Follicular, Luteal and Uterine Hemodynamics before and after Dominant Follicle Aspiration in Aged Mares

To study the effect of follicle aspiration on the follicular, luteal, and uterine dynamics and hemodynamics associated with estradiol and nitric oxide changes, five aged mares >18 years were granted from Police department due to aging were subjected to transvaginal dominant follicle aspiration (TVA) on Day 12 after ovulation (Day 0). Before TVA, three complete estrous cycles were studied. The three large follicles were tracked after spontaneous ovulation and follicle aspiration starting from the day of aspiration (Day 0) till Day 12 and Day 15 of the first and second estrous cycles following aspiration. Follicle number, diameter, antral diameter, area, antral area, color area, color area %, granulosa area, and granulosa color area % in relation to the diameter of the dominant and subordinate follicles were determined during the spontaneous estrous cycles. Follicle diameter, antral diameter, area, antral area, color area, color area %, granulosa area, granulosa color area %, CL color area % and uterine horns color area % in relation to days before or after follicle aspiration were determined during the spontaneous estrous cycles. Blood samples collected on the same day of ultrasound and Doppler assessment were used to assay estradiol and nitric oxide concentrations. Days after ovulation influenced Uterine horn area (P<0.05) and color area (P<0.05), CL color area (P< 0.05) and CL color area % (P<0.05), Estradiol (E2, P<0.0001), and Nitric oxide (NO, P<0.0001). Days after aspiration influenced follicle antrum (P<0.01), follicle circulatory (P <0.0001), CL diameter (P<0.05), CL area (P<0.05), and E2 (P=0.007). Aspiration influenced the follicle circulatory (P<0.0001) and CL color area (P<0.05) and tended to influence E2 (P>0.05). In conclusion, aspiration of the dominant follicle simulates spontaneous ovulation in aged mares. Day 12 after ovulation could be selected for aspirating the dominant follicle without disturbing the follicular dynamics and hemodynamics. Aspirated dominant follicle become a corpus luteum with 2-3 days after aspiration.