Origin of the preovulatory follicle after induced luteolysis during the early luteal phase in ewes

1998 ◽  
Vol 78 (3) ◽  
pp. 429-431 ◽  
Author(s):  
Carolina Viñoles ◽  
Edgardo Rubianes
Keyword(s):  
Key Words ◽  
Luteal Phase ◽  
Preovulatory Follicle ◽  
Plateau Phase ◽  
Dominant Follicle ◽  
Follicular Waves

The origin of the preovulatory follicle (POF) was determined by daily transrectal ultra-sonographic examinations in ewes given PGF2α on day 5 (n = 8) or day 9 (n = 8) post-ovulation. In all day-9 ewes, the POF originated from wave 2 while in the day-5 group it originated from wave 1 (n = 5) or wave 2 (n = 3). When the POF originated from wave 2 in day-5 ewes, the dominant follicle of wave 1 emerged earlier than in ewes with the POF from wave 1 (day –1.0 vs. day 0.8, P < 0.05) and was regressing at the time of PGF2α treatment (diameter 4.1 ± 0.4 vs. 2.8 ± 0.3 mm, P < 0.05). The dominant follicle of wave 1 became POF if it was in the growing or plateau phase at the time of luteolysis. If it was already in the regressing phase, the dominant follicle of wave 2 became the POF. Key words: PGF2α, luteolysis, ovarian follicular waves, ultrasonography, ewes

Effect of the dominant follicle on regression of its subordinates in heifers

1993 ◽  
Vol 73 (2) ◽  
pp. 267-275 ◽  
Author(s):  
G. P. Adams ◽  
K. Kot ◽  
C. A. Smith ◽  
O. J. Ginther
Keyword(s):  
Key Words ◽  
Maximum Diameter ◽  
Sham Operation ◽  
Dominant Follicle ◽  
Follicular Waves ◽  
Follicular Wave ◽  
The Relationship ◽  
Small Follicle

The relationship between a dominant follicle of a follicular wave and the suppression of subordinate follicles was studied during the first postovulatory wave (Wave 1) in Holstein heifers. The dominant follicle (largest follicle) was cauterized or a sham-operation was done on day 3 (day 0 = ovulation) using seven heifers per group. In the cautery group, compared to the controls, the largest subordinate follicle attained a larger diameter (11 7 vs 8 0 mm; P < 0.01), reached maximum diameter at a later day (day 9.2 vs. day 3.1; P < 0 01) and began to regress at a later day (day 14.3 vs. day 5.7; P < 0.01). In addition, the emergence of Wave 2 was hastened (day 6.4 vs. day 9.3; P < 0.05) and more heifers had more than two waves per interovulatory interval (5 of 6 vs. 2 of 7; P < 0.05). In heifers with the dominant follicle eliminated, the largest subordinate grew to the diameter of a dominant follicle during Wave 1 (n = 3) or became the dominant follicle of a newly emerged wave (n = 2). A subordinate sometimes persisted as a small follicle (e.g., 5 mm) for several days before resurging. However, it was not convincingly demonstrated that a subordinate follicle could resurge after it had begun to regress (decrease in diameter). Results supported the hypothesis that suppression of subordinate follicles is a prolonged process, so that resurgence of a subordinate can occur if the dominant follicle is removed. Key words: Ovaries, follicular waves, selection, cattle, cauterization

Effect of mid-luteal phase progesterone levels on the first wave dominant follicle in cattle

1994 ◽  
Vol 74 (2) ◽  
pp. 281-285 ◽  
Author(s):  
C. Taylor ◽  
R. Rajamahendran
Keyword(s):  
Key Words ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Follicular Growth ◽  
Dominant Follicle ◽  
Prostaglandin F ◽  
Follicular Dynamics

