Open main menu Search Edit Watch this page Read in another language Pigs are amenable to many different styles of farming. Intensive commercial units , commercial free range enterprises, extensive farming - being allowed to wander around a village, town or city, or tethered in a simple shelter or kept in a pen outside the owners house. Historically pigs were kept in small numbers and were closely associated with the residence of the owner, or in the same village or town. [1] They were valued as a source of meat, fat and for the ability to turn inedible food into meat, and often fed household food waste if kept on a homestead. Pigs have been farmed to dispose of municipal garbage on a large scale. [2] All these forms of pig farm are in use today. In developed nations, commercial farms house thousands of pigs in climate-controlled buildings. [3] Pigs are a popular form of livestock , with more than one billion pigs butchered each year worldwide,