The aim of this study was to assess the uterine blood flow (UBF) and corpus luteum blood flow (CLBF) in llamas 8 days post-mating, using color-Doppler ultrasonography (CDU), to determine the possible relationship between vascularization and the presence of an embryo. Adult females (n = 25) were used to monitor ovarian dynamics by palpation and transrectal ultrasonography until detection of a ≥6 mm growing follicle. Females were randomly assigned to one of two groups: Group I (n = 19), were mated and ovulation was induced by a single dose of buserelin (GnRH analog) that same day (Day 0); and Group II (n = 6), only ovulation was induced (control). On Day 8, UBF and CLBF were evaluated transrectally in both groups. The color-flow images obtained were analyzed with Image J1.52a software to determine the vascularization area and the percentage of corpus luteum with blood flow emission (CLBF%) together with the percentage for each uterine horn (UBF%). Statistical analysis was performed using an ANOVA test. In Group I, uterine flushing was performed to obtain the embryos, thus dividing the females into Group I+ (n = 10), when an embryo was recovered and Group I- (n = 9), when no embryo was recovered. Embryo recovery rate was 52.63% (10/19). In Group I+, UBF% was significantly higher compared to Group I- and Group II (P <0.05). UBF appears to be a good predictor for embryo presence, with an area under the curve (AUC) of 0.9 and an optimal cut-off value of 9.37% (with a sensitivity of 90% and specificity of 88.9%). The CLBF% did not differ between groups (P > 0.05). In conclusion, it is possible to detect a local increase of UBF in the presence of an embryo on day 8 post-mating in llamas. This could be useful to achieve an early pregnancy diagnosis or to decide whether to carry out the uterine flushing in a llama embryo transfer program.

这项研究的目的是使用彩色多普勒超声（CDU）评估交配后8天在美洲驼中的子宫血流量（UBF）和黄体血流量（CLBF），以确定血管形成与存在之间的可能关系胚胎 成年女性（ñ= 25）用于通过触诊和经直肠超声检查监测卵巢动力学，直到检测到≥6 mm的生长卵泡。女性被随机分为两组：第一组（ñ= 19），在同一天（第0天）交配并通过单剂量的buserelin（GnRH类似物）诱导排卵；和第二组（ñ= 6），仅诱导排卵（对照）。在第8天，两组均经直肠评估UBF和CLBF。使用Image J1.52a软件分析获得的彩色血流图像，以确定血管化面积和黄体的血流量百分比（CLBF％），以及每个子宫角的百分比（UBF％）。使用ANOVA检验进行统计分析。在第I组中，进行子宫冲洗以获得胚胎，从而将雌性分为I +组（ñ = 10），则当胚胎恢复并且I-组（ñ= 9），此时未恢复任何胚胎。胚胎回收率为52.63％（10/19）。在I +组中，UBF％明显高于I-组和II组（P<0.05）。UBF似乎是胚胎存在的良好预测指标，曲线下面积（AUC）为0.9，最佳临界值为9.37％（灵敏度为90％，特异性为88.9％）。两组之间的CLBF％无差异（P> 0.05）。总之，有可能在美洲驼交配后第8天检测到胚胎存在时UBF的局部增加。这对于实现早孕诊断或决定是否在美洲驼胚胎移植程序中进行子宫冲洗很有帮助。