As far as I know, there is no research available that proves rats are more nutritious than mice. Most folks feed rats because its generally more economical to feed a single rat per feeding than 2-3 mice. But mice are just as nutritious as rats and some BPs will only take mice. I have one myself and she is 3 years old and weighs in at 2100gm and is fat and healthy eating 2 jumbo f/t mice per week and she'll fast for a month or two sometimes as well and all's good.
Having said that, I would feed her rats if I could - everybody else eats rats and it would make my life easier if that's what she'd take. But really, its mostly a matter of convenience and preference.
I agree with Aaron - get 50 weaned rats and 50 smalls and that should be about right.
But I wouldn't feed twice a week. I would feed 1 weaned rat every 5 days instead until she's ready for the smalls and then go once a week. Every 5 days is often enough while she's on the weaned size. Every 3-4 (twice a week) is a little too frequent.![]()