Intensive pig farming, also known as pig factory farming, is the primary method of pig production, in which grower pigs are housed indoors in group-housing or straw-lined sheds, whilst pregnant sows are housed in gestation crates or pens and give birth in farrowing crates.

The use of gestation crates for pregnant sows has lowered birth production costs; Gestation crates or individual stalls are used as a way to nurture the animals and protect them first during pregnancy. Because the animals are vulnerable during this time, with some sows more aggressive than others, the practice of separating the animals in crates keeps them from fighting and injuring each other. In addition, the case has also been made that crates make it easier for hog farmers to monitor individual sow health and administer vaccines as needed. Many of the world's largest producers of pigs (US, China, and Mexico) use gestation crates. The European Union has banned the use of gestation crates after the fourth week of pregnancy. Intensive pig farmers often cut off tails, testes or teeth of pigs without anaesthetic. Although combined use of an anesthetic and analgesic appears to be the most effective method for controlling pain associated with surgical castration, regulatory requirements and cost remain obstacles to practical application. Use of pharmaceuticals can burden producers with direct and indirect costs; the latter are associated with time delays and a potential need for additional veterinary assistance. Extra-label use of anesthetics and analgesics, while an option, is not ideal. Knowledge of effectiveness is not as great as it is for drugs approved for particular species and purposes. Extra-label use can also discourage research and development necessary to approve drugs for specific purposes.

The environmental impacts of pig farming include problems posed to drinking water and algal bloom events.