This review updates the causal mechanisms and risk factors for multiple ovulations (MOV) in cattle. Clearly, MOV can lead to twin pregnancies, which negatively affects the health, production, and reproduction of cows. Therefore, a better understanding of the factors causing MOV may help to reduce twinning. Multiple ovulations occur after two or more follicles deviate and achieve codominance. The MOV rate is influenced by a complex network of hormones. For example, MOV is more common during periods of low progesterone (P4), that is, in anovulatory cattle or when luteolysis coincides with the selection of the future ovulatory follicle. There is also strong evidence for the luteinizing hormone (LH) being the primary factor leading to codominance, as high P4 concentrations suppress the transient LH surges and can reduce the ovulation rate in cattle or even inhibit deviation. Rates of MOV are increased in older and higher-producing dairy cows. Increased milk production and dry matter intake (DMI) increases hormone clearance, including P4; however, the association between milk yield and MOV has not been consistent. Additional risk factors for MOV include ovarian cysts, diet, season, and genetics.
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http://dx.doi.org/10.3390/ani8050062 | DOI Listing |
Cancer Cell Int
December 2024
Center for Prevention and Therapy of Gynecological Cancers, Department of Research, Hualien, 970, Taiwan, ROC.
Mol Med
December 2024
Reproductive Medicine Center, Shunde Hospital of Southern Medical University (The First People's Hospital of Shunde), Foshan, 528300, China.
Background: Primordial follicle activation is vital for the reproduction of women with advanced age and premature ovarian insufficiency (POI). But there is a lack of effective and safe therapeutic options to activate their primordial follicles in vivo. Berberine (BBR) possesses multiple pharmacological properties, but its impact on primordial follicle activation remains unclear.
View Article and Find Full Text PDFNutrients
November 2024
Experimental Gynaecology, Obstetrics and Gynaecological Endocrinology, Johannes Kepler University Linz, Altenberger Strasse 69, 4040 Linz, Austria.
Unlabelled: Female fertility and reproductive system disorders are influenced by a complex interplay of biological, physiological, and environmental factors. Minerals have emerged as crucial yet often overlooked elements that impact fertility and the prevalence of reproductive system disorders.
Background/objectives: This review aims to provide a comprehensive overview of the multifaceted role of minerals in female fertility, focusing on key areas such as oocyte quality, ovulation, embryo development, oxidative stress, miscarriage, hormonal regulation, environmental exposure, and in-vitro fertilization (IVF) outcomes.
Hum Reprod
December 2024
Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
Study Question: Are there differences in psychosocial and physical wellbeing among women and male partners undergoing modified natural cycle (mNC) frozen embryo transfer (FET) in immediate compared to postponed cycles after ovarian stimulation (OS) and oocyte pick-up (OPU)?
Summary Answer: Significantly more women in the immediate group reported physical symptoms than women in the postponed group whilst fewer were emotionally affected by waiting time, although the latter difference lost statistical significance after adjustment for multiple testing.
What Is Known Already: Infertility and fertility treatment are known to cause psychosocial distress in women and couples longing for a child. The treatment may be long-term and delayed for various reasons, such as the elective postponement of FET after a fresh transfer without pregnancy or an elective freeze-all cycle, possibly further increasing the level of distress.
J Dairy Sci
December 2024
Department of Medical Science, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706. Electronic address:
The present study aimed to determine the relationship between circulating progesterone (P4) concentrations and milk yield during the ovulatory follicular wave on the proportion of multiple ovulation in multiparous high-producing Holstein cows (n = 1,345). First-service multiparous cows submitted to a Double-Ovsynch program (GnRH; 7 d later, PGF; 3 d later, GnRH; 7 d later, GnRH [G1]; 7 d later, PGF [PG1]; 1 d later, PGF; ~32 h later, GnRH [G2]; ~16 h later, timed AI [TAI]) were used. To assess ovulatory response and proportion of multiple ovulation (MOV), ovarian ultrasonography examinations were performed at G1 (n = 1,215) and G2 (n = 1,345) and from 40 to 48 h after each GnRH.
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