dun

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Duncan MacIntyre
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Post by Duncan MacIntyre »

I don't think Clive has read it wrongly, what I think is being said is that we have to accept that certain things will show when two genes come together from both parents which may not meet the breed standard. The alternative to this would be to gene test the entire breed and eliminate all animals which carry the genes we do not want. Who knows what other characteristics would be eliminated by doing this? What we will do by not breeding from colours which do not meet the breed standard is discriminate against these genes to preserve accepted breed character without eliminating them and narrowing our genetic base, which the genetics project has shown to be much wider and indicate less inbreeding in the Dexter than many of us would have expected.

A physical defect which crops up once in a while is wry tail, where the tail is set on at an angle. We would not wish to deliberately breed lots of Dexters with tails coming out squint, so such animals would be rejected on inspection for eg a pedigree sale or the bull scheme. But the genes will probably be in the background at a low level all the time. I think there is nothing wrong with a wide genetic base and much to commend it, but we have to have a balance between that and maintaining a breed with a clear identity.

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Broomcroft
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Post by Broomcroft »

Yes I agree with you Duncan.
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Post by Broomcroft »

Where do I go to get cattle colour DNA tested?
Clive
Duncan MacIntyre
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Post by Duncan MacIntyre »

The same lab in the Netherlands which does our chondrosysplasia tests does red for certain and I think dun as well but I have never asked to have dun tested. If you have already submitted samples for any animals they should be able to do additional stuff on the same sample .

Duncan
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Post by wagra dexters »

Kirk, thank you for your reply to my previous posting. I was away for a few days and didn't check in.
Margaret.
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Post by Kirk- Cascade Herd US »

Just to add a little twist, we usually think of red OR dun. Well, I have a theory where you can exhibit both red AND dun. What? you are saying... how can that be possible?

Well, first remember that there are only two pigments, eumelanin (black) and phaeomelanin (red). Now remember that true reds (Ee/Ee) have only red pigment, while blacks (ED) have primarily black pigment and little, if any, red pigment. So, when an otherwise black animal also has two dun genes (Bb/Bb), the black pigment remains unfinished leaving the animal a shade of brown (dun). But a true red animal with homozygous dun genes (Bb/Bb) cannot exhibit dun because it has no black pigment to leave unfinished.

Now for the Red AND Dun theory: Imagine one of our E+ red animals with one or more of the shading patterns and imagine that the animal is also Bb/Bb homozygous dun. Theoretically any black shading on that red animal will be unfinished and will be brown (dun) shading. Now because the dun is not as distinguishable from red as black is, the shading should be not as dramatic. Imagine one of the very dark shaded E+ wildtype red animals that start as red and then turn rather black. Well, they should start off red and then turn rather dun (rather than turning rather black). I would love to hear from someone that has a tested E+/E+ Bb/Bb animal who believes they see some dun shading (instead of black shading) on this otherwise red animal.

Kirk
Inger
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Post by Inger »

Yes Margaret, the Brindle coloured steer was a Grade 3 (88% Dexter) from a female line with the foundation cow being a Jersey. The Sire is a decendant of the Saltaire Platinum line and his dam's line started with a foundation Jersey cow, 7 generations ago. This is the only brindle I've had.

The sire has produced 2 red heifers in the time that we have had him. Both are from the same cow and were true reds. We haven't had any more red bull calves from him.

I've mated the mother of the brindle steer to a red bull this season. So I await the results in October. If its not a heifer, she's going in the freezer anyway. She's had enough chances and we've got higher grade heifers coming on-line now, which also carry a red gene.
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Post by wagra dexters »

Hello folks. I suspect that meat quality tests will end up just as complicated as colour. There will eventually be inhibiting factors, modifying genes, etc., etc..
When that comes to light, I will toss it all back to Kirk, throw my hands in the air and beg, "Help".
Margaret.
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Post by Broomcroft »

Can meat quality tests tell us why Dexter Beef is so tasty?
Clive
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Post by wagra dexters »

No taste stars yet, so far as I know.
As an extended family, we eat a lot of beef, and we haven't eaten any other than Dexter beef for 17 years. The absolute tastiest Dexter meat we have ever had, were all young steers by a bull who scored 2;5;5 genestars. Nothing fantastic. Those steers seemed to be much saltier/tastier than any since.
It could have been that they all lived in the bush, with a bit of eucalypt and acacia browsing as part of their diet, whereas we now have oats and pasture to run them on as well.
We have some of the old bull's straws in the tank, so we are going to give him another try, to see if it is just in our imagination.

He can legitimately squeeze into this topic ,...he was dun. (Perhaps that's the flavour difference!)

Margaret
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Post by wagra dexters »

Hi, Marion, if you are out there.
We have been waiting for a Salty calf that could have been dun or red, but is the higher probability, black. Nevertheless gorgeous, he does well over Hedgehog cows.
Margaret.
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Rutherford
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Post by Rutherford »

Kirk, I bow to your vastly superior knowledge of colour inheritance, but in the case of brindle Dexters, all those I have come across have a Jersey lurking in the pedigree; commonly used as an outcross, before the bulldog problem was solved.
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Post by Liz D »

Hi guys, back to the boarder bit between the States and Canada. Live cattle can cross, with age restrictions, as of November 19 and I am told that semen can cross also...but that I am currently checking for a friend in the States with our co-op. Stew are you in Canada or the States? Liz (cdn)
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Post by wagra dexters »

So far as I know, brindle is still an unregisterable colour in Australia.
Margaret.
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Kirk- Cascade Herd US
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Post by Kirk- Cascade Herd US »

Rutherford wrote:Kirk, I bow to your vastly superior knowledge of colour inheritance, but in the case of brindle Dexters, all those I have come across have a Jersey lurking in the pedigree; commonly used as an outcross, before the bulldog problem was solved.

Nearly all Jerseys have the E+ (wild-type) red gene as a selection criteria for the breed. So if Jerseys were used in outcrosses with Dexters, they could be a minor or major source of the E+ gene in Dexters.

The brindle gene is at a different locus and it requires an E+ gene (or possibly two E+ genes) at the E locus in order to exhibit. So a brindle animal might have inherited the E+ gene from a remote Jersey and the brindle gene itself might have been hiding in another branch of the animal's pure Dexter pedigree. So it could make it appear as though the brindle came from the Jersey when it was the E+ red that came from the Jersey.

Just a thought, no proof.

Kirk

PS. I blush at the high compliment paid by the creator of the Woodmagic herd, whom I refer to daily in my attempts to create and manage a closed herd.




Edited By Kirk- Cascade Herd US on 1197959212
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