"Stunning" refers to the methods of attempting to render an animal or bird unconscious prior to slaughter. The main methods used in the general slaughtering industry for cattle and sheep are:
• captive bolt gun: a steel bolt is shot into the skull at the front of the animal’s brain.
• electric shock: electrodes are clamped to the animal's head/heart and the animal is electrocuted.
These methods are contrary to Jewish law, because an animal intended for food must be healthy and uninjured at the time of shechita. The above stunning methods injure the animal, making it treifa (non-kosher and thus prohibited). If the stunning kills the animal it makes it neveila (an animal which has not been shechted) and is forbidden as food for Jews.
With these methods, during the delay between the stun and sticking or cutting, the animal can regain consciousness, as has been reported by animal welfare groups. The stun effected by shechita is irreversible and there is no delay. Shechita therefore, is humane and efficient.
Apart from the halachic prohibition against the above methods of stunning, there is no conclusive evidence that these methods render an animal insensible to pain. There is evidence that they are only paralyzed, and thus prevented from displaying their pain. Furthermore when the captive bolt method fails, as it does in a significant percentage of cases, it causes considerable additional suffering and distress to the animal. In such cases, the conscious animal is in acute pain as the captive bolt gun is reloaded and reapplied, or the electrical tongs reapplied to re-stun the animal. Shechita avoids these problems of ineffective stunning, since there is no mechanical or electrical appliance to be misapplied or go wrong. Shechita produces an effective and irreversible stun as well as being a humane and efficient slaughter method.
How about right after schechita? What amount of time must pass after the cut before you stun an animal or eg instantly decapitate it? Does it need to bleed out as part of halacha, before anything else can be done? If so, what are your sources?
As we clearly see on video a completely certified kosher process can result in an animal being lifted by its hind leg and suffering for minutes while bleeding out. Can stunning and / or decapitation take place right away after the incision?
According to Rav Moshe Feinstein stunning after shechita is fine, as long as enough time is given for the blood to drain (usually around 30 seconds).
Are there any halachic authorities that say the stun can happen one second after the cut? Because for example of the principle that Hillel had, that a vase falling from a great height is already considered as a broken one? So breaking it again in midair one is not liable for its cost? So here - the schehita incision was performed at a time the animal was alive. Why does the blood drain need 30 seconds specifically? Perhaps some poskim rule that one can wait a mere second or less before stunning the animal.
This has major implications for animal welfare as you can imagine. And the consequences are basically: which orthodox or ultra orthodox Jewish groups will accept such a schechita as I described?