Originally Posted by fisherlady
As Troyer said, this seems to vary based on season and even the hen involved. Most of ours stay 5 to 8 weeks, usually the longer time frames in cooler weather. It does seem like the broody understands that some just don't need them as long as others. When my Gracie hatched out banty types who were smaller (and the weather was cooler) she stayed with them 8 weeks, when she hatched out large fowl chicks (such as the EEs she just finished) she pushed them away at 5 weeks.
But remember, broody raised chicks at 5 weeks are nothing like brooder raised at 5 weeks. These chicks head out in the morning and free range all day, they were feathered from about 3.5 weeks old and have been dusting outside and doing their own foraging since 3 or 4 days old with the broody.
Generally I see a progression of behavior with all of the broodies and chicks... Day 1-3... mostly stay in nest or in immediate area, short trips to area within a few feet of nest to get food and water and maybe scratch a little (if that is an option)
days 3-6... roaming a bit farther from the nest, but rarely more than 10 or 15 feet from the coop, broody is taking them outside but frequently stops and sets to allow them under for warm ups (usually about 5 minutes out of every 15 or 30, depending on outside temps) Broody is heading into the coop by mid or late afternoon and settles the youngsters into her chosen floor nest then till morning.
1 week to 3 weeks... broody is getting them out and about as much as weather permits. Stopping for warm ups is getting less and less frequent but hen still gets them into coop well before dark and they all stay under her (as much as possible) for the night. Broody tends to keep chicks within a close distance at this stage, mostly see them moving as a group within a circle of 4 or 5 feet... though there is usually one explorer in each group that gives the mama fits.
3 wks+... their time outside is getting more like the other birds' schedule, warm ups are rarer, chicks are ranging farther and farther away from the broody and she isn't freaking about it, often one gets 'left behind' and will be heard cheeping frantically as it realizes it missed seeing the group move on while it was exploring. Mama usually goes back for it and it then rushes to rejoin the group. At night the mama still nests with them, but often some will be seen laying around her rather than under her... she will start trying to get them up onto a roost like the other chickens around week 4 or so many times (at least ours do)
When you notice mama hen starting to eat treats herself rather than immediately give everything to the chicks then you know it won't be long till she goes back to the roost and leaves them to fend for themselves.. Broodies can be vicious about it... once she is done with the chicks she may peck them any time they try to come close to her or roost near her... some hens are more gradual about it, but I have a couple who are absolutely finished the day they decide the chicks can do for themselves...
The 'abandoned' chicks sound pathetic for a day or two, but they form their own little group and will run together all day and sleep together at night until they are nearly ready to lay eggs or crow, and by then they will often have established a small foothold in the coop pecking order. I often notice our broody raised 'siblings' will remain closer to each other than to other flock members even after a year or two, though not always. If all but one or two from a broody hatch are sold the remaining chicks quickly assimilate into the rest of the flock. (but ours are raised in the flock, not separately, so that may be why they mix in so quickly)
Your broody should give up the meat birds by about week 5 I would think... so well before butcher time.
I won't hurt her to have the egg shell choice, but she doesn't need the calcium right now... she won't start egging until she has decided it is time to leave the little ones or even just that they are big enough to do things on their own, even if she is willing to let them hang around with her. Our hens eat whatever the youngsters are getting for the most part, though there is always an oyster shell dispenser available in the coop I never see a broody with chicks anywhere near it.