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.

scholarly journals Proteomic Analysis Identifies Potential Markers for Chicken Primary Follicle Development

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1108
Author(s):  
Armughan Ahmed Wadood ◽  
Jingyuan Wang ◽  
Liping Pu ◽  
Qaisar Shahzad ◽  
Muhammad Waqas ◽  
...  
Keyword(s):  
Proteomic Analysis ◽  
Egg Production ◽  
Potential Role ◽  
Protein Localization ◽  
Follicular Development ◽  
Egg Laying ◽  
Follicle Development ◽  
Phosphate Binding ◽  
Primary Follicle ◽  
Mannose Metabolism

Follicles’ development in chicken imparts a major impact on egg production. To enhance the egg-laying efficiency, comprehensive knowledge of different phases of follicular development is a prerequisite. Therefore, we used the tandem mass tag (TMT) based proteomic approach to find the genes involved in the primary follicular development of chicken. The primary follicles were divided into two groups—small primary follicles (81–150 μm) and developed primary follicles (300–500 μm). Differential expression analysis (fold change > 1.2, p-value < 0.05) revealed a total of 70 differentially expressed proteins (DEPs), of which 38 were upregulated and 32 were downregulated. Gene ontology (GO) enrichment analysis disclosed that DEPs were intricate with cellular protein localization, the establishment of protein localization, and nucleoside phosphate-binding activities. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway indicated the involvement of DEPs in different metabolic pathways such as glycolysis, pyruvate metabolism, galactose metabolism, and fructose and mannose metabolism. The current proteomic analysis suggested suitable markers such as Anxa2, Pdia3, and Capzb, which may serve as a potential role for primary follicle development. The present study provides the first insight into the proteome dynamics of primary follicle development and would play a potential role for further studies in chicken to improve egg productivity.

The effect of acute immuno-neutralisation of inhibin in ewes during the early luteal phase of the oestrous cycle on ovarian hormone secretion and follicular development

1995 ◽  
Vol 145 (3) ◽  
pp. 479-490 ◽  
Author(s):  
B K Campbell ◽  
B M Gordon ◽  
C G Tsonis ◽  
R J Scaramuzzi
Keyword(s):  
Luteal Phase ◽  
Follicular Development ◽  
Experimental Period ◽  
Ovarian Follicles ◽  
Passive Immunisation ◽  
Follicle Development ◽  
Ovarian Steroid ◽  
Blood Samples ◽  
Steroid Secretion ◽  
Antibody Titres

Abstract Ewes with ovarian autotransplants received either inhibin antiserum (10 ml i.v. raised in sheep against recombinant 32 kDa human inhibin; n=6) or sheep serum (10 ml i.v.; n=5) on day 3 of the luteal phase with additional daily injections (1 ml i.v.) from 48 h after the initial bolus until day 13. Jugular and ovarian venous blood samples were taken 4-hourly over days 2–13 of the luteal phase. Blood samples were also taken at more frequent intervals (every 10–15 min for 2–3 h) to examine pulsatile secretory responses from the ovary to endogenous and gonadotrophin-releasing hormone-induced (150 ng i.m.) LH pulses on days 4, 6, 8, 10 and 12 of the luteal phase. Plasma FSH levels, ovarian steroid secretion and ovarian follicular development were measured. The ovarian follicle population was estimated daily by real time ultrasound scanning. Immunisation against inhibin resulted in a 3- to 4-fold increase (P<0·001) in plasma FSH levels within 8 h with levels remaining elevated over controls for 6–7 days. Within 24 h of immunisation there was an increase in the number of small ovarian follicles (P<0·05) and by 3 days after treatment immunised ewes had 4–6 large ovarian follicles/ewe with this increase in the total number of large follicles being maintained for the rest of the experimental period (P<0·05). Mean ovarian oestradiol secretion during intensive bleeds was not different from controls 24 h after immunisation, but by 3 days after immunisation it was elevated 4- to 5-fold (P<0·001) over controls with this increase being maintained throughout the experiment. Similar responses to immunisation against inhibin in androstenedione secretion were observed although mean androstenedione secretion was not elevated until 7 days after treatment. In vitro antibody titres in immunised ewes remained elevated but declined steadily (P<0·001) over the experimental period. We conclude that the initial stimulation of follicle development and ovarian steroid secretion following passive immunisation against inhibin can be attributed to increased blood FSH. However, the fact that with time FSH declined but increased follicle development was sustained, despite maintenance of high circulating antibody titres, suggests that on a longer term basis inhibin immunisation may stimulate ovarian function by interfering with the modulation of follicle development by inhibin at an ovarian level. Journal of Endocrinology (1995) 145, 479–490

scholarly journals Effects of IGF-I bioavailability on bovine preantral follicular development in vitro

