pig

Any even-toed hoofed mammal of the family Suidae. They are omnivorous, and have simple, non-ruminating stomachs and thick hides. The Middle Eastern wild boar Sus scrofa is the ancestor of domesticated breeds; it is 1.5 m/4.5 ft long and 1 m/3 ft high, with formidable tusks, but not naturally aggressive. The smallest member of the pig family is the pygmy hog Sus salvanus. Males are 65 cm long (25 cm at the shoulder) and weigh 8–9 kg.

Wild pigs include the babirusa and the wart hog. The farming of domesticated pigs was practised during the Neolithic period in the Middle East and China at least 11,000 years ago and the pig was a common farm animal in ancient Greece and Rome. Over 400 breeds evolved over the centuries, many of which have all but disappeared in more recent times with the development of intensive rearing systems; however, different environments and requirements have ensured the continuation of a variety of types. The Berkshire, Chester White, Poland, China, Saddleback, Yorkshire, Duroc, and Razorback are the main surviving breeds. Modern indoor rearing methods favour the large white breeds, such as the Chester White and the originally Swedish Landrace, over coloured varieties, which tend to be hardier and can survive better outdoors. Since 1960, hybrid pigs, produced by crossing two or more breeds, have become popular for their heavy but lean carcasses.