Take the puppy with you when you take care of the animals, correct any chasing/nipping behaviour and praise the behaviour you want. Age has nothing to do with trustworthiness. You'll have to wait and see how the pup reacts to the birds, how your basic commands and conditioning goes, etc.Thanks for all the feedback so far. I still can't decide on a breed but I feel getting a puppy is best. How should training go? How do you teach a dog their job is with the flock while not letting them alone with the flock till they are older. Actually how old should they be before they are left alone?