I'll try anything once, twice if i like it!!!
this is something I tried once. There used to be a guy down in Springville that was into it. He rented goats, had boothes at the outdoor shows, etc. I talked with him, and it sounded promising. I rented 3 of them for a late cow hunt to give it a try. Loaded them up with their little cross-bucks and panniers, with my lunch, rifle, etc. Off we went. Or should i say off THEY went. It was a foot race. all of them critters trying to keep ahead of the others. When i caught them and rescued my gear, i loaded them down with rocks to where they could hardly walk. then they tailed along pretty good!! Shot a big ole cow that day, though, and they packed it all out, boned of course- none of them could carry two quarters. between the 4 of us, not too bad.
So i bought 3 of them, along with the whole kit and kaboodle of equipment. they were 3 yr olds, and had been "started".
OK- here is the rub- you gotta be good with animals. any Joe that just decides that he can go out and load a bunch of stuff on a critter and wander off into outback nirvana is gonna be really disappointed. I am fair with something with a key. The animal mind and mine are way to far out of kilter.
The one time i tried to pack with them was a disaster. I ended up almost having to drag one of them back, even though I had taken his whole load off him. I left him tied in camp the next day, and he ripped the back of my tent out ( I tied him behind it to keep him out of the wind, didn't want him freezing!!)he then climbed into the tent, took a long nap on my new down bag, pee'd and pooped on my buddies gear, and made a general mess of everthing. Ever slept in a goat pee saturated bag? not good.
I am pretty sure a guy could do well, providing he has the time and temperment. But not me. My pack animals say "honda" on them.