The sow at weaning is removed from a comfortable warm farrowing house at around 20ºC (68ºF) into what is probably one of the coldest parts of the dry sow house because there is such a low density of pigs. The environment should be controlled at an ambient temperature of 20ºC(68ºF) from weaning to 21 days post mating and depending on the external temperature this may involve the provision of heat or some form of evaporative cooling. This helps to maintain an anabolic (positive) energy status and provide a level of comfort necessary to achieve good reproductive performance.