Reproduction ◽  
2007 ◽  
Vol 133 (6) ◽  
pp. 1121-1128 ◽  
Author(s):  
Fiona H Thomas ◽  
Bruce K Campbell ◽  
David G Armstrong ◽  
Evelyn E Telfer
Keyword(s):  
Follicular Development ◽  
Follicle Development ◽  
Dependent Manner ◽  
Igf Binding Proteins ◽  
Preantral Follicles ◽  
Follicle Diameter ◽  
Igf I ◽  
Igf Binding ◽  
Development In Vitro

The aim of this study was to determine the effect of regulation of IGF-I bioavailability on preantral follicle development in vitro. Bovine preantral follicles were cultured for 6 days in serum-free medium with increasing doses of Long R3 (LR3) IGF-I (an analog with low affinity for IGF-binding proteins (IGFBPs)), or human recombinant IGF-I (hrIGF-I). Follicle diameter and estradiol production were measured every second day. On day 6, ratios of oocyte/follicle diameter and oocyte morphology were assessed by histological examination, and IGFBP-2 and -3 were detected by immunocytochemistry and in situ hybridization respectively. Both types of IGF-I increased follicle diameter in a dose-dependent manner (P < 0.05) and increased estradiol production over control levels (P < 0.05). However, follicles treated with LR3 IGF-I and the highest concentration of hrIGF-I (1000 ng/ml) had smaller oocyte/follicle ratios, and increased oocyte degeneration, compared with controls or follicles treated with physiological concentrations of hrIGF-I (P < 0.05). IGFBPs were detected in cultured preantral follicles, indicating a requirement for regulation of IGF bioavailability during the early stages of follicular development. Specifically, IGFBP-3 mRNA was found to be expressed in oocytes, and IGFBP-2 immunoreactivity was detected in oocytes and granulosa cells of cultured follicles. In summary, the regulation of IGF-I bioavailability by IGFBPs is necessary for the co-ordination of oocyte and follicle development in vitro.

scholarly journals Importance of Dietary Phosphorus for Bone Metabolism and Healthy Aging

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3001
Author(s):  
Juan Serna ◽  
Clemens Bergwitz
Keyword(s):  
Bone Metabolism ◽  
Inorganic Phosphate ◽  
Healthy Aging ◽  
Current Knowledge ◽  
Atp Synthesis ◽  
The Body ◽  
Endocrine Regulation ◽  
Critical Function ◽  
Dietary Phosphorus ◽  
Different Tissues

Inorganic phosphate (Pi) plays a critical function in many tissues of the body: for example, as part of the hydroxyapatite in the skeleton and as a substrate for ATP synthesis. Pi is the main source of dietary phosphorus. Reduced bioavailability of Pi or excessive losses in the urine causes rickets and osteomalacia. While critical for health in normal amounts, dietary phosphorus is plentiful in the Western diet and is often added to foods as a preservative. This abundance of phosphorus may reduce longevity due to metabolic changes and tissue calcifications. In this review, we examine how dietary phosphorus is absorbed in the gut, current knowledge about Pi sensing, and endocrine regulation of Pi levels. Moreover, we also examine the roles of Pi in different tissues, the consequences of low and high dietary phosphorus in these tissues, and the implications for healthy aging.

scholarly journals 215SUCCESSFUL OUT-OF-BREEDING SEASON ESTRUS SYNCHRONIZATION FOLLOWED BY FIXED TIME INSEMINATION IN WATERBUFFALO (BUBALUS BUBALIS)

