hi everyone, I'm will try to incubate chicken eggs again, last time I raise chicks I've hatched using incubator, they all died because of unknown(to me) disease, even the other chicken that hatched naturally also died. When I contact my friend, who is the egg seller (he owns a chicken hatchery) he said that all chicks must be vaccinated in order to keep them away from disease, I told him, I've been raising chicken for more than 10 years and I never give any vaccine to all my chicken. He said that's the must to give vaccine. Unfortunately, vaccine is quite tricky, each bottle can be used up to a hundred chicks and must be used in one and half hours before the vaccine become damaged no matter what you do. While I only need vaccine for about a dozen chicks It seems that vaccinating chicks won't be able to be done by me. so, the question is, should I vaccine the chicks (haven't even put the eggs into bator) ? how to keep them healthy and strong against disease without vaccinating them? I realize that the circumstance in US/Europe will be different than my homeland here though thank you in advance.