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Post by Cascade Meadows Farm - Kirk on Dec 2, 2012 12:25:17 GMT -5
We can make this complicated or we can keep it simple. I vote for keeping it simple. The ADCA already has a "policy" that can address the current genetic defect, PHA, that is of primary concern and considered as a threat to our breed. It is found in the Code of Ethics and it reads as follows: "Represent my animals honestly to prospective buyers and give such advice or assistance to the buyer as may be reasonably requested." To address the issue of PHA, the Board can take the following action: Require a PHA test and report before any untested registered Dexter cow or bull can be transferred to another breeder. The PHA report would have to be submitted with every transfer application and the status of that animal noted in the ADCA Online Pedigree. The cost of the PHA test is now only $20 at Texas A&M. The cost of having a PHA and Chondro test done at the same time for an individual animal is only $30. If the Board wanted to keep the cost of transfer at $20, it could waive the transfer fee in lieu of receiving the PHA test report. If the Board wanted to increase the transfer fee to $30, it could waive the transfer fee in lieu of receiving both a PHA and a Chondro test report. In this manner, every Dexter cow and bull sold and transferred after a specified date would be represented honestly as a carrier or non-carrier. I hope that the Board will consider this approach. It is do-able, it rewards those who have already tested and those who are willing to test, and it represents an honest and practical solution that most people can understand and follow through on. Patti I think Patti's approach is very workable (for BOTH PHA AND CHONDRO) because it would eliminate the uncontrolled and undocumented spread of the existing 2 known genetic defect genes in the US. But we would also need policies to help find NEW genetic defects before they spread the way PHA did. Here are the 4 policy areas again 1. Existing Defect Tracking (Patti's approach is workable for this as long as we REQUIRE ALL tests be logged in pedigree system at time of transfer to new owner) 2. AI Bull Testing Requirements = A policy that addresses appropriate procedures to attempt to find any sign of genetic defects before the bulls are used widely. Sire/Daughter testing requirements, etc. 3. Defect Reporting = A policy to REQUIRE that defective animals be reported with photos and DNA samples (this would include bull-dog looking calves because they might not be bull-dogs). 4. Defect Elimination (do we ever attempt to eliminate defects? or do we just let them accumulate and simply require documenting them at transfer time?) Let's say a new defect arises in a tiny handful of animals and we could easily eliminate the defect by refusing to register them.... Do we just track the spread of the new defect (via Patti's proposal), or do we try to stop it via refusing calf registrations? PS. For those who asked about the science of multiple forms of chondrodsyplasia: Chondrodsyplasia is a genetic disease that impacts the normal growth of collagen/cartiledge at bone growth plates. There are one or more genes that direct the normal growth. If these normal genes get broken, then you get the Chondrodyplasia condition. There are many, many ways to break (misspell) a normal gene. To think of it in terms of spelling, there is only one way to spell the word "NORMAL" accurately, but there are innumerable ways to misspell it. In the case of chondrodysplasia, we have found 2 misspelled versions of "NORMAL" so far and we will find others in the future (it's the scientific law of genetic mutation).
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Post by kansasdexters on Dec 2, 2012 12:29:42 GMT -5
Rezz,
The Association could put a time limit on this program and it would have complete control over the number of waived transfer fees it could afford to give, in return for the information needed to reduce the threat of PHA in registered Dexters in the United States. The Association would also have the option of compensating for this apparent initial loss in revenue by increasing subsequent transfer fees on the animal.
Patti
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Post by Cascade Meadows Farm - Kirk on Dec 2, 2012 12:51:22 GMT -5
Here's another thought: For obligate PHA-free animals, a genotype showing that it's sire and dam qualified would be required in order to have the transfer fee waived and for the animal to be given PHA-free status in the registry. Can you further describe this wording a little more and discuss fairness to those who have already scrubbed their herds of known genetic defects at their own effort and cost. Patti, I assume you are using "PHA" as an example because it strikes fewer nerves.... But I assume you mean this to apply to ALL genetic defects including any forms of CHONDRO.
