Regardless of breed, individual dogs can be good around children and other animals, or they can be deadly I just read where a family's pet dog, a lab mix, killed their two week old baby in Houston, TX. The parents were in the room with the dog and baby, so there was supervision. Any dog needs to be well trained FIRST, and still not trusted with children or livestock for a very long time.
I heard black labs are bird hunters. However, my boy Ace is the perfect chicken sitter. And he's great with kids, too. He's so calm, he can lay on the floor next to a new born baby and he won't bother that child for a second. He watches the chickens and doesn't bother them. He isn't even phased by them anymore. He lets small children crawl all over him. He also recently helped me take care of new kittens. He actually cried when they did, which he also does with babies. I think if a dog is raised right, any of them can be around chickens.
My rescue labbie-mix thinks she's a mother hen to my chicks. She sniffs them and nudges them back on the tarp when I bring them upstairs to play in the family room. She shows no interest in eating them, but she will bark at and chase off anything else that steps on our property.
Although not visible in the above pictures, my cat was laying on the tarp as well. He sniffs the chicks and runs away if they get too close. He's more into chasing bugs and the light from a flashlight. Silly cat shows no interest in the chickens!