I have a allmost 2 year old pit bull female who could care less about my chicks. It took us maybe 3 horus or so to let her know she wont be eating nuggets for dinner. Never a smack or a harsh word. The word " no " and some misdirected focus did the trick for us.. yours may vary tho since you have so many dogs.
that beeing said...
There is a big difference with 5 or more dogs or just one dog.Pack mentality, prey drive etc all come into play.
They can be tought to leave them alone but it wont be a fast process.I would suggest you have a fence separating them first.. mayeb for a week or more to have them get used to each other. Stay with the dogs and let them sniff the chicks etc.If they act like they want to take a bite out of the chicks tell them no and repeat until they get the drift. Once the chicks wont flap and carry on and run off they wont be such a drive from the to give chase.
They will get used to each other , its just a matter of time. Supervise at all times.
Luckily retrievers are one of the breeds that can and will get along with anything. A good fence and lots of time side by side will do the tirck. you wiat.. in a few weeks they wont even give the chickens a second look.