Vascularization to preovulatory follicle and corpus luteum-a valuable predictor of fertility in dairy cows

Luteal blood flow measured by Doppler ultrasonography during the first three weeks after artificial insemination in pregnant and non-pregnant <i>Bos indicus</i> dairy cows

“…Furthermore, CDU was used to compare the LBF with luteal size (LS) and concentrations of progesterone (P4) during the estrous cycle of mares [18], Holstein cows [19], Italian Mediterranean buffaloes [20], and ewes [21, 22]. Subsequently, researchers became interested in using this technique to predict the pregnancy in crossbred beef cows [23], German Holstein cows [24], Italian Mediterranean buffaloes [25], mares [26], beef heifers [27], and Holstein Friesian cows [28]. More recently, it was used to predict the occurrence of embryonic loss based on the uterine and ovarian vascular dynamics in dairy cows [29].…”

Caracterización ultrasonográfica modo-B y Doppler del cuerpo lúteo en llamas

“…The echotexture of the LC of recipient llamas effectively shows them to be uniform, circumscribed, hypoechogenic and homogeneous structures (Figure 1), due to the fact that their ovarian stroma is related to the active angiogenic process that occurs during the initial stages of luteal development in mammals, mediated by angiogenic factors such as vascular endothelial growth factor (VEGF), whose increase leads to rapid mitosis of the endothelial cells of the capillaries of the LC14 22,23 , in addition to the fact that most steroidogenic cells are adjacent to one or more capillaries and the perfusion of the luteal blood flow is so intense that it affects the acoustic impedance of the organ, resulting in the characteristic echotexture of the LC12 24 , as occurs in other species with the same hypoechogenic characteristics in relation to the ovarian stroma 25,26 . In B-mode ultrasonography of the CL in recipient llamas show morphometric characteristics such as area, volume and diameter highly related to studies on follicular dynamics in llamas specifically with sizes of donor follicles reaching diameters of 10.0±2.0 mm and 11.8±1.6 mm respectively 3,27 , the maximum follicular diameter is related to the future diameter of the CL since these follicles have active angiogenesis after theca formation, which promotes the permeability of blood vessels, ovulation and subsequent formation of the CL 28 , in cows for meat and milk production, ovulation of a preovulatory follicle of greater diameter leads to a CL of good size; this characteristic seems to be associated with fertility 29,30 .…”

In Vivo Follicular and Uterine Arterial Indices as an Indicator of Successful Hormonal Stimulation for Inactive Ovaries in Repeat-Breeder Crossbred Dairy Cows Using a Short-Term Progesterone-Based Programme

“…Although the information regarding the relationship between ovarian and uterine arterial indices and the resumption of follicular activity after hormonal stimulation in infertile dairy cows is scarce, the blood flow to the preovulatory follicle (POF) is markedly reduced in heat-stressed beef cows (vascularised area in pixels and %) with a synchronised ovulatory cycle [10] and heat-stressed dairy cows (Doppler index) with a spontaneous oestrous cycle [21]. Similar to normally cyclic dairy cattle [22], the vascularity (vascularised area in pixels) of POF and CL is a valuable predictor of pregnancy outcomes in fertile dairy cows. For these female dairy cattle, cows with a high POF vascular index underwent a normal pregnancy [22].…”

“…Similar to normally cyclic dairy cattle [22], the vascularity (vascularised area in pixels) of POF and CL is a valuable predictor of pregnancy outcomes in fertile dairy cows. For these female dairy cattle, cows with a high POF vascular index underwent a normal pregnancy [22]. Investigations in normal beef heifers and cows receiving the 7-day Co-Synch + CIDR protocol [23] have observed that blood flow (vascularised area in pixels) of large POF (14.1-17.5 mm in diameter) tended to be greater than small POF (10.8-12.8 mm in diameter).…”