Our Llama (Dalai) was originally purchased to be the herd guard animal. He has filled that role well and integrated into the family quite well. His personality is still stand offish unless you have food in your hand, in which case he is your very best friend!
Llama make great protectors, and seem to instinctively know the role. Dalai has cornered our large dogs on more than one occasion, not hurting them, but certainly containing them. We have had no predator losses in the area covered by the Llama, so while that is not definitive confirmation of efficacy, it certainly does support the case!
Dalai is from Chile, or more accurately, his father is from Chile. He was bred to be larger and of the guard temperament.