Post by buxombeefcowdairy on Jun 30, 2009 14:07:03 GMT -5
I am surprised that the Dexter Association did not get back quicker because DNA samples from both parents and the affected calf are of critical importance to identifying the defect, and developing a test so that reputable Dexter breeders (and I'm sure there are plenty of them) can work to minimize this gene in the Dexter population.
There is an unfortunate precedent of a breed association ignoring good evidence of a problem gene. The American Angus Association dismissed evidence from Austrailians regarding a recessive genetic defect originating in US Angus cattle, with regards to the Fawn Calf Syndrome genetic defect. Calves born with the defect cannot get up and nurse for themselves, though with assistance for up to two weeks, they can recover somewhat. So it is not strictly a lethal genetic defect, affected calves in commercial herds calving on their own would not survive. Dr. Beever thus has termed it a 'semi-lethal' defect.
If you take a look at this site,
www.advantagecattle.com/forum/topic.asp?TOPIC_ID=1959
you will see that in 2006 the Australian geneticists and Australian Angus Assocition had compelling evidence of a genetic defect. They gave this information to the American Angus Association at that time. Not until early 2009 did the Am,AA communicate this problem to US Angus breeders, requesting that breeders seeing this problem send calves and/or genetic material to Dr. Steffen and Dr. Beever. (This is following the revelation of a separate lethal genetic defect in another line of cattle, for which the Angus Association sent out requests for abnormal calves in September of 2008.)
My point with this is NOT that I am sure that the Dexter Association is ignoring Kim. I DOUBT that. But in some cases, you have to go forward with the scientists yourself, without any 'official plans' from the breed association- because it is the right thing to do.
Usually, once we see a recessive genetic defect, it has spread itself through the population of breeding animals. To suggest that culling the bull because he's not any good anyway is appropriate, but it does not help very much in reducing the frequency of the defective gene. It will be passed on from the cow, and it will be passed on from the relatives of the breeding bull. If this is a gene that needs to be addressed (it is not a lethal recessive problem, which I would say is more important to get rid of) then the best thing to do is develop a DNA test so that breeders can be aware of it, and produce cattle that are not affected by it.
There is an unfortunate precedent of a breed association ignoring good evidence of a problem gene. The American Angus Association dismissed evidence from Austrailians regarding a recessive genetic defect originating in US Angus cattle, with regards to the Fawn Calf Syndrome genetic defect. Calves born with the defect cannot get up and nurse for themselves, though with assistance for up to two weeks, they can recover somewhat. So it is not strictly a lethal genetic defect, affected calves in commercial herds calving on their own would not survive. Dr. Beever thus has termed it a 'semi-lethal' defect.
If you take a look at this site,
www.advantagecattle.com/forum/topic.asp?TOPIC_ID=1959
you will see that in 2006 the Australian geneticists and Australian Angus Assocition had compelling evidence of a genetic defect. They gave this information to the American Angus Association at that time. Not until early 2009 did the Am,AA communicate this problem to US Angus breeders, requesting that breeders seeing this problem send calves and/or genetic material to Dr. Steffen and Dr. Beever. (This is following the revelation of a separate lethal genetic defect in another line of cattle, for which the Angus Association sent out requests for abnormal calves in September of 2008.)
My point with this is NOT that I am sure that the Dexter Association is ignoring Kim. I DOUBT that. But in some cases, you have to go forward with the scientists yourself, without any 'official plans' from the breed association- because it is the right thing to do.
Usually, once we see a recessive genetic defect, it has spread itself through the population of breeding animals. To suggest that culling the bull because he's not any good anyway is appropriate, but it does not help very much in reducing the frequency of the defective gene. It will be passed on from the cow, and it will be passed on from the relatives of the breeding bull. If this is a gene that needs to be addressed (it is not a lethal recessive problem, which I would say is more important to get rid of) then the best thing to do is develop a DNA test so that breeders can be aware of it, and produce cattle that are not affected by it.