Currently in the game, the only thing that we can butcher with are axes and swords. I imagine the actual tool of preference would be a sort of a hunting knife.
The gag with a hunting knife is that it would be made with less materials than an axe or sword so therefore is easier to mass produce at a higher quality and for nabs to buy cheaply, would use some other material in crafting (like leather) again to ensure it is more feasible to achieve a higher quality, and it's only use would be butchering animals.
I imagine it should also have some kind of bonus while butchering animals as well (since butchering with a knife would be so much easier than a hatchet or sword) such as increased speed for butchering.
I know knives and daggers have been discussed before, but this is not to be used as a weapon, rather as a utility tool for hunters and a cheap alternative to buying/making an HQ metal axe which takes 2(!) entire bars of hard metal.