Kosher slaughter today is mainly carried out in large factory settings, with each shochet slaughtering hundreds of animals or even thousands of birds every day.

The required ritual inspections of various internal organs is also carried out in a similar fashion.

 

This is very different than the way kosher slaughter was performed for most of Jewish history. I would like to better understand both the history, and the halacha, behind modern commercial kosher slaughterhouse operations. 

• When did this practice begin?

• Which halachic authorities gave explicit permission to eat meat from commercial kosher slaughterhouses?

• Was/Is there any notable opposition, within the kosher-keeping world, to the practice of mass-produced kosher meat?
   

Nowadays, the whole process is done so quickly, and repeated so many times a day, that the risk of human error with its grave consequences cannot be overlooked. It's hard to believe that this process was just blindly accepted, without any discussion or concern. We're talking about issurey d'oraisa here. Speeding up the process and doing it repetitively lends itself to more mistakes.

 

The various hashgochot - at least here in Israel - do "pride themselves" on their "speed limits" they impose; as per your concerns - the schochet/mashgiach checks every knife after every animal.

 

On erev yom kippur we certainly find that one shochet would shecht a lot in one day

Simla Chadasha writes (18:12) that on erev Yom Kippur, if we would insist that the knife be checked after every שחיטה as it should, it is more than likely that the checking would be substandard.

In this case it is preferable to check the knife less often and if the knife is discovered to be blemished we need to disqualify all the birds in that bracket - we assume the worst, the knife became damaged on a feather of the very first bird Shechted, thus all the birds were Shechted with a blemished knife.

 

Matteh Asher records that the leniencies permitted on Erev Yom Kippur became the norm in big cities where they are always that busy. He notes that the frequency of knife checks is determined by

• the quality of the knife, the old iron knives are far softer and accordingly require far more frequent checking than the newer hard, steel knives

• the tough or soft nature of the skin and סימנים 

• the method and style of sharpening the blade

• ultimately each שוחט must know his powers of concentration, the nature of his knife and the types of animals being Shechted in order to determine safe limits at which he checks his knife.

 

The Kashau Rebbe was opposed to the practice of factory kashrus in America, and would not eat meat unless he saw the animal being schected. His Hasidim today follow this practice .

 

The mishnah berura 605.2...

There are places where large crowds gather to shecht the Kapparos chickens. Bedlam reigns, people are pushing, the shochtim are awake all night, they are angry and stressed by the work and people shouting at them, they do not test the knife and if they do it is not properly tested.

This situation is rife with risk that  many well meaning people who on this day of all days are recklessley playing with the serious prohibition eating neveylah.

It is far better to perform the kaparos and shecht a day or two before Yom Kippur. Alternatively, kaparos shold be performed with money. This is a great merit for them, having avoided the risks of eating neveylah, Heaven forfend.

 

The slaughterers must sleep well beforehand, so that they will not feel faint. They must also prepare several valid knives.

At the time of slaughter they should again examine the knife, and do so each and every time they are about to slaughter.

 

Even slaughter performed at private homes draws many many neighbours to bring their chickens for slaughter. Again this leads to all the problems outlined above. It is highly unlikely that the shochet will meticulously examine his knife with the required 12 checks and with adequate concentration.

 

Simla Chadosho encourages those who fear Hashem to eat meat only if 

he knows the shochet to be a Gd fearing Yid

or the rabbanim responsible for the shechitah are Gd fearing

or he checks the knife shochet