High Quality Content by WIKIPEDIA articles! Intensive piggeries are a type of factory farm specialized in the raising of domestic pigs up to slaughter weight. In this system of pig production, grower pigs are housed indoors in group-housing or straw-lined sheds, whilst pregnant sows are confined in sow stalls and give birth in farrowing crates. Pigs are kept in large stalls with large numbers of pigs per square metre. The temperature is raised which allows the pig to spend less energy on keeping its body heat at the right temperature so it gets fat quicker enabling the process to be much more efficient. 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 use sow stalls, but some nations and some U.S. states have banned them.