MEASUREMENTS AND SPECTRAL-ANALYSIS OF TYMPANIC TEMPERATURE REGULATIONIN SWINE

Thermoregulation in farm animals is directly related to performance, e fficiency, health, and well being. Tympanic temperature serves as a me asure of thermoregulatory responses to environmental conditions. Tympa nic temperature was measured as a basis for characterizing thermoregul atory responses of swine. Fourier spectral analysis and short-time Fou rier transforms (STFT) were applied to the tympanic time series record and used to determine sampling rate guidelines and to evaluate thermo regulatory responses of ad-libitum-fed, growing swine subjected to alt ernating constant temperatures from 21 degrees to 30 degrees C thermal environments. Analysis of data from three swine suggests sampling rat es of 1 sample every 8 to IO min, although a faster rate of one sample every 2 to 3 min was recommended to allow for digital filtering. STFT analysis indicated that even in constant environmental temperatures, the amplitude of the diurnal tympanic temperature cycle increased unde r elevated ambient temperature. The amplitude of all tympanic temperat ure cycles also increased following transitions between different ambi ent temperature conditions.