[Evaluation of the postoperative "state of health" using the example of the body core temperature rhythms of sheep].

A postoperative (p.op.) estimation of "healthiness"--especially an estimation of duration of possible existing changes, caused by surgical treatment--is important not only for the ongoing of the healing up process. A re-activation of treated farm or laboratory animals which is set up too early might produce reduction of efficiency or falsification of experimental results. Investigations on p.op. de-synchronisation have proved that "healthiness" means--besides the absence of clinical symptoms--also stable relations among the circadian rhythms. As the ultradian rhythms (wavelength less than 24 h) which exist beside the circadian ones depend on endogenic and exogenic factors much more than the circadian rhythms do, the aim of this study was to investigate strength and especially duration of changes p.op. in using core temperature rhythms of sheep as example, by setting great value on investigating ultradian rhythms. The core temperatures of 5 Merino-mixed sheep were permanently measured for 4 weeks p.op. by special radiotelemetric equipment, under controlled circumstances. All recorded data have been expertised "macroscopically" and Fourier-analysis was employed for judging phase shift and intensity of existing rhythms. Though no signs for systemic disturbances could be found and the recorded temperature always was in between the physiological range, important shifts of phases and variations in intensities in the ultradian scope as well as in the circadian one occurred. The "normal" or final phase relations and the constant daily pattern of intensities in sheep were reached 16 days p.op. earliest.