Just to let responders know where I'm coming from, I do have an advanced degree in genetics so I'm very familiar with why inbreeding is bad. I also grew up on a sheep farm and my experience with that is when it came breeding time, we never had rams mate with their offspring and got new rams every few years. As an adult, I have chickens for the first time. I've been breeding my flock for something fun to do with my young kids. I sell the chicks online on a popular website. However, as I'm learning more about different breeds and want to start crossing them to try to achieve desired characteristics, at what point do I have to introduce new genes to avoid the negative aspects of inbreeding in chickens? What is everybody's experience? Or should I try to keep multiple lines of the same crosses going to try to avoid close relatives from breeding?