Wow, I've been breeding ASFs for a while and I've never had an incident with cannibalism. They do need higher protein than regular rats so maybe that's why? I have 200 of them mostly in two very large aquariums dropping a litter every other week. I feed off the males first to slow down the breeding so there's not many males to females. I put weanlings and juveniles of the same sex in other large aquariums to grow to adult size before c02 at freezing. They get along fine too. I'd hate to see that happen so if you have any insight as to what caused that I'd appreciate the tip. From what I see, the males are affectionate and caring for the babies just as much as the females. This is really surprising to me.
Otherwise, I've had great success feeding and breeding with them. I don't separate nursing moms or try to introduce any older than weaned to another colony.