White Brad J, Anderson David E, Renter David G, Larson Robert L, Mosier Derek A, Kelly Lindsey L, Theurer Miles E, Robért Brad D, Walz Michelle L
Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66502, USA.
Am J Vet Res. 2012 Apr;73(4):490-7. doi: 10.2460/ajvr.73.4.490.
To characterize clinical and behavioral changes in calves following inoculation with Mycoplasma bovis and evaluate relationships between those changes and pulmonary disease.
22 healthy Holstein steers.
20 calves were inoculated intranasally with < 10(8) CFU or > 10(9) CFU of M bovis. Calves were assigned a clinical illness score (CIS) on a scale of 1 through 4 twice daily on the basis of severity of cough, labored breathing, and lethargy. For each calf, distance traveled and time spent near the waterer, feed bunk, or shelter were determined via a remote location monitoring device. Calves were euthanized and necropsied 22 days after inoculation.
13 calves became clinically ill after challenge inoculation; 3 calves were euthanized within 20 days. Among all calves, consolidation was evident in 0% to 79.9% of the lungs; extent of lung consolidation did not differ between the challenge dose groups. Distance traveled and percentages of time spent in proximity to the feed bunk and shelter were associated with CIS; calves with more severe disease traveled less distance and spent less time at the feed bunk and more time in the shelter. Distance traveled by calves was negatively associated with extent of lung consolidation (< or ≥ 10% of lungs affected); this effect was modified by trial day.
Following inoculation with M bovis, calf behavior patterns were associated with both CIS and severity of pulmonary disease. Use of behavior monitoring systems may aid in recognition of respiratory tract disease in calves.
描述接种牛支原体后犊牛的临床和行为变化，并评估这些变化与肺部疾病之间的关系。
22头健康的荷斯坦公牛。
20头犊牛经鼻接种低于10⁸CFU或高于10⁹CFU的牛支原体。根据咳嗽、呼吸困难和嗜睡的严重程度，每天两次为犊牛评定1至4级的临床疾病评分（CIS）。对于每头犊牛，通过远程监测设备确定其行走距离以及在饮水器、饲料槽或庇护所附近停留的时间。接种22天后对犊牛实施安乐死并进行尸检。
13头犊牛在接种激发后出现临床疾病；3头犊牛在20天内被安乐死。在所有犊牛中，肺部实变率为0%至79.9%；激发剂量组之间的肺实变程度无差异。行走距离以及在饲料槽和庇护所附近停留的时间百分比与CIS相关；疾病较严重的犊牛行走距离较短，在饲料槽停留的时间较少，而在庇护所停留的时间较多。犊牛的行走距离与肺实变程度（肺部受累<或≥10%）呈负相关；这种影响因试验天数而异。
接种牛支原体后，犊牛的行为模式与CIS和肺部疾病严重程度均相关。使用行为监测系统可能有助于识别犊牛的呼吸道疾病。
