Ovarian and uterine arteries blood flow velocities waveform, hormones and nitric oxide in relation to ovulation in cows superstimulated with equine chorionic gonadotropin and luteolysis induction 10 and 17 days after ovulation.
Authors: Abdelnaby Elshymaa A, Alhaider Abdulrhman K, El-Maaty Amal M Abo, Ragab Refaat S A, Seida Adel A, El-Badry Diya A
Journal: BMC veterinary research
Summary
# Editorial Summary Researchers investigating the physiological mechanisms underlying controlled ovulation in cattle used Doppler ultrasound to track changes in ovarian and uterine blood flow patterns, alongside hormonal and nitric oxide measurements, in eight Holstein cows stimulated with equine chorionic gonadotropin (eCG) and subjected to luteolysis on days 10 and 17 post-ovulation. The superstimulation protocol yielded approximately five ovulations per ovary from an initial cohort of ≥13 follicles, with peak systolic velocity (PSV) in ovarian arteries increasing whilst uterine artery PSV decreased during the peri-ovulatory window (day -4 to day 0); notably, ovarian artery haemodynamic parameters (diameter, resistance index, PSV, end-diastolic velocity and systolic/diastolic ratio) showed strong positive correlations, whereas pulsatility index correlated negatively. Oestradiol concentrations rose and progesterone declined from day -5 to ovulation, with post-ovulatory progesterone peaking on day 9 before declining, whilst nitric oxide exhibited biphasic peaks—one pre-ovulatory (day -3) and another during early luteal phase (days 3–9). These findings demonstrate that ovarian and uterine haemodynamic profiles respond distinctly to the reproductive cycle phases, with blood flow patterns differing markedly between pre- and post-ovulatory states—information potentially useful for clinicians evaluating reproductive efficacy in assisted breeding programmes or interpreting ultrasound-based assessments of follicular and luteal development.
Read the full abstract on PubMed
Practical Takeaways
- •Doppler ultrasound assessment of ovarian and uterine artery hemodynamics can provide objective markers of reproductive status and ovulation timing in superstimulated cattle
- •Different hemodynamic patterns between ovarian and uterine arteries suggest distinct physiological roles during follicular and luteal phases; practitioners should recognize these differences when using ultrasound for reproductive evaluation
- •The temporal relationships between blood flow, hormone levels, and nitric oxide may help optimize timing of breeding programs and gonadotropin-assisted reproduction protocols in dairy herds
Key Findings
- •eCG superstimulation resulted in 5 follicles ovulating from both ovaries (from ≥13 follicles) with increased antrum area until day -1
- •Ovarian artery blood flow parameters (PSV, EDV, S/D, RI) positively correlated while PI negatively correlated, opposite to uterine artery patterns (P<0.0001)
- •Peak ovarian artery velocity increased from day -4 to day 0 while uterine artery velocity decreased during the same period
- •Estradiol peaked at ovulation (day 0) while progesterone reached maximum on day 9 post-ovulation; nitric oxide showed two peaks (day -3 and days 3-9)