I have replied to your intro post but will reply here too. I think you said you got these mice from the RSPCA? If so you need to let them know what has happened ASAP. They should take any babies back to rehome as it is their fault that they mis-sexed them after you repeatedly asked. It's not hard to sex mice so they are definitely to blame IMO. They also need to re-sex any others they have left there as they're probably going to have a few more surprises otherwise.
As for the does you have, if all 9 are pregnant that is a LOT to cope with for someone who has never bred before, which I don't think you have? It would not be likely that all would survive healthily if you had 9 litters together, so in answer to your question, no, they can't all stay together if they're all pregnant. I'd go for either three groups of three or three groups of two and one group of three. That would give the babies the best chance if you were going to try and raise them all. On the other hand you have mentioned culling, and I don't think that is such a bad idea. After all, the babies *may* or may not be unhealthy or weak because they have not been selectively bred and it does put a strain on the does to raise them (I think these does were too young to mate anyway really?). If all you want is pets then perhaps culling might be best, or at least only raising a couple of the 9 litters.
In answer to some of your other questions, the bucks need to be separated from mum and sisters between four and four and a half weeks old. Sexing is not too difficult, there are lots of photos on the internet that will help you. All I had when I bred my first litter were diagrams and I haven't gone wrong yet :lol: You'll be fine.
As for the does you have, if all 9 are pregnant that is a LOT to cope with for someone who has never bred before, which I don't think you have? It would not be likely that all would survive healthily if you had 9 litters together, so in answer to your question, no, they can't all stay together if they're all pregnant. I'd go for either three groups of three or three groups of two and one group of three. That would give the babies the best chance if you were going to try and raise them all. On the other hand you have mentioned culling, and I don't think that is such a bad idea. After all, the babies *may* or may not be unhealthy or weak because they have not been selectively bred and it does put a strain on the does to raise them (I think these does were too young to mate anyway really?). If all you want is pets then perhaps culling might be best, or at least only raising a couple of the 9 litters.
In answer to some of your other questions, the bucks need to be separated from mum and sisters between four and four and a half weeks old. Sexing is not too difficult, there are lots of photos on the internet that will help you. All I had when I bred my first litter were diagrams and I haven't gone wrong yet :lol: You'll be fine.
