Older chicks and newer chicks, can they be mixed?

[chickie fam]

I'm getting some new chicks in a couple of weeks and I was wondering if my new chicks are able to go in with the chicks I have now? The ones I have now will be 5 weeks old and the new chicks will be between 1-3 days old.

Another question is, do the chicks that I'm getting from a hatchery have to be quarantined before introducing them to the older chicks?

 

[A.T. Hagan]

I personally would not try to mix chicks with that much age difference between them. Chances are high that the older ones would bully and possibly injure the younger ones.

 

[Judy]

Most people don't bother quarantining hatchery chicks, I don't think. But they may well be too far apart in age for mixing to go well. You could get them all outdoors with treats and see how it goes.

 

[chickie fam]

Whats the maximum age difference where the mixing would still go smoothly?

Does this mean they'll never mix well, even out in the coop?

 

[HEChicken]

They have such different requirements at those ages it would probably be better to keep them separate for a few weeks. The day old chicks still need to be at 90-95, whereas the chicks that are already 5-weeks old should be mostly feathered out and about ready to go outside in your climate. When they are closer in size to each other you could try integrating them. At these ages, the size difference will be such that there would be a real risk of bodily harm to the little ones.

 

[chickie fam]

Oh ok. I keep forgetting how quickly the chicks grow! Hopefully when the new ones are older the integration will go smoothly!

 

[thewhyblockl]

I just went through a week and a half long introduction saga with a group of 6x (then)3 1/2 week old BR chicks and 6x (at the time)6 1/2 week old BR chicks. I took a long time, put the brooder and brooder run right inside the big run where the older chicks ran free. I gave them over a week to get used to one another and then put the small ones into the run and observed their first interactions with the big chicks. The big chicks ganged up and quite brutally attacked the little ones. Lots of group cornering, serious pecking, chasing... I stood watch, protected the little ones as well as I could and then put them back in the brooder run. I had to do this over and over for about 9 days before the biggies finally started to leave the little ones alone. FINALLY I can leave them all together unattended, but I still coop them up separately at night.
Maybe it helps to do it earlier, maybe it's worse. I just know that they can be very territorial and agressive, so however you decide to do it make sure you stay there to watch them closely for few days before you leave them together unattended.