I tend to agree with FFOTB, ThreeCorners.

Autosomal inheritance is an overly simplistic way of looking at genetics...it conveniently works for some traits in mammals...but most characteristics are not so easily determined.

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.

Many traits are consistent in human family lines, and seem to "withstand" even the addition of totally opposite traits (like olive skin in my family, survived multiple additions of pale Irish skin)

Obviously, that's not a very detailed explanation...but just because you breed an animal to another animal that DOESN'T share the characteristic, it doesn't mean that the trait will be lost.