Guimarães C R B, Oliveira M E, Rossi J R, Fernandes C A C, Viana J H M, Palhao M P
Department of Animal Science, José do Rosário Vellano University (Unifenas), Alfenas, Minas Gerais, Brazil.
Department of Veterinary Medicine, José do Rosário Vellano University (Unifenas), Alfenas, Minas Gerais, Brazil.
Theriogenology. 2015 Jul 15;84(2):237-41. doi: 10.1016/j.theriogenology.2015.03.005. Epub 2015 Mar 18.
The aim of the present study was to use blood flow evaluation of the CL at 14 days after embryo transfer to detect nonpregnant animals and optimize the management of bovine recipients. The estrous cycle was synchronized in 165 recipients, and the day of expected ovulation was considered to be Day 0. Embryo transfer was performed 7 days later, on Day 7. On Day 21, pregnancy was diagnosed on the basis of blood flow evaluation of the CL (DG21-predictive diagnostic). To validate this methodology, visual scores for blood flow were compared to objective data extracted from CL ultrasound images recorded in the Doppler mode. The size was also evaluated using recorded images of the CL in the B mode. Blood samples were also collected for further analysis of the progesterone (P4) concentration. The diagnosis of pregnancy was confirmed at 35 days after estrus (DG35-definitive diagnostic). The DG21 showed that 55.2% (90 of 163) of the animals were presumptively pregnant, and this value was higher (P < 0.04) than that obtained at DG35 (43.6%, 71 of 163). The predictive diagnostic achieved moderate specificity (79.3%) for the detection of pregnancy, but most importantly, high sensitivity (100%) for the detection of nonpregnant recipients. The overall accuracy of the diagnosis was 88.3%. The P4 concentrations were different (P < 0.02) and correlated with each visual score assigned for the CL size. Visual scores for CL blood flow were also efficient (P < 0.0001) to distinguish animals with different levels of P4; however, P4 concentrations were higher for scores 1 and 2 (high and regular blood flow, respectively) than those for score 3 (low blood flow). This technique showed high sensitivity and facilitated the early detection of nonpregnant animals. The DG21 would allow about 79.3% of nonpregnant animals to be resynchronized 9 to 14 days earlier, when compared to conventional management based on pregnancy diagnosis at Days 30 to 35.
本研究的目的是利用胚胎移植后14天黄体（CL）的血流评估来检测未怀孕动物，并优化牛受体的管理。165头受体的发情周期被同步化，预计排卵日被视为第0天。7天后，即第7天进行胚胎移植。在第21天，根据黄体的血流评估进行妊娠诊断（DG21 - 预测性诊断）。为验证该方法，将血流的视觉评分与从多普勒模式记录的黄体超声图像中提取的客观数据进行比较。还使用B模式下黄体的记录图像评估其大小。同时采集血样以进一步分析孕酮（P4）浓度。在发情后35天确认妊娠诊断（DG35 - 确定性诊断）。DG21显示，55.2%（163头中的90头）的动物被推测为怀孕，该值高于DG35时获得的值（43.6%，163头中的71头）（P < 0.04）。预测性诊断在检测妊娠方面具有中等特异性（79.3%），但最重要的是，在检测未怀孕受体方面具有高敏感性（100%）。诊断的总体准确率为88.3%。P4浓度不同（P < 0.02），且与为黄体大小分配的每个视觉评分相关。黄体血流的视觉评分在区分不同P4水平的动物方面也很有效（P < 0.0001）；然而，评分1和2（分别为高血流和规则血流）时的P4浓度高于评分3（低血流）时的P4浓度。该技术显示出高敏感性，并有助于早期检测未怀孕动物。与基于第30至35天妊娠诊断的传统管理相比，DG21可使约79.3%的未怀孕动物提前9至14天重新同步发情周期。