A wave-like-pattern of follicular growth and regression during the luteal phase has been described in the bovine. The factors responsible for inducing the onset of regression of nonovulatory dominant follicles are unknown. The present study was designed to examine the effect of progesterone (P4) administration early in the estrous cycle on the first wave dominant follicle. Nine heifers were administered P4 on day 3 (200 mg), day 4 (100 mg) and day 5 (50 mg) of the estrous cycle (Day 0 = day of estrus) and seven heifers received vehicle to serve as controls. All heifers received a luteolytic dose of prostaglandin F2α (PGF2α) on day 7. Follicular dynamics were monitored by daily ultrasonography. All seven control heifers ovulated the first wave dominant follicle. In four P4 treated heifers, the first wave dominant follicle regressed prior to PGF2α administration and a dominant follicle from the second pool of follicles ovulated. The remaining five P4 treated heifers ovulated the first wave dominant follicle. However, in these heifers the growth of the first wave dominant follicle was slower (0.65 ± 0.13 mm day−1 between days 3 to 7 for treated vs 1.46 ± 0.23 mm day−1 for control; P < 0.05) and estrus and ovulation were delayed compared to controls (3.8 ± 0.3 vs 2.4 ± 0.2 and 5.2 ± 0.4 vs 3.9 ± 0.2 days after PGF2α, respectively; P < 0.05). The results indicate that P4 administered early in the estrous cycle to mimic the mid luteal phase levels alters follicular dynamics and is capable of inducing premature regression of the first wave dominant follicle. Key words: Progesterone, dominant follicle, cattle, atresia, ovulation

scholarly journals Effect of the metabolic environment at key stages of follicle development in cattle: focus on steroid biosynthesis

2012 ◽  
Vol 44 (9) ◽  
pp. 504-517 ◽  
Author(s):  
S. W. Walsh ◽  
J. P. Mehta ◽  
P. A. McGettigan ◽  
J. A. Browne ◽  
N. Forde ◽  
...  
Keyword(s):  
Luteal Phase ◽  
Ovarian Follicle ◽  
Regulatory Protein ◽  
Follicle Development ◽  
Preovulatory Follicle ◽  
Dominant Follicle ◽  
Beef Heifers ◽  
Steroid Biosynthesis ◽  
Lh Surge ◽  
Lactating Cows

Cellular mechanisms that contribute to low estradiol concentrations produced by the preovulatory ovarian follicle in cattle with a compromised metabolic status are largely unknown. To gain insight into the main metabolic mechanisms affecting preovulatory follicle function, two different animal models were used. Experiment 1 compared Holstein-Friesian nonlactating heifers ( n = 17) and lactating cows ( n = 16) at three stages of preovulatory follicle development: 1) newly selected dominant follicle in the luteal phase (Selection), 2) follicular phase before the LH surge (Differentiation), and 3) preovulatory phase after the LH surge (Luteinization). Experiment 2 compared newly selected dominant follicles in the luteal phase in beef heifers fed a diet of 1.2 times maintenance (M, n = 8) or 0.4 M ( n = 11). Lactating cows and 0.4 M beef heifers had higher concentrations of β-hydroxybutyrate, and lower concentrations of glucose, insulin, and IGF-I compared with dairy heifers and 1.2 M beef heifers, respectively. In lactating cows this altered metabolic environment was associated with reduced dominant follicle estradiol and progesterone synthesis during Differentiation and Luteinization, respectively, and in 0.4 M beef heifers with reduced dominant follicle estradiol synthesis. Using a combination of RNA sequencing, Ingenuity Pathway Analysis, and qRT-PCR validation, we identified several important molecular markers involved in steroid biosynthesis, such as the expression of steroidogenic acute regulatory protein ( STAR) within developing dominant follicles, to be downregulated by the catabolic state. Based on this, we propose that the adverse metabolic environment caused by lactation or nutritional restriction decreases preovulatory follicle function mainly by affecting cholesterol transport into the mitochondria to initiate steroidogenesis.

scholarly journals Investigations on the vaginal temperature, cycle stages, and steroid hormone concentrations during the breeding season in camels (Camelus dromedarius)

2021 ◽  
pp. 1102-1108
Author(s):  
Ragab H. Mohamed ◽  
Amal M. Abo El-Maaty ◽  
Rasha S. Mohamed ◽  
Axel Wehrend ◽  
Fatma Ali ◽  
...  
Keyword(s):  
Temperature Cycle ◽  
Ovarian Activity ◽  
Dominant Follicle ◽  
Data Logger ◽  
Temperature Changes ◽  
Animal Reproduction ◽  
Follicular Waves ◽  
Release Device ◽  
Cyclic Changes ◽  
Vaginal Temperature

