Do you all vacinate your birds, if so what do you vacinate for and at what age? I have a small flock for few years but am gonna try and hatch 36 eggs just looking for little feedback because when you start researching about it I find there is about 1/2 dozen vacines out there for chickens and it looks like it could get a little pricey! The stores, online or local will sell you all you can buy if you know what I mean.Which ones are really needed.