Vessels Required To Be Severed At The Time Of Slaughter

With regards to the Qurbani of a sheep, there are four vessels which are normally severed:

1. The windpipe (trachea)

2. Oesophagus (food pipe)

3. The two jugular veins.

The severing of at least three of these four vessels is a condition for the validity of the Qurbani. After  severing these vessels, one should not continue cutting until the spine, as this  causes unnecessary pain to the animal.

RasoolAllah Sallallahu Alayhi Wa Sallam said, “Allah Ta’ala has made it compulsory that a person should act in a pleasant manner with regards to all things. Thus, when you kill and slaughter, do it in a pleasant manner, sharpen your knife, and give comfort and ease to the animal.”
(Saheeh Muslim)