traits and also the extent of it. Of course in cattle a Y chromosome (or the necessary signal molecules) are needed to express male traits, but the traits themselves and the code for the intensity of these differences can also be found on the X chromosome or autosomes. So both cows and bulls pass on dimorphic traits. <br />To your second question: If you are talking about sexual dichromatism, in Lidia the situation is often unclear because there are many lightly coloured bulls and dark cows, but there seem to be some herds where the dimorphism is ok but not perfect (so basically similar to what we see in Heck cattle). Corriente seems to be quite good regarding sexual dichromatism based on what I have seen so far. In Camargue, the sexual dichromatism cannot be judged because it is masked under the black colour allele E^d. <br />The only aurochs-like breed that I am aware of that almost always has a clearly marked sexual dimorphism is Maronesa; to a varying extent. Daniel Foidlhttps://www.blogger.com/profile/02924677790606716751noreply@blogger.comtag:blogger.com,1999:blog-1222590081823739642.post-25545223471691891972017-08-04T04:25:26.547-07:002017-08-04T04:25:26.547-07:00"As for selecting on sexually dimorphic trait..."As for selecting on sexually dimorphic traits, I think the conventional method won’t work here. Always simply choosing red cows and dark bulls, or small cows and large bulls, or whatever sexually dimorphic trait, probably will work not here."<br />So is it that both cows and bulls can pass on the sexual dimorphism, are they weighted equally ? Or may it be mostly the bulls that carry pass these on, could it be bound to the Y-chromosomes ? In the first case you would be rigth, otherwise it could work for cows...but one should be more picky with the bulls. Then the cows should be red, and the bull-lines should be from breeds with cows that show little or no black color. <br /><br />"These include Lidia, Corriente and Camargue (and it is probably not a coincidence that these breeds are not bred for docility and mass, but for agility and “fighting spirit”). As with sexual dimorphism, it might be useful to rely heavily on those breeds where the developmental set is obviously still right to produce an aurochs-like body shape."<br />Is sexual dimorphism especially high in this breeds ? Or could the cows here have a larger influence on the appereance of their male offsprings ? This breeds also have athletic cows, so maybe it's just that the bulls look auroch-like because the extra-muscles are build on the right frames ? Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1222590081823739642.post-70971329270076598212017-08-04T02:59:15.013-07:002017-08-04T02:59:15.013-07:00"As for selecting on sexually dimorphic trait..."As for selecting on sexually dimorphic traits, I think the conventional method won’t work here. Always simply choosing red cows and dark bulls, or small cows and large bulls, or whatever sexually dimorphic trait, probably will work not here."<br />So is it that both cows and bulls can pass on the sexual dimorphism, are they weighted equally ? Or may it be mostly the bulls that carry pass these on, could it be bound to the Y-chromosomes ? In the first case you would be rigth, otherwise it could work for cows...but one should be more picky with the bulls. Then the cows should be red, and the bull-lines should be from breeds with cows that show little or no black color. <br /><br />"These include Lidia, Corriente and Camargue (and it is probably not a coincidence that these breeds are not bred for docility and mass, but for agility and “fighting spirit”). As with sexual dimorphism, it might be useful to rely heavily on those breeds where the developmental set is obviously still right to produce an aurochs-like body shape."<br />Is sexual dimorphism especially high in this breeds ? Or could the cows here have a larger influence on the appereance of their male offsprings ? This breeds also have athletic cows, so maybe it's just that the bulls look auroch-like because the extra-muscles are build on the right frames ? Anonymousnoreply@blogger.com