Chullin 15: Intention and Slaughter

The majority of today's daf focuses on the implications of things done unintentionally.  For example, the  rabbis discuss shechita that is done unintentionally.  Can such offerings be consumed? Sold?  Benefited from in any way?  Do these offerings result in punishments?  The rabbis also discuss one who cooks on Shabbat unwittingly. Can such food be eaten? By whom?  Does it make a difference if one is very sick?  During or after Shabbat?   

At the end of our daf we are introduced to a new Mishna.  It teaches that it is valid to slaughter an animal with:

• the smooth side of a hand sickle,
• a sharpened flint
• a reed that was cut lengthwise and sharpened

It is valid to slaughter using any item the cuts except for

• the serrated side of the harvest sickle
• a saw
• the teeth of an animal still attached to its jawbone
• a fingernail

This is because all of these things are serrated and may strangle the animal without cutting its windpipe and gullet, which are required.  

The Gemara discusses in-between cases; for example, is it valid to slaughter an animal with a tool where the handle fell off and then was reattached?