Goat ranching is a common industry in Missouri.
Predator callers can imagine the effect that 100 plus baby goats constantly, loudly crying, which sounds like classic distress sounds, would have on the neighborhood coyotes. Depredation is a major problem there and I had access to several goat opereations when I lived in the Ozarks. ALL of them used guard animals of one kind or another and sometimes , in desperation, they would use several with the idea if one kind was effective, one each of three different kinds would be three times as effective. Some of the ranches had llamas, donkeys, and guard dogs,(Great Pyrenes were most common although a few had Komondors and Akbars)all together in the compounds with the goats.
The problem was that the guard animals supposedly bond with the goats and become protective against predators. That works a little better if only one type of guard animal is introduced. If others are present they apparently don't bond and are not effective.
One ranch that had all three animals guarding the goats was losing 3-5 kids a week. When I went in and called for them the donkey and llama followed me from stand to stand. The llama would lie down a few feet away from me and the donkey hung back several yards and both watched. Seemed to be entertaining to them. I appreciated the llama, it would hear a coyotes approach through the hollow long before I did and I knew one was coming in from the llamas attention. Regardless the llama would just lie there and watch without taking any action at all.
I've read study results of research that APHIS conducted on guard animals and western sheep and the results are mixed. Apparently even the aggressive dogs are unable to cope with the coyotes strategy of having one coyote decoy the dogs to one side of a large flock while another coyote kills a lamb on the opposite side..