Mutts are great. I think the best of the breeds survives in each one. I go to the local pound weekly and there are PLENTY of mutts there. They try to give an approximate guess of what type of dogs they might be. I think your plan to get a young dog is a good one. If you have a few bossy chickens to teach him not to mess with them, maybe he never will. I have 3 dogs and 2 ducks. I had the dogs first, they are about 4 or 5 years old. When I got the ducks, I showed them the ducks in the cat carrier, took them outside and made them sit with me while I released the ducks. The dogs seemed to absorb that I was giving care to the ducks so they belonged to the pack. They don't bother the ducks. Now if I could get the ducks to leave the dogs alone.
Happy puppy hunting,
Cindy