[kelsalkins]

Has anyone put different batches of chicks together at 5 weeks old. I have 4 from my incubator and 4 with the hen could I put them together or will the hen attack them

[Steph Hen]

No, the hen will almost certainly attack them, I'd say it's  not worth the risk at all. Sorry.
You can certainly fool a hen at first, if I had a broody sit I'd always try to get some eggs for the incubator as well I fooled a lovely light Sussex to mummy I think it was 26 chicks one year (might have been 24). But they need to be introduced very soon after her own eggs have hatched, ideally at night, before she leaves the nest.

[bj_cardiff]

Are both sets 5 weeks old? If they are I'd separate the hen from her chicks and mix them. I assume you would like to mix them so you can put them out in a secure pen. Agree with the other poster, the hen would certainly attack the chicks

[Marches Farmer]

The hen will probably drift the chicks quite soon anyway.  Put both lots in their new area with plenty of fresh shavings to distract them, just before dusk.  Apart from an occasional peck they should settle down quickly, unless you have an aggressive breed or strain somewhere in the mix.  Let the broody have a well-deserved rest on her own, well away from the chicks, for a few days. We add chicks from the incubator at a maximum of three days old - old enough for us to be happy they're OK and eating and drinking, young enough so the broody hasn't yet got too familiar with "her" chicks to kill outsiders.

[macgro7]

If they are both 5 weeks old you can actually "wean" them of their broody mum and put both batches together. She is unlikely to want to take care of 5 week old chicks that's she has never seen before and they are unlikely to know to follow her either.