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Intensive pig farming is a subset of pig farming and of Industrial animal agriculture, all of which are types of animal husbandry, in which domestic pigs are raised up to slaughter weight. These operations are known as AFO or CAFO in the U.S. In this system of pig production, grower pigs are housed indoors in group-housing or straw-lined sheds, whilst pregnant sows are housed in sow stalls (gestation crates) or pens and give birth in farrowing crates. The use of sow stalls for pregnant sows has resulted in lower birth production costs; however, this practice has led to more significant animal welfare concerns. Many of the world’s largest producers of pigs (US, Canada, Denmark, Mexico) use sow stalls, but some nations (e.g., the UK) and some US states (e.g., Florida, Arizona, and California) have banned their use. The European Union has banned the use of gestation crates after the 4th week of pregnancy. ==Intensive piggeries== Intensive piggeries are generally large warehouse-like buildings or barns. Indoor pig systems allow the pigs' conditions to be monitored, ensuring minimum fatalities and increased productivity. Buildings are ventilated and their temperature regulated. Most domestic pig varieties are susceptible to sunburn and heat stress, and all pigs lack sweat glands and cannot cool themselves. Pigs have a limited tolerance to high temperatures and heat stress can lead to death. Maintaining a more specific temperature within the pig-tolerance range also maximizes growth and growth-to-feed ratio. Indoor piggeries have allowed pig farming to be undertaken in countries or areas with unsuitable climate or soil for outdoor pig raising (e.g., Australia).〔(Australian pork page on Pig welfare )〕 In an intensive operation, pigs will no longer need access to a wallow (mud), which is their natural cooling mechanism. Intensive piggeries control temperature through ventilation or drip water systems (dropping water to cool the system). Pigs are naturally omnivorous and are generally fed a combination of grains and protein sources (soybeans, or meat and bone meal). Larger intensive pig farms may be surrounded by farmland where feed-grain crops are grown. Consequently, piggeries are reliant on the grains industry. Pig feed may be bought packaged, in bulk or mixed on-site. The intensive piggery system, where pigs are confined in individual stalls, allows each pig to be allotted a portion of feed. The individual feeding system also facilitates individual medication of pigs through feed. This has more significance to intensive farming methods, as the proximity to other animals enables diseases to spread more rapidly. To prevent disease spreading and encourage growth, drug programs such as vitamins and antibiotics are administered preemptively. Indoor systems, especially stalls and pens (i.e., ‘dry,’ not straw-lined systems) allow for the easy collection of waste. In an indoor intensive pig farm, manure can be managed through a lagoon system or other waste-management system. However, waste smell remains a problem which is difficult to manage. Pigs in the wild or on open farmland are naturally clean animals. The way animals are housed in intensive systems varies. Breeding sows will spend the bulk of their time in sow stalls (also called gestation crates) during pregnancy. The use of stalls may be preferred as they facilitate feed management and growth control and prevent pig aggression (e.g., tail biting, ear biting, vulva biting, food stealing). Sows are moved to farrowing crates, with litter, from before farrowing until weaning, to ease management of farrowing and reduce piglet loss from sows lying on them. Dry or open time for sows can be spent in indoor pens or outdoor pens or pastures. Houses should be clean and well ventilated but draught-free. Piglets can be subjected to castration, tail docking to reduce tail biting, teeth clipping (to reduce injuring their mother's nipples), and earmarking and tattooing for litter identification. Treatments are usually made without pain killers. Weak runts may be slain shortly after birth. Injections with a high availability iron solution often are given, as sow's milk is low in iron. The docking due to tail biting is a common practice in intensive rearing facilities as animals in that environment are more prone to increased levels of aggression and instability.〔EFSA. Scientific Opinion of the Panel on Animal Health and Welfare (Question No EFSA-Q-2006-013) Adopted on 06 December 2007 (The risks associated with tail biting in pigs and possible means to reduce the need for tail docking considering the different housing and husbandry systems )〕 Piglets are weaned and removed from the sows at between two and five weeks old〔(Revisiting weaning age )〕 and placed in sheds, nursery barns or directly to growout barns. Grower pigs – which comprise the bulk of the herd – are usually housed in alternative indoor housing, such as batch pens. Group pens generally require higher stockmanship skills. Such pens will usually not contain straw or other material. Alternatively, a straw-lined shed may house a larger group (i.e., not batched) in age groups. Larger swine operations use slotted floors for waste removal, and deliver bulk feed into feeders in each pen; feed is available ad libitum. Many countries have introduced laws to regulate treatment of farmed animals. In the US, the federal Humane Slaughter Act〔(US Federal Humane Slaughter Act )〕 requires pigs to be stunned before slaughter, although compliance and enforcement is questioned. There is concern from animal liberation/welfare groups that the laws have not resulted in a prevention of animal suffering and that there are "repeated violations of the Humane Slaughter Act at dozens of slaughterhouses".〔(Animal Welfare Institute Quarterly – Humane Slaughter Act Resolution Introduced )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Intensive pig farming」の詳細全文を読む スポンサード リンク
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