Background and Aim: Estrus detection plays a crucial role in the success of animal reproduction. It was previously reported that body temperature changes during estrus. This study aimed to investigate the relationship between vaginal temperatures (VTs) measured by a data logger, ovarian activity, and hormonal cyclic changes in camels. Materials and Methods: Six mature, healthy, non-pregnant dromedary, and 10-12-year-old camels were included in the study. The ovarian activity was monitored with ultrasonography, and estrus behavior was evaluated using an active and virile male camel. Animals were inserted with a blank controlled internal drug release device attached with an intravaginal data logger. Every hour, the ambient temperature was recorded by another data logger. Blood samples were collected, and sera were used to measure estradiol and progesterone levels. Results: The whole follicular cycle lasted 25.41±1.36 days, and the maximum sizes of the dominant follicle in the first and second follicular waves were 1.63±0.27 cm and 1.94±0.42 cm, respectively. There was a significant positive correlation between the follicular diameter and estradiol-17β level (p<0.01, r=0.397). There was no correlation between the follicular diameter and progesterone level (p>0.05, r=0.038), which remained low during the whole period of the experiment. The mean daily VT was significantly correlated with the diameter of the dominant follicle (1.7-2.2 cm, p<0.01, r=0.52). Conclusion: Measurement of VT will improve the accuracy of estrus prediction. Further studies are recommended to validate VT in camel reproduction.

Defining the gonadotrophin requirement for the selection of a single dominant follicle in cattle

2020 ◽  
Vol 32 (3) ◽  
pp. 322 ◽  
Author(s):  
Jin G. Gong ◽  
Bruce K. Campbell ◽  
Robert Webb
Keyword(s):  
Major Effect ◽  
Follicle Development ◽  
Preovulatory Follicle ◽  
Ultrasound Scanning ◽  
Dominant Follicle ◽  
Initial Exposure ◽  
Preovulatory Follicles ◽  
Gonadotrophin Releasing Hormone ◽  
Follicular Response ◽  
Selection Of

The aim was to define the pattern and physiological concentrations of FSH and LH required for the selection of a single dominant follicle in mono-ovulatory species. A series of five experiments was carried out using gonadotrophin-releasing hormone agonist-induced hypogonadal heifers. Animals were infused with different patterns of either FSH and/or LH followed by an ovulatory dose of human chorionic gonadotrophin. Follicular response was monitored by ultrasound scanning and blood samples were collected to measure concentrations of FSH, LH, oestradiol and progesterone. The main findings were: (1) physiological concentrations of FSH given as a continuous infusion and for an adequate duration, in the presence of basal LH, with or without LH pulses, are capable of inducing a superovulatory response, (2) initial exposure to FSH followed by LH pulses alone stimulate the development of multiple preovulatory follicles, confirming that ovarian follicles are capable of transferring dependence on gonadotrophins from FSH to LH, (3) while LH pulses appear not to have a major effect on the pattern of preovulatory follicle development, adequate LH pulsatile support is required for full oestradiol synthesis and (4) the duration of initial exposure to FSH and the ability to transfer the dependence from FSH to LH are critical for the selection of a single dominant follicle. In conclusion, this experimental series confirms that the duration of initial exposure to FSH and the ability of the selected follicle to transfer its gonadotrophic dependence from FSH to LH are critical for the selection of a single dominant follicle in cattle.

Vaccination against follistatin and the effect on ovulation rate in estrus-induced gilts

2003 ◽  
Vol 83 (3) ◽  
pp. 487-492
Author(s):  
C. R. Christensen ◽  
M. J. Redmond ◽  
B. Laarveld
Keyword(s):  
Treatment Group ◽  
Key Words ◽  
Luteal Phase ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Significant Difference ◽  
Ovarian Morphology ◽  
Antibody Titers

Primiparous sows were vaccinated against follistatin to determine the effect on ovulation rate following typical commercial estrus induction and synchronization. Seventy-five gilts received four vaccinations against a recombinant porcine follistatin (FS) or a sham vaccine (CTL). At 85 kg, gilts were induced into estrus with a combination of PG600 and hCG and synchronized using PGF2α. At the second estrus, antibody titers ranged from 0 to1:6400 in the FS-vaccinated treatment group and no FS antibodies were detected in the CTL group. Late in the second subsequent luteal phase the reproductive tracts of the gilts that had displayed two estruses were collected. There was no significant difference in the number of corpora lutea (FS = 13.2 ± 0.5, CTL = 14.5 ± 0.7) or corpora albicantia (FS = 12.1 ± 1.9, CTL = 12.3 ± 2.0) between treatments. Follistatin-vaccinated gilts displayed an increased number of luteal structures which resembled corpora hemorrhagica (P = 0.04). This study shows that vaccination of gilts against FS concurrent with estrus induction and synchronization affected ovarian morphology, although an effect on ovulation rate was not apparent. Key words: Swine, follistatin, immunoneutralization, fecundity, ovulation rate

