Read Semencic? LOL Thats the same guy that says the Canary Islands name comes from the aboriginal dogs that lived there.... Pretty good source, huh? Look, killing or driving off predators has NOTHING to do with livestock guarding... If your dogs dont live 24/7 with the herd, they are not livestock guardians...if they do, then I apologize and you probably have real livestock guarding WEB. A livestock guardian is a dog that is LEFT alone for days with the herd, BONDS with them and protects them...PREY drive is very low, making this animal UNSUITABLE for retrieving or catching the cattle. Dont tell me about White English Bulldogs being pure yada yada, because there is a whole lot of cur blood in those so called "old time bulldogs that come from the farms of our forefathers"............Hence why the crossbreeding to smaller bulldog types in order to develop a more capable dog for tasks that demanded more heart than you get from a type of dog loaded with cur genes.