brookcove
Posted : 5/7/2008 12:44:44 PM
Just being CEA free and good hips isn't enough in collies. You also
need to REALLY know what the heck is out there as far as the things
that you can't test for- like epilepsy.
Depth of pedigree is a good point. However, if you've got a good line of dogs (I'm very impressed with a CEA-free line of collies that work!), one shouldn't hesitate to breed based on the "what ifs". That's where finding good complementary lines, with all the factors worked out, comes in.
That's why a deep, healthy gene pool is needed - one where the "gold dogs" are plentiful and representative of the best possible in the breed at the moment, the "orange dogs" are healthy, up to standard, and breedworthy in their own right, and the "green dogs" in the outside ring, are still nice dogs, healthy, and capable of being "upgraded" if one of them possesses a unique trait to add to the gene pool.
To clarify where "green dogs" come from: they largely come from responsible breedings of dogs from the "orange" and "gold" levels. They may also come from the occasional contribution of a dog in the "Green" level.
But breeding mostly "green" dogs - remember, these are nice, healthy, pet quality dogs - will mean that "green" becomes the norm, and while "orange" and "gold" are bumped into obscurity (hunted with a Golden retriever lately?), dogs of even lesser quality than the former "Green" dogs enter the scene and claim significant and influential roles in the gene pool.
This is not speculation. This is a genetic law of population change. It's been observed in both wild populations where natural selection is the driving force, and in domestic populations where breeding is dictated by human needs and whims.