Wow, I have heard of that too. Never seen it tho! That's the exact reason I decided against the breed for an LGD though. The name is derived from how they nip at the cattle's heels, and do have some prey drive. My sweet donkey is showing good promise as a guardian so I have decided against a dog for now. She races at the owl whenever it swoops at my ducks! I love giant dog breeds but they just aren't safe around my parents.
We had a Rottweiler, and she was fantastic with children and other animals--just a very maternal dog. I have had no luck at all with boy dogs so far of any breed, though. If this puppy hadn't been free and kind of foisted, I wouldn't have taken him. Pitbulls aren't exactly known for being great LGDs. He savaged the hen far more than I'd given him credit for being able to do, but she weighed as much as he does (big CX, small but growing terrier). Don't think the tying thing would have worked (plus, I don't have other dogs to work on shaming him or keep him warm outside during this "shaming").