Since the 1960’s there have been significant changes in swine housing and management to improve production related to restrictions on animal movement, social interactions, thermal comfort, and welfare (Esmay, 1969; Pinheiro et al., 2002; Tolon, 2002). Current knowledge states that appropriate housing should meet the physiological needs of sows (Rapp et al., 1988; Turner et al., 1998; Bridges et al., 1998; Nääs, 2000). High temperatures affect swine performance, which can be evaluated by physiological response (Curtis, 1983; Perdomo, 1994; Banhazi et al., 2000). When subjected to heat stress sows tend to decrease productivity by reducing feed consumption; reduce reproductive efficiency (Love, 1978; Love, 1981); deliver less piglets (Domínguez, et. al., 1996), and present low performance of piglets at weaning (Mount, 1974; Quiniou & Noblet, 1999; Sousa, 2002; Tolon, 2002; Brown-Brandl & Eigenberg, 2000). Adult sows are more resistant to cold than to excessive heat exposure, benefiting from the use cooling acclimatization in housings (Curtis, 1983; Nääs, 2000; Barbari & Guerri,
2005). Environmental control alleviates heat stress improving productive responses (Müller, 1982; Bortolozzo et al., 1997; Hannas, 1999). Reduction of the heat load can be achieved by properly designed ventilation and cooling systems, in both gestating and nursing housing (Bull et al., 1997; Gates et al., 1991a). Room evaporative cooling and head ventilation systems help reducing the negative effects of high temperatures in farrowing rooms (Dong et al., 2001; Barbari & Guerri, 2005). Misting systems are lower in efficiency when compared to conventional pad systems (Roller & Goldman, 1969; Bottcher et al., 1991) but the equipment noise may cause animal agitation (Barbari & Guerri, 2005). Thermal index evaluation in swine confinement has been used to identify regions suitable for a particular housing design (Turner et al., 1998). This study evaluated the use of distinct environmental cooling equipments on sow performance, both on the gestation and on nursing in open sided housing. Two treatments were tested in the gestation building: natural ventilation and mechanical ventilation associated to fogging; while in the nursing rooms three treatments were tested: natural ventilation; mechanical ventilation; and evaporative cooling with forced ventilation. Sows were randomly chosen from the same genetic lot form six combined treatments. The evaporative cooling system in the farrowing room differed for piglet performances, at birth (4% higher) and on daily weight gain (15% higher), and also for sow physiological response improving the respiratory rate (8%) and back fat thickness (3%), without influencing skin temperature. The use of evaporative cooling directed to the sow head during nursing improved the physiological and productive results.