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Post by wvdexters on Dec 2, 2012 13:16:53 GMT -5
Kirk,
I am sorry. Again I will be more clear. I fully understand the basic principles of the genetics we are discussing here at this time. I will not represent myself in a way that would lead people to believe I am fully educated and trained in this area and am therefor an expert in the field, but I did do very well in high school biology as well as biology 101 in college. I asked about the numbers being given. Your source, for these numbers. The science behind the figures being quoted. Are they (these figures) valid (backed by scientific data) or are they being pulled from the air to legitimize your stand. Proof that we ALL MUST STOP and FOLLOW YOUR recommendations. You see, it is just that they keep changing, growing worse; leading to more dire scenarios. I like to base my decisions on facts not conjecture.
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Post by wvdexters on Dec 2, 2012 13:25:55 GMT -5
And Kirk please remember we have more than two instances of what is labeled "genetic defects". Under your guidelines naturally polled dexters will have to be dealt with. They carry a genetic defect causing the affected animal to be polled (born without horns) Any true genetic defect elimination policy must include these affected animals. And who knows it could get worse. More of these types of "polled genetic defects" could arise at any time. We will need to protect the dexter herd from these "threats" also. If you are right a new one could be lurking just around the corner.
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Post by wvdexters on Dec 2, 2012 13:34:54 GMT -5
Formal testing is the important thing here. Testing done by an accredited lab, documented and proved. Anything less is meaningless and can not be used for genetic purposes. There can be no bias, no exceptions. Equal measures for all Dexter owners/breeders.
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Post by lakeportfarms on Dec 2, 2012 13:52:28 GMT -5
Huh? Wasn't it just a few pages ago you were basically saying "too bad, so sad" for owners of existing chondro and PHA dominanted herds for the sake of "purity"?
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Post by lakeportfarms on Dec 2, 2012 13:59:27 GMT -5
Makes great sense to me.
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Post by Cascade Meadows Farm - Kirk on Dec 2, 2012 14:07:38 GMT -5
Huh? Wasn't it just a few pages ago you were basically saying "too bad, so sad" for owners of existing chondro and PHA dominanted herds for the sake of "purity"? Actually if you go back a few pages ago, you'll see that I requested that folks propose some specific wording of how we might handle things. You and others scoffed at me and said QUOTE " there is no answer that I would give that you would find acceptable". Patti (smart person that she is), proposed some specific wording that's quite good. Next time, when I ask for proposals, don't assume that I won't listen. I do listen.
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Post by Cascade Meadows Farm - Kirk on Dec 2, 2012 14:26:56 GMT -5
Under your guidelines naturally polled dexters will have to be dealt with. They carry a genetic defect causing the affected animal to be polled (born without horns) Again, for those who missed it the many other times this has been addressed: The list of serious genetic defects usually contains ALL lethal genes and any genes that interfere with important biological functions that cause deformity and pain and illness. This list has links to information about each common defect found in cattle. The polices we are discussing here are for SERIOUS BIOLOGICAL DEFECTS of this nature. www.cdnangus.ca/breed/Genetic_Defects.htmOther cosmetic "defect" genes like the color Dun, or too much white, or Polled, are addressed in the Dexter breed standards/description.
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Post by lakeportfarms on Dec 2, 2012 16:48:03 GMT -5
Kirk, I don't have the time nor inclination to cut and paste the numerous times when I suggested that rather than an outright ban of future registrations of chondro or PHA, that a policy of testing and reporting, combined with both sire and dam qualification for any claim of obligate status. No sooner than I would bring this up, you would keep going back to timelines for the denial of registration of chondro and PHA calves.
Have you backed off from that? If so, welcome! Now let's come to some agreement on a proposal.
In a thread some time back, prior to when I believe you began posting here, there was a discussion about reporting and registration. I suggested some type of limited registration for animals not tested for PHA and Chondro, or both sire and dam qualified, along with a full description of why the registration was "limited" on the back side of the certificate. Fully tested animals would receive a "Full Registration" certificate. This had NOTHING to do with the animals chondro/PHA status, only with the reporting of that status. Carriers would receive full registration if they were fully tested. Obligate non-carriers would receive full registration if the sire and dam were both genotyped. I don't recall right now why it wasn't thought to be a good plan, but perhaps somebody can chip in and refresh my memory why it wasn't practical. Perhaps it was cost.
