A slaughterhouse or abattoir is a facility where animals are processed for consumption as food products. Approximately 45-50% of the animal can be turned into edible products (meat). About 15% are waste, and the remaining 40-45% of the animal are turned into byproducts such as leather, soaps, candles (tallow), and adhesives. In the United States, around nine billion animals are slaughtered every year (this includes about 150.4 million cattle, bison, sheep, hogs, and goats and 8.9 billion chickens, turkeys, and ducks) in 5,700 slaughterhouses and processing plants employing 527,000 workers; in 2007, 28.1 billion pounds of beef were consumed in the U.S. alone. In Canada, 650 million animals are killed annually. In the European Union, the annual figure is 300 million cattle, sheep, and pigs, and four billion chickens.

Workers and cattle in a slaughterhouse.