Pigs have featured in human culture since Neolithic times, appearing in art and literature for children and adults, and celebrated in cities such as Bologna for their meat products.

The pig has a large head, with a long snout strengthened by a special prenasal bone and a disk of cartilage at the tip.

Exceptionally, a pig called Big Bill weighed 1,157 kg (2,551 lb) and had a shoulder height of 1.5 m (4 ft 11 in).

Mongooses, honey badgers, hedgehogs, and pigs all have different modifications to the receptor pocket which prevents α-neurotoxin from binding.

[10] Pigs have small lungs for their body size, and are thus more susceptible than other domesticated animals to fatal bronchitis and pneumonia.

Over the next 3,000 years they interbred with European wild boar until their genome showed less than 5% Near Eastern ancestry, yet retained their domesticated features.

More recently there have been complex exchanges, with European domesticated lines being exported, in turn, to the ancient Near East.

[25] Among the animals that the Spanish introduced to the Chiloé Archipelago in the 16th century Columbian Exchange, pigs were the most successful in adapting to local conditions.

[46] The mother's body recognises that it is pregnant on days 11 to 12 of pregnancy, and is marked by the corpus luteum's producing the sex hormone progesterone.

Sows root in the ground to create depressions the size of their body, and then build nest mounds, using twigs and leaves, softer in the middle, in which to give birth.

[54] The sow separates from the group and seeks a suitable nest site with well-drained soil and shelter from rain and wind.

[55] The onset of nest-building is triggered by a rise in prolactin level, caused by a decrease in progesterone and an increase in prostaglandin; the gathering of nest material seems to be regulated more by external stimuli such as temperature.

Sensory inputs (vocalisation, odours from mammary and birth fluids, and hair patterns of the sow) are particularly important immediately post-birth to facilitate teat location by the piglets.

[9] Most bristled pigs "blow their coat", meaning that they shed most of the longer, coarser stiff hair once a year, usually in spring or early summer, to prepare for the warmer months ahead.

[65] Where pigs are allowed to roam freely, they walk roughly 4 km daily, scavenging within a home range of around a hectare.

It first happens when piglets are born to obtain their mother's milk, and can become a habitual, obsessive behaviour, most prominent in animals weaned too early.

Transmission can be prevented by thorough sanitation on the farm; by meat inspection and careful commercial processing; and by thorough cooking, or alternatively by sufficient freezing and curing.

[85][86] Like all animals, pigs are susceptible to adverse impacts from climate change, such as heat stress from increased annual temperatures and more intense heatwaves.

[87] Around 600 breeds of pig have been created by farmers around the world, mainly in Europe and Asia, differing in coloration, shape, and size.

[89] The smallest known pig breed in the world is the Göttingen minipig, typically weighing about 26 kilograms (57 lb) as a healthy, full-grown adult.

[91] Male and female swine that have not been de-sexed may express unwanted aggressive behavior, and are prone to developing serious health issues.

[112] As with the other forms of meat, producing pork is more energy-intensive than plant-based foods, and it is associated with more greenhouse gas emissions per calorie.

[115] Intensive pig production is also associated with water pollution concerns, as the swine waste is often stored above ground in so-called lagoons.

These lagoons typically have high levels of nitrogen and phosphorus, and can contain toxic heavy metals like zinc and copper, microbial pathogens, or hold elevated concentrations of pharmaceuticals from subtherapeutic antibiotic use in swine.

[117] However, lagoon spills, such as from heavy rains in the wake of a hurricane, can lead to fish kills and algal blooms in local rivers.

[116] Intensive pig production involves practices such as castration, earmarking, tattooing for litter identification, tail docking, which are often done without the use of anesthetic.

[119] [120] Painful teeth clipping of piglets is also done to curtail cannibalism, behavioural instability and aggression, and tail biting, which are induced by the cramped environment.

[123] Pigs often begin life in a farrowing or gestation crate, which is a small pen with a central cage, designed to allow the piglets to feed from their mother while preventing her from attacking or crushing them.

[127][128] Of the piglets born alive, 10% to 18% will not reach weaning age, instead succumbing to disease, starvation, dehydration, or accidental crushing by their mothers.

[132][133] Pigs, widespread in societies around the world since Neolithic times, have been used for many purposes in art, literature, and other expressions of human culture.