Another good option may be a Bernese Mountain Dog, they are amazing family dogs, and bomb proof still aloof and specific with the people it likes. But if raised with chickens, cats or other small animals they are fine with them. They are big and a little less energetic than a shepherd I will always have a soft place for them, Ruby was my first dog she was a Bernese. No prey drive, and the love babies of any species, will protect them.
My Bernese nearly killed another dog for getting to close to my cats kittens, and she took out raccoon regularly who prayed on my chickens and ducks. But never ever wandered from home, and was never aggressive with people just cautious and wary. A very good nanny dog. At one time my young daughter at around 3 wandered around the corner from us towards a swampy area and she would run back and fourth from her to us barking till we clued in and followed her to get my daughter.
And they are not rank driven, so will not challenge your authority, very easy amazing dogs. You don't need to be overly dominant to convince them.
That is what I would recommend, even over a shepherd, since they can have a fair amount of prey drive, and a lot more energy than a Bernese.
