The World Federation One Stop Fiqh

Ruling 2608

The method of slaughtering an animal is that four ducts must be severed completely:
the windpipe (trachea);
the food pipe (oesophagus);
3–4. the two thick arteries on the two sides of the oesophagus and trachea. Based on obligatory precaution, simply making an incision in them or severing only the trachea is not sufficient. Severing these four ducts can only happen by severing from below the protrusion from which the trachea and oesophagus separate.