Quote:
Sarcasta said, "Unlike breeding out a single allele, many traits are complex in nature and could very feasibly be carried forward through multiple generations, even without a re-injection."


This is correct. To add, imagine the possibilities of reinforcing certain traits through intense inbreeding or linebreeding on the female line. Add to that the genetic aptitude for certain traits passed down through a mare line on their MtDNA. That's pretty powerful stuff. You can't dilute that down, breed it out, or otherwise eliminate that influence from a pedigree.

Add to that the mindset of many that it's all about the stallions, along with the belief that anything past three generations has minimal (if any) influence, and one can see why people don't look past the immediate ancestors. They've been told it doesn't matter, and the ones who linebreed do so to nothing but stallions.

These foundation registries don't help matters much, by their inaccuracies in pedigree format and their belief that every ancestor passes down equal influence on a horse.