Objective: To compare oestrus synchronisation using two treatments of gonadotropin-releasing hormone (GnRH) and one of prostaglandin F2 alpha (PG) with a double prostaglandin synchronisation protocol under southern Australian conditions.
Design: A clinical trial.
Procedure: Eight hundred and forty, seasonally calving, lactating dairy cows within nine herds in the Tallangatta district of northeast Victoria were randomly allocated to treatment and control groups. The treatment (GnRH) group received gonadotropin-releasing hormone followed by prostaglandin F2 alpha and then a second treatment with gonadotropin-releasing hormone. These cows were inseminated at a fixed time after the second gonadotropin-releasing hormone treatment. Cows in the control (PG) group received two injections of prostaglandin F2 alpha, 14 days apart, and were inseminated according to detected oestrus.
Results: The effect of GnRH treatment on first service conception rate (CRS1) and 30 day pregnancy rate (PR30) varied between herd (P < 0.001 and P < 0.02, respectively). A significant difference in CRS1 between treatment (GnRH) and control (PG) groups existed in pooled data from eight of the nine herds (38.1% vs 65.9%, P < 0.001). A significant difference also existed in PR30 between treatment (GnRH) and control (PG) groups in pooled data from eight of the nine herds (64.1% vs 72.4%, P = 0.03). Pregnancy rates after 56 days of mating for both groups were not significantly different (79.8% vs 84.1%, P = 0.13 for treatment (GnRH) and control (PG) groups, respectively). Submission rates (proportion of cows submitted for insemination) for the treatment (GnRH) groups were 100%. There was significant variation in submission rates in the control (PG) groups.
Conclusion: The GnRH protocol may be of benefit in herds where a poor response to the double prostaglandin program is anticipated. However, in the majority of herds in this trial, the double prostaglandin program achieved better results with fewer inseminations.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1111/j.1751-0813.2000.tb10536.x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Leveraging Model-Based Simulations to Optimize Extended Dosing of Leuprolide 6-Month Intramuscular Depot Formulation.
Eur J Drug Metab Pharmacokinet
January 2025
School of Pharmacy, National Defense Medical Center, Taipei, Taiwan.
Background And Objective: A gonadotropin-releasing hormone (GnRH) agonist such as leuprolide is widely used to achieve sustained suppression of testosterone levels, which play a critical role in the treatment of prostate cancer. Recent advances in drug delivery systems have led to the development of long-acting depot formulations, such as the 6-month intramuscular (IM) leuprolide formulation, which aim to simplify dosing and improve convenience for both patients and healthcare providers. Exploring extended dosing intervals for such formulations represents a promising approach to further optimize treatment regimens, potentially balancing efficacy with patient-centered care.
View Article and Find Full Text PDFSelected plant extracts and female fertility: role in the regulation of the hypothalamo-pituitary-ovarian axis in normal and pathological conditions.
Reprod Fertil Dev
January 2025
CNRS, INRAE, Université de Tours, PRC, Nouzilly, France.
Female infertility, which affects 10-20% of couples worldwide, is a growing health concern in developing countries. It can be caused by multiple factors, including reproductive disorders, hormonal dysfunctions, congenital malformations and infections. In vitro and in vivo studies have shown that plant extracts regulate gonadotropin-releasing hormone, kisspeptin, and gonadotropin expression and/or secretion at the hypothalamic-pituitary level and modulate somatic and germ cells, such as steroidogenesis, proliferation, apoptosis, and oxidative stress at the ovarian level.
View Article and Find Full Text PDFOral contraceptives (OCs) are approved for use after onset of menarche, which is well before brain maturation is complete. OC use may induce biochemical changes in the brain, especially during the neurobiologically dynamic adolescent/young adult years. MicroRNA cargo in L1CAM-associated extracellular vesicles was measured from serum samples collected from young women using the miRCURY LNA miRNA Focus PCR Panel (Qiagen) and validated using quantitative PCR.
View Article and Find Full Text PDFGlutamatergic Input from Arcuate Nucleus Kiss1 Neurons to Preoptic Kiss1 Neurons is Required for LH Surge in Female Mice.
Endocrinology
January 2025
Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, USA.
Hypothalamic kisspeptin (Kiss1) neurons are vital for maintaining fertility in the mammal. In the female rodent, Kiss1 neurons populate the anteroventral periventricular/periventricular nuclei (Kiss1AVPV/PeN) and the arcuate nucleus (Kiss1ARH). Kiss1ARH neurons (a.
View Article and Find Full Text PDFDistribution of the kisspeptin system and its relation with gonadotropin-releasing hormone in the hypothalamus.
Vitam Horm
January 2025
Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina. Electronic address:
Kisspeptin (KISS1), originally catalogued as metastin because of its capacity as a metastasis suppressor in human melanoma and breast cancer, is now recognized as the major puberty gatekeeper and gonadotropin-releasing hormone (GnRH) neuroendocrine system modulator. It is a member of the family of RFamide-related peptides that also includes the neuropeptide FF group, the gonadotropin-inhibitory hormone, the prolactin-releasing peptide, and the 26RFa peptides. The KISS1 precursor peptide is processed into a family of peptides known as kisspeptins.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!