I think it depends on what you want the end result to be.
With that being said, I wanted my dogs and chickens to be able to be in the yard together and me not have to worry or watch every move. I train my dogs and like children the rules are inforced daily and just a part of the daily activities. (unlike most households). My two cocker spaniels, wanted to play and chase at first. I even used them to herd the chicks as I new they would not purposely hurt them. When they got plucked on the nose too many times, they learned chickens can hurt them. Now they are of no help what so ever.
The rottwieler on the other had was a different story. She was taught right off the bat that they are mine, dont look at them. She was worked with for a good year and is extremely respectful of the chickens. I am proud of her! and us! we took the time to make it happen.
The german shepherd....... well we fostered her momma so she was born seeing them. She has a great sense of humor and knows they are off limits and dont look at them. LOLOL "but......... mom, your 100 feet away!" So, we started more training from distances with her and still enforcing not looking at the chickens. When she was abit over a year old she found out that you can grab a rotty by the head, and nothing happens. You can grab a cocker spaniel by the head and you get your face ripped off. You grab a chicken by the head..................... It POPS right off. She was absolutely dumbfounded. She is a personality you can shame.......... with verbage so she got that. She new I was mad and that was a part of the family. Back to inforcing rules and boundries and "teaching her" again what I want. Now, if she has a squeaky toy and it squeaks she drops it afraid of hurting it. Its quite funny.
Now, about 2 years later she is great with them. Every now and then she will get a look on her face like "what if I do this?"
And she gets called to me or told a command like sit. Dont tell a dog to do something, if you can reinforce it.
They need to be taught and you need to have a vision. Now my dogs, correct foster dogs or companies dogs from even "looking" at the chickens. That is what they were taught and they inforce it for me now. It all takes time, work and consistance. I do not believe in hurting or abusing a dog. I believe in balanced training with praise and discipline. there are many tools to help you with your dog. But, DO NOT use a tool you have not worked with before. A good dog trainer can help show you how and what to use. Every dog is different and I believe the dumb dogs are the easiest to train! The smart ones are the ones that question you.
good luck to all with dogs........ It CAN be done.