2004 ◽  
Vol 16 (2) ◽  
pp. 229 ◽  
Author(s):  
R.M. Züge ◽  
U. Rodacki ◽  
A.T. Grandi ◽  
J.M.J. Aerts ◽  
P.E.J. Bols
Keyword(s):  
Breeding Season ◽  
Buenos Aires ◽  
Fixed Time ◽  
Estradiol Benzoate ◽  
Sao Paulo ◽  
Reproductive Efficiency ◽  
São Paulo ◽  
Estrus Synchronization ◽  
The Impact ◽  
Synchronization Protocol

The most important barrier to the increase of buffalo productivity is an overall poor reproductive efficiency, characterized by late sexual maturity, seasonal anestrus and long periods of postpartum ovarian inactivity resulting in extended calving intervals and poor expression of estrus behavior (Singh J et al., 2000, Anim. Reprod. Sci. 60–61, 593–604). Buffaloes are seasonal breeders with the highest reproductive activities during winter (short day lengths) and a high frequency of anestrus during the summer months (Singh G et al. 1985, Ind. J. Anim. Res. 19, 57–60). Recent research demonstrated that a combination of progesterone, estradiol benzoate and equine chorionic gonadotropin (eCG) was effective for estrus induction and synchronization in buffalo heifers under Mediterranean conditions (Barile et al. 2001, Livestock Prod. Sci. 68, 283–287). The aim of the present study was to investigate the impact of an estrus synchronization protocol on reproductive efficiency of water buffalo during out of the normal breeding season. A total of six heifers (21 to 23 months of age) and three cows (5, 6 and 18 years of age) were enrolled in an estrus synchronization protocol lasting for 12 days. All animals were kept under tropical conditions in the coastal part of Paraná (Antonina), about 450km south of São Paulo. The experiment was performed in December, 2002, during the Brazilian summer season, when reproductive efficiency of buffaloes is greatly reduced. On the first day of the protocol (Day 0), animals were implanted with an intravaginal device containing 1g of progesterone (DIB, Syntex SA, Buenos Aires, Argentina) and injected with 10mg estradiol benzoate (Estrogin, Famavet, São Paulo, Brazil). On Day 9, the DIB implant was removed and the animals received 150μg (i.m.) of cloprostenol (Prolise, Syntex SA, Buenos Aires, Argentina) and 2500 IU of eCG (Novormon, Syntex SA, Buenos Aires, Argentina). On Day 11, all animals received 1500 IU of hCG (Vetecor, Lab. Calier, Spain). Artificial insemination (AI) was performed on Day 12 using frozen-thawed semen from a bull of proven fertility. Only one AI was performed per heifer/cow. Pregnancies were determined by ultrasound examination at 53 days following AI and confirmed by rectal palpation at 90 days post AI. The use of this estrus synchronization protocol, followed by fixed-time insemination, resulted in four pregnant heifers (66%) and three pregnant cows (100%). Our results demonstrate that buffalo reproduction can be successful during out-of-breeding season when adequate hormonal treatment is used. Additional experiments should be done to validate the protocol.

175 FOLLICULAR DEVELOPMENT AND OVARIAN BLOOD FLOW IN MARES WITH EARLY OR LATE OVULATION POSTPARTUM

2015 ◽  
Vol 27 (1) ◽  
pp. 178
Author(s):  
K. M. Lemes ◽  
L. A. Silva ◽  
E. C. C. Celeghini ◽  
M. A. Alonso ◽  
G. Pugliesi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Postpartum Period ◽  
Follicular Development ◽  
Ovarian Activity ◽  
Follicle Development ◽  
Follicular Growth ◽  
Dominant Follicle ◽  
Vascular Perfusion ◽  
Early Postpartum ◽  
Linear Probe

