They are actually in VERY good shape for battery chickens, i worked in a battery chicken farm once for a couple of days and it was hell on earth, never seen so much misery, desease and cruelty in my life; i used to have chickens for about 12years so i know a fair amount about them.
They put chicks into the mincer/food processer alive for cat and dog food, many chickens wern't even killed properly and were still alive when they started to be prepared for food, many chickens didn't even know how to walk they had been in a cage for their entire lives that when they died you had to cut their legs off just to get them out of the cage because their feet had grown around the cage bars.
A chicken naturally lays 2 eggs a day, battery chickens are forced to pump out 36 on average day(thats like us giving birth once a week), chickens naturally take a year on average to mature, battery chickens are forced to mature in 6months via been feed hormones and chemicals- they even somtimes get their beaks cut off so they can be force fed to produce more eggs. Don't even let me go on to barn range chickens if you thought you were buying healthier chickens than battery range ones.
I could go on, but you did a very good thing saving those chickens

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What are you feeding them on currently? If the weather gets bad you may have to take the ones with the least feathers indoors so they don't get a cold(yes chickens get colds like we do

). Chickens will scratch around in the earth to look for food naturally but you may have to teach your chickens how to do this as they are battery ones by imitating pecking around for food and scratching the ground yourself as they are intelligent creatures that will learn from you

.