Circumventing the natural, frequent oestrogen waves of the female cheetah (Acinonyx jubatus) using oral progestin (Altrenogest)

2017 ◽  
Vol 29 (8) ◽  
pp. 1486 ◽  
Author(s):  
Adrienne E. Crosier ◽  
Pierre Comizzoli ◽  
Diana C. Koester ◽  
David E. Wildt
Keyword(s):  
Corpus Luteum ◽  
Ovulation Induction ◽  
Wave Pattern ◽  
Follicle Development ◽  
Short Term ◽  
Acinonyx Jubatus ◽  
Ovarian Suppression ◽  
Concentration Pattern ◽  
Glucocorticoid Production ◽  
Follicular Activity

Cheetah are induced ovulators, experiencing short, variable oestrogen waves year-round. Exogenous gonadotrophin administration induces ovulation, but success is variable and often improves if ovaries are quiescent. After affirming the presence of short-term oestrogenic waves, we examined the effect of the timing of administration of exogenous equine and human chorionic gonadotrophins (eCG–hCG) within the oestrogen concentration pattern on subsequent follicle development and oocyte and corpus luteum quality. We also investigated ovarian suppression using an oral progestin (Altrenogest, 7 days) and assessed whether Altrenogest moderated adrenal activity by reducing glucocorticoid metabolites. All cheetahs exhibited short (every ~7–10 days), sporadic, year-round increases in faecal oestradiol punctuated by unpredictable periods (4–10 weeks) of baseline oestradiol (anoestrous). Gonadotrophin (eCG–hCG) efficacy was not affected by oestradiol ‘wave’ pattern if administered ≥3 days after an oestrogen peak. Such cheetahs produced normative faecal progestagen patterns and higher numbers (P < 0.06) of mature oocytes than females given gonadotrophins ≤2 days after an oestradiol peak. Altrenogest supplementation expanded the interval between oestradiol peaks to 12.9 days compared with 7.3 days without progestin pretreatment. Altrenogest-fed females excreted less (P < 0.05) glucocorticoid metabolites than non-supplemented counterparts. Results show that Altrenogest is effective for suppressing follicular activity, may contribute to reduced glucocorticoid production and may result in more effective ovulation induction via gonadotrophin therapy.

scholarly journals Identification of measures predictive of age of puberty onset in gilts

2019 ◽  
Vol 4 (1) ◽  
pp. 285-292 ◽  
Author(s):  
Kody L Graves ◽  
Bethany R Mordhorst ◽  
Elane C Wright ◽  
Benjamin J Hale ◽  
Kenneth J Stalder ◽  
...  
Keyword(s):  
Ovarian Development ◽  
Age At Onset ◽  
Developmental Time ◽  
Follicle Development ◽  
Central Hypothesis ◽  
Estrus Detection ◽  
The Mean ◽  
Puberty Onset ◽  
Time Point ◽  
Follicular Activity

Abstract A potential indicator of female lifetime productivity in swine is age of puberty, when a gilt achieves her first behavioral estrus. Follicular activity, as determined by tertiary follicle development, in prepubertal gilts begins during postnatal day (PND) 75 to 115. The central hypothesis of this study is that gilts demonstrating tertiary follicle development earlier in life, assessed using vulva size as a proxy, achieve puberty earlier in life compared with counterparts of a similar age and weight that lack tertiary follicle development. The objectives of this project were to identify a developmental time point when variation in ovarian development exists and to determine whether a relationship between the age prepubertal ovarian development and the age at onset of puberty exists. To accomplish this, 155 gilts of similar age (± 2 d) were weighed and vulva size measured on PND 75, 85, 95, 105, and 115. Vulva measures, including vulva width (VW), vulva length (VL), and vulva area (VA), were utilized as developmental proxies for follicular activity. At each time point, gilts (n = 10) were sacrificed and ovarian follicular activity recorded. In a subset of gilts (n = 105), estrus detection was conducted daily on PND days 126 to 200. Mean VA on PND 75, 85, 95, 105, and 115 was 596 ± 206, 683 ± 190, 864 ± 212, 1014 ± 228, and 1265 ± 252 mm2, respectively. Of the gilts demonstrating behavioral estrus, 28 were within PND 140 to 160, 36 between PND 161 to 180, 15 between PND 181 to 200, and 26 did not demonstrate estrus behavior within 200 d of age. All gilts euthanized at PND 75 lacked follicular activity as defined by having a minimum of 2 antral follicles per ovary, whereas 60%, 80%, 90%, and 100% demonstrated follicular activity on PND 85, 95, 105, and 115, respectively. Body weight at PND 75 and VW at PND 115 were correlated to age at first estrus (P &lt; 0.05). Of the gilts whose VA was less than 1 SD from the mean on PND 95 (i.e., &lt;652 mm2), 31% and 50% demonstrated their first behavioral estrus by PND 180 and 200, respectively. However, of gilts whose VA was within or greater than 1 SD of the mean (i.e., ≥652 mm2), 66% and 79% exhibited estrus prior to PND 180 and 200, respectively. These data support utilization of VA changes between 95 and 115 d of age as a useful tool to identify replacement gilts prior to puberty for inclusion into the sow herd.

