Agreed with above. Malnourished for sure, possibly over crowded. Bald heiney may be an indication of feather mites. I would give them a good dusting of permethrin, be sure to get it down to the skin. Treatment for internal parasites is optional. I would rather spend the money for a fecal float than to medicate them for a non existent parasite load. Put them on a high protein feed: either non medicated chick starter or multi flock (no more than 22% protein). You might even want to give them an extra poultry vitamin. Do not do the electrolyte packet mixes. THEY DON'T NEED electrolytes. Poultry Nutri Drench is a good vitamin for all ages, but there are others.
I understand what you are saying re: the concern about bringing unhealthy birds into your yard. They may come with "issues", and any malnourishment will surely affect them in the long term. On the other hand, they are already there. You've saved a lot of money on the front end, b/c you've not had to buy, brood or feed them. Any money spent on high quality feed, a can of permethrin, and a fecal float will all come out in the wash. You'd most likely be paying for all that stuff eventually, no matter where you get your birds from. It's amazing what good care will do for any animal that starts out in a neglectful situation. If you want to give them even more nutritional benefit, consider fermenting their feed. (there's an article in my signature about FF) When their run becomes void of greens, I recommend that you turn the run into a deep litter run. You can do a topic search for more info on that subject. Enjoy. I bet a few weeks of good care will result in a flock of birds that you can be proud of.
I understand what you are saying re: the concern about bringing unhealthy birds into your yard. They may come with "issues", and any malnourishment will surely affect them in the long term. On the other hand, they are already there. You've saved a lot of money on the front end, b/c you've not had to buy, brood or feed them. Any money spent on high quality feed, a can of permethrin, and a fecal float will all come out in the wash. You'd most likely be paying for all that stuff eventually, no matter where you get your birds from. It's amazing what good care will do for any animal that starts out in a neglectful situation. If you want to give them even more nutritional benefit, consider fermenting their feed. (there's an article in my signature about FF) When their run becomes void of greens, I recommend that you turn the run into a deep litter run. You can do a topic search for more info on that subject. Enjoy. I bet a few weeks of good care will result in a flock of birds that you can be proud of.