Corpus luteum development and its morphology after aspiration of a preovulatory follicle is related to size and steroid content of the follicle in dairy cows

Abstract

Secretion of adequate levels of progesterone from a proper corpus luteum (CL), which develops out of the cells of a healthy preovulatory follicle, is a key-factor for establishment of a pregnancy. The aim of this study was to investigate the relationship between morphological and secretory characteristics of preovulatory follicles and their corresponding corpus luteum with regard to the post-partum period in high-yielding dairy cows. Therefore, ultrasound-guided aspirations of preovulatory follicles were performed repeatedly, using 20 first lactating cows between 26 and 121 days after parturition. Heat was induced with a PGF analogon followed by administration of a GnRH analogon. The dominant follicle was aspirated 21 h after administration of the GnRH analogon. The diameters of the follicles were estimated at aspiration and the morphology of the resulting luteal tissue was examined on day 14 after follicle aspiration using ultrasonographic examinations. Concentrations of progesterone (P 4 ) and 17-beta-oestradiol (E 2 ) were determined in the follicular fluids (FF) and P 4 concentration was estimated at the time of CL examination in plasma. A CL development occurred in 82% after dominant follicle aspiration. The interval of time between parturition and follicle aspiration did not affect the investigated variables. The diameter of the aspirated preovulatory follicle was positively correlated to the cross-section area of the developed luteal tissue (R = 0.60; P < 0.01) as well as to the plasma P 4 concentration on day 14 after follicle aspiration (R = 0.47; P < 0.05). Also, E 2 concentrations in FF were positively correlated to cross-section area of the luteal tissue (R = 0.54; P < 0.05). Comparing the FF of the follicles that gave rise to a CL after aspiration to follicles that did not, both types had comparable P 4 , but the former type harboured higher E 2 concentrations. In conclusion, preovulatory follicle diameter as well as steroid concentrations in the follicular fluid could be used prospectively to identify cows which will have well-developed CLs and high plasma P 4 levels later. On the other hand, CL development after follicle aspiration can be used as a retrospective quality parameter of dominant follicles. These results will help to identify suitable animals for breeding or recipients for embryo transfer.Keywords: post-partum period; ultrasound; fertility; progesterone; oestradiol; follicle fluid List of abbreviations CL = corpus luteum, DM = dry matter, E 2 = 17-beta-oestradiol, FF = follicle fluid, GnRH = gonadotropin realising hormone, P 4 = progesterone, PGF = prostaglandin F2 alfa, TMR = total mixed ration

Application of Embryo Transfer Technology to Improve Fertility Using GnRH Plus Progesterone and Estradiol Combination (FTAI) of Local South Pesisir Cow in West Sumatra

“…This means when the number of CL increase , the number of embryo significant will be increase. This present study supported by [46] that as a follicle size and concentrations of progesterone and estradiol in the follicular fluid showed significant correlations with the later development of a corpus luteum as well as morphology and progesterone concentration. The donor of south pesisir cows had the high inbreeding without breeding management control, caused of limited bull to bred the cow at the time breeding seasons.…”

“…The effect of inbreeding depression on ovarian activity in super ovulated cows. The regression equation was significant for transferable embryos was`R²= 0.91 [46]. In this result indicated that uncontrolled of breeding programme in rural farm increased inbreeding depression caused the number of embryos production and the number of transferable embryos had a negative impact on reproduction.…”

LOX‐1 regulates estrogenesis via intracellular calcium release from bovine granulosa cells

“…Periovulatory follicles were produced by heat induction with a prostaglandin F2α analog (cloprostenol) followed by an ovulation induction of the developed dominant follicle with a GnRH analog (depherelin) as described . In brief, mural granulosa cells (MGCs) were isolated from preovulatory ovaries sampled by ovariectomy using Holstein heifers (420 ± 30 kg in body weight, 16 ± 2 month old) after cycle synchronization and from follicle > 15 mm in diameter.…”

“…In brief, mural granulosa cells (MGCs) were isolated from preovulatory ovaries sampled by ovariectomy using Holstein heifers (420 ± 30 kg in body weight, 16 ± 2 month old) after cycle synchronization and from follicle > 15 mm in diameter. Morphological assessment and 17β‐estradiol concentration of the follicle fluid (at least 20 ng/ml), exceeding the progesterone level, indicated that the follicle were healthy (vascularized, estrogenic) and maturing into the final preovulatory stage . Sixteen hours post‐GnRH administration, the ovary bearing the periovulatory follicle was removed by ovariectomy and MGCs were prepared.…”

Exposure of Lactating Dairy Cows to Acute Pre-Ovulatory Heat Stress Affects Granulosa Cell-Specific Gene Expression Profiles in Dominant Follicles

“…7 days HS in an environmental chamber) E2 and P4 production was found unchanged in dominant follicles [ 31 ], whereas in another study it was reported that acute heat stress exposure during the winter season reduced the E2 concentrations [ 33 ], which is also in line with the observation that E2 production was lower during the hot (autumn and summer) compared to the cool season (winter). However, a smaller diameter and lower steroid concentrations in pre-ovulatory follicles lead to a smaller corpus luteum and a lower progesterone plasma concentration in the later dioestrus and therefore may compromise implantation and development of an embryo [ 34 ]. But a larger number of animals however, might be necessary in future experiments to confirm the relatively weak effects of acute HS during the late follicular growth phase.…”