I have been a hobby chicken raiser off and on for over 20 years and am now getting back into it. I would like to be able to be self sufficient in raising and keeping my flock going through the years. Is this a goal that is reasonable? Do I need to introduce new genes every so often? I read that in order to be able to be self sufficient in providing my own flock through the years I need to stick with one breed since hatching rates drop dramatically after the 2nd generation of mixed breeds. What are your experience in this area? Is this true? Maybe that is why none of the eggs I got from my neighbor seem to be viable. They were all mixed.