Thank you for sharing, Mark. I too find this information very interesting. I don't think people finding this interesting means they're going to run out and try to force a female into having this many babies. I think something a lot of people like to ignore is that breedbacks are not uncommon, especially among larger breeders.
Now, no breeder will continue with breedbacks if the female looks worn down. NO breeder wants to kill their females. You can tell if a female can handle breedbacks by their weight and the condition of their coat when they have kits. I have a female that will more than likely have three litters this year. She hasn't dropped one gram other than baby weight and her coat is in great condition. She LOVES her babies and she never looks miserable when pregnant.
I've heard people say a MILLION times in the real world and on this forum about how some people are just "made to carry and have babies". Why can't this also apply to chinchillas? Some are naturally GOOD at growing and rearing babies. Granted, I can't talk to my chinchillas, but there are some that just look miserable with kits on them and yet, I have some females that put on huge amounts of weight when they have kits with them and they perk up like they actually enjoy their babies.
Mark already stated the female's condition was not poor after rearing that many babies. As a long time breeder, I trust his evaluation of an animal's health. I, for one, do not feel sorry for this chinchilla. Even with those multiple litters, she was well taken care of...any female has to be well taken care of to be able to rear that many kits. Not to mention she's a ranch chin. It's the BYB's chins you all need to feel sorry for, they get YEARS of back to back breeding with ill kept cages, poor food, bad water, and little to no hay. I've taken in plenty of them that the females are skin and bone with scraggly coats and huge bloated bellies from yet another litter of babies.