Pregnant Mare Research Articles

Regulator of G-Protein Signaling 2 Knockout in CD4+ T Cells Promotes Anti-Inflammatory T Cells, Enhancing Ovulation, and Oocyte Yield.

To determine the downstream effects on ovarian function and immune cell differentiation in the ovary and uterus using a model in which RGS2 was knocked out specifically in CD4+ T cells. Laboratory based experiments with female mice. Female congenic (fully backcrossed) and non-congenic (mixed strain) mice with CD4 T cell-specific RGS2 knockout. Four-week-old female CD4 RGS2 knockout (CD4 RGS2 KO ) mice and their littermate controls (CD4 RGS2 CTL ) were subjected to superovulation using pregnant mare serum gonadotropins. Oocyte numbers, lymphocyte populations in the ovary and uterus, and serum estradiol and progesterone concentrations. In non-congenic (mixed strain) mice, CD4 RGS2 knockout (KO) promoted higher oocyte ovulation and increased uterine total leukocyte numbers. Similarly, congenic (fully backcrossed strain) mice showed higher oocyte numbers and increased uterine total leukocytes in the CD4 RGS2 KO mice compared to CD4 RGS2 CTL mice. Pro-inflammatory CD4+ T helper (T H ) 1 and T H 17 cell frequencies in the ovary and uterus were unchanged, while Treg and T H 2 cell frequencies were elevated, along with increased concentrations of estradiol and progesterone in the serum of CD4 RGS2 KO mice. Our study highlights the important role of RGS2 in CD4+ T cells within the context of reproduction. The dysregulation of immune responses due to RGS2 knockout in CD4+ T cells appears to enhance oocyte production. Further research is warranted to elucidate the precise mechanisms by which RGS2 influences reproductive outcomes, including its impact on fecundability, endometrial receptivity, and successful implantation.

Plasma Lipidomics Reveals Lipid Signatures of Early Pregnancy in Mares

Understanding the systemic biochemistry of early pregnancy in the mare is essential for developing new diagnostics and identifying causes for pregnancy loss. This study aimed to elucidate the dynamic lipidomic changes occurring during the initial stages of equine pregnancy, with a specific focus on days 7 and 14 post-ovulation. By analysing and comparing the plasma lipid profiles of pregnant and non-pregnant mares, the objective of this study was to identify potential biomarkers for pregnancy and gain insights into the biochemical adaptations essential for supporting maternal recognition of pregnancy and early embryonic development. Employing discovery lipidomics, we analysed plasma samples from pregnant and non-pregnant mares on days 7 and 14 post-conception using the SCIEX ZenoTOF 7600 system. This high-resolution mass spectrometry approach enabled us to comprehensively profile and compare the lipidomes across these critical early gestational timepoints. Our analysis revealed significant lipidomic alterations between pregnant and non-pregnant mares and between days 7 and 14 of pregnancy. Key findings include the upregulation of bile acids, sphingomyelins, phosphatidylinositols, and triglycerides in pregnant mares. These changes suggest enhanced lipid synthesis and mobilization, likely associated with the embryo’s nutritional requirements and the establishment of embryo–maternal interactions. There were significant differences in lipid metabolism between pregnant and non-pregnant mares, with a notable increase in the sterol lipid BA 24:1;O5 in pregnant mares as early as day 7 of gestation, suggesting it as a sensitive biomarker for early pregnancy detection. Notably, the transition from day 7 to day 14 in pregnant mares is characterized by a shift towards lipids indicative of membrane biosynthesis, signalling activity, and preparation for implantation. The study demonstrates the profound lipidomic shifts that occur in early equine pregnancy, highlighting the critical role of lipid metabolism in supporting embryonic development. These findings provide valuable insights into the metabolic adaptations during these period and potential biomarkers for early pregnancy detection in mares.

