Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland; Tierarztpraxis Herrmann, Rankhofstraße 24, 79274 St. Märgen, Germany.
Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
J Dairy Sci. 2022 May;105(5):4534-4546. doi: 10.3168/jds.2021-21006. Epub 2022 Mar 17.
Up until now, bovine fetometry has been entirely based on 2-dimensional ultrasonography. Fetal size is estimated by several linear measurements such as crown-rump length (CRL). However, the advent of 3-dimensional ultrasonography (3D-US) provides in vivo access to the volumes of the fetus and its amniotic sac. The objective of this preliminary observational study was to determine the variability of conceptus-related volumes using transrectal 3D-US in dairy cows and to identify factors affecting them. Furthermore, relationships between the gained measurements and calf birth weight were investigated. In total, 315 Simmental and Holstein-Friesian dairy cows were transrectally examined at d 42 after breeding using a portable ultrasound device (Voluson I, GE Healthcare). Gestational volumes including fetal volume (FV) and amniotic sac volume (ASV) were determined with the software tool VOCAL (Virtual Organ Computer-Aided Analysis, GE Healthcare), whereas amniotic fluid volume (AFV) values were derived from the subtraction of FV from ASV. The CRL was determined by means of 3-dimensional data. The mean values and standard deviations for FV, ASV, AFV, and CRL were 1.47 ± 0.25 cm, 5.86 ± 1.22 cm, 4.38 ± 1.02 cm, and 2.38 ± 0.18 cm, respectively. All gestational volumes and CRL values were affected by breed. In Simmental cattle, larger concepti were observed compared with pregnancies derived from Holstein-Friesian animals. Parity affected only ASV and AFV, with heifers showing greater values than lactating cows. The CRL was positively associated with milk protein content. It was not possible to predict calf weight at birth by using FV, ASV, or AFV; however, tendencies were found for ASV and AFV. The present study was the first to adopt 3D-US volumetry to assess early pregnancy development in dairy cattle. Our results showed that this method could be used successfully to identify minor variations in conceptus growth.
到目前为止，牛胎儿测量学完全基于二维超声。通过几个线性测量来估计胎儿大小，例如头臀长（CRL）。然而，三维超声（3D-US）的出现为胎儿及其羊膜囊的体积提供了体内访问。本初步观察性研究的目的是使用直肠 3D-US 确定奶牛胚胎相关体积的可变性，并确定影响这些体积的因素。此外，还研究了获得的测量值与犊牛出生体重之间的关系。总共对 315 头西门塔尔牛和荷斯坦-弗里森奶牛在配种后第 42 天使用便携式超声设备（GE Healthcare 的 Voluson I）进行了直肠检查。使用 VOCAL 软件工具（GE Healthcare 的 Virtual Organ Computer-Aided Analysis）确定了包括胎儿体积（FV）和羊膜囊体积（ASV）在内的妊娠体积，而羊水体积（AFV）值则通过从 ASV 中减去 FV 得出。CRL 通过三维数据确定。FV、ASV、AFV 和 CRL 的平均值和标准差分别为 1.47 ± 0.25cm、5.86 ± 1.22cm、4.38 ± 1.02cm 和 2.38 ± 0.18cm。所有妊娠体积和 CRL 值均受品种影响。与荷斯坦-弗里森动物的妊娠相比，西门塔尔牛的胚胎较大。胎次仅影响 ASV 和 AFV，小母牛的数值大于泌乳牛。CRL 与乳蛋白含量呈正相关。使用 FV、ASV 或 AFV 无法预测犊牛出生体重；然而，ASV 和 AFV 有趋势。本研究首次采用 3D-US 容积法评估奶牛早期妊娠发育。我们的结果表明，该方法可成功用于识别胚胎生长的微小变化。
