I have a few questions, I'm looking to set up a small skill operation of breeding rats.
I'm looking to only produce up to Mediums - with large a possible within the first year of starting.

Number one question is, How long should I wait in between litters to reintroduce the male? I don't want to stress the female rats out by breeding them too fast. I want happy rats.

How many Mediums, Small, and weaned can a single rat produce in a month?

How do people kill them in this business? I'm guessing Co2? or is there a better way of killing them?

Also, how do you Sex a rat? Is it self explanatory?