Racewicz Przemysław, Sickinger Marlene, Włodarek Jan, Jaśkowski Jędrzej M
Dr. Przemysław Racewicz, Poznań University of Life Sciences, Institute of Veterinary Sciences, ul. Wołyńska 35, 60-637 Poznań, Poland, Email:
Tierarztl Prax Ausg G Grosstiere Nutztiere. 2016 Jun 16;44(3):151-6. doi: 10.15653/TPG-150816. Epub 2016 Apr 19.
To evaluate the efficiency of different ultrasound devices in achieving an early diagnosis of pregnancy in dairy herds.
A total of 1976 Holstein Friesian cows and heifers were artificially inseminated (AI) according to the herd manager's regime. Pregnancy diagnostics were performed between day 26 and 35 after AI using six different types of ultrasound systems (linear vs. sector scanners). Manual rectal palpation between day 45 and 60 after AI was used as the gold standard for pregnancy diagnostics. Sensitivity (SENS), specificity (SPEC), positive (PPV) and negative predictive value (NPV) and diagnostic accuracy (ACC) of the diagnostic measures were determined.
Average SENS was 82% (range 67.7-95.2%) with a mean SPEC of 73% (range 50.0-81.0%). ACC was 78.2% with a minimum of 64.6% and a maximum of 89.4%, depending on the ultrasound system. The PPV (ratio of the number of pregnant cows with a positive examination result to the number of cows actually pregnant) was 80.8% (range 59.1-88.1%), whereas the NPV (defined as the ratio of the number of cows correctly diagnosed negative to the number of cows actually open) was 74.4% (72.3-91.9%). Significant differences for these parameters were found depending on the ultrasound system used (p ≤ 0.01; Cramer's V. = 0.14).
Regardless of the ultrasound device used, early pregnancy diagnostics between day 26 and 35 show a moderate diagnostic efficiency. Comparing the accuracy of the different devices, there may be a significant influence of type and technical parameters. Even though ultrasound systems with mechanical sector probes are not as convenient to use as systems with linear probes, according to this study, sector scanners are a reasonable alternative.
评估不同超声设备对奶牛群早期妊娠诊断的效率。
根据牛群管理者的方案，对1976头荷斯坦弗里生奶牛和小母牛进行人工授精（AI）。在人工授精后第26至35天，使用六种不同类型的超声系统（线阵扫描仪与扇扫扫描仪）进行妊娠诊断。人工授精后第45至60天进行的直肠触诊被用作妊娠诊断的金标准。确定诊断措施的敏感性（SENS）、特异性（SPEC）、阳性预测值（PPV）和阴性预测值（NPV）以及诊断准确性（ACC）。
平均敏感性为82%（范围67.7 - 95.2%），平均特异性为73%（范围50.0 - 81.0%）。根据超声系统的不同，诊断准确性为78.2%，最低为64.6%，最高为89.4%。阳性预测值（检查结果为阳性的妊娠母牛数量与实际妊娠母牛数量之比）为80.8%（范围59.1 - 88.1%），而阴性预测值（定义为正确诊断为未妊娠的母牛数量与实际未妊娠的母牛数量之比）为74.4%（72.3 - 91.9%）。根据所使用的超声系统不同，这些参数存在显著差异（p≤0.01；克莱默V系数 = 0.14）。
无论使用何种超声设备，在第26至35天进行的早期妊娠诊断显示出中等诊断效率。比较不同设备的准确性，类型和技术参数可能有显著影响。尽管带有机械扇扫探头的超声系统不如带有线阵探头的系统使用方便，但根据本研究，扇扫扫描仪是一种合理的替代选择。