112 Effects of maternal body condition on colostrum, foal weight, and foal IgG concentration

Abstract Foals are born with little to no immunity and rely on maternal colostrum to develop adequate circulating immunoglobulin G (IgG) concentrations in the periparturient period. Colostrum directly impacts the health of the foal, and there are limited data assessing how maternal metabolism and body condition impacts IgG in colostrum and in the foal postnatally. To determine the influence of maternal body condition score (BCS) and cresty neck score (CNS) on glucose and insulin metabolism in the pregnant mare, colostrum composition, and colostrum and foal IgG concentrations, light breed mares (n = 6) were divided into two groups based on BCS and CNS at 315 ± 0.45 d of gestation. The groups were identified as moderately obese (MO; n = 3, BCS) and lean (LN; n = 3). Mares were fasted overnight and then underwent an intravenous (iv) glucose tolerance test at 315 ± 0.45 d gestation. Blood samples were collected at -30, -15 and 0 min and mares were administered dextrose iv [0.3 g/kg body weight (BW)] over 3.7 ± 0.17 min followed by an intravenous infusion of insulin (0.3 mU/kg BW) 20-min later. Additional blood samples were collected 2, 5, 10, 15, 20, 25, 30, 45, 60, and 120 min after initiation of dextrose infusion. At parturition, a colostrum sample was collected before foals nursed and analyzed for protein and fat, and IgG concentration. A foal blood sample was collected 18 h after birth to determine passive transfer of IgG. Placental, mare, and foal weights were measured at birth. Data were analyzed using a t-test with significance at P ≤ 0.05 and a tendency at 0.05 < P ≤ 0.10. The MO group had greater BCS (P = 0.01) and CNS (P = 0.01) than the LN group. Moderately obese mares tended to have 9% greater glucose area under the curve (AUC) after dextrose (P = 0.10) and a 9% greater glucose AUC after insulin infusion (P = 0.10) than LN mares. Colostrum IgG concentrations, and protein and fat content (P ≥ 0.3) did not differ between groups. Foal serum IgG concentrations, foal BW, and placental weights were similar between groups (P ≥ 0.8). The ratios between foal BW and placenta weight, and between foal BW and mare BW were similar between groups (P ≥ 0.3). Moderately obese maternal BCS and CNS scores may decrease maternal glucose clearance during late gestation but did not impact colostrum quality or foal IgG concentrations within 24 h postpartum. As the equine fetus matures later in gestation than other livestock species and relies heavily on glucose uptake from the placenta, it is critical to increase our understanding of the impacts of maternal obesity and glucose clearance on foal development and pre- and post-natal health.

Effects of maternal dietary supplementation with antioxidants on clinical status of mares and their foal

BackgroundThe peripartum period constitutes a delicate physiological moment in mares showing a transient state of oxidative stress. Diet supplementation with antioxidants during pregnancy in women appears to have a beneficial effect on mother and neonate health. The aim of this work was to evaluate the effects of diet supplementation with a commercial product containing a mix of antioxidants (Oxyliver®, Candioli) on the length of gestation, weight, and haemato-biochemical parameters in Italian Salernitano mares and their newborn foals. Eight late-term pregnant mares were randomly divided into two groups: Antiox group receiving 30 g/day of antioxidants, and Car group receiving the same amount of carrot powder, from 290 to 320 days of gestation. The following parameters were evaluated in mares: weight, colostrum composition, haemato-biochemical parameters, progesterone, and cortisol blood concentrations, along with blood oxidant/antioxidant status. Assessments were conducted at specific time points: immediately before the start of diet supplementation (T0), 15 days after (T1), at the end of diet supplementation (T2), within 8 h after parturition (T3), and 10 days post-partum (T4). Foal parameters such as weight, haemato-biochemical values, cortisol concentration, and blood oxidative stress variables were assessed within 8 h of birth (TF0) and at 10 days of age (TF1).ResultsPregnancy was shorter in the Antiox group (P < 0.05) compared with the Car group; the foals’ weight increase of group Antiox (40%) was higher (P < 0.05) compared to those of the Car group (28.6%). The colostrum of the Antiox group exhibited higher levels of Brix, total solids, protein, nonfat solids, casein, urea, density, free fatty acids, and glucose, while lower levels of fat and lactose were observed compared to the Car group (P < 0.05). Mares’ serum albumin at T1 and T3, creatinine, glucose, total proteins, total bilirubin, AST, and ALT at T3 were lower in Antiox than in the Car group. No significant differences were found in foals.ConclusionsWhile the limited sample size and the potential variability of evaluated parameters, the observed outcomes suggest that Oxyliver® supplementation in mares might safely decrease gestation length and enhance liver function, thus potentially improving colostrum quality and offspring development.