109 EFFECT OF SHORT TERM PROGESTERONE SUPPLEMENTATION ON CIRCULATING PROGESTERONE CONCENTRATION, CORPUS LUTEUM SIZE, AND EARLY EMBRYO DEVELOPMENT IN CATTLE

2013 ◽  
Vol 25 (1) ◽  
pp. 202
Author(s):  
L. O'Hara ◽  
N. Forde ◽  
D. Rizos ◽  
V. Maillo ◽  
A. D. Ealy ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Early Embryo ◽  
Negative Effects ◽  
Short Term ◽  
Concentration Data ◽  
Interferon Tau ◽  
Fluid Medium ◽  
Conceptus Development ◽  
Oviduct Fluid

The aim of this study was to investigate the effect of short term progesterone (P4) supplementation on circulating P4 concentrations, corpus luteum (CL) size, and conceptus development in cattle. The oestrous cycles of crossbred beef heifers were synchronised using a 7-day PRID® Delta (1.55 g P4) treatment with administration of a PGF2α analog (Enzaprost®) the day before PRID® Delta removal. Only those recorded in standing oestrus (Day 0) were used. In Experiment 1, heifers were randomly assigned to 1 of 5 groups: (1) control: no treatment, (2) placebo: insertion of a blank device (no P4) from Day 3 to 7, (3) insertion of a PRID® Delta from Day 3 to 7, (4) insertion of a PRID® Delta from Day 3 to 5, or (v5) insertion of a PRID® Delta from Day 5 to 7. In vitro produced blastocysts were transferred to each heifer on Day 7 (10 blastocysts per heifer) and conceptuses were recovered at slaughter on Day 14. In Experiment 2 heifers were artificially inseminated at oestrus and randomly assigned to 1 of 3 treatment groups (1) placebo, (2) PRID® Delta from Day 3 to 5, or (3) PRID® Delta from Day 3 to 7. All heifers were slaughtered on Day 16, and recovered conceptuses were incubated in synthetic oviduct fluid medium for 24 h; spent media and uterine flushes were analysed for interferon-tau (IFNT). In both experiments, daily blood samples were taken to measure serum P4 concentration. Data were analysed using the PROC MIXED procedure of SAS (SAS Institute Inc., Cary, NC, USA). Insertion of a PRID® Delta resulted in an increase (P < 0.05) in serum P4, which declined following removal. In Experiment 1, serum P4 concentration was significantly lower from Day 9 to 14 (P < 0.05) and Day 14 CL weight was lower in the PRID® Delta Day 3 to 7 group than the placebo or control groups. P4 supplementation from Day 3 to 5 (17.0 ± 1.4 mm) or Day 3 to 7 (11.3 ± 2.3 mm) increased conceptus length compared to the placebo (2.1 ± 1.8 mm). In Experiment 2, serum P4 was significantly lower in the two supplemented groups following PRID® Delta removal compared with the placebo (P < 0.05) and was associated with a lower CL weight in the Day 3 to 7 group. Supplementation from Day 3 to 5 (94.0 ± 18.8 mm) or Day 3 to 7 (143.6 ± 20.6 mm) increased conceptus length on Day 16 compared to the placebo (50.3 ± 17.4 mm). Conceptus length was strongly correlated with the concentration of IFNT in the uterine flush (r = 0.58; P = 0.011) and spent culture medium (r = 0.68; P < 0.002). These findings highlight the somewhat paradoxical effects of P4 supplementation when given in the early metoestrus period in terms of its positive effect on conceptus development and its potentially negative effects on CL lifespan. Supported by CEVA Sante Animale and Science Foundation Ireland (07/SRC/B1156).

scholarly journals A review of the physiology behind letrozole applications in infertility: are current protocols optimal?