Comparison of bovine uterine horns for progesterone and oxytocin levels with bilateral corpus luteum

1996 ◽  
Vol 76 (3) ◽  
pp. 463-464 ◽  
Author(s):  
W. A. Cerbito ◽  
M. P. B. Wijayagunawardane ◽  
M. Takagi ◽  
K. Sato ◽  
A. Miyamoto ◽  
...  
Keyword(s):  
Key Words ◽  
Corpus Luteum ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Uterine Horn ◽  
Corpora Lutea ◽  
Uterine Tissue ◽  
Tissue Samples ◽  
Significant Difference ◽  
The Right

Bovine uterine horns with both ovaries containing a corpus luteum (CL) were compared for progesterone (P4) and oxytocin (OT) concentrations during the luteal phase of the estrous cycle. Uterine tissue samples from five Holstein cows with bilateral CL obtained from the slaughterhouse were used for this study. No significant difference was observed in P4 and OT levels in the right and left horns with corpora lutea in both ovaries. The data clearly indicate that both sides of the uterine horn having a functional CL are exposed to similar levels of P4 and OT, supporting the hypothesis that luteal products are delivered locally to the uterus. Key words: Progesterone, oxytocin, uterine horn, bilateral, corpus luteum, cow

1 PROGESTERONE AS THE DRIVING REGULATORY FORCE BEHIND SERUM FSH CONCENTRATIONS AND ANTRAL FOLLICULAR GROWTH IN CYCLIC EWES

2010 ◽  
Vol 22 (1) ◽  
pp. 159
Author(s):  
T. E. Baby ◽  
P. M. Bartlewski
Keyword(s):  
Treatment Group ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Follicular Development ◽  
Serum Levels ◽  
Time Frame ◽  
Corpora Lutea ◽  
Research Station ◽  
Follicular Growth ◽  
Follicular Waves

Ovarian antral follicles in sheep grow in an orderly succession, producing typically 3 to 4 follicular waves per 17-day estrous cycle. Each wave is preceded by a transient increase in circulating FSH concentrations. The mechanism controlling the number of recurrent FSH peaks and emerging follicular waves remains unknown. During the ewe's estrous cycle, the time between the first 2 FSH peaks and days of wave emergence is longer than the intervals separating the ensuing FSH peaks and follicular waves. The prolonged inter-peak/inter-wave interval occurs early in the luteal phase when low levels of progesterone are secreted by developing, or non-fully functional, corpora lutea. The purpose of the present study was to determine the effect of varying progesterone (P4) levels on circulating concentrations of FSH and antral follicular development in sheep. Exogenous P4 (15 mg per ewe i.m.) was administered twice daily to 6 cycling Rideau Arcott × Dorset ewes from Day 0 (ovulation) to Day 4 (the mean duration of the inter-wave interval); 6 animals served as controls. Follicular growth was monitored in all animals by daily transrectal ultrasonography (Days 0 to 9). Jugular blood samples were drawn twice a day from Day 0 to 4 and then daily until Day 9 to measure systemic concentrations of P4 and FSH. The first FSH peak post-ovulation was detected on Day 1.4 ± 0.2 and 4.0 ± 0.2 in treated and control ewes, respectively (P < 0.05). The next FSH peak(s) occurred on Days 3.4 ± 0.3 and 5.2 ± 0.2 in the treatment group and on Day 5.5 ± 0.3 in controls. Consequently, the treatment group had, on average, 3 follicular waves emerging on Days 0, 3, and 6, whereas the controls produced 2 waves emerging on Days 0 and 5 (P < 0.05).We then retrospectively analyzed and compared daily serum concentrations of P4 and FSH obtained in cyclic Western White Face ewes (Columbia × Rambouillet) that had 3 (n = 10) or 4 (n = 19) follicular waves per cycle. Mean P4 concentrations were greater (P < 0.05) in sheep with 4 waves per cycle compared with their counterparts, which had 3 waves of follicular growth. Interestingly, the ewes with 3 waves exceeded (P < 0.05) all animals with 4 follicular waves in mean serum FSH concentrations on Days 0 to 2, 6 to 7, and 9 to 15 post-ovulation. In summary, creation of mid-luteal phase levels of P4 in metestrus shortened the time to the first post-ovulatory FSH peak in ewes, resulting in emergence of one more follicular wave compared with control animals during the same time frame. The ewes exhibiting 4 waves of follicular emergence had greater serum levels of P4 but lower FSH concentrations compared with sheep with 3 waves per cycle. Therefore, progesterone appears to be a key endocrine signal governing the control of periodic increases in serum FSH concentrations and the number of follicular waves in cyclic sheep. This study was funded by OMAFRA and NSERC grants. Appreciation is extended to Norman C. Rawlings, Susan Cook, and Sekallu Srinivas (University of Saskatchewan) and the staff at Ponsonby Sheep Research Station.

179 CORPUS LUTEUM DEVELOPMENT AFTER FOLLICLE ASPIRATION IS RELATED TO CHARACTERISTICS OF THE ASPIRATED FOLLICLE IN DAIRY COWS

2013 ◽  
Vol 25 (1) ◽  
pp. 238
Author(s):  
A. Vernunft ◽  
J. M. Weitzel ◽  
T. Viergutz
Keyword(s):  
Corpus Luteum ◽  
Cross Section ◽  
Quality Parameter ◽  
Preovulatory Follicle ◽  
Dominant Follicle ◽  
Cross Section Area ◽  
Section Area ◽  
Luteal Tissue ◽  
The Cross ◽  
Follicle Aspiration

The aim of this study was to investigate whether morphology or function of a corpus luteum (CL), which developed after an aspiration of a preovulatory follicle, is related to follicular characteristics such as size or steroid content. If so, CL morphology or function could be used as a retrospective quality parameter for the aspirated follicle or the follicular characteristics as a prospective parameter for the quality of the developing CL. Therefore, 44 aspiration sessions were performed using 18 cows between 26 and 121 days after parturition during the first lactation. Heat was induced in mid-dioestrus with Cloprostenol. A GnRH analogon (Depherelin) were administrated 54 h later. The dominant follicle was aspirated 21 h after administration of the GnRH analogue. The diameter of the dominant follicle at aspiration and the cross-section area of the resulting luteal tissue 14 days later were measured by ultrasound. Concentrations of progesterone (P4) and 17-β-oestradiol (E2) in blood and follicular fluid (FF) were determined by H3-RIA. A CL development occurred in 82% of aspiration sessions after aspirating the dominant follicles. The interval of time between parturition and follicle aspiration did not affect variables investigated. As expected, cross-section area of the luteal tissue was positively correlated with plasma P4 concentration on Day 14 after follicle aspiration (r = 0.54; P < 0.01). The diameter of the aspirated follicle was positively correlated with the plasma P4 concentration on Day 14 after follicle aspiration (r = 0.52; P = 0.02), but the diameter was not correlated with the cross-section. Comparing the FF of follicles that originated a CL after aspiration with follicles that did not, both types had comparable P4 concentrations (578 ± 79 ng mL–1 v. 398 ± 84 ng mL–1; P = 0.2), but the former type presented higher E2 concentrations (206 ± 23 ng mL–1 v. 64 ± 29 ng mL–1, P < 0.01) compared with the latter. The P4 concentrations in FF of follicles that originated a CL after aspiration were positively related to cross-section area of the CL (r = 0.48; P = 0.04), but neither P4 nor E2 concentrations in the FF of preovulatory follicles could be used as a predictor for the plasma P4 concentration at day 14. In conclusion, CL development after follicle aspiration can be used as a retrospective quality parameter of aspirated dominant follicles. Preovulatory follicle diameter as well as cross-section area of the luteal tissue could be used prospectively to identify cows with high plasma P4 levels, and this may help to identify suitable recipients for embryo transfer. This study was supported by the German Research Foundation (DFG WE 2458/7-2).

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