Can the keets leave the brooder?

[BurchFam]

I have had my keets in a large brooder for 3 weeks now (got them at 1 week old). We are using a smaller 2'x4' shed as a coop for them for summer, while we determine a better coop for them for winter. The shed has a door I replaced with a hardwire mesh door so its 3 sided. The evenings get down to about 50 degrees here. With a heat lamp in the coop (I could shut it up at night if that's the concensus) can I put the keets out there? Also, the shed is in a covered run that is about 15' x 30'. I'd keep them solely in the coop for 2 weeks, and then give them a few weeks just in the covered run before letting half of them out to forage each day.

We have 8 total. I hope I gave all the background info needed to help with this.

 

[lightchick]

Yes, I had my chicks living outside in that same type of weather without a heat lamp.