"zombies run around in circles trying to catch hanging bait traps, all the while turning a turbine that provides energy for the humans in the ranch."
Hopefully there is still enough surplus zombie labor that popping a few in the melon is still possible, don't want skills to get rusty, ya know?
PS - It's probably one of those "if ya have to ask" deals, but...how much would it cost to get a zombie ranch built?