Answer
(Fatwa: 1259/1027=D/1430)
While slaughtering, the animal should be laid down facing Qiblah and it should be slaughtered by sharp knife with reciting Bismillah Allahu Akbar until its four veins are cut down: (a) windpipe (b) oesophagus, the passage of food and water (c, d) two jugular veins on either side of the windpipe. If out the four, only three veins were cut, the slaughtering will be valid; it will be lawful for eating. But, if only two veins were cut, the animal will be haram and eating will be unlawful.
(2) It is mokrooh (disliked) to slaughter with flat knife. Likewise, it is makrooh to peel off the skin and cut it into parts before it cools down.
(3) Once the four veins are cut, it is makrooh to continue slaughtering. If the neck of a chicken was cut off completely, the chicken will remain halal, not makrooh, but over-slaughtering is makrooh, the chicken will not be makrooh.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband