Page 1 of 1
Posted: Thu Nov 01, 2007 3:43 pm
by Nikola Thompson
I am very interested in old lines of the Dexters and the "Rare Breed" side. Are Dexters with the polled gene all from other cattle breeds. Is it possible to trace far enough back to find out about pedigrees. I do think the online pedigree search is such a help, particularly for people like myself that are so new to Dexters. I am trying to build up a herd without the polled gene which I know is just personal preference. I have found the hardest Dexter to find without the polled genenare the red.
Edited By Nikola Thompson on 1193928441
Posted: Thu Nov 01, 2007 7:22 pm
by Kirk- Cascade Herd US
The polled gene is a single dominant gene and animals with this gene are polled. An animal can't "carry" a dominant gene, it must exhibit that gene. There is no such thing as "polled genetics". A horned animal with a polled ancestors does NOT carry "polled genetics". If an animal has horns, it is 100% certain that the animal has NO polled genetics and 100% certain that it only has horned genetics.
Concerning the source of the polled gene, imagine if you had to make countless copies of an entire book by retyping it, over and over and over. Surely you would make an occasional typographical error. In animal breeding, mutations occur during the DNA copy process when an imperfect copy is made and a "typo" is introduced. In all breeds of cattle, a mutation occurs that flips a switch that interferes with horn growth. Many animal science programs believe these mutations may occur as frequently as 1 in 10,000 calves but most estimate the frequency to be 1 in 20,000. Many of these mutations in cattle have been proven via DNA testing and are indisputable. The only question is how often they really occur.
When these mutations do occur, they almost always raise the suspicion of parentage errors. Imagine having a polled calf born to two horned parents. This just shouldn't happen (unless there is a mutation). Without DNA parentage testing in these cases, folks rightfully suspect that a neighboring polled bull (perhaps from another breed) might have jumped a fence.
Purebred Polled Dexters do exist today that have inherited polled genes that are reportedly the result of mutations within the Dexter breed. In each case, the parentage of these calves have been doubted simply due to the rarity of mutations. While DNA testing was not available when these calves were born, blood-typing was available but was not utilized. In the case of the particular mutation that has led to the most common source of the polled gene in Dexters, we will never know for certain whether the gene was the result of a mutation or the result of a bull jumping a fence, because the parents of the mutated calf are long dead and were not tested.
That said, parentage errors occur regularly in all animals (unless DNA parentage testing is utilized) and there is likely at least one error on every pedigree if you go back as far as 10 generations. Without historical DNA testing we have to doubt the accuracy of all pedigrees.
Because of the way genetics work and the occasional parentage reporting errors, paper pedigrees of animals can only act as a rough guide to the animal you see standing in the field. On paper, each great-grandparent represents 1/8 of the animal, but that isn't how genetics work. In fact it's possible that an animal has little or no genetics from one particular great grandparent, and yet has an abundance of genetics from another.
Every purebred Dexter has old genetics. When you say you want these old genetics what does that mean to you? Does it really mean you want a particular phenotype (look and feel) that you believe reflects an older style? If that's the case, I would recommend less focus on the paper pedigrees (which all have some flaws anyway) and instead focus on the animals themselves. I would recommend building in your mind's eye a vision of that "old" type and visit farms looking for herds that match that vision. Obtain purebred registered stock from those farms and when you select animals that match your vision, also make certain that all of their close relatives also match your vision. This will help assure that the animal you acquire has the genes you desire and you will achieve your goal (assuming your goal is not a paper goal).
I really hope this helps!
Kirk
Edited By Kirk- Cascade Herd US on 1193942200
Posted: Thu Nov 01, 2007 8:21 pm
by Nikola Thompson
That is a big help. It is definately a certain type that I like. I have been lucky enough to have 3 Boram heifer (thanks Rob and Alison) and some lovely Castlemoor which are from the Woodmagic line. I think type is very personal.
Your information on the colours is very interesting too. I breed connemara ponies and have a white mare that was born white which I was told was impossible. I presume that this must come from the mutant genes you refer to?
