I've read that female donkeys are usually better with sheep. I had a small standard male donkey and he was NOT good with my sheep and goats. In fact, he killed one goat and would chase the others.
Have you read up on other types of guardian animals? Like dogs or llamas? Sometimes donkeys don't work out that well, and they're very smart and most equines like other equine company, not just ovine company.
I have a standard size jenny , about 350#, with my boer goats; She is priceless...You want to make sure the animal is in fact a donkey not a mule...mules are more like horses and you probably won't like what you get unless you need a pack animal.
I have a mini male gelded and he works out fine ...likes to chase them but you know goats they get in his face until he has had enough... funny to watch.
I had both a female and a male mini donkey to guard my goats and both would pick my goats up by the necks and sling them around. I think it's pretty rare for donkeys to actually be good guards. Sure they might keep the predators out. But they will also chase and kill goats.
Just my experience. I wanted mini donkeys so bad. But needless to say they both got new homes.
I dog would probably be better, but then again some of those chase goats too....
Yeah. I have no guard animal right now because my guard animals seemed pleased chasing goats while keeping predators out.
All of the above plus the BRRRAAAAAYYYING in the early mornings. My neighbor got a gelded donkey to guard their sheep from coyotes. This donkey killed 3 of their lambs within 1 week. I threatened to shoot my neighbor's donkey due to constant braying at the wee hours of the morning ... then he got rid of it when his wife threatend more extreame mayhem on his more personal parts.
We have a couple friends who have gotten female donkeys from the Bureau of Land Management sales. I think donkey price is $25.
Both sets of friends have sheep, no goats, that the donkeys live with. Donkeys are about 48 inches tall, give or take some. So far as I know, they have had no problems with the donkeys killing or hurting the sheep. Fields are not small corrals, room to move apart if they want. Ewes are able to get into a creep feeder area, for the extra feed just before lambing. Otherwise they are just fed big bales free choice.
Local dogs were the problem for both sheep breeders, pets running loose and packing up to harass the sheep. Coyotes moving into the area as well.
Both have said that just having the donkeys has prevented any problems from happening. Donkey takes care of the issue before things get bad, and they REALLY finish the problem unless dog gets away from them. These donkeys are kept trim, no fat on them. They run VERY fast, big enough to face big dogs. Donkeys are kept together in pairs, so they have "backup" if one animal should meet several dogs at once.
Donkeys need trimming by a hoof care person, once or twice a year if they are active. Soft ground, small paddocks, might need hoof care more often with not wearing them down moving much. With the BLM donkeys, many are not super friendly, not trained to handle hooves so you need the Vet to tranq them for trims. Some even get a hoof tied up for trimming to protect the hoof person.
So another option, buying from the BLM on their forays thru the eastern states. Here in Michigan they usually make a couple stops at fairgrounds for folks who might like to adopt a donkey or mustang. You can go look them over.
Our friends have said the donkeys allow them to stay in the sheep business, no losses from predators. Price of donkey upkeep is offset by what they prevent happening.
No one I know uses mini donkeys for protection. Just not enough animal to manage a big dog or a couple of them. Don't have the same motivation to get dogs that the BLM donkeys do.
You may have the same problems with sheep abuse having Llamas, that was mentioned with donkeys. Biting, kicking, tossing them about. Not every Llama or donkey is a protection animal. Especially the ungelded males of either species. Females seem to be best, and kept in pairs for company. Braying can be an issue. Mules are not a good choice for protection, they usually will chase ANYTHING small and hurt them.
I've never used a guard Donkey, but my Guard Llama is the best. He is very good with the sheep and goats, even the newborn lambs and kids. We have not lost a single, Goat or sheep since we got him or a chicken for that matter.
Llamas eat way less, about a quarter flake of hay and a cup of grain per day, and they are way quieter and gentler. He never even makes a sound, plus llama wool can be sold along with your sheep wool to earn their keep.