The postpartum period is characterised by the rapid uterine involution process and return of ovarian activity (foal heat), resulting in a fertile oestrus in most of the mares. However, the follicular development and selection processes during this period are not completely known in horses. We aimed to study the characteristics of follicular growth and vascular perfusion in the ovary during the early postpartum period in mares that demonstrated oestrous behaviour and had early (<10 days) or late (≥10 days) ovulation. Ten mares were scanned daily from the first day postpartum (Day 1) until the day of the first postpartum ovulation (Day 0). The animals were split in the early (n = 3) and late (n = 7) ovulation groups (averaged interval between parturition and ovulation: 8.0 ± 0.0 and 14.7 ± 1.2 days, respectively). For ultrasound exams a Duplex B-mode and colour Doppler instrument (M5VET®, Mindray, Shenzhen, China) was used with a multifrequency linear probe. Data were analysed for the main effects of group, day, and their interaction using the PROC MIXED procedure of SAS software (version 9.3, SAS Institute Inc., Cary, NC, USA). For the follicular growth, no difference (P > 0.05) was detected between the groups when the data were analysed for the days relative to ovulation (from Day 7 to Day 1). However, the dominant follicle was larger (P < 0.05) in the early-ovulated group (37.2 ± 1.6 v. 21.9 ± 1.1) in all days during early postpartum (Day 1 to Day 7). The number of follicles with >25 mm diameter was also greater (P < 0.05) in the early-ovulated group (1.1 ± 0.1 v. 0.1 ± 0.1) during the first 3 days postpartum. In addition, the late-ovulated mares showed greater number of follicles with 20–25 mm during Day 4 to Day 7 (2.0 ± 0.2 v. 0.7 ± 0.1). For the blood flow characteristics, no difference (P > 0.05) was detected in the coloured signals of blood flows in the follicular wall of the dominant follicle or in the ovarian pedicle ipsilateral to the largest follicle. Therefore, the characteristics of the follicle growth on the preceding days of ovulation were similar between the early- and late-ovulated mares and consistent with the follicular dynamics expected in non-pregnant and non-lactating mares. However, when the data were analysed for the days relative to parturition, a greater follicle development was present in mares that ovulate earlier during the postpartum period (<10 days). In conclusion, the results suggest that important events may occur previous to the parturition, resulting in an early follicle development, mainly in those mares that show heat signs and ovulate within 10 days postpartum. Research was supported by FAPESP process number 2010/10692-9 and CNPq process number 135954/2011-8.

509. REGULATING MURINE FOLLICLE DEVELOPMENT BY STIMULATION OF THE JAK2/STAT3 SIGNAL TRANSDUCTION PATHWAY

2009 ◽  
Vol 21 (9) ◽  
pp. 108
Author(s):  
R. A. Keightley ◽  
B. Nixon ◽  
S. D. Roman ◽  
D. L. Russell ◽  
R. L. Robker ◽  
...  
Keyword(s):  
Significant Role ◽  
Granulosa Cells ◽  
Ovarian Follicle ◽  
Expression Patterns ◽  
Follicular Development ◽  
Janus Kinase ◽  
Follicle Development ◽  
Mrna Levels ◽  
Primordial Follicles ◽  
Stat3 Signalling

Follicular development requires the recruitment of primordial follicles into the growing follicle pool following initiation of multiple cytokine signalling pathways. Suppression of follicular development is thought to be key to maintaining the population of primordial follicles and allowing for controlled release of these follicles throughout the reproductive lifespan of the female. However, little is known of the processes and signalling molecules that suppress primordial follicle activation and early follicle growth. Our group has identified significant upregulation of the Janus Kinase 2 (JAK2)/ Signal Transducer and Activator of Transcription 3 (STAT3) signalling pathway inhibitor the Suppressor of Cytokine Signalling 4 (SOCS4) that coincides with the initial wave of follicular activation in theneonatal mouse ovary. Further studies by our group have localised the SOCS4 protein to the granulosa cells of activating and growing follicles, suggesting SOCS4 expression may be linked to follicular activation. We have focused on examining protein localisation and gene expression patterns of the eight SOCS family members CIS and SOCS1-7. We have recently demonstrated that co-culture of neonatal ovaries with Kit Ligand (KL) for 2 days increases the mRNA levels of all SOCS genes. We also demonstrated the co-localisation of SOCS2 proteins with the KL receptor c-kit in the mural granulosa cells of antral, and large pre-antral follicles suggesting a significant role for SOCS2 in the later stages of follicular development. We have also shown that culturing ovaries with the potent JAK2 inhibitor AG490 substantially reduces mRNA levels of all SOCS and STAT genes that we have so far measured. We hypothesise a significant role for JAK2/STAT3 signalling in promoting the activation and early growth of ovarian follicles. Our investigations have identified significant roles for JAK2/STAT3 and the SOCS family in the regulation of ovarian follicle development.

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.

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