Equine ICSI: an update on semen perspective.

Intracytoplasmic Sperm Injection (ICSI) has increased usage in cases of stallion fertility issues, particularly for older stallions, those with reduced sperm numbers or quality, or stallions that have passed away, and only a limited amount of frozen semen is available. By manipulating the frozen semen through thawing, diluting, and refreezing or by cutting the straw under liquid nitrogen, the supply of semen for ICSI can be extended. While ICSI requires a minimal number of spermatozoa per procedure, it is important to consider sperm quality as a crucial factor affecting fertilization and embryo development.

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.

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.

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.

Comparative Assessment of Oxidative and Antioxidant Parameters in Mule and Horse Neonates during Their First Month of Extrauterine Adaptation.

After parturition, a rapid transition occurs from the intrauterine to the extrauterine milieu, exposing neonates to physiological circumstances characterized by oxidative conditions that instigate the generation of reactive oxygen species. These free radicals play pivotal roles in physiological processes; however, an imbalance between their production and the removal of antioxidants can result in severe cellular damage. The main objective of this study was to compare the oxidative and antioxidant profiles in mule and horse neonates immediately post-parturition, as well as at subsequent time points (1, 6, 12, and 24 h, 7 and 30 days) during their extrauterine existence.

Comparative stereological evaluation of the term allantochorion membrane in the mare pregnant with mule foals and equine foals.

Mules are derived from crossing horse mares with a donkey, in which the interest is due to gentleness and ability to work and equestrian sports. As the placenta is responsible for fetal development and maturation, knowing its typical microstructure allows us to understand how fetomaternal interactions occur in this interspecific pregnancy. Thus, the study performed a comparative stereological evaluation of volumetric composition and fetomaternal contact surface in the uterine body (UB), gravid uterine horn (GUH), and nongravid uterine horn (NGUH) of Mangalarga Paulista mare's term allantochorion membrane in mule and equine pregnancies.

Postnatal Dynamics of Circulating Steroid Hormones in Mule and Equine Neonates.

It is necessary to study hormonal patterns from mules to recognize alterations and neonatal maladaptation. Our objective was to evaluate concentrations of hormones in mule (n = 6) and equine foals (n = 6). Blood was collected at T0, 1, 6 and 12 h after birth.

Prenatal or postnatal corticosteroids favor clinical, respiratory, metabolic outcomes and oxidative balance of preterm lambs corticotherapy for premature neonatal lambs.

Challenges of the extrauterine environment can be life threatening for a premature fetus with inadequate fetal maturity. Maternal corticosteroids therapy is widely employed to induce fetal pulmonary maturation. Nevertheless, whenever therapeutic pregnancy interruption has to be performed in a time manner insufficient to treat the dam, postnatal corticotherapy can be considered an alternative.

First Confirmed Diagnosis of Nocardioform Placentitis (Amycolatopsis lexingtonensis) in South America.

Nocardioform placentitis is a pathologically unique form of placental disease first diagnosed in central Kentucky in the mid-80s. Since then, the occurrence of nocardioform placentitis in the region has varied over the years, from sporadic cases to outbreaks. The disease has been sporadically detected in other countries and has not been confirmed in South America.

Exogenous surfactant replacement immediately at birth as preventive therapy for lung prematurity in neonatal lambs.

Surfactant treatment is a manner to reduce alveolar superficial tension and increase pulmonary compliance in premature neonates. Thus, we aimed to analyze the effect of exogenous surfactant treatment in combination with manual ventilation for preterm lambs. We used 15 ewes and their lambs (n = 16), prematurely born at 135 days.

Evaluation of Blood Glucose and Lactate Concentrations in Mule and Equine Foals.

Information about mule physiology is scarce. Glucose and lactate serve as prognostic tools in neonates; thus, real-time evaluations would be beneficial. Our main objective was to measure glucose and lactate concentrations from healthy mule and equine foals from birth to 720 hours.

Elevated blood urea nitrogen alters the transcriptome of equine embryos.

High blood urea nitrogen (BUN) in cows and ewes has a negative effect on embryo development; however, no comparable studies have been published in mares. The aims of the present study were to evaluate the effects of high BUN on blastocoele fluid, systemic progesterone and Day 14 equine embryos. When a follicle with a mean (±s.

Oxidative state in equine neonates: Anti- and pro-oxidants.

Background: In newborns, exposure to the extrauterine environment with high oxygen tension and sudden pulmonary adaptation leads to an increase in reactive oxygen species (ROS). ROS have several physiological roles, which are essential for neonatal development, however, when unbalanced, these highly unstable molecules can cause cellular destabilisation, compromising vital processes.

