One thing to remember when integrating new chickens: A flock can be immune to a disease but still carry it. This means they will look healthy but will be carriers of the disease. If you integrate those chickens into your flock, your flock may not be immune to the disease and will catch it quickly. It’s always risky to incorporate older chickens from other farms or flocks into your coop. We recommend never doing so. However, if the chicks have been raised on your farm from little on up, chances are they do not carry any diseases that your older flock has not already been exposed to.
There are different ways to do it and chickens have different personalities so the methods can vary a little. One of the best methods is to integrate the new chickens slowly. Wait until your chicks are old enough to handle themselves. Then introduce them to your flock but keep a wire mesh fence between them. This will allow your flock to get used to the new chickens while giving your chickens a refuge from the pecking order. Do this everyday for a week or two. Then let them mingle but keep an eye on the new members just to make sure they don’t get picked on excessively. Some picking is normal as this is how chickens establish pecking orders in the flock. The new members must find their place.
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