Development of a 3D in vitro model to study corpus luteum of felids based on luteinized cells from antral follicles.

The study aimed to establish a long-term 3D cell culture model using luteinized follicular cells to investigate the functionality and life cycle of the CL in felids. A mixture of cell types from antral follicles was luteinized in vitro and cultured for up to 23 days. The method, initially applied to the domestic cat, was later extended to Persian and Clouded leopards.

Stress response of 18-, 24- and 30-month-old sport horse stallions to a pretraining programme.

Warmblood sires traditionally have been presented for stallion licencing at 2 years of age, but the age at which horses are mentally fit for training is a point of controversy. We have therefore investigated the stress response of young stallions to pretraining for licencing. Salivary cortisol concentration, heart rate and heart rate variability (HRV) were determined repeatedly over 12 weeks.

Assessment of fetal development during mid and late term pregnancies by standard B-Mode ultrasonography in Shetland ponies.

Transrectal and transabdominal ultrasonography is an established method to monitor pregnancy, fetal growth and wellbeing in different species. Growth charts with multiple bio-morphometric parameters to estimate days of gestation and days before parturition exist in small companion animals, sheep and goats, riding type horses and large ponies but not in small horse breeds like Shetland ponies. The aim of this study was to apply fetal biometric assessment and detailed description of physiologic fetal development to mid and late term pregnancies in Shetland mares and to generate reference data for clinical practice and for future research.

In mares resistant to endometrial infection, periovulatory treatment with ecbolic drugs does not influence uterine clearance or luteal development.

We aimed to determine associations between experimentally impaired uterine clearance or treatment with ecbolic drugs on luteal development in estrous mares after insemination. In a crossover design, eight mares were treated with saline (CON), clenbuterol (CLEN), oxytocin (OXY) and carbetocin (CARB) from the day of first insemination until 2 days after ovulation. Between treatments, the mares rested for one cycle.

Tumor necrosis factor-α is transferred to equine neonates via colostrum but is not associated with their health status.

We followed the hypothesis that equine neonates with reduced transfer of tumor necrosis factor-α (TNFα) are at increased risk of neonatal infection. We investigated TNFα concentrations in colostrum of healthy mares and blood of their neonates in a non-hospitalized population of Warmblood mares where delivery, neonatal adaptation and health was closely monitored by veterinarians. Concentration of TNFα and IgG was determined in colostrum respective milk and in neonatal blood collected immediately after delivery and 18 h thereafter in 97 foals that were assigned to groups failure of passive transfer (FPT; n = 31) and control (CON; n = 66) based on serum IgG concentration at 18 h of age.

Involvement of somatotrophic hormones in the postpartum regulation of ovarian activity in mares.

Mares resume ovarian activity rapidly after foaling. Besides follicle-stimulating hormone (FSH) and luteinizing hormone (LH), the pituitary synthesizes prolactin and growth hormone which stimulate insulin-like growth factor (IGF) synthesis in the liver. We tested the hypothesis that follicular growth is initiated already antepartum, mares with early and delayed ovulation differ in IGF-1 release and that there is an additional IGF-1 synthesis in the placenta.

Bacterial diversity in semen from stallions in three European countries evaluated by 16S sequencing.

The microbiome plays a significant role in shaping the health and functioning of the systems it inhabits. The seminal microbiome of stallions has implications for the health of the reproductive tract, sperm quality during preservation and antibiotic use in semen extenders. Diverse bacteria are present on the external genital tract and a mix of commensal microorganisms populates various parts of the reproductive tract, influencing the seminal bacterial content.

Endocrine changes induced by GnRH immunisation and subsequent early re-stimulation of testicular function with a GnRH agonist in stallions.

Context: Resumption of testicular function after gonadotrophin-releasing hormone (GnRH) immunisation varies among individual animals and some stallions regain fertility only after a prolonged time.

Aims: This study evaluated endocrine effects of GnRH immunisation and early subsequent re-stimulation with a GnRH agonist. We hypothesised that GnRH agonist treatment advances resumption of normal endocrine function in GnRH-vaccinated stallions.

