Introducing a new hen to my flock; what steps to take?

[Ohhhdear]

I have 12 ISA Browns which are a little more than 5 months old and laying pretty much daily. I want to go to the Thursday flea market/swap meet/farmer's market and get maybe 2-4 more hens about their age. My coop will fit maybe 4 more more adult birds on the roosts.

Question #1: How do I tell how old a chicken is?
Question #2: How do I tell if she's healthy, outside of shiny feathers, alert eyes, healthy looking feet? I do know how to check for lice, ticks, fleas, bugs, etc.
Question #3: If/when I get a couple more birds, what do I do next? Quarantining them, but for how long, and what am I looking for during that period? How do I know they need quarantining in the first place? What do I do with any eggs produced during a quarantine period (or should I even worry about eggs if/when they are laid?).
Question #4: Do chickens always moult during a quarantine?
Question #5: Should I automatically figure on worming an addition to the flock during quarantine? If so, with what, what dosage, and how? Most meds I've seen at the feed mill clearly say not to give to laying hens.

Looking forward to some great help!

 

[Mahonri]

Quote:
1. you can't tell how old a chicken is, but I look at how heavy they are and the size of their legs. Thicker legs means an older hen.
2. Are your Isa Browns healthy? Look for pullets that look healthy like yours. Check around the vent, along the neck and under the wings for lice and mites.
3. Quarantine for at least two weeks. I'd check their eggs out and if they look good, you could eat or incubat them if they were with a roo.
4. No, chickens don't always molt during a quarentine.
5. I use albendazole (brand name Valbazen). It's a sheep/cattle wormer, so that's the dept. you will find it in at the farmer's co-op, farm supply store, etc.
You give 1/2 cc orally, undiluted, per standard bird. Bantams get 1/4 cc. Works for chickens. Just open their beaks and squirt it in.

You'll probably get differing opinions on wormers here. The above is simple, easy and it works and it's what I use.