Line Breeding / Outcrossing

[kc261]

One thing to remember is that inbreeding does not cause deformities or other problems to spontaneously appear out of nowhere. The animals in question have to already carry a bad gene for it to be expressed in the inbred offspring.

However, what can happen is that a snake (or dog or human or...) may have for example, 4 recessive bad genes. If you breed it with something unrelated, the odds of any one of those bad genes being carried by the mate are slim, and it is extremely unlikely you'll hit more than one. But if you inbreed, then you may get all 4 of the bad traits expressed. This is why inbreeding is associated with "train wreck" levels of deformities or other issues.

Considering I don't think I've seen a single report of an actual case where BP inbreeding has caused issues, I would not be too concerned. What I have seen is that certain morphs have certain issues, but from what I've seen, it appears those issues are directly tied to the morph, rather than being a different gene that showed up due to inbreeding.

We know LOTS of breeders do projects where they breed father-daughter or brother-sister type pairings to prove out a morph or produce a new combo, so it seems highly likely that those are safe, otherwise we'd be hearing more reports of inbreeding related problems.

I don't think anyone knows for sure, though, so I would still avoid doing breeding where I am breeding multiple generations back to each other without introducing new blood. For example, to start with a het pied male x normal, take offspring from that and breed het back to phet daughters, take a pied male offspring from that and breed back to the phet females that proved out, take offspring from that and breed pied male back to pied daughters, take highest white brother & sister from that and breed together to try to select for high white... that's 5 generations of inbreeding, and no new blood! I'd avoid that.

On the other hand, to start with a het pied male x normal, take offspring from that and breed het back to phet daughters, take a pied male offspring from that and breed to a pastel female, take pastel het pied offspring from that and breed back to pied male, take pastel pied offspring from that and breed to a cinnamon, take pewter het pied brother & sister and breed together to produce... well, that clutch would be awesome wouldn't it? But the point is new blood is being introduced every other generation, and that is a lot less likely to have inbreeding issues show up.

As far as how to strengthen a bloodline... well, it depends on what you want to strengthen. If you just mean how to avoid problems due to inbreeding, doing an outcross every few generations will help, but nothing is guaranteed.