Im here to say rats are better than mice.
Having a female 2 years in a row lay 14 fertile eggs that go down hill who would only eat mice. She has since been moved to rats and i will be even more convinced next season when she lays a healthy clutch.
This female is also 4.5 years old at 1500g peaked. On mice she would not get any bigger than this eating 2 breeder mice a week. I feed all adults 50-80g per feeding and thats all they ever need. Ever since she laid her eggs 2 months ago, she has already filled out and passed up 1500g being on rats only now.
Males on other hand IDC what their eating as long as they eat.