What is the ruling on slaughtering an animal after stunning it, which renders it unconscious before slaughter, and what is the ruling on slaughtering an animal without stunning it, and are the two rulings equivalent?

There should be no equivalence between slaughtering in a manner safe from stunning and a method that involves stunning. The former is done in accordance with Islamic Sharia, whereas the latter is not free from shortcomings; because stunning is a form of torture for the animal, and it may lead to its death before slaughter, even though the principle is to leave what is doubtful for what is not doubtful.