Theriogenology.
Publisher:
Geron-X.. [New York, N.Y.?] : Elsevier
Frequency: Sixteen no. a year
Country: United States
Language: English
Start Year:1974 -
ISSN:
0093-691X (Print)
1879-3231 (Electronic)
0093-691X (Linking)
1879-3231 (Electronic)
0093-691X (Linking)
Impact Factor
2.8
2022
| NLM ID: | 0421510 |
| (OCoLC): | 02504829 |
| (DNLM): | T08780000(s) |
| Coden: | THGNBO |
| Classification: | W1 TH677K |
Gestational length of Thoroughbred mares kept in tropical and subtropical climates. Gestation length (GL) in horses varies widely, influenced by multiple variables, including maternal, fetal, and environmental factors. This study aimed to investigate and quantify the relative contributions of climatic (photoperiod and temperature-humidity index - [THI]), maternal (age and parity), fetal (sex) and environmental (year and month of foaling) variables influencing gestation length in Thoroughbred mares. Retrospective data encompassing 704 pregnancies across nine breeding seasons in tropical and subtropical Brazilian climates were analyzed. Stepwise regression analysis identified f...
Oocyte holding and in vitro maturation duration between 28 and 34 hours do not affect equine OPU-ICSI outcomes. Previous studies in the horse highlight the potential benefit of prolonged in vitro maturation (IVM) (34 h) compared to short IVM (24 h) with or without prior oocyte holding, but little is known about the optimal IVM duration within this interval. To determine the effect of oocyte holding and duration of IVM ranged between 28 and 34 h on nuclear maturation, cleavage, blastocyst formation, and pregnancy rates, a retrospective study was performed in an equine clinical OPU-ICSI setting. The study included data of 2114 aspirated oocytes from 201 OPU-ICSI sessions. Duration of IVM was divided in...
Beneficial effects of pentoxifylline on spermatogenesis and germ cell apoptosis in stallions subjected to scrotal heat stress. This study evaluated the effects of oral pentoxifylline on testicular biometry, histology, and gene expression in stallions subjected to scrotal heat stress. Fourteen stallions were divided into three groups: Control (CRL, n = 4), Testicular Degeneration (DEG, n = 5), and Testicular Degeneration Treated with Pentoxifylline (DEG + PTX, n = 5). Testicular degeneration was induced by scrotal insulation, twice daily, over two consecutive days (D-1 and D0). Starting the next day (D1), oral pentoxifylline (17 mg/kg) was administered every 12 h for 30 days. Testicular biometry was measured ...
IVF with frozen-thawed sperm after prolonged capacitation yields comparable results to ICSI in horses: A morphokinetics study. Intracytoplasmic sperm injection (ICSI) is the current clinical practice for the in vitro production of equine embryos. The use of conventional fertilization methods such as in vitro fertilization (IVF), has historically been associated with poor success in horses. However, recent improvements have led to better outcomes with IVF, though only when using fresh semen, which limits its use in clinical practice. IVF remains in its infancy in equine reproduction, and several unknowns remain about the technique. One significant gap in knowledge concerns the morphokinetics of IVF embryos and how they...
Periovulatory anticoagulant therapy enhances embryo recovery rates in superovulated mares. Although protocols for superovulation have been described in horses, this technique has been discouraged due to the low embryo recovery rates in superovulated mares. The reason for these poor results is poorly understood, but the formation of a blood clot in the ovulation fossa following ovulations has been hypothesized. Therefore, this study aimed to assess the safety and effect of periovulatory anticoagulant therapy on embryo recovery of superovulated mares. In experiment 1, five mares were assigned to receive five anticoagulant treatments in a crossover design: intravenous injections of 150...
Effect of refreezing extender on stallion sperm quality and embryo production after intracytoplasmic sperm injection. Intracytoplasmic sperm injection (ICSI) is a valuable assisted reproduction technology in clinical practice, especially when semen availability is limited. Since the number of sperm required per ICSI cycle is much less than the number of sperm available in a standard straw of frozen semen, refreezing semen at lower sperm concentrations could yield multiple straws for ICSI use. However, there is little data on the effect of sperm refreezing on ICSI outcomes, especially on the effect of extender used for refreezing. The objective of the present study was to evaluate the effect of refreezing exte...
Effect of intrafollicular administration of PGE2 or PGF2α in early estrus on ovulation, hemorrhagic anovulatory follicles formation, progesterone secretion and pregnancy outcome in the mare. This experiment was performed to evaluate whether intrafollicular treatment of PGE2 or PGF2α administered in early estrus would induce normal ovulation, progesterone production (Experiment 1) and pregnancy (Experiment 2). In Experiment 1, mares in estrus after 2 days of endometrial edema were injected in all largest dominant follicles (28-35 mm in diameter) with 0.5 mL of sterile water containing 500 μg PGE2 (n = 6), 125 μg PGF2α (n = 6) or placebo (n = 7) (Hour 0). Ultrasound examinations were performed daily, until ovulation or anovulation was detected, and daily blood samples ...