Objectives: To characterise the oxidative status in healthy equine neonates, evaluating an indicator of lipid peroxidation and both enzymatic and nonenzymatic antioxidant systems, during the first week of life.

A High Protein Model Alters the Endometrial Transcriptome of Mares.

High blood urea nitrogen (BUN) decreases fertility of several mammals; however, the mechanisms have not been investigated in mares. We developed an experimental model to elevate BUN, with urea and control treatments (7 mares/treatment), in a crossover design. Urea-treatment consisted of a loading dose of urea (0.

Small RNA (sRNA) expression in the chorioallantois, endometrium and serum of mares following experimental induction of placentitis.

Intrauterine infection and inflammation remain a major cause of preterm labour in women and mares, with little known about small RNA (sRNA) expression in tissue or circulation. To better characterise placental inflammation (placentitis), we examined sRNA expression in the endometrium, chorioallantois and serum of mares with and without placentitis. Disease was induced in 10 mares via intracervical inoculation of Streptococcus equi ssp.

Are mule pregnancies really longer than equine pregnancies? Comparison between mule and equine pregnancies.

In equine management, it is important to predict the approximate foaling date of mares to monitor parturition and allow early identification and intervention of problems during the perinatal period. There are no studies comparing accurate gestational length (GL) when mares are carrying mule foals and no controlled comparisons between GL of mares pregnant with equine or mule foals. Therefore, the objectives of this study were to compare GL of mares pregnant with equine or mule foals and establish normal reference values for GL of mares pregnant with male and female mules.

Transplacental transmission of Theileria equi in mules: Should we worry?

Equine piroplasmosis, disease globally responsible for significant economic losses, is caused by the transmission of the hemoprotozoa Theileria equi and Babesia caballi by ticks. Transplacental transmission has been reported previously in horses, which is not the case for mules´ foals. The present study investigated, by Real Time-PCR (RT-PCR), the presence of both Theileria equi and Babesia caballi in newborn mules before the ingestion of colostrum.

Redox, acid-base and clinical analysis of preterm and term neonatal lambs.

During pregnancy, fetal lambs are exposed to low oxygen tension. Thus, an effective antioxidant mechanism is partially developed which sensitizes fetus to oxidative stress. Consequently, term and preterm neonates are susceptible to molecular and cellular injury caused by oxygen species (ROS).

Sex-steroid receptors, prostaglandin E2 receptors, and cyclooxygenase in the equine cervix during estrus, diestrus and pregnancy: Gene expression and cellular localization.

The cervix is a dynamic structure that undergoes dramatic changes during the estrous cycle, pregnancy and parturition. It is well established that hormonal changes, including estrogens, progestogens and prostaglandins, regulate the expression of key proteins involved in cervical function. The arachidonic acid cascade is important in the remodeling and relaxation of the cervix in the days preceding parturition.

Reproductive stem cell differentiation: extracellular matrix, tissue microenvironment, and growth factors direct the mesenchymal stem cell lineage commitment.

The mesenchymal stem cells (MSCs) have awakened interest in regenerative medicine due to its high capability to proliferate and differentiate in multiple specialized lineages under defined conditions. The reproductive system is considered a valuable source of MSCs, which needs further investigations. Many factors have been reported as critical for these cell lineage specification and determination.

Artificial activation of bovine and equine oocytes with cycloheximide, roscovitine, strontium, or 6-dimethylaminopurine in low or high calcium concentrations.

Knowledge on parthenogenetic activation of oocytes is important to improve the efficiency of nuclear transfer (NT) and intracytoplasmic sperm injection (ICSI) because artificial activation of oocyte (AOA) is an essential step to achieve embryo production. Although different procedures for AOA have been established, the efficiency of in vitro production of embryos remains low, especially in equines and Bos taurus bovines. In an attempt to improve the techniques of NT and ICSI in bovine and equine species, we tested different combinations of drugs that had different mechanisms of action for the parthenogenetic activation of oocytes in these animals.

Use of bayesian inference to correlate in vitro embryo production and in vivo fertility in zebu bulls.

The objective of this experiment was to test in vitro embryo production (IVP) as a tool to estimate fertility performance in zebu bulls using Bayesian inference statistics. Oocytes were matured and fertilized in vitro using sperm cells from three different Zebu bulls (V, T, and G). The three bulls presented similar results with regard to pronuclear formation and blastocyst formation rates.