Blood sample collection from the caudal vena cava at the site of uterine–ovarian drainage provides a more exact evaluation of the concentration and pattern of secretion of uterine or ovarian secreted products for studies of reproductive processes in cyclic and pregnant cattle compared with samples collected from general circulation. This paper describes a thorough and updated procedure for cannulating the coccygeal vein into the caudal vena cava for the collection of serial blood samples at or near the site of uterine–ovarian drainage. Concentrations of progesterone were quantified in cows of different reproductive tract sizes with an active corpus luteum to assess the distance for proper catheter placement compared with circulating concentrations collected from the jugular vein. This procedure has a low risk for side effects, can be used effectively in pregnant animals with no major consequence to the viability of the pregnancy, and provides means for frequent collections up to 12 d.

中文翻译：

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技术说明：尾骨静脉插管用于从子宫-卵巢引流中采集生殖道衍生产品

从子宫-卵巢引流部位的尾腔静脉采集的血液样本与从一般采集的样本相比，可以更准确地评估子宫或卵巢分泌产物的浓度和分泌模式，以研究周期性和怀孕牛的生殖过程循环。本文描述了将尾骨静脉插管到尾腔静脉的彻底和更新的程序，以便在子宫 - 卵巢引流部位或附近收集连续血液样本。与从颈静脉收集的循环浓度相比，对具有活跃黄体的不同生殖道大小的奶牛的孕酮浓度进行量化，以评估正确放置导管的距离。该程序的副作用风险低，