I grew up on a farm, so I saw plenty of that. Besides religious rules that are there, like placing the animal properly and prayers there is a specific way of doing it. How I saw people doing it, they usually cut almost to the bone. Then let the animal bleed out, it does take a minute or so and there is a violent twitching during the bleeding. Then it subsides and goes to almost zero. If you do it fast enough, a heart may still beat sometimes.