Here's the thing about highland fur, it tangles into stuff very easily. Add to that, Highlands and more than likely all cows, don't like you playing with their back legs. They can't see what you're doing and they're not able to defend themselves. It took some scissors, some patience and some luck, but we got it out!
To answer why we have barbed wire, we don't. It is buried everywhere underneath the ground here. Everytime we find some, we dispose of it, but sometimes the animals find it for us. Don't bury barbed wire people, it's a horrible thing to do.