2020 ◽  
Vol 37 (9) ◽  
pp. 2093-2104
Author(s):  
Bruce I. Rose ◽  
Samuel E. Brown
Keyword(s):  
Ovulation Induction ◽  
Medical Literature ◽  
Negative Impact ◽  
Follicle Development ◽  
Antral Follicles ◽  
Ovulatory Follicle ◽  
Menopausal Women ◽  
Post Menopausal ◽  
Cell Mitosis ◽  
Physiologic Data

Abstract Letrozole is a targeted aromatase inhibitor which has primarily been used in post-menopausal women with breast cancer. Recently, it has been utilized in infertile pre-menopausal women because of its ability to enhance FSH production for ovulation induction. However, the ovarian follicle’s response to FSH is only a part of the endocrine events occurring in a developing follicle. The health of the small antral follicles is driven primarily by androgens, which contribute to granulosa cell mitosis, sensitivity to FSH, and resistance to atresia. In contrast, elevated androgens in the late antral to pre-ovulatory follicle have a negative impact on follicle health and lead to atresia and cystic follicle formation. This ovarian physiologic data suggests that current applications of letrozole to infertility may be squandering some of the primary benefits available in using letrozole to promote follicle development. Four applications of letrozole to infertility that have appeared in the medical literature are reviewed. Androgen-related benefits are reviewed and various questions put forward about how letrozole could be more effectively used to help patients in these settings.

Seasonal changes in the ovarian structure ofthe Cape fur seal, Arctocephalus pusillus pusillus

2002 ◽  
Vol 50 (5) ◽  
pp. 491 ◽  
Author(s):  
P. N. Odendaal ◽  
M. N. Bester ◽  
M. van der Merwe ◽  
W. H. Oosthuizen
Keyword(s):  
Corpus Luteum ◽  
Seasonal Changes ◽  
Maximum Size ◽  
Annual Reproductive Cycle ◽  
Histological Changes ◽  
Naked Eye ◽  
Fur Seal ◽  
Ovarian Structure ◽  
Cape Fur Seal ◽  
Follicular Activity

The annual reproductive cycle of the female Cape fur seal (Arctocephalus pusillus pusillus) was described by noting monthly gross changes in ovaries from 159 females, histological changes in 46 females and placental scars in 119 females. The size and weight of an ovary containing a corpus luteum was significantly greater than that of an ovary containing a corpus albicans for most of the year, the latter only approaching, or exceeding the former during the breeding season. Follicular activity initially increased in ovaries containing either a corpus luteum or a corpus albicans; however, it declined in the ovary containing a corpus luteum after implantation, while in that containing a corpus albicans it increased, reaching a maximum in December of 32.0 ± 10.08 follicles, averaging 5.41 ± 0.73 mm. The corpus luteum increased in size following ovulation, attaining a maximum size of 22.28 ± 3.38 mm in August (eight months after ovulation). Thereafter, it gradually decreased in size, generally becoming invisible to the naked eye by 30–32 months after ovulation. Luteal cells increased until seven months after ovulation, reaching a maximum size of 34.36 ± 1.26 μm before regressing, disappearing from the corpus luteum by 18 months after ovulation. Using placental scarring and CA counts in 119 females, a pregnancy rate of 77.4% was calculated, with 6.5% abortions and 16.1% non-implantations making up the remainder.

scholarly journals 204 ASSOCIATION BETWEEN SOME ULTRASONIC CHARACTERISTICS OF CORPUS LUTEUM ANDPROGESTERONE VALUES IN CASPIAN MINIATURE MARES

2005 ◽  
Vol 17 (2) ◽  
pp. 252
Author(s):  
F. Gharagozloo ◽  
A. Shirazi
Keyword(s):  
Corpus Luteum ◽  
Maximum Size ◽  
Wave Pattern ◽  
Repeated Measure ◽  
Minimum Size ◽  
Blood Collection ◽  
Hormonal Changes ◽  
Estrus Cycle ◽  
Plasma Progesterone ◽  
Caspian Miniature Horse

