This is a very interesting topic. I'm a pretty firm beleiver in "if it ain't broke, don't fix it". I have to agree with the opinion that if your current crop of coyotes aren't killin your stock, why take them out and invite maybe more aggresive ones in?
Mike, I've got a question for ya though. With the re-introduction of wolves through the west, will a coyote group defend it's territory against an invading wolf pack or will the coyotes just move on.