In order to get the basic information on evaluating and controlling the thermal environment in open-type livestock barns under hot weather based on physiological reponses of animals, the authors measured dynamic physiological responses (repiration rate, rectal temperature and pulse rates) of seven fattening pigs (38.0 to 50.5 kg weight) to hot enviromnent.
    Dynamic characteristics of physiological responses when pigs were exposed to air temperatures of 30 and 35 centigrade with 40, 60 and 80 % humidities were revealed by the present measurement (Table 2 and 3, and Figs. 1 to 3). And dynamic responses when they were exposed to long wave-length radiant heat of about 550 and 850 kcal/m²h at 20 and 30 centigrade with 60 % humidity were presented (Figs. 5 to 8).