Collateral Uterine Blood Flow in Holstein Cows during the Third Trimester of Pregnancy

Abstract

Abstract. Blood flow to the gravid and nongravid uterine horns of four multiparous Holstein cows (mean ± SD, BW=641.8 ± 95.4 kg; age=4.8 ± 1.2 years; parity=3.0 ± 1.2) was measured on days 225, 248, and 266 of gestation. Surgery was conducted on day 214.5 ± 4.0 of gestation through the flank of the standing cows. Transit-time ultrasonic flow probes (diameter 12 or 14 mm) were fitted surgically around the uterine arteries of each cow. Surgery was completed within two hours of anesthesia, and the animals recovered rapidly following surgery. Uterine blood flow (UBF, l/min) was recorded at 10 sec intervals for approximately 23.5 hours; these values were averaged to determine UBF. The mean gravid UBF was significantly (P<0.05) greater than the nongravid UBF in this study. The range of the gravid and nongravid UBFs varied from 3.61 to 14.05 and 0.72 to 6.54 l/min, respectively. There were no changes (P>0.1) in the mean gravid and nongravid UBFs from day 225 to 266 of gestation.

Effects of a protracted induction of parturition on the incidence of retained placenta and assessment of uterine artery blood flow as a measure of placental maturation in cattle

“…Mean BFV values in the last days before parturition were consistently higher and RI values lower in the uterine artery located ipsilateral to the pregnant uterus horn compared to values measured in the uterine artery contralateral to the fetus. These results are in agreement with findings of previous studies [27,28,43]. They may be associated with the increasing demands of the fetus during the last two-thirds of pregnancy [42].…”

“…In previous studies, significant increases in blood flow of both uterine arteries throughout gestation [27,41,42], steeping mainly during the last two-thirds of pregnancy [27], as well as no differences in uterine blood flow during the last third of pregnancy [28] were observed. The large increases in uterine blood flow during the last half of gestation were explained by the continuously increasing demands of the fetus [42].…”

“…However, in previous studies it was noticed that the repeated application of corticosteroids during late pregnancy decreased ovine uterine and umbilical blood flow and consequently placental and fetal growth [24,25]. Although there were some studies measuring uterine blood flow in the last period of pregnancy in cattle [26][27][28], until now there are no data about uterine blood flow in the last few days of pregnancy. It has been shown that the large increase in transplacental exchange during the second half of gestation depends primarily on uterine blood flow [29,30].…”

Changes in blood flow to the umbilicus, placentomes, and uterus in Surti buffaloes during complete gestation

“…Nishida, Hosoda, Matsuyama, & Ishida, 2006). The perfusion rate (PR) increased (P < 0.001), and the blood flow volume (BFV) of the ipsilateral uterine artery decreased between 4.5 and 0.5 weeks pre-partum in cows (Kim-Egloff, Hässig, Bruckmaier, & Bleul, 2016).…”