I used to breed rats a few years ago but then I went away to college and stopped because I didnt have the time to give the babies the attention they need. just recently I got back into owning rats, but never planned on breeding again because it is alot of work. the male that I have I got from a certified breeder or dumbo rats, she had been breeding that line for I believe 5 years, his name is odin and he has never been ill. The female was a rescue from the adoption section at petco... I only wanted to give her and her sister a good home, and care, but never planned to breed them, especially because I didnt know their background. however I went away for a few days to visit my boyfriends family and left my sister in charge... she didn't realize that they were of opposite sex, and when I came back I found kit in Odins cage. I asked her about it, and she said she didn't know they weren't supposed to be together. My mistake I guess, I assumed that it was an easy task just to feed my rats for a few days, but I assumed wrong. however I wasn't worried, I'm back from school and I know how to raise rats... they are all very curious and playfull, very nice and I think their all going to be good pets.
Since I got back into caring for rats i've focused more on rescue, except for Odin, I always wanted a dumbo rat, so I bought him.
I feed my own mix, a mix I got from the lady I bought Odin from, hard dog food, crackers or some kind, I usually throw in some trail mix so there is dried fruit and nuts, uncooked pasta, and little bits of other treats that come into the house, right now its cheese pop corn

they enjoy it, and every so often I buy some rodent block from the local pet store and mix that in too... I try to keep it interesting so they dont get tired of the same food all the time.
hope this helps