In present study the transtracheal aspiration technique using a commercial polypropylene 5 fr. urinary catheter with 13-gauge 2.5 inch hypodermic needle was applied to bovine medicine in order to determine the availability of this procedure for diagnosis of lower respiratory tract disease. The subjects were forty adult cattle which consisted of thirty-one cows with respiratory signs such as cough and nasal discharge and nine cows without these signs. This procedure appeared suitable for collecting specimens of the lower respiratory tract secretions without uncontamination by the flora of the mouth, respiratory distress and any complications. The most of microorganisms isolated was Pasteurella multocida (48.7 %) and a mucopurulent inflammatory response was the most appeared accounting for 40 % of cytological basis. Most cows with severe clinical signs showed a mucopurulent inflammation (60 %) and Pasteurella multocida were isolated dominantly in severe cases (63.2 %). Cows with mild clinical signs were distributed in each of the five cytological classification and Pasteurella multocida was the most isolated accounting for 40 % of mild cases. In the cytologic examination, a few neutrophils and epithelial cells were seen in the fluid of mucoid inflammation, and many neutrophils with epithelial cells and thick mucoid exudate were seen in the fluid of mucopurulent inflammation. Various number of neutrophils, lymphocytes, macrophages and epithlial cells were examined in the fluid of mixed cell inflammation. The columnar ciliated epithelial cells were examined mainly in normal aspirates. From these results the transtracheal aspiration technique as a diagnostic aid for lower respiratory tract disease of cow is considered as a simple, safe and useful method and can be performed in the field situation

The frequency of appearance of HI antibody against Japanese encephalitis virus was investigated over the three-year period 1982 through 1984. The sample population consisted of 1306 cattle in Saitama prefecture (located in central Japan), and 536 cattle in Kagoshima prefecture (located in southern Japan). During the study period, there was no significant difference in the average antibody-positive rate between cattle in Kagoshima (68.8 %) and those in Saitama (65.5 %). Variations in the monthly antibody-positive rate and mean monthly antibody titer in the Saitama cattle followed a mountain-like pattern with the peak observed during summer. In the Kagoshima cattle, both parameters also increased in summer and these increases persisted even in winter. The distribution of antibody-positive rate as a function of age ranged from 64.0 % to 82.8 % in Saitama, though no correlation was observed between these two factors. In the Kagoshima cattle, however, the antibody-positive rate increased with age as follows; the values averaged 29.4 % in the one-year-old cattle group, 50.0 % in the two-year-old group, 47.4 % in the three-year-old group and 74.5 % in the four-year-old group. There was no significant correlation between the mean antibody titer and age in either Saitama cattle (15.3-22.5) or Kagoshima cattle (20.0-32.3)