I know a lady who lives in the country and has a lot of chickens. She bought a Great Pyrenees pup and it actually killed its first coyote when she was a little over six months old and brought it back to the barn! I had an English Mastiff female years ago that I let sleep on my back porch. She started raising cain about 10 each night, I scolded her at first and realized that wasnt like her. So the next night when she started up , I let her off the porch. She tore out after something in the back yard and chase it across a cattle pasture before returning. So the next day I put ot some cut up chicken right at my fence line and right beside my night light. After dark, I hid under a pine tree with a 12 guage and waited. Sure enough about 10, I heard the cattle start moving off and then saw a coyote come right up about 15 yards from my backdoor. I watched for a moment then shot it. Poor thing was missing a leg and already in rough shape so I probably saved it a slow death come winter. Get a good large breed dog would be a start. Pyrenees are good. English Mastiffs are great, very good with kids and will protect when necessary.