Pigs are normally kept in thermally insulated buildings with forced or natural ventilation. There are large differences in pig housing systems both between and within countries in Europe. Also, different designs are used for different stages of production (sows, weaned piglets from weaning up to 25–30 kg liveweight, growers-finishers or fatteners from 25–30 kg up to 90–160 kg liveweight).
