Behavioural changes related to air temperature in sows kept in different housing conditions

The behaviour of pigs greatly changes in hot conditions. The pig takes the position of lateral decubitus, giving the maximum body surface to the air and to the floor contact. It tries to find isolated positions, far from other animals in the pen, and possibly in areas with air streams. Furthermore, the pig reduces the feed ingestion but drinks high amounts of water. When possible it uses the drinker as a “shower” and lies on the floor wetted with water or dung. Particularly the latter behaviours are of great importance in reducing the heat stress in adult pigs, if housed in pens with solid floors. On the other hand they involve a considerable worsening of hygienic conditions of the pen, an increase of ammonia emissions and a rise of air humidity. The study aims to contribute to definition of temperature values, which can cause changes in the behavioural patterns of the sows. The individuation of thermal levels connected to behavioural changes can be useful to set the working parameters of cooling systems in pig houses.