I'm not a bleeding heart or anything, but there's really no need to beat the shit out of the animals. I'm sure that they're so jacked up they don't feel it, but still. Just kill them the way you're supposed to. If there's something that's a nuisance with their current protocols (perhaps it's too slow and arduous) then appeal to someone until a "better way" is passed.
Just seems like more of a cluster fuck to chase sketched out, jacked up animals that are shocked and tripping balls in and out of consciousness.