When the chicks were tiny, we kept her on a leash if we brought them outside and she tugged at the leash, her wolf-like teeth snapping. But she paid attention to us. Border Collies are very amenable to training.
I believe in progress--the proof is right in front of us. The chickens are big enough that they live outside all the time now. And we eventually started letting Gracie roam around without the leash.
This is her one of the first times she put the chickens back in the ark without a leash. (I apologize for the loud wind in the recording.)
I wish I could say it has gone that smoothly since. She sometimes blocks the entrance to the ark and a chicken will circle trying to get in with the others while this big scary dog stands in her way. But she is getting the hang of it.
Of course, at night the chickens put themselves to bed and Gracie's "help" only slows things down, but we're training her. There might be a time when we need to corral them away from a predator, and Gracie's skills could come in very handy.
For now, she herds them all the time.
She watches them very closely. Often too close for comfort. But we know now that even if she makes them nervous, she is not planning her dinner.