Monofrequency oscillation technique in healthy and pneumonic calves younger than 2 months--physiological values and...

Using the monofrequency oscillation technique, the oscillatory measured resistance of the respiratory system (Ros) was determined in healthy and pneumonic calves younger than 2 months. Using a face mask, measurements were done in unsedated animals directly in the calfhouse. 106 clinically healthy calves were examined to determine the physiological range of Ros. Calves suffering from pneumonia showed significantly higher values of Ros which were positively correlated with the severity of pneumonic lesions as established by pathological investigations. In healthy calves, the variability of Ros due to biological aspects was found to be much higher than methodologically caused variability. It is concluded that the monofrequency oscillation technique is useful especially in individual investigations, e.g. control of therapy.