The influence of lactation on insulin and glucose metabolism, lipid profile, and cytokines in pregnant mares. Glucose metabolism adapts to gestation, resulting in progressive physiological insulin resistance and increased insulin secretion to maintain maternal euglycemia and glucose availability for the developing fetus. These changes can impact mare fertility and maternal and neonatal health. This is the first comparison of body condition, regional adiposity, insulin and glucose dynamics, lipid metabolism, and cytokine production between lactating and non-lactating mares before, during pregnancy, and early postpartum. Twelve pregnancies from 9 broodmares, five nonlactating (NL) and seven lactating (L...
Anti-Müllerian hormone in feline cryptorchidism: Serum levels, tissue expression, and implications for testicular health. Anti-Müllerian hormone (AMH) has become a pivotal subject in the study of testicular descent, maturation, integrity, and male fertility. Recent studies explored its roles and implications across various domestic species. A prominent approach involved the understanding of the modulation of AMH in reproductive disorders, including cryptorchidism. While substantial findings have been reported in dogs, ruminants, swine, and horses, data on AMH in feline cryptorchidism remains limited. Here, we aimed to bridge this gap by comparing AMH serum levels among cryptorchid, healthy intact, and castrated ...
Collagen and collagenases in mare’s endometrium with endometrosis. Equine endometrosis is a degenerative and predominantly fibrotic condition resulting from progressive and irreversible multifactorial causes that influence the endometrium of mare. Tissue remodeling in the equine endometrium occurs as part of the pathogenesis of endometrosis, a process characterized by a shift in extracellular matrix (ECM) components. The relationship between matrix metalloproteinases and their specific inhibitors is crucial for the remodeling process. Collagen play a significant role in maintaining a healthy uterus and may promote fibrotic processes. The aim of this study was...
In vitro, the aging of stallion spermatozoa at 22 °C is linked to alteration in Ca2+ and redox homeostasis and may be slowed by regulating metabolism. Conservation of equine semen in the liquid state is a central procedure in horse breeding and constitutes the basis of associated reproductive technologies. The intense mitochondrial activity of the stallion spermatozoa increases oxidative stress along the storage period, leading to sperm demise within 24-48 h of storage, particularly when maintained at room temperature. Recently, the relationship between metabolism and oxidative stress has been revealed. The study aimed to extend the period of conservation of equine semen, at room temperature through modification of the metabolites present i...
Placental homogeneity: Characterizing transcriptional variation among equine chorioallantoic locations. The proper function of the placenta is essential for the health and growth of the fetus and the mother. The placenta relies on dynamic gene expression for its correct and timely development and function. Although numerous studies have identified genes vital for placental functions, equine placental molecular research has primarily focused on single placental locations, in sharp contrast with the broader approach in human studies. Here, we hypothesized that the molecular differences across different regions of the equine placenta are negligible because of its diffuse placental type with a macro...
Saliva and plasma metabolome changes during anoestrus, the oestrous cycle and early gestation in the mare: A pilot study. Successful reproductive management of domestic mammals depends primarily upon timely identification of oestrous cycle stages. There is a need to develop an alternative non-invasive, welfare-friendly, accurate and reliable method to identify reproductive cycle stages. This is of particular interest for horse breeders, because horses are high-value farm animals that require careful management and individual monitoring. Saliva sampling is non-invasive, painless and welfare-friendly. Thus, we performed a metabolomic analysis of equine saliva during different reproductive stages to identify changes...
A comparative study across mule, equine and equine clone pregnancies regarding the determination of the day of birth. Monitoring equine parturition effectively is essential for preemptive intervention in periparturient issues and ensuring the overall well-being of both mares and foals. However, its implementation in breeding farms is challenging due to variable gestational lengths and nocturnal births. Predictive techniques have the potential to streamline the monitoring process, reduce labor intensity, and minimize costs. Research on foaling prediction in mares carrying mule or equine clone fetuses is scarce. Therefore, this study aimed to comparatively analyze foaling prediction parameters in mares pregnant...
Can the reduced GH, IGF-1, and ovarian steroids concentrations be considered as suspected biomarkers of age-associated functional deficit in mares? In humans' and experimental animals' components of the somatotropic axis, such as growth hormone (GH) and insulin-like growth factor 1 (IGF-1) concentrations, decrease with advancing age. Although there is evidence regarding IGF-1, the effect of age on GH in mares, as well as the relationships between both parameters, have not yet been elucidated. On the other hand, although GH and IGF-1 are related to follicular development, it is unknown if they could be correlated with the circulating concentrations of ovarian steroids in mares, as occurs in other species. The hypothesis of this study was t...