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), were used. Evaluations were performed on the day of ovulation, at 55, 110, 165, 220, 275, and 330 days of gestation (D55, D110, D165, D220, D275, D330) and 21 days postpartum (21pp). Mares in the L group had lower basal insulin and glucose at the beginning of pregnancy, smaller area under the curve of insulin and glucose, and greater insulin sensitivity and glucose tolerance. Resistin was higher in D110 and D165 than in D0, D275, 330 and 21pp, while leptin was higher in D55, and in D110, at D110 it was equal to D0, D220, and D275, but higher than at D330 and D21pp. As for the groups, L presented lower body condition score (BCS), crest neck score (CNS), rump fat thickness (RUM), basal insulin, glucose area under the curve (AUCg), MIRG and higher RISQI, adiponectin and tumor necrosis factor (TNFα). There was no effect over time in non-esterified fatty acids (NEFA) concentrations between the L mares; in the NL, D275 presented higher concentrations than those of D0, D55, and D110, which in turn were equal to the other time points; there were higher concentrations in NL mares than L in samples D165 and D275. In conclusion, a different metabolic profile during pregnancy was detected, and NL mares were closer to the metabolic threshold for the occurrence of metabolic syndrome during pregnancy. Understanding the impacts of these differences on mare's health and their offspring's future is fundamental as most of our recipient mares for embryo transfer are non-lactating. Therefore, we suggest that further studies be performed to evaluate lactation's influence on mares' metabolic parameters.

Feeding a Saccharomyces cerevisiae Fermentation Product to Mares in Late Gestation Alters the Biological Activity of Colostrum.

The quality of equine colostrum is typically defined by refractometry or the concentration of maternal antibodies. However, the activity of other equine colostral bioactive molecules has not yet been investigated. This study analyzed whether the administration of a Saccharomyces cerevisiae fermentation product (SCFP) influences the biological activity of mare colostrum and whether the biological activity of colostrum has a lasting immunomodulating effect for foals. A total of fourteen pregnant mares received 20 g/day of a SCFP for a period of twelve weeks prior to the calculated date of birth (SCFP-group). Twelve pregnant mares without supplementation served as controls (CON). Colostral Brix values were determined within three hours after parturition. The concentration of IgG in blood sera and colostrum samples was determined with an ELISA. The biological activity was determined in a cell growth assay with a porcine epithelial cell line (IPEC-J2). Mares (at three weeks before the calculated date of birth) and foals (at the age of 5-8 months) received a parenteral active vaccination against influenza and tetanus. The administration of SCFP did not alter the mare's serum and colostrum IgG concentrations and did not exert a significant influence on the mares' early response to the vaccination. Growth and diarrhea episodes were comparable between foals of supplemented mares (SCFP) and foals of mares without supplementation (CON). Colostrum samples from SCFP-supplemented mares exhibited heightened biological activity. While SFCP and CON foals did not differ in their early response to vaccination, the vaccination-induced alterations in circulating neutrophilic granulocyte numbers were significantly correlated with the biological colostrum activity. These findings suggest that the supplementation of mares in late gestation with SCFP can enhance the biological activity of colostrum, which subsequently influences the innate immune responses of their offspring in later life.

A Comparative Analysis of the Gene Expression Profiles in the Mammary Glands of Lactating and Nonlactating Mares at the Second Month of Gestation.

