Kosher slaughter was established based on principles in the Torah (five books of Moses), and developed based on the most humane methods available. The stated goal of the process, and of the method used by the Shochet (ritual slaughterer), was to assure that there was absolutely no unnecessary pain or discomfort to the animal. In short, without being too graphic; when done properly it causes an immediate loss of blood to the brain with attendant unconsciousness of the animal within a very tiny window of time, so that there is an absolute minimum of pain, no suffering, and virtually no awareness of what is happening.
There are extensive requirements for the training of the Shochet, for the quality and state of the tools and utensils involved, for the health of the animal, for the conditions under which ritual slaughter may be done, and for other aspects of the process; violation of any of which renders all of the meat and products from that animal un-Kosher (not fit for sale or use as Kosher).
The method of Kosher ritual slaughter is ancient, as you say, but I am not too sure that your assumption that newer methods are more humane has any basis in fact. Again, I am no expert, but what I have read over the last ten to fifteen years has led me to believe that these newer methods are no better, and in many cases, far worse, than the traditional methods for Kosher slaughter.
Any internet search will turn up lots of information on methods of slaughter; a quick reading about any or all of them will show that none of them is perfect or foolproof.
Let us leave aside the forms of slaughter where no concern is given to the feelings of the animal, and there is no thought for humane methods – those are simply cruel, in my opinion, and have no place in this discussion – they simply should be outlawed.
For methods proposed as ‘humane’, if you do an internet search for ‘shackling and hoisting’ you will see that this method of hanging the animal by its back leg and killing it is no improvement, as the animal is terrified by being placed in an unnatural and painful situation before it is killed. There has been speculation that the animal releases enzymes and hormones as a response to this fear and terror which may contaminate the meat – not a happy thought for those who are the end consumers.
The method of ‘stunning’ which is mentioned often is not much better. Given the thickness of the animal’s skull (assuming cattle as the main subject for this discussion), the hammer blows that are used to render it unconscious in many cases are fatal themselves by crushing in the skull, and more than one blow is often required. I don’t see death by hammer as particularly humane.
In the more ‘advanced’ form of stunning, a massive electric charge is administered to the skull of the animal, which is supposed to stun it, but the charge is not infrequently misapplied, leading to the animal suffering before being killed by cooking its brain using electricity. We have been moving away from capital punishment by electrocution; this is no different in my view.
The bottom line is that without experiencing it myself, simply from reading about it, on looking at all the forms of slaughter used, I believe that the Kosher method is the least painful and distressing overall for the animal. Despite ‘advances’ and newer technology, this is not a process which lends itself to machine-like precision, and the expertise and attention of a Shochet is the only approach that seems to me to offer the attention and care that is required for each situation encountered.
I am not addressing the issue of whether we should eat meat; nor the question of whether we should observe Kashrut (Kosher rules); only the method of slaughter. For that question, I would disagree with your premise, and say that the Kosher method is the most humane (both when it was established, and now), and encourage that we follow it. And yes, as we learn more, and if we find better ways to be humane in this process, we should seriously consider incorporating them. At this point, however, given the demand for meat, and without some new technique that is far superior, I would urge continuing use of the Kosher slaughter standards.
Kashrut is not a universally observed practice among Reform Jews. Some follow it; some do not; yet others are vegetarians or vegans. It is left as a personal choice. Their reasons vary. Those in other movements, Orthodox and Conservative, for example, are more likely to follow these practices as a matter of religious belief. Whatever the reason, whichever movement, the principles of humane treatment of animals and awareness of the sanctity of life (in all its forms) are core principles and values that are raised in this issue, as in others.
The unasked question here has to do with the issue that has been in the news of late; to what should Kosher certification standards apply – is it only applicable to the animal itself and the slaughter of it as has been the case, or should it be extended to the conditions under which the animal is kept and raised, the working conditions for the farmers, slaughterers, and other laborers involved in the process of producing the meat, the impact of the process on the community and on the environment and ecology, or all of these factors. Fortunately, this has been raised in another question submitted on this web site, and you can see the responses there shortly, if they are not already shown.