Application of blood parameters for the early diagnosis of natural ascending placentitis in pregnant mares. Placental infection is an important cause of late-term pregnancy loss and neonatal diseases in horses. Detection of changes in blood parameters especially during early placentitis could improve the diagnostic accuracy, treatment decision, and potential outcomes. The objectives of this 2-part study were to identify differences in circulating immunological, inflammatory, and hormonal parameters between mares with natural ascending placentitis and control mares; evaluate each and combination of parameters as predictors of placentitis; and determine how these parameters indicate severity of placen...
Use of excised ovaries for oocyte recovery by ultrasound guided follicular aspiration – Validation of an experimental model for research purposes in live mares ovum pick up. Ovum pick-up (OPU) by transvaginal ultrasound guided follicle aspiration in mares is a common assisted reproductive technique used for oocyte recovery and in vitro production of horse embryos. There has been relatively little research into the factors influencing oocyte recovery in OPU from live mares. The objective of this study was to compare oocyte recovery and morphology of ultrasound-guided follicle puncture and aspiration in live mares and in postmortem excised ovaries, in order to validate an experimental model for research purposes of the efficiency of OPU in mares. Data from OPU perfo...
Prostaglandin-related genes are differentially expressed in equine endometrium with different biopsy grade, degrees of inflammation, and fibrosis. Prostaglandins have many roles in the equine reproductive tract, including but not limited to luteolysis, luteal support, ovulation, transport through the uterine tube, uterine contraction, embryonic mobility, inflammation, and fibrosis. Altered secretion of inflammatory proteins are likely to disrupt the balance of endometrial function and could impair fertility. Our overall goal was to measure the expression of several prostaglandin- and inflammation-related genes in mares with different degrees of endometrial histological changes. Our hypothesis was that mares with neutrophilic and lymphocy...
A study on methods for preimplantation genetic testing (PGT) on in vivo- and in vitro-produced equine embryos, with emphasis on embryonic sex determination. Two methods for preimplantation genetic testing (PGT) have been described for equine embryos: trophoblast cell biopsy (TCB) or blastocoele fluid aspiration (BFA). While TCB is widely applied for both in vivo- and in vitro-produced embryos, BFA has been mostly utilized for in vivo-produced embryos. Alternative methods for PGT, including analysis of cell-free DNA (CFD) in the medium where in vitro-produced embryos are cultured, have been reported in humans but not for equine embryos. In Experiment 1, in vivo- (n = 10) and in vitro-produced (n = 13) equine embryos were subjected to BFA, cultu...
Use of regenerative medicine in the treatment of endometritis in mares: A systematic review and meta-analysis. Defining the optimal therapy for endometritis remains a significant challenge for clinicians. Given the public health threat posed by antibiotic resistance and the inconclusiveness of traditional therapies, regenerative medicine has been proposed as an alternative. The objective of this study was to conduct a comprehensive systematic review and meta-analysis, to investigate the efficacy of regenerative medicine products in the treatment of both post-breeding persistent and chronic degenerative endometritis (PBIE/CDE) in mares, following the PRISMA guidelines. This research could be a comprehen...
Post-cooling sperm processing can rescue sperm quality of cooled-stored stallion semen. Poor sperm quality in cooled-shipped semen has been related to subpar fertility in horses. Therefore, this study aimed to evaluate the ability of post-cooling sperm processing to improve sperm parameters of cooled-stored stallion semen for artificial insemination. For all experiments, ejaculates were collected, processed, and diluted in skimmed milk-based (SM) medium and stored at 5 °C/24h. In all experiments an aliquot of unprocessed cooled semen was used as a control. In the first experiment (Exp 1.), cooled-stored semen from 16 stallions (n = 32) was processed by SpermFilter or centrifu...
Bacterial endometritis-induced changes in the endometrial proteome in mares: Potential uterine biomarker for bacterial endometritis. Equine endometritis is one of the main causes of subfertility in the mare. Unraveling the molecular mechanisms involved in this condition and pinpointing proteins with biomarker potential could be crucial in both diagnosing and treating this condition. This study aimed to identify the endometritis-induced changes in the endometrial proteome in mares and to elucidate potential biological processes in which these proteins may be involved. Secondly, biomarkers related to bacterial endometritis (BE) in mares were identified. Uterine lavage fluid samples were collected from 28 mares (14 healthy: ne...
