Can I add new chicks to 7-8 week chicks?

[steve&kris]

I have 10 BO chicks (I think 5 hens / 5 roos) that are 7-8 weeks now. I'm eventually going to be thinning the roos to 1. I'd like to add some straight run black australorps (maybe 3-4). If I buy young chicks and have them in a brooder until they're 5-6 weeks, can I put them in with the older chicks (which would at that point be 13-15 weeks), or is that enough of an age difference that the older would hurt the younger?

Thx!!

 

[vanalpaca]

I would go by size as much as possible so that the chicks are the same size. If there were double the younger chicks going in with the older chicks, then that would be safer. Can you just do a grow out pen until they are the same size? Or let them range in turns?