I have a pet Llama, and not particularly used her for defense, but she has "spoken" to us with her body language. She has alerted me when something was out of the ordinary on the property, including a large predator/cat/mountain lion and coyote. She did not attack, they were on the other side of the fence. What she does is "FREEZE". It's her pose and refusal to budge that alerts me.
Big Sweetie is a female, so I'm not sure if that makes a difference. She is an elderly pack llama, not a raised to be Guard Llama....so she doesnt attack anything.
I think it would depend on how you trained your Llama.
Big Sweetie has been around Chickens, Turkeys, Ducks, Geese, Goats, and my Pot Belly Pig.
Then again, when the skunk was decimating my flock one by one, they were walking right around her, and she never batted an eye. We saw it once. Didnt bother her a bit. She's lived in a mixed flock so long, I guess she thought we must have put another stinkin pet in the yard?
Good luck.