Transrectal ultrasonographic assessment of the fetal proximal phalanx: A new tool to assess fetal age and bone development in horses. Fetal age in Quarter Horses can be predicted within 2 weeks from 100- to 200- days of gestation using femur length, biparietal diameter (cranium diameter) and eye approximated volume. However, as pregnancy advances, the femur and cranium become too large to be imaged in their entirety using ultrasound and the corresponding biometric parameters can no longer be measured. In this longitudinal study, the proximal phalanx (P1) was evaluated as a novel biometric parameter for late gestation to predict fetal age and bone maturation. Transrectal ultrasound was performed in ten pregnant mares with kno...
Effect of exogenous sperm capacitation inducers on stallion sperm. Although under appropriate laboratory conditions, sperm from different mammalian species can be capacitated in vitro, the optimal conditions for sperm capacitation in the stallion have been elusive. This study evaluated the effect of different capacitating inducers in Whitten and Tyrode media and assessed their impact on capacitation-related factors. Stallion sperm were incubated with different combinations of capacitating inducers at 38.5 °C in an air atmosphere. Sperm quality variables such as motility, mitochondrial membrane potential, and lipid peroxidation were assessed. Membrane fluidi...
Effect of duration of estradiol exposure on embryo survival and endometrial gene expression in anestrous embryo recipient mares. Previous studies indicate a positive correlation between the duration of estrus prior to ovulation and likelihood of pregnancy in embryo recipient mares. However, the mechanisms by which the duration of estrus before may affect fertility remains unclear. This study aimed to determine the effect of different durations of estradiol exposure, prior to progesterone administration, on embryo viability in anestrous recipient mares, and endometrial expression of genes thought to influence embryo survival. Three groups of anestrous recipient mares treated with different duration of estradiol were used...
The effect of uterine massage and number of embryo flushing attempts on embryo recovery in mares. The aims of this study were to determine the effect of the embryo flushing technique and the number of flushing attempts performed by operators of different experience on embryo recovery (ER). Ten non-lactating mares were inseminated with the same stallion in six cycles each (n = 60). Embryo flushing (EF) was performed 7-9 days after ovulation by three operators (OP; 20 EF cycles each): OP1 had performed >500 EF before the study, while OP2 and 3 had performed 0 EF. Each EF was performed with 2 flushing attempts (FA) using 1L of ringer's lactate "in-and-out" using two EF techniques: 1) ...
Effect of pregnancy on isolation efficiency and in vitro proliferation of equine peripheral-blood derived mesenchymal stromal cells. Mesenchymal stromal cells (MSCs) have regenerative and immunomodulatory potential and may be used to treat injured tissues. Pregnancy has been associated with increased MSCs in the peripheral circulation in multiple species, but to date, there are no reports on this matter in horses. This study aimed to evaluate the effect of pregnancy on isolation efficiency and proliferation capacity of equine MSCs derived from the peripheral blood (PB) of mares. Venous blood samples were collected at the 11th month of gestation and 1 month after delivery from clinically healthy Arabian mares that presented ...
Changes in characteristics of spermatogonial stem cells in response to heat stress in stallions. Spermatogonial stem cells (SSCs) are essential for the maintenance of male fertility and survival of species. Environmental conditions, notably heat stress, have been identified as important causes of male infertility and have a negative impact on SSCs. Animals with cryptorchid testes (CT) are optimal models for the study of long-term heat stress-related changes in germ cells. The effect of heat stress on germ cells differs depending on the spermatogenesis stage. Thus, verifying whether the specific phase of spermatogenesis is dependent or independent of heat stress in stallions is important. ...
Successful equine in vitro embryo production by ICSI – effect of season, mares’ age, breed, and phase of the estrous cycle on embryo production. This retrospective study aimed at identifying factors that contribute to the success of equine in vitro embryo production by intracytoplasmic sperm injection (ICSI). A total of 7993 ovum pick-up (OPU) sessions were performed, totaling 2540 donor mares and semen from 396 stallions. Oocytes were aspirated at multiple sites in Brazil and were sent to the laboratory, within 6 h from OPU, in pre-maturation medium where they were in vitro matured (IVM) followed by ICSI and in vitro embryo culture for 7-8 days. The number of recovered oocytes, matured oocytes, cleaved embryos and blastocysts were us...
Characterizing the relationship between gonadotropin releasing hormone (GnRH), kisspeptin, and RFamide related peptide 3 (RFRP-3) neurons in the equine hypothalamus across the estrous cycle and in the anovulatory seasons. To understand better the role that kisspeptin plays in regulating seasonal and estrous cycle changes in the mare, this study investigated the number, location and interactions between GnRH, kisspeptin and RFRP-3 neurons in the equine hypothalamus. Hypothalami were collected from mares during the non-breeding season, vernal transition and various stages of the breeding season. Fluorescent immunohistochemistry was used to label the neuropeptides of interest. GnRH cells were observed primarily in the arcuate nucleus (ARC), while very few labeled cells were identified in the pre-optic area (POA). ...