Newbie getting nervous!

keep your dogs on a lead until you are sure. It is natural for them to chase the hens even if just to play but in doing so they can kill the birds 

also - don't scold the pup as they get close to smell. watch the body language...you'll see the difference/change when they go from curious sniffing to play/stalk/attack mode....

as soon as the body language changes distract them by making a high pitched sound... i do the noise mum's make when kids are about to help themselves to something without asking. 3 short, high pitched noises and pup walks/runs towards me instead to check if i'm ok.

when they arrive by your side, lots of praise and maybe, just maybe a small piece of cheese

our boys will be 4 this year. shehra ignores them, veer sometimes forgets and tries to grab them and mahi is still learning but she's only 6 months old!

I've had the most horrendous 6 weeks with one of my two Jack Russell cross terriers, (both bitches)....dashing out to the pen, barking, snapping etc and generally challenging the girls, (who dont give a monkeys about the dog whatsoever!!)...but then a break through last Friday..this probably wont work for every dog, but mine hates football whistles....I acquired one and on the first occasion of confrontation, i blew the whistle, her tale went down and she sloped off away from the chickens....i've probably only had to blow it 5 or 6 times in the space of a week, and the dog is now calmly going out to the pen, or doesnt even bother....i know i've still a fair way to go, but i am now able to take the dog outside on a lead whilst the girls are free ranging around her, and she is fine.  I have the whistle in my pocket if needed, and hoping that with patience and effort, i will eventually get the peace and harmony between feathered and four-legged friends.
Another tool could be the empty plastic bottle shaken with a few old coppers in.
And of course i reward with treats when all has gone well.....Good luck!!

Hi

We have 2 Jack Russells and when we first got our girls they were bouncing of the wire to try to get at them.  We kept them on a lead and when it was time to let the girls free range we sat out with them all and scolded the dogs if they became too interested (hunt mode).
They now all live happily together, in fact the dogs are scared of the chickens but I still wouldn't leave them alone together.