On 10551 (or 0.E-1011-GDB44C38) with no mods. I just finished dismembering a Zombie Cop, then remembered that I left my knife in the shelter basement. After taking a brief look through the inventory to see if there were any other items with Butchering and seeing none I made a new world, spawned in zombies via the Debug Menu, killed them off with the same, then attempted Butchery. The game informs you that your best tool has 0 Butchering, but allows you to continue anyway.
You’d think a survivor would need at least 6 unarmed to knife hand a Kevlar Hulk’s arms off, but hey, now I don’t feel so inadequate when every NPC I run into is a cross between Rambo and Ip Man.