To investigate molecular regulation involved in lactation during pregnancy, this study focused on the transcriptomic profiles of mammary tissue from lactating and non-lactating Mongolian mares at the second month of gestation. A total of 4197 differentially expressed genes were identified by comparing mammary tissues from pregnant mares at two different states, including 1974 differentially expressed genes such as the milk protein-related genes a-s1-casein (CSN1S1), k-casein (CSN3), lactalbumin (LALBA), and lactoferrin (LTF), which were highly expressed in the lactating mares group, and overall, these differentially expressed genes were mainly associated with biological processes such as endoplasmic reticulum protein processing, the Toll-like receptor signaling pathway, steroid biosynthesis, cytokine-cytokine receptor interactions, and amino sugar and nucleotide glycolysis. These findings serve as a foundation for investigating the molecular underpinnings of lactation in pregnant equids.

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 with mule, equine, or equine clone fetus. The study included vulvar relaxation, sacroiliac ligament tension, pH, BRIX index, and concentrations of calcium, phosphorus, magnesium, sodium, and potassium in prepartum mammary secretions. Sixty pregnant mares were used for this study and grouped as follows: 25 mares with mule fetuses (MF), 20 with equine clone fetuses (CF), and 15 with equine control fetuses (EF). Results showed significant differences in vulvar relaxation and sacroiliac ligament tension only in MF group (p < 0.05) on the day of parturition compared to the other days evaluated, different from the other groups. Levels of pH notably decreased on parturition day (mean 5.7 ± 0.04, p < 0.0001), with lower values in MF (6.05 ± 0.02) and CF (6.08 ± 0.04) compared to EF (6.26 ± 0.04) (p < 0.03). The BRIX index showed variation across mares and was not a good parameter for foaling prediction. Electrolytes correlated positively with impending parturition, showing no significant differences among groups. The MF and CF groups exhibited a substantial increase (102.13 % and 110.66 %, respectively) in mean calcium concentrations on the day before foaling, unlike EF (38.29 %). In conclusion, the pH values were different in mammary secretions between mares carrying mule and clone fetuses, in contrast to equine control fetuses. Nevertheless, there was a trend of decreasing pH values closer to parturition in all groups. Conversely, the BRIX index serves as a valuable indicator of colostrum quality yet does not offer insights into the proximity of parturition. While electrolyte concentrations did not reveal significant differences among groups, it is worth noting that the evaluation of phosphorus emerges as a new parameter to explore in mares nearing parturition, since it obtained a pattern similar to calcium.

The Effects of Oral Progestagen Administration on the Fertility of Synchronized Goats During the Breeding Season

The objective of this study was to assess the impact of oral progesterone (altrenogest) administered after mating on fertility in goats synchronized during the breeding season. A total of 47 Hair goats were included in the study. A progesterone-impregnated intravaginal sponges were administered for 12 days. On day 10 of intravaginal sponge administration, 480 IU pregnant mare's serum gonadotropin (PMSG) and 0.075 mg cloprostenol were injected intramuscularly to the goats. Animals were exposed to bucks for 12 hours after detection of estrus by the foraging buck. The goats were randomly assigned to two distinct groups: Group 1 (G1, n=23) and Group 2 (G2, n=24). G1 goats were orally administrated 4.4 mg of altrenogest per day for 30 days after mating. G2 goats served as controls. Pregnancy examinations were performed by transrectal ultrasonography on the 30th and 42nd days after mating. Blood samples were taken from one day after mating to 30 days (3-day intervals). Statistical analysis comparing G1 and G2 revealed no significant differences between the groups regarding progesterone concentrations, conception rate, pregnancy rate, lambing rate, multiple birth rate, fecundity, and litter size (p&gt;0.05). In conclusion, this study revealed that oral progesterone use had no impact on fertility parameters. Moreover, further research is warranted to explore the efficacy of various oral progesterone analogs.

