At least for me, personally - I won't breed under 1500 grams - at least for now and until I get to know my animals even better.

After seeing just how much weight is lost after laying eggs, I'm not personally comfortable breeding much less than that. You hear how thin the girls are afterwards, but I don't think anything really prepares you for the sunken in stomach and the extremely thin posterior until you see it in person.

I have nothing but mad respect for those who do breed lighter/younger successfully, as they have the experience necessary to make that decision.