Reduced bacterial load in stallion semen by modified single layer centrifugation or sperm washing.

The presence of bacteria poses a significant challenge to the quality of stallion semen used in artificial insemination. The bacterial content of insemination doses arises from various sources, such as the healthy stallion, environment, and collection equipment, and is implicated in fertility problems as well as reduced sperm quality during storage. The conventional approach of adding antibiotics to semen extenders raises concerns about antimicrobial resistance and potential negative effects on sperm characteristics, and may not be effective in inhibiting all bacteria.

Short communication: Retrospective analysis of obligatory testing results for Equine virus arteritis reveals a decrease of its seroprevalence in stallions used for artificial insemination.

Equine viral arteritis (EVA) can induce a persistent carrier state in stallions which then shed the virus via semen. About 30 years ago, obligatory EVA testing of stallions used for artificial insemination (AI) was implemented in the European Union. Information on the efficacy of these regulations on the prevalence of EVA in stallions are not yet available.

Protamine 2 and phospholipase C zeta 1 are possible biomarkers for the diagnosis of male subfertility in frozen-thawed stallion semen.

Subfertility is one of the main issues in horse breeding and the study of mRNAs in sperm might help in elucidating the reasons that lead to this diagnosis. The present study aims at assessing the differences in the expression of 10 potential candidate genes in stallions of different fertility. Frozen-thawed semen of 29 stallions was included.

In vivo dynamics of pro-inflammatory factors, mucins, and polymorph nuclear neutrophils in the bovine oviduct during the follicular and luteal phase.

Dynamic functional changes in the oviductal microenvironment are the prerequisite for the establishment of pregnancy. The objective of this study was to gain the first insights into oestrous cycle-dependent dynamics of polymorph nuclear neutrophils (PMN) and the mRNA abundance of selected genes and their correlations in the oviduct of living cows. Mini-cytobrush samples were taken from the oviducts of healthy heifers (n = 6) and cows (n = 7) during the follicular (FOL) and luteal phase (LUT) by transvaginal endoscopy.

Low progesterone concentration in early pregnancy is detrimental to conceptus development and pregnancy outcome in horses.

High progesterone concentrations in the early luteal phase support pregnancy, whereas subphysiological progesterone concentrations delay embryonic development at least until placentation. In this study, fetal growth and development of pregnancy was investigated in pregnancies with prostaglandin F-induced low progesterone concentrations (PGF) in the early luteal phase and control pregnancies (CON) in the same mares (n = 12). Mares were inseminated and in PGF pregnancies received the prostaglandin F analogue cloprostenol (62.

Abundance of Anti-Muellerian hormone in cat ovaries and correlation of its plasma concentration with animal age, weight and stage of the estrous cycle.

In female animals of different species, Anti-Müllerian hormone (AMH) is produced by follicular granulosa cells and has been associated with the ovarian follicle pool. Because concentration of AMH in plasma of ovary-intact female cats is apparently more variable than previously assumed, we have analysed AMH concentration in blood of cats (n = 93) presented for routine ovariectomy and assessed ovarian histology and AMH protein expression in the surgically removed ovaries. We hypothesised that AMH is synthesized only in preantral and small antral follicles and that plasma AMH concentration reflects the antral follicle count (AFC).

Shipping duration and temperature influence the characteristics of cryopreserved horse semen stored in different shipping devices for up to 14 days.

This study aimed to investigate the effects of storing horse semen either in a dry shipper (≤ -150 °C) or on dry ice (≤ -78 °C) for up to 14 days. A total of 264 frozen semen straws from male horses (n = 8) stored in liquid nitrogen were transferred on day 0 (d0) to a dry shipper or a dry ice styrofoam box. On d1, d3, d7, d10, and d14, straws from the dry shipper and dry ice were returned to the liquid nitrogen container.

Double semen collection at a 1-h interval in dogs decreases the bacterial contamination of canine ejaculates.

