Early maps of London show numerous stockyards in the periphery of the city, where slaughter occurred in the open air or under cover such as wet markets.
"[4] An additional motivation for eliminating private slaughter was to impose a careful system of regulation for the "morally dangerous" task of putting animals to death.
[6] By the middle of the 19th century, in the course of a single year 220,000 head of cattle and 1,500,000 sheep would be "violently forced into an area of five acres, in the very heart of London, through its narrowest and most crowded thoroughfares".
[7] By the early 19th century, pamphlets were being circulated arguing in favor of the removal of the livestock market and its relocation outside of the city due to the extremely low hygienic conditions[8] as well as the brutal treatment of the cattle.
[9] In 1843, the Farmer's Magazine published a petition signed by bankers, salesmen, aldermen, butchers and local residents against the expansion of the livestock market.
At the same time, the first large and centralized slaughterhouse in Paris was constructed in 1867 under the orders of Napoleon III at the Parc de la Villette and heavily influenced the subsequent development of the institution throughout Europe.
These slaughterhouses were regulated by law to ensure good standards of hygiene, the prevention of the spread of disease and the minimization of needless animal cruelty.
The slaughterhouse had to be equipped with a specialized water supply system to effectively clean the operating area of blood and offal.
Veterinary scientists, notably George Fleming and John Gamgee, campaigned for stringent levels of inspection to ensure that epizootics such as rinderpest (a devastating outbreak of the disease covered all of Britain in 1865) would not be able to spread.
[16] Attempts were also made throughout the British Empire to reform the practice of slaughter itself, as the methods used came under increasing criticism for causing undue pain to the animals.
[17] As early as 1853, he designed a lethal chamber that would gas animals to death relatively painlessly[citation needed], and he founded the Model Abattoir Society in 1882 to investigate and campaign for humane methods of slaughter.
This expansion has been accompanied by increased concern about the physical and mental conditions of the workers along with controversy over the ethical and environmental implications of slaughtering animals for meat.
[3] The Edinburgh abattoir, which was built in 1910, had well lit laboratories, hot and cold water, gas, microscopes and equipment for cultivating organisms.
The Aberdeen slaughterhouse sent hooves to Lancashire to make glue, intestines to Glasgow for sausages and hides to the Midland tanneries.
[20][non-primary source needed] She suggested that reducing the stress of animals being led to slaughter may help slaughterhouse operators improve efficiency and profit.
This can cause conflicts with national regulations when a slaughterhouse adhering to the rules of religious preparation is located in some Western countries.
In Jewish law, captive bolts and other methods of pre-slaughter paralysis are generally not permissible, due to it being forbidden for an animal to be stunned prior to slaughter.
In some parts of western Japan, prejudice faced by current and former residents of such areas (burakumin "hamlet people") is still a sensitive issue.
Because of this, even the Japanese word for "slaughter" (屠殺 tosatsu) is deemed politically incorrect by some pressure groups as its inclusion of the kanji for "kill" (殺) supposedly portrays those who practise it in a negative manner.
This act, like those in many countries, exempts slaughter in accordance to religious law, such as kosher shechita[citation needed] and dhabiha halal.
It includes interviews of slaughterhouse workers in the U.S. who say that, because of the speed with which they are required to work, animals are routinely skinned while apparently alive and still blinking, kicking and shrieking.
Eisnitz argues that this is not only cruel to the animals but also dangerous for the human workers, as cows weighing several thousands of pounds thrashing around in pain are likely to kick out and debilitate anyone working near them.
According to the HFA, Eiznitz interviewed slaughterhouse workers representing over two million hours of experience, who, without exception, told her that they have beaten, strangled, boiled and dismembered animals alive or have failed to report those who do.
[39] On average, one employee of Tyson Foods, the largest meat producer in America, is injured and amputates a finger or limb per month.
[41] In a 2018 study in the Italian Journal of Food Safety, slaughterhouse workers are instructed to wear ear protectors to protect their hearing from the loud noises in the facility.
"[54] As authors from the PTSD Journal explain, "These employees are hired to kill animals, such as pigs and cows that are largely gentle creatures.
This emotional dissonance can lead to consequences such as domestic violence, social withdrawal, anxiety, drug and alcohol abuse, and PTSD.
[59] In a report by Oxfam America, slaughterhouse workers were observed not being allowed breaks, were often required to wear diapers, and were paid below minimum wage.