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 placentitis. Reproductive examination and blood sampling were prospectively performed on pregnant mares in a natural setting. Study 1 enrolled mares diagnosed with early stage of ascending placentitis based on ultrasonographic findings (n = 12), and gestationally age-matched mares with healthy pregnancies as controls (n = 12). Blood samples were classified as pre-onset (before) and early onset (at the time of ultrasonographic changes) of placentitis. There were no detected statistically significant differences between groups and timepoints in immunological and inflammatory parameters, including peripheral lymphocyte subpopulations, cytokine, and serum amyloid A concentrations. The placentitis group showed a reduced (P = 0.01) DHP/20α-DHP ratio when compared to the control group at the early onset timepoint. Plasma estradiol-17β concentration <359 pg/mL predicted ascending placentitis with acceptable accuracy (area under the curve, AUC = 0.71). Combined albumin <3.7 g/dL, estradiol-17β < 499 ng/mL, and DHP <33 ng/mL predicted 100 % of cases of ascending placentitis. In study 2, samples were classified according to the presence and severity of the abnormal ultrasonographic findings as mild (n = 11) and moderate-severe (n = 23), and gestationally age-matched with samples from control mares (n = 34). Mares with moderate-severe ascending placentitis had increased (P = 0.03) plasma 20α-DHP concentration and reduced (P = 0.03) DHP/20α-DHP ratio when compared to control mares. Our results suggest that the early events of ascending placentitis detected by ultrasonographic findings include hormonal alterations of feto-placental metabolism measurable in the mare's circulation, yet without obvious systemic immunological and inflammatory changes. Additional studies are warranted to further assess how hormonal markers and cutoff values could guide decisions for timely therapeutic intervention.

Early Evidence of Post-Mortem Fetal Extrusion in Equids: A Case from the Western Zhou Period (1045-771 BC) Site of Yaoheyuan in Northwestern China.

Post-mortem fetal extrusion, also known as "coffin birth", refers to the phenomenon where a fetus is pushed out of a deceased female due to pressure from decomposing gas in the abdominal cavity. While post-mortem fetal extrusion has been documented in humans at several archaeological sites, there are few reports of it occurring in non-human animals. In this study, we present a case of post-mortem fetal extrusion in equids observed in a chariot-horse pit (CMK2) at the Western Zhou period site of Yaoheyuan in northwestern China, dating to the early first millennium BC. This specific pit, one of four excavated at the site, contained at least 29 horses and 3 wooden chariots. Most of these horses were young adults aged between 4 and 12 years. Out of the 22 horses with sex estimates, 21 were males. Among these individuals, one adult female horse (Horse 6) and one infantile horse (Horse 10) were of particular importance. Based on the age-at-death, sex, and head orientation of the two individuals, alongside their spatial relationships, it is highly likely that Horse 6 was the fetus of Horse 10 and was extruded in the pit. According to the parturition stage of Horse 10, Horse 6 was likely interred in CMK2 in late spring or early summer of the year, during which the relatively high temperature may have generated gas that led to the extrusion of the fetus. Although the specific reason for the inclusion of a pregnant mare in a chariot-horse pit at Yaoheyuan remains a topic for future research, this case marks the first report of post-mortem fetal extrusion in archaeological horses. The findings offer insights into the timing of horse interment as part of ritual practices among the settled elites during the Bronze Age in China and provide valuable reference data for contemporary equine veterinary science.

P-526 Identification of mouse cumulus cell-specific miRNAs and their role in the acquisition of the oocyte developmental competence

