Centro de Parasitologia Veterinária, Escola de Veterinária E Zootecnia, Universidade Federal de Goiás, Goiânia, Goiás, Brazil.
Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Vet Res Commun. 2022 Sep;46(3):879-902. doi: 10.1007/s11259-022-09915-6. Epub 2022 Apr 1.
Data regarding parasitemia (blood smears), rectal temperature (RT), packed cell volume (PCV) and vaginal mucosa coloration (VMC) of Gyr x Holstein female calves between 3-7mo were accessed to evaluate different techniques for monitoring the bovine tick fever agents (TFA). The 1 experiment determined the correlation between the TFA parasitemia with RT and PCV. The 2, evaluated the associated risk of A. marginale parasitemia with RT and PCV in relation to the / genetic proportion (/,/,/ and /) using Receiver Operating Characteristic Curve (ROC). The 3, two groups were performed: cattle monitored by RT (T01) and by PCV (T02), during their 80-210 days of age, data regarding TFA parasitemia, RT, PCV, VMC and weight were registered. In 1st experiment, RT showed weak correlation with TFA parasitemia, while PCV showed a strong correlation with A. marginale and B. bigemina, but not with B. bovis parasitemia. In experiment 2, the ROC curve analysis showed that when the genetic proportion of B. t. taurus increased, least reliable RT was to monitor calves infected with A. marginale. The PCV for monitoring A. marginale was the best technique, showing sensitivity of 74.2% and specificity of 97.0% than other techniques that used RT and VCM as a monitoring tool. In general, calves monitored by PCV (T02) showed higher PCV values, lower A. marginale parasitemia, less pneumonia as co-infection and less salvation treatment were performed than in animals monitored by RT (T01). Furthermore, animals from T02 gained 23.5 kg more than those from T01. The low frequency of B. bovis and B. bigemina found in this study made impossible to compare the monitoring techniques for these pathogenic agents.
本研究旨在评估不同技术监测牛泰勒虫病（TFA）的效果，收集了 3-7 月龄 Gyr x Holstein 雌性犊牛的寄生血症（血涂片）、直肠温度（RT）、红细胞压积（PCV）和阴道黏膜颜色（VMC）数据。实验 1 确定了 TFA 寄生血症与 RT 和 PCV 的相关性。实验 2 评估了 A. marginale 寄生血症与 RT 和 PCV 相关的风险与遗传比例（/，/，/和/）之间的关系，并采用接收者操作特征曲线（ROC）进行分析。实验 3 将两组牛进行比较：一组通过 RT（T01）监测，一组通过 PCV（T02）监测，监测时间为 80-210 日龄，记录 TFA 寄生血症、RT、PCV、VMC 和体重数据。在实验 1 中，RT 与 TFA 寄生血症呈弱相关，而 PCV 与 A. marginale 和 B. bigemina 呈强相关，但与 B. bovis 寄生血症无关。在实验 2 中，ROC 曲线分析表明，当 B. t. taurus 的遗传比例增加时，RT 监测 A. marginale 感染牛的可靠性最低。PCV 是监测 A. marginale 的最佳技术，其敏感性为 74.2%，特异性为 97.0%，优于 RT 和 VCM 作为监测工具的其他技术。一般来说，通过 PCV（T02）监测的犊牛的 PCV 值更高，A. marginale 寄生血症更低，肺炎等混合感染更少，救治治疗更少，且增重比通过 RT（T01）监测的动物更多。此外，T02 组动物比 T01 组动物增重 23.5kg。本研究中发现的低频率 B. bovis 和 B. bigemina 使得无法比较这些病原体的监测技术。
