Here is a thought. Slaughtering should be performed by some one after they obtain a licence to do so and not by any random person. Anything that is done in a controlled setting tend to have better outcomes.
Look at the direction of the knife. These are called EDUCATION. I have seen in Bangladesh field it is going the opposite way (where going from trachea (hard part) inward).. Cows running with half of its throat cut.
You can argue evolution and that there is actully nothing wrong with inflicting pain on your prey as thats the laws of the universe but as an animal of superior intelligence, morals - it is your duty to alleviate that suffering of your prey as much as possible. That's my opinion. You can disagree and that's fine with me too...
But don't GIVE me some Bullshit logic that because everybody practice this way - it's the religious way - so it's the best way - and if you disagree you suffer from this or that...or get all defense over nothing like pedro did it this way why i can't i do it this way.