Hans
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Post by wvdexters on Dec 2, 2012 17:15:47 GMT -5
Wait a minute. I thought we were talking about Dexters here. I thought we were discussing the "Genetic Defect Elimination Policy" you advocate. The policies we have been discussing throughout this thread. Following the examples and information you gave and brought to the board for discussion. It is all there in the earlier pages of this thread.
I would think for a breed of horned cattle to suddenly lose their horns.... Serious. Not cosmetic.
Kirk, still waiting for you to answer my question about the source(s) for those figures you are giving out. Please make this information available to us all so we as a group can read it for ourselves. I like to research information and check the facts before I make important decisions.
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Post by rezzfullacres on Dec 2, 2012 17:44:44 GMT -5
We raise horned dexters, we breed at least 1 chondro carrier, probably 2....Here is my point, from what I can see Chondro has been part and parcel of the Dexter breed from the very beginning. PHA has not, it is a new genetic variant...I do believe that the vast majority of Dexter Breeders would get on board with a program to eliminate PHA, I do believe if you want to eliminate Chondro you might as well get a barrel and try to go up Niagara Falls you will have the same success. Kirk, if you truly want to eliminate genetic defects than polled would have to be in the discussion, you can not pick and choose which genetic defects you wish to eliminate, using the lethal term is immaterial and nothing more than a smokescreen, especially when you are raising polled animals, you lose credibility and look to have a self serving interest...If you truly want to improve the breed and better the association drop the chondro and focus on identifying the PHA carriers that have not been identified and getting those breeders to do something about it.... Patti has a very interesting idea, IF the ADCA could afford it, it may be the best way to get started...
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Post by wvdexters on Dec 2, 2012 17:48:58 GMT -5
We all agree that testing is the first step and the most important step in dealing with genetic issues (present and possible future). This will be a great endeavor for dexter owners/breeders. I state again that formal testing from an accredited lab must be the requirement for everyone. There can be NO exceptions to this rule. Obligate status can only be given if the animal has been parentage verified and both parents found free of the condition being tested for. For any herd to be considered free all animals must be either individually tested for the condition and found free or obligates with proven parentage. Facts and Documentation must be the rule.
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Post by Cascade Meadows Farm - Kirk on Dec 2, 2012 18:31:26 GMT -5
Kirk, still waiting for you to answer my question about the source(s) for those figures you are giving out. Please make this information available to us all so we as a group can read it for ourselves. I like to research information and check the facts before I make important decisions. Dwarfism in cattle is caused by defects (spelling errors) in several different genes. We've stumbled upon 2 forms of the lethal dwarfism defect in Dexters so far (without doing an extensive search for others). 'Dexter dwarfism is a form of chondrodysplasia also caused by defective endochondral ossification due to 2 different mutations in aggrecan 1 (ACAN) (6). Homozygous mutants display a “bulldog†phenotype, including a retruded muzzle, cleft palate, abdominal hernia, shorted and misshaped long bones, and lethality at approximately 7 months of gestation. Individuals heterozygous for mutations in the ACAN gene exhibit disproportionate dwarfism (4, 6)'.
We've found 2 different "misspellings" in the aggrecan 1 (ACAN) gene, that deactivate the functionality of the normal gene and cause dysfunction. There are many different ways that genes can be "misspelled" to deactivate a function. While we've found 2 (without even looking very hard), we could easily find others. Now that's just the ACAN related dwarfism found in Dexters. There are several other forms of dwarfism in cattle caused by various other misspellings of other genes. The PRKG2 gene is another one that when misspelled, interrupts important normal functions and causes dwarfism How many different ways can we misspell these normal genes? "Many" is the answer. Could easily be 10 or 20 or 30 different ways to misspell them over the long haul. They've found a good number of dwarfism-related "misspellings" in cattle and we've found 2 in dexters in just a single decade. We're just scratching the surface and more mutations arise in every generation of cattle. Here are two articles... there are many more link.springer.com/article/10.1007/s00335-007-9066-9/fulltext.htmlwww.pnas.org/content/106/46/19250.full
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