Semen extenders usually contain antibiotics with the aim to minimize bacterial growth, but the indiscriminate use of antibiotics increases the emergence of multidrug-resistant bacteria. A limiting factor of semen processing in dogs is the low total sperm count that limits the number of insemination doses that can be obtained from one ejaculate. Therefore, two ejaculates collected at a short interval can be combined to increase the number of AI doses.

General and comparative aspects of endometritis in domestic species: A review.

Endometritis is a leading cause of sub- and infertility in domestic animal species. The healthy uterus is colonized by commensal bacteria, viruses and yeast/fungi that represent the nonpathogenic microbiota. A shift in the number or type of organisms accompanied by immune dysfunction, however, may trigger uterine infection and inflammation.

Selection of frozen-thawed stallion semen by microfluidic technology.

The use of microfluidic technology is increasing in artificial reproduction technologies: With a small amount of semen, it allows for the selection of sperm with the best characteristics of kinetics, morphology and chromatin integrity. The ZyMot Multi (850 μl) is the most popular device of ZyMot Fertility Inc. To date, it was proven to be a valid instrument for sperm selection for in vitro fertilization and intracytoplasmic sperm injection in men.

Low plasma progesterone concentration during the early luteal phase delays endometrial development and the beginning of placentation in mares.

While detrimental effects of reduced plasma progesterone concentration in the early luteal phase on conceptus development in horses have recently been demonstrated, there is no information on associated effects on the endometrium, allantochorion (AC), and chorionic girdle (CG) in this species. We hypothesised that reduced early postovulatory progesterone concentration in pregnant horses is detrimental to endometrial function and development of the embryonic membranes and is an underlying cause of delayed conceptus development. After insemination and ovulation, mares (n = 11) were assigned to treatment (TREAT) or control (CON) during two pregnancies.

Re-stimulation of testicular function in GnRH-vaccinated stallions by daily GnRH agonist treatment.

In stallions temporarily not intended for breeding, reversible suppression of testicular function by vaccination against GnRH can be of interest. In the present study, effects of GnRH agonist treatment on the resumption of testicular function after GnRH vaccination were investigated. Testis size, testosterone release, semen characteristics and behavior were evaluated.

An optimized workflow for microCT imaging of formalin-fixed and paraffin-embedded (FFPE) early equine embryos.

Here, we describe a workflow for high-detail microCT imaging of formalin-fixed and paraffin-embedded (FFPE) equine embryos recovered on Day 34 of pregnancy (E34), a period just before placenta formation. The presented imaging methods are suitable for large animals' embryos with intention to study morphological and developmental aspects, but more generally can be adopted for all kinds of FFPE tissue specimens. Microscopic 3D imaging techniques such as microCT are important tools for detecting and studying normal embryogenesis and developmental disorders.

Suppression of reproductive behaviour and gonadal function in female horses-An update.

The behaviour of mares is often detrimental to their performance resulting in frequent demand for methods to suppress gonadal function. In addition, prevention of unintended reproduction especially in feral horse populations may require methods for suppression of gonadal function. Surgical ovariectomy is a safe method but not an acceptable approach in feral mares and undesired in mares where future breeding is considered.

Altrenogest treatment reduces the stress response of three-year-old warmblood mares during their initial equestrian training.

Horse mares are frequently treated with the progestin altrenogest with the aim to suppress estrous behavior and its negative impact on equestrian performance. Progestogens, however, also have sedative effects in males, and females of different species. The aim of our study was therefore to investigate altrenogest-induced changes in the stress response of female horses during initial equestrian training.

Development of Foals Until One Year of Age When the Dam was Exposed to Blue Monochromatic Light Directed at One Eye During Late Pregnancy.

In horses, blue LED light directed at one eye of pregnant mares shortens gestation length and results in the birth of foals with lower wither heights, similar weight and reduced hair length compared to controls. In this study, we have therefore analysed postnatal development of foals born to either blue LED light-treated (n = 20) or control mares (n = 20). Size, weight and hair coat changes were determined for 1 year and heart rate, heart rate variability (HRV) and selected haematology parameters for 1 month.