Introducing new chickens

Quarantine is a powerful tool but like any tool it needs to be used properly. In your case it is probably a good idea. For disclosure, I do not introduce new chickens to mine except from a hatchery which I trust to be disease free or I get eggs and hatch them myself. I do take biosecurity seriously.

A flock of chickens will often develop its own flock immunities. The chickens are exposed to certain things, usually as chicks, and develop immunity to them. They may still be carriers of that disease and can infect other chickens but they themselves are not affected. Coccidiosis is a great example but there are other more serious diseases like this. By observing them in quarantine, you would never know they have a disease but if they come into contact with other chickens, they can spread the disease. With the other chickens not immune, it can get serious. Just a straight quarantine is not of much benefit in detecting one of these diseases. It’s possible that the stress of moving and quarantine will weaken the chicken enough to show symptoms of some things, but it is unlikely.

Where quarantine comes into its strength in chickens is to protect your flock from diseases that the new chickens have come into contact with in the last month or so. Most diseases take some time to show up, but most will show within a month. If the new chickens are coming from a source where they have been isolated from other chickens, they have in essence been in quarantine. You just hope the person taking care of them would recognize a disease if it shows up.

With your birds coming from a local supplier, I get the impression that the chickens are exposed to new birds on a regular basis. This is the strength of quarantine. In this case I think quarantine is a great idea. It’s something I think you should strongly consider. It’s also a great time to worm and treat the new chickens for mites and lice, just in case.

It is possible that your flock is the one that has built up flock immunities and will infect the new chickens. This has nothing to do with your chickens being healthy and hard. A healthy immune system will resist diseases. If the new chickens are the ones that get sick after they are merged, consider that your chickens could be the source of the infection.

There is a way to help guard against the new chickens having an immunity to a disease that won’t show up in quarantine. Select a potentially sacrificial chicken from your flock and house it with the new flock. That way, you put one of your birds at risk, not all of them.

Good luck!