Wplyw promieniowania podczerwonego [IR] na ksztaltowanie sie parametrow biotermicznych u cielat

Studies were undertaken to determine selected biothermal parameters in calves exposed to IR-irradiation. An increased sensitivity of heated calves to microclimatic factors was found, expressed by a more pronounced influence of air temperature and cooling on the temperature of the calves, skin than that observed in non-heated calves. It was stated that heat emitted by IR radiators and then absorbed by calves brought about an increased heat loss from the skin surface at thermolabile sites in order to attain the organism heat balance and changes in heat loss structure. In heated calves heat losses occurred mainly due to convection (85,6%) and radiation (14,4%), whereas in non-heated animals the proportions were arranged inversely amounting to 64,5% and 35,5% for radiation and convection, respectively. The skin temnperature at thermostabile and thermolabile sites of the heated and non-heated calves increased regularly as they grow older. In non-radiated calves heat losses decreased every day of their lives whereas in heated calves they increased.