Elaine
05-01-2008, 04:42 AM
Mr Hilt posted this link on a thread below... I thought the article was worth reading. It is titled "A very liberally edited version of an article by Jerold S. Bell, D.V.M. that appeared in the September 1992 American Kennel Club Gazette, " The Ins and Outs of Pedigree Analysis, Genetic Diversity, and Genetic Disease Control"
http://www.westwindgsps.com/linebreeding.htm
I believe that Dr. Bell is now at Tufts... we had occasion to contact him this past January. Though I enjoyed the linked article, I would like to read his original article... absent the editing. Also, the article is over 16 years old... I would like to hear what Bell says in 2008. None-the-less it is well worth the read... a hint, grab a cup of coffee, it will take a while :)
Here are a few quotes I found intersting:
In choosing a line of dogs to breed it is wise to choose a line with "critical mass". A line in which the most prepotent individual was mated many times and produced many superior offspring. Without enough genetic diversity it will be difficult to find animals that do not also share the faults of the most prepotent individual. These will be faults the breeder will have the most difficulty in eliminating. No matter how limited the critical mass the breeder must never breed animals that are poor examples of what they are trying to reproduce simply because they share common ancestors. [emphasis added by Elaine]
Every breeder is fighting "the drag of the breed," which is the tendency for all animals to breed back toward mediocrity. Unsuccessful breeders overlook an animal that has a great trait because it also has a minor fault in favor of an animal that has no faults but no great traits. Successful breeders use specimens within their line that have at least one truly great trait and breed them with specimens that in turn are great where the other dog is weak. In so doing it is possible to linebreed offspring that are better than both the sire and the dame. The resulting specimens in turn can pass the great traits on to the next generation, unlike the F1 hybrid animal that results from outcrossing to get the same traits.
http://www.westwindgsps.com/linebreeding.htm
I believe that Dr. Bell is now at Tufts... we had occasion to contact him this past January. Though I enjoyed the linked article, I would like to read his original article... absent the editing. Also, the article is over 16 years old... I would like to hear what Bell says in 2008. None-the-less it is well worth the read... a hint, grab a cup of coffee, it will take a while :)
Here are a few quotes I found intersting:
In choosing a line of dogs to breed it is wise to choose a line with "critical mass". A line in which the most prepotent individual was mated many times and produced many superior offspring. Without enough genetic diversity it will be difficult to find animals that do not also share the faults of the most prepotent individual. These will be faults the breeder will have the most difficulty in eliminating. No matter how limited the critical mass the breeder must never breed animals that are poor examples of what they are trying to reproduce simply because they share common ancestors. [emphasis added by Elaine]
Every breeder is fighting "the drag of the breed," which is the tendency for all animals to breed back toward mediocrity. Unsuccessful breeders overlook an animal that has a great trait because it also has a minor fault in favor of an animal that has no faults but no great traits. Successful breeders use specimens within their line that have at least one truly great trait and breed them with specimens that in turn are great where the other dog is weak. In so doing it is possible to linebreed offspring that are better than both the sire and the dame. The resulting specimens in turn can pass the great traits on to the next generation, unlike the F1 hybrid animal that results from outcrossing to get the same traits.