One chick is being picked on!

[Carly Avgeris]

Our week and a half old chicks are all ganging up on one. We have two RIR's and two Barred Rock's, and one Cornish. The two sets are ganging up on the Cornish. They are pecking her, not letting her eat as often as she would like, and the four sleep together and leave her out of the pile. It's so sad!
We got the two sets on a Tuesday, and then two Cornish came to us the following day. One Cornish died that same day. We also did not know that they were Cornish. We only intended on having egg layers, but these two were given to us by a family member who was misinformed on the breed when purchasing. but, since the day we added them to the brooder, they have all been mean to the remaining one.
Anyone have any advice on what we should do?

 

[Kadu]

I would keep the cornish one separate. Maybe you can put a screen in the brooder itself and let them see the cornish but not get to it. Also I'm assuming you mean Cornish X meat chickens? They do lay eggs, but not very productive if you want to keep her. But if they eat too much they'll develop leg/heart problems later on.