Mixing new birds with old ones. Diseases? Sickness?

[Meat Hunter]

Heres the deal. I have an established flock of 16 birds. One Roo, the rest hens. A lady down the road is getting out of the egg business and says I can have as many of her young hens as I like. They are about 5 months old. I have read several places that one MUST keep a new batch of chickens away for at least 30 days, sometimes longer to make sure no diseases get passed on. I have also read that people say nahhh, just throw em together. I do not want to lose any of my birds. So, is quarantining the birds the right move? Is there anything I can add to the feed or water as a preventative measure?

 

[BetterHensandGardens]

I feel strongly that you need to quarantine, and it's because we lost our flock because we didn't, story here: http://www.betterhensandgardens.com/2010/05/11/painful-chicken-lesson/ Birds diseases can be transmitted rather easily, and you can't go back once it's happened.