Abstract Study question Do cumulus cells (CCs), during mouse germinal vesicle (GV)-to-metaphase II (MII) transition, produce miRNAs with a role in the acquisition of the oocyte developmental competence? Summary answer We identified a group of 74 miRNAs with a known role in key processes of oocytes maturation and developmental competence. What is known already We recently developed a co-culture platform whereby CC-free, denuded, GV oocytes (DOs) were matured to MII upon a feeder layer (FL) of CCs derived either from developmentally competent (FL-SN-CCs) or incompetent (FL-NSN-CCs) oocytes. When cultured upon FL-SN-CCs, DOs displayed a developmental competence equal to that showed by control cumulus-enclosed oocytes (COCs). Instead, when cultured upon FL-NSN-CCs, all DOs arrested at the 2-cell stage. We found that CCs released into the medium large amounts of extracellular vesicles (EVs), whose content analysis by NGS led to the identification of candidate miRNAs. Study design, size, duration Five-eight-week-old CD1 mouse females (Charles River) were injected with 10 I.U. Pregnant Mare Serum Gonadotropin (PMSG). After 48 hr, the ovaries were isolated and their surface punctured with a thin sterile needle to collect fully-grown antral oocytes which were separated from the surrounding CCs. Eight-ten DOs were cultured upon FL-SN-CCs or FL-NSN-CCs for 15 hr in 50 µl exosome-free alpha-MEM Glutamax medium for EVs production. Experiments were performed in triplicates. Participants/materials, setting, methods EVs were collected and processed for EVs characterisation by Amnis-Imaging-flow-cytometer and transmission electron microscopy (TEM), or for RNA extraction (miRNeasy Micro Kit, Qiagen), libraries production (Small RNA-Seq Library Prep kit, Lexogen) and NGS (Illumina Genome Analyzer and the NextSeq 500/550 High Output v2.5). To identify miRNA’s target genes, we used “mirPath v.3” server of the DIANA tools website (https://dianalab.e-ce.uth.gr/html/mirpathv3/index.php?r=mirpath). Then, STRING and KEGG were used to highlight the pathways in which these genes are involved. Main results and the role of chance Imaging flow cytometry recorded an amount of released EVs in both FL-SN-CCs or FL-NSN-CCs in the mean range of 5-5.9 x 10(8) particles/ml (p &amp;gt; 0.05), with &amp;gt;96% positive to CD9 exosome surface marker. TEM analysis showed an EVs size in diameter comprised between 18.5-54.9 nm. By comparing FL-SN-CCs vs. FL-NSN-CCs, NGS of EVs’ miRNAs content displayed 74 differentially expressed miRNAs, 43 up- and 31 down-regulated. Of them, 7 resulted involved in the regulation of 71 target genes with a known function in meiosis resumption (N = 24), follicle growth (N = 23), fertilisation (N = 1) and in the acquisition of the oocyte’s developmental competence (N = 23). Limitations, reasons for caution We used an in vitro platform to mimic the cumulus-oocyte-complex environment and, thus, the artificial set-up may differ from that of the natural condition. Also, our hypothesis on the role of these miRNAs, needs to be further confirmed by functional assays (e.g., miRNA inactivation). Wider implications of the findings Overall, our results indicate CC-derived miRNAs as candidates of the CC-to-oocyte bidirectional communication and suggest a group of miRNAs as potential regulative molecules in the acquisition of the oocyte developmental competence. Trial registration number NOT APPLICABLE

Divergent strains of EHV-1 in Swedish outbreaks during 2012 to 2021

Equid alphaherpesvirus 1 (EHV-1) is a ubiquitous and significant viral pathogen in horses worldwide, causing a range of conditions, including fever, respiratory disease, abortion in pregnant mares and the severe neurological disease called equine herpes myeloencephalopathy (EHM). Despite that EHV-1 is a notifiable animal disease in Sweden, there is limited knowledge about the circulating strains. This study aimed to analyze the genetic diversity of EHV-1 strains in equine samples from different Swedish outbreaks by partial genome sequencing. Genotyping based on three selected open reading frames ORF11, ORF30, and ORF34 in the viral genome was conducted for 55 outbreaks of EHV-1 spanning from the years 2012 to 2021. The analysis revealed 14 different genovariants, with one prominent genovariant identified in 49% of the outbreaks. Additionally, the study identified seven mutations not previously described. Three new mutations were demonstrated in ORF11, all synonymous, and four new mutations in ORF34, two synonymous, and two non-synonymous. Notably, different EHV-1 genovariants were found in five out of six studied EHM outbreaks, but clonal spreading was shown within the outbreaks. Moreover, the study demonstrated that healthy (recovered) horses that returned from an EHM outbreak at an international meeting in Valencia