Common abattoirs, or slaughterhouses, are used to process meat for human consumption as well as animal by-products. Meat for human consumption accounts for 45 to 50% of all products that comes out of abattoirs. Slaughterhouses with products unfit for human consumption are referred to as "knackeries."
Many modern-day abattoirs in the United States, especially, are modelled after the designs of Dr Temple Grandin. Dr Grandin's study of animal psychology combined with her fascination of patterns and flow led to the design of what many consider a less-stressful mode of slaughtering for the animal. This design incorporates many sweeping curves in the path from holding pen to abattoir. This design keeps the animal (generally cattle) focused on the back end of the animal in front of them instead of what lies ahead. The many curves in the path prevent the animal to see far enough ahead of themselves to become panicked.
There are many regulations that limit how and which animals may be slaughtered. Abattoirs in various nations abide by their own sets of laws. In a few cases, such as Hindu and Jewish cultures, the laws are bound by not only culture, but also by religion. For example, the process of slaughter includes a stunning process. In cattle, this is done with an electric shock to the back of the skull, rendering the animal incapacitated. In swine abattoirs, however, the plant may use either the stunning method or gas the animal with CO2 to knock out the animal. In the US, this is in accordance with the Humane Slaughter Act of 1958. In the Jewish culture, however, it is unlawful by Jewish law to allow an animal to be unconscious while it perishes. Therefore, there are strict guidelines that follow the kosher practice of slaughter, especially in the United States, where this method is otherwise illegal. In Hindu cultures, such as India, cows are considered sacred and therefore, the slaughter of such animal is unlawful. In Nepal, the slaughter of cattle and the importation of beef product are prohibited. Additional laws which follow cultural needs include the law in the United States that horses may not be slaughtered for human consumption. However, the meat may be sent to Europe and Japan of such purposes and may also be used in the US pet food market. This follows the cultural practice of many citizens keeping horses as pets. The same follows for dogs. It is prohibited to slaughter dogs in many countries, while in others it is completely accepted.
What Happens To The Rest?
As 45 to 50 % of all products that leaves an abattoir are for human consumption, one may ask where the other half of the slaughtered animal goes. About 40% of the post animal by-product is used in industry for adhesives, soaps, and leathers. Additionally, lard is often sent out to be rendered and can also be used for bio fuels. Abattoirs make the slaughtering process quick, efficient, and cost-effective by the use of machinery. Abattoirs account for most of the meat processed for human consumption, as the butcher is a trade that is held onto more for nostalgia than for productivity.