Reproductive characteristics of the Caspian miniature horse have some similarities to other equine breeds, but several differences such as follicular wave pattern, multiple ovulations, and the size of ovulatory follicle have been reported. Still there are some other characteristics to be determined. This study was carried out to investigate ultrasonic and hormonal changes of the Caspian mares during estrus cycle. Eleven clinically healthy and cycling Caspian mares, aged 3–17 years and weighing 159–236 kg L.W., were used from April to July. Using an ultrasound scanner equipped with a 5-MHz, B-mode, linear array rectal transducer, formation of the corpus luteum was observed from Day 0 (day of ovulation), and changes in plasma progesterone were investigated by daily blood collection and assay by means of an RIA method. Repeated measure ANOVA test was used for statistical analysis. The maximum size of the corpus luteum was seen at Day 3 postovulation (36.6 ± 1.91 mm), and remained up to 10 days after ovulation. At Days 10–11 a significant decrease in size was observed; thereafter gradual regression occurred and minimum size was reached by Days 16–17 (17.3 ± 1.46 and 16.9 ± 1.20 mm, respectively). The first significant increase in progesterone level was detected 24 h after ovulation and average high values of 8 ng/mL by Day 4 after ovulation. The average peak value of progesterone was detected on Days 7 to 10 of the cycle (11.6 ± 1.37 ng/mL) and remained so until Day 12. The lowest plasma progesterone concentration (less than 1 ng/mL) was observed from Day 14 till one day postovulation, coinciding with the CL regression found in sonographic observations. The results of this study revealed that the pattern of corpus luteum formation and Its changes in size and the plasma progesterone levels during the estrus cycle in this breed follow a pattern similar to that of other equine breeds. The authors wish to thank the University of Tehran for funding and Khojir stud farm for providing animals.

scholarly journals Supplementation of c-type natriuretic peptide during the whole in vitro growth period benefits the development of murine secondary follicles

2020 ◽  
Author(s):  
Ang Li ◽  
Haixia Cao ◽  
Hongxia Li ◽  
Ruijiao Li ◽  
Huaixiu Wang ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Ovulation Induction ◽  
Germinal Vesicle ◽  
Antral Follicle ◽  
Control Group ◽  
Follicle Development ◽  
In Vitro Growth ◽  
Germinal Vesicle Breakdown ◽  
Preovulatory Follicles

Abstract Background Supplementation of c-type natriuretic peptide (CNP) in the culture medium shortly before in vitro maturation (IVM) has been reported to be effective in delaying meiotic resumption of murine oocyte. The present study investigated the effect of CNP supplementation during the whole period of in vitro growth (IVG) on the development of murine secondary ovarian follicles.Methods Late secondary ovarian follicles isolated from ovaries of Kunming mice were cultured in vitro with and without supplementation of CNP. In experiment 1, CNP was supplemented at the early stage and the follicle development was evaluated. In experiment 2 and 3, CNP was supplemented during the whole period of IVG. In experiment 2, follicle development and oocyte maturity were evaluated. In group 3, follicle development and rate of cleaved embryos after in vitro fertilization (IVF) was assessed.Results In control group in all 3 experiments, granulosa cells migrated from within follicle and adhered to the plate at different degrees. The follicles flattened and could not reach antral stage. About 39.8% (39/98) of the oocytes ovulated nakedly. As no antral follicle was obtained, IVF was not performed in control group in experiment 3. In experiment group in all 3 experiments, no migration of guanulosa cells was observed and the follicles grew three-dimensionally. Ovulation of naked oocyte decreased substantially. The rate of antral stage follicle were 45% (18/40) in experiment 1. This parameter was 75.9% (44/58) in experiment 2 and 3 combined. In experiment 2, in preovulatory follicles without ovulation induction, oocytes at germinal vesicle (GV) stage and germinal vesicle breakdown (GVBD) stage were 87.5% (14/16) and 12.5% (2/16), respectively. In preovulatory follicles with ovulation induction, no GV stage oocyte was retrieved, oocytes at GVBD and metaphase II (MII) stage were 50% (8/16), respectively. In experiment 3, among 18 follicles cultured, 12 cumulus-oocyte complexes (COC) ovulated automatically after ovulation induction. Eleven oocytes were fertilized and cleaved. Compared with control groups, the follicle development assessed by naked oocyte ovulation and follicle stage (preantral follicle and antral follicle) in experiment groups were significantly superior (p<0.0001). CNP effectively maintained oocytes’ meiotic arrest and enhanced fertilization competency.Conclusions The supplementation of CNP in culture system of murine late secondary follicle during the whole period of IVG could sustain the 3-dimensional structure of follicle, increase the antral formation rate. As a result, the oocyte’s competency to be fertilized was greatly improved.

