I have "heard" that hairless do not carry the same nutritional value as regular rats. I have a colony of hairless that I sell as pets and to pet stores, I don't feed them. One thing I notice that may lead me to believe the nutrition thing is that they stay in the same enviroment, eat the same thing, and drink the same water but do not get as fat and healthy looking as regular rats. They also seem to get more sores and ulcers (that may be because you can see them due to the lack of hair). I don't feed hairless but have no sound evidence not to other than my personal observations.