We raised our first small flock of 5 chickens in the past 7 months and it hasn't gone well. They are barrred rocks, raised from 1 week of age. We've already lost 3 of the girls to what is presumed to be Marek's disease (the chicks were not vaccinated, we later learned). The remaining 2 girls are carriers and we've been told we should adhere to the "all in, all out" rule before expanding our flock. We will need to completely clean everything with a strong viruscide and start all over - so sad. What chicken breeds are most disease resistant? We will need to have disease resistant chickens now that we've had Marek's disease onsite. Any suggestions? I certainly don't want to EVER go through this heartbreak again. Thanks in advance for any help/advice.