scholarly journals Effect of GnRH treatment following a short-term estrous induction protocol on estrus and ovulation in Saanen goats, during the transitional period

2021 ◽  
Vol 71 (4) ◽  
pp. 2569
Author(s):  
I. DOGAN ◽  
M. B. TOKER ◽  
S. ALCAY ◽  
D. UDUM KUCUKSEN
Keyword(s):  
Transition Period ◽  
Plasma Concentrations ◽  
Physiological Saline ◽  
Transitional Period ◽  
Follicle Development ◽  
Estrus Cycle ◽  
Short Term ◽  
Pooled Data ◽  
Buserelin Acetate ◽  
Synchronization Protocol

The objective of this study was to compare the effect on the ovulation time and estrus parameters of a GnRH agonist (buserelin acetate) administered 24 or 36 h following a short-term estrus induction and synchronization treatment in non-lactating Saanen goats during the transitional period. Goats received 20 mg FGA sponges for 6 days plus 300 IU eCG and 125 μg d-cloprostenol 24 h prior to sponge removal. After removal of the sponges, goats were given either 1 ml physiological saline (0.9% NaCI) solution (Group1; n = 9) after 12 h, 0.004 mg GnRH (Group2; n = 10) after 24 h or 0.004 mg GnRH (Group3; n = 10) after 36 h. The follicle development and ovulation in the ovaries were monitored by transrectal ultrasonography starting from the sponge application until the fifth day of the estrus cycle. Blood samples were collected on the same days to determine the plasma concentrations of progesterone (P4) and estradiol (E2). No statistical differences among groups were detected in any synchronization parameters, ultrasonic evaluations and plasma P4 and E2 concentrations. The evaluation of pooled data showed that the response of Saanen goats to treatments was comparable to the results of other published trials. Results of this study indicate that administration of GnRH at 24 h or 36 h after sponge removal, at the end of a short estrus induction and synchronization protocol, does not affect plasma P4 and E2 concentrations, estrus parameters and ovulation time in goats, during the transition period.

scholarly journals Biological and technological background of estrus synchronization and fixed-time ovulation induction in the pig

2011 ◽  
Vol 27 (3) ◽  
pp. 533-545 ◽  
Author(s):  
K.P. Brüssow ◽  
M. Wähner
Keyword(s):  
Ovulation Induction ◽  
Current Knowledge ◽  
Follicular Development ◽  
Fixed Time ◽  
Follicle Development ◽  
Endocrine Regulation ◽  
Estrus Synchronization ◽  
Gnrh Analogues ◽  
Active Substances ◽  
Poor Management

A technology that allows for manipulating of estrus and ovulation, and would then also allow for fixed-time insemination, can be of great benefit for swine farms that operate using sow batch management. Such technology at least in part, saves labor and permits the production of large batches of evenly developed pigs. Thanks to the current knowledge on endocrine regulation of follicle development and ovulation, and the availability of numerous reproductively active substances such a technology is now available. This 'biotechnology of reproduction' will be reviewed. It covers procedures for synchronizing estrus based on the use of altrenogest in gilts and of batch-wise weaning in sows, for stimulating follicle development using eCG and for inducing of ovulation using hCG or LH as well as GnRH analogues. While the procedures for estrus synchronization stand alone, other procedures require additional treatments. If fixed-time insemination is the goal, estrus needs to be synchronized and follicular development and ovulation induced by the use of GnRH analogues and hCG with ovulation occurring within 36-42 hrs. It is a general recommendation to inseminate those animals twice, i.e. 24 and 40 hrs after ovulation induction. However, the aforementioned technology requires healthy animals and a solid management and cannot be used to compensate for poor management.

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