Are your chickens full grown? If so, it's not too likely that they'll bother them. Especially if they're well fed cats. I have a wild barn cat that lives by my chicken coops and doesn't bother my adult chickens at all, and my chickens are free ranged all day, every day without supervision. I wouldn't put any bets on if they'd leave chicks alone, though. That's a whole different ball game. Any cat will take a chick.
I have two barn cats, and both showed interest in the chickens and ducks, but the chickens will defend themselves. I watched as one was stalking a chicken, and the chicken all of a sudden poofed herself up, spread her wings, charged the cat and pecked her on the nose. The cat jumped 3 feet straight up in the air! A similar thing happened to the other cat. Both are excellent hunters, bringing back birds, mice, chipmunks, squirrels etc, but they leave the chickens and ducks alone. The only thing that tempts them is a duck who is flying and coming in for a landing. Sometimes they will try and catch them, but the duck just turns on the afterburners and heads back up and lands a short distance way. I have seen the two cats napping in the lawn, surrounded by 18 sleeping ducks! Last year, my ducks got too close to the road, and 4 were hit by a car. Three were killed instantly, and one limped her way back to the house. Both cats followed her, and laid down next to her and stayed with her. Sadly, she did not make it, but she was kept company by the two cats, one on either side.