Posted: Thu Nov 01, 2007 8:22 pm
by ann
Hi Nicola
There are red lines around that are not polled, I to prefer the pedigree's and the heads of the horned cattle although I do de horn and none of my red's are polled.
Ann:) 
Posted: Fri Nov 02, 2007 3:47 pm
by redhill
Nikola, If youre ever in the Forest of Dean area,come and have a look at our herd,our foundation Dexters are Woodmagic,and Cobthorn,with a touch of Harron Rocket.We have blacks,duns,and reds,all complete with their horns, you would be very welcome,they love visitors Bill and Sue
Posted: Fri Nov 02, 2007 5:04 pm
by Nikola Thompson
That's very kind. I love seeing other people's Dexters. It is very interesting that since we have had Dexters, everyone in the Dexter society seems to say that their Dexters are good tempered animals (ours are excellent).. The first thing that people who don't have Dexters say is that they are really bad tempered. I hear that all the time. I am very proud of my Dexters, looks and temperament.
Posted: Fri Nov 02, 2007 5:19 pm
by Woodmagic
Well said Kirk I endorse your analysis, there is far too much emphasis put on paper pedigrees by some. On the whole they will be reasonably accurate, most breeders try to ensure that they are, but mistakes happen in human and animal pedigrees, and DNA analysis is comparatively new. When the Dexter Herd Book was set up as recently as just over 100 years ago that is exactly how the animals gained entry – on inspection. By all means use pedigrees, they should help to provide animals that breed true, but don’t treat them as sacred. In the final analysis it is what pleases you that matters. If you can inspect the last three generations and they are breeding true for what you want, that is probably the animal for you.
Posted: Fri Nov 02, 2007 5:50 pm
by Nikola Thompson
I totally agree about what everyone has said about what a person likes in an animal and not to totally rely on paper pedigrees but the rare breed society seems to split the Dexter breed into the original (rare breed) and todays breed. How can you tell and how have they been able to do this?
Nikola
Posted: Sat Nov 03, 2007 9:14 am
by Woodmagic
The answer is you cant. The information has to come from the written pedigrees, and in most cases you are relying on something that cannot be verified and undoubtedly is occasionally wrong. Pedigrees can give you a general picture that will enable you to select an animal that will largely breed true to type, but until such time as you have a DNA endorsement, it has to remain a qualified guestimate. Used as a breeding tool they are the best means available, but shouldn’t be treated as sacred. It must always be borne in mind too, the lottery of inheritance means that any animal in that pedigree may have largely contributed, or have no input whatsoever.
Posted: Sat Nov 03, 2007 1:36 pm
by redhill
This is where I show my ignorance, is the Dexter still on the RBST.list ,or did the Irish claim cancel them out? Sue
Posted: Sat Nov 03, 2007 2:04 pm
by Duncan MacIntyre
Hello Sue,
the problem is not the RBST list, it is the list of UK Native Breeds. Because the Irish have listed Dexters and some others, as Irish Native Breeds, the EEC authorities decide that they cannot therefore be UK Native Breeds. This may need some delicate sorting out, and I believe negotiations are under way. The sort of problem it creates is that if you are part of a grant scheme which requires stock to be native breeds. I first became aware of it when the Scottish branch of defra began ruling Dexters out of sush schemes and Gaye Murray from Skye got in touch with me. DCS and RBST have been aware of the situation for well over a year, but these things take time to sort out I suppose.
Duncan
Posted: Sat Nov 03, 2007 3:13 pm
by Penny
The Dexter has been removed from the RBST list, which affects subsidy claims etc, but NOT from the RBST Beef Marketing Scheme, which has financial implications for the RBST ie it would personally lose out if the breed was taken out of the scheme. So one rule for them, and another for everyone else.
I am not trying to rock the boat for anyone who supplies the RBST Beef marketing Scheme, but the apparent double standards could be questioned.
Posted: Sun Nov 04, 2007 11:51 am
by Broomcroft
Where do you get the prices for the Beef Marketing Scheme? I've tried it in the past but no-one ever calls you back.