scholarly journals Anatomical and histological changes during the oestrous cycle in the mare

1941 ◽  
Vol 130 (858) ◽  
pp. 1-23 ◽  
Keyword(s):  
Corpus Luteum ◽  
Reproductive Organs ◽  
Oestrous Cycle ◽  
Maximum Diameter ◽  
Histological Changes ◽  
Graafian Follicle ◽  
Heat Period ◽  
To Come ◽  
Time Required ◽  
Dominant Part

The mares chosen for the investigation of the changes in the reproductive organs during the oestrous cycle were kept under observation for some time before they were killed. The duration of the heat period in these animals was 7 days and the length of the dioestrus was 16 days. Ovulation takes place at about a day before the end of oestrus. The size of the ovary during the oestrous cycle is chiefly influenced by the growing Graafian follicle. The number of follicles present at different stages varies greatly. The numerous small follicles present at the beginning of oestrus disappear later in the cycle; it is suggested that this may be due to the lack of follicle-stimulating hormone. The colour of the corpus luteum varies greatly at different stages of the cycle. The rupture of the follicle is associated with some bleeding. The active stage of the corpus luteum is very short, and the maximum diameter of the corpus luteum seems to be always below that of the Graafian follicle. The greater development of the Graafian follicle, with its secretion of oestrin, in the mare leads to its playing a more important role than in the cow and the sow, in which species the corpus luteum takes a m ore dominant part in the cycle. It appears that the much longer oestrus in the mare than in the cow is due to the longer time required by the follicle to come to the surface and to break through. This is probably due to the peculiar structure of the ovary in the mare, since the ovulation, which is spontaneous, can only occur in the small ovulation fossa. No pronounced secretion stage occurs during oestrus in the Fallopian tubes.

Pregnancy in a marsupial, the Tasmanian pademelon (Thylogale billardierii)

1999 ◽  
Vol 11 (3) ◽  
pp. 175 ◽  
Author(s):  
R. W. Rose ◽  
J. A. A. Horak ◽  
A. D. Shetewi ◽  
S. M. Jones
Keyword(s):  
Corpus Luteum ◽  
Reproductive Biology ◽  
Plasma Concentrations ◽  
Tammar Wallaby ◽  
Reproductive Organs ◽  
Model Species ◽  
Histological Changes ◽  
Plasma Progesterone ◽  
Embryonic Growth ◽  
Background Data

The Tasmanian pademelon, Thylogale billardierii, is a medium-sized wallaby that adapts well to captivity and, unlike the well-studied tammar wallaby, is capable of breeding all year round. It may, there-fore, be a useful model species for research into the reproductive biology of macropod marsupials. This paper presents necessary background data on histological changes in the reproductive organs and the rate of embryonic growth during gestation in T. billardierii. After Day 4 RPY (removal of young from the pouch) the gravid and non-gravid uteri differ significantly in some histological parameters. The corpus luteum becomes active by Day 6 RPY and is fully developed by Day 14 RPY; it begins to degenerate from Day 19 RPY. Plasma progesterone concentrations through gestation follow a pattern similar to that in the tammar wallaby. There is an early, smaller, peak at Day 5 RPY, with plasma concentrations of progesterone then falling until the larger pre-partum peak occurs several days before birth.

scholarly journals Doppler sonography of the corpus luteum during the oestrus cycle in dairy cows

2020 ◽  
Vol 76 (06) ◽  
pp. 6417-2020
Author(s):  
GABRIELE MARINO ◽  
FLAVIA PRUITI CIARELLO ◽  
MICHELANGELO LA SPISA ◽  
FRANCESCO MACRÌ ◽  
ALESSANDRA SFACTERIA ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Corpus Luteum ◽  
Doppler Ultrasound ◽  
Vertical Plane ◽  
Oestrous Cycle ◽  
Maximum Diameter ◽  
Flow Mode ◽  
Image Analysis System ◽  
Oestrus Cycle ◽  
Significant Difference

Doppler ultrasound has recently emerged as one of the main innovations in cattle practice and has mainly found application in the evaluation of luteal blood perfusion (LBF). LBF has been evaluated during different phases of the oestrous cycle, but the technique is poorly standardized. The aim of the study was to evaluate visual and quantitative changes of size of corpus luteum (CL) and LBF in dairy cattle during an oestrous cycle at 2 follicular waves using colour flow mode (CFM) and power flow mode (PFM) doppler ultrasound. Ten Friesian cows were selected and synchronized. The CL was evaluated at 3/4-day intervals until the next oestrus onset. After identifying the spiral luteal artery entry at the base of the CL, multiple scans of the vertical plane at the maximum diameter of the CL from the apex to the base were recorded in B-mode, CFM and PFM for each cow and session. An Esaote Mylab vet 30 gold was employed with the following setting: pulse repetition frequency 2.1 (CFM) or 2.8 (PFM), gain 70%. The real area of CL (RACL) was calculated subtracting the area of the eventual inner cavity. The LBF was quantified off-line by means of a visual score and of an image analysis system (Digimizer 4.1). Student and Anova tests were used for statistical analysis. Data were presented as means and standard deviations. There were significant individual variations for the RACL and LBF when calculated in CFM. PFM minimized these variations, although, at day 15-16, it was also affected by individual factors (p < 0.01). The combined study of RACL and LBF during a 2-wave oestrous cycle distinguished 3 phases: a phase of CL formation (3-4 days) with LBF of 0.3 ± 0.3 cm2 on a RACL of 3.1 ± 0.9 cm2, a central phase (7-16 days) with LBF of 0.7 ± 0.4 cm2 on a RACL of 4.8 ± 0.8 cm2 and a regression phase (19-20 days) with a minimum LBF of 0.1 ± 0.1 cm2 in a CL of 3.3 ± 0.6 cm2. According to this study, there is no significant difference of LBF from 7 to 16 days of the oestrus cycle; although the RACL significantly changes in this period, the dimensional variations are too thin to be clinically appreciated. However, this study contributed to defining the values of RACL and LBF during a 2-wave oestrous cycle of dairy cattle.

PROGESTERONE IN THE HUMAN PERIPHERAL BLOOD IN THE PREOVULATORY PERIOD OF THE MENSTRUAL CYCLE

1967 ◽  
Vol 55 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Benno Runnebaum ◽  
Josef Zander
Keyword(s):  
Menstrual Cycle ◽  
Corpus Luteum ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Progesterone Secretion ◽  
Graafian Follicle ◽  
The Mean ◽  
Mean Concentration

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.

Ultrastructural studies of the bovine Graafian Follicle and corpus luteum

1968 ◽  
Vol 91 (4) ◽  
pp. 554-573 ◽  
Author(s):  
Janis Priedkalns ◽  
Alvin F. Weber
Keyword(s):  
Corpus Luteum ◽  
Ultrastructural Studies ◽  
Graafian Follicle

A comparative study of the corpus luteum

1995 ◽  
Vol 7 (3) ◽  
pp. 303 ◽  
Author(s):  
RT Gemmell
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Secretory Granules ◽  
Hormonal Control ◽  
Egg Laying ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Embryonic Diapause ◽  
Alternative Reproductive Strategy ◽  
Uterine Development

The corpus luteum (CL) is a transitory organ which has a regulatory role in reproduction. Sharks, amphibians and reptiles have corpora lutea that produce progesterone which influences the rate of embryonic development. The egg-laying monotremes and the two major mammalian groups, eutherian and marsupial, have a CL that secretes progesterone. Most eutherians have allowed for the uterine development of their young by extending the length of the oestrous cycle and the CL or placenta actively secretes progesterone until birth. Gestation in the marsupial does not extend beyond the length of an oestrous cycle and the major part of fetal development takes place in the pouch. Where the extension of the post-luteal phase in the eutherian has allowed for the uterine development of young, the marsupial has extended the pre-luteal phase of the oestrous cycle and has evolved an alternative reproductive strategy, embryonic diapause. The mechanism for the secretion of hormones from the CL has been controversial for many years. Densely-staining secretory granules have been observed in the CL of sharks, marsupials and eutherians. These granules have been reported to contain relaxin, oxytocin or mesotocin, and progesterone. A hypothesis to suit all available data is that all hormones secreted by the CL are transported within such granules. In conclusion, although there are obvious differences in the mode of reproduction in the two main mammalian groups, it is apparent that there is a great deal of similarity in the hormonal control of regression of the CL and parturition.

Studies on Ovarian Follicular Dynamics and Steroid Profiles in Sahiwal Cattle

2021 ◽  
Author(s):  
Vinny Dodiyar ◽  
Parkash Singh Brar ◽  
Narinder Singh ◽  
Mrigank Honparkhe
Keyword(s):  
Corpus Luteum ◽  
Estrous Cycle ◽  
Maximum Diameter ◽  
Endocrine Regulation ◽  
Dominant Follicle ◽  
Estrous Cycles ◽  
Significant Difference ◽  
Sahiwal Cattle ◽  
Sahiwal Cows ◽  
Follicular Dynamics

Background: Understanding of ovarian follicular dynamics and endocrine regulation is essential to design and use interventions to optimize reproductive efficiency. Bos indicus and Bos taurus cows have some differences in their follicular dynamics and ovarian steroidal hormones. The present study was planned to understand follicular dynamics vis-a-vis ovarian steroids profiles in Sahiwal cattle. Methods: The study was conducted in normal cyclic, pluriparous, non-lactating Sahiwal cows (n=7). Trans-rectal ultrasonography was performed to record the location, size, number of follicles and size of corpus luteum (CL) from the beginning, till the end of experiment. The dataset was used to characterize the follicular wave emergence, growth, regression, time of selection and ovulation of the dominant follicle in each cow. Result: Three Sahiwal cows showed two wave and four cows showed three wave estrous cycles with mean interovulatory length of 20.33±0.33 and 22.50±0.28 days, respectively. No significant difference was recorded in the maximum diameter of corpus luteum, P4 and E2 plasma levels between 2-wave and 3-wave estrous cycles. The peak progesterone values of 6.00±0.91 and 6.2±1.2 ng/ml and peak estradiol values of 15.83±0.60 and 14.31±0.44 ng/ml were recorded in 2-wave and 3-wave estrous cycle, respectively. The results showed that Sahiwal cows had 2-wave and 3-wave estrous cycle and the 3-wave estrous cycle had comparatively longer inter-ovulatory period and smaller maximum diameter of second wave dominant follicle than 2-wave estrous cycle.

Reproduction of the Red-Bellied Pademelon Thylogale billardierii (Marsupialia)

1982 ◽  
Vol 9 (1) ◽  
pp. 27 ◽  
Author(s):  
RW Rose ◽  
DJ McCatney
Keyword(s):  
Corpus Luteum ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Seasonal Breeder ◽  
The Mean ◽  
Duration Of Gestation

'Thylogale billardierii, which is abundant in Tasmania, is a seasonal breeder with most births in the months April, May and June. Parturition is followed by mating, and the zygote so produced remains dormant until either sucking becomes intermittent near the end of pouch life or the young is lost. The mean length of the oestrous cycle was determined at 30.3 days, not significantly longer than the duration of gestation (30.2 days). Removal of pouch young results in the birth of a new young 28.7 days later. Removal of the corpus luteum results in oestrus 11 days later. Pouch life is 202 days, and vacation of the pouch by the young coincides precisely with parturition and post-partum mating. The young mature at about 14-15 months.

Induction of estrus by electrical stimulation

1959 ◽  
Vol 196 (4) ◽  
pp. 899-900 ◽  
Author(s):  
R. L. Hays ◽  
C. H. Carlevaro
Keyword(s):  
Electrical Stimulation ◽  
Rectal Wall ◽  
Reproductive Organs ◽  
Normal Heat ◽  
Heat Period ◽  
Stimulation Of

Using the apparatus designed for the electroejaculation of bulls, the reproductive organs of anestrous cows were electrically stimulated through the rectal wall. Forty-three per cent of the cows which had been in anestrus for 50 or more days after calving came in heat within 7 days after an electrical stimulation as compared to 13% of the controls. Fifty per cent of cows which had shown anestrus for 50 or more days after a normal heat period showed estrus in 7 days after stimulation as compared to 5% of the controls. Ovulation occurred at this estrus as determined by palpation and by conception after breeding. It is suggested that gonadotrophic hormones are released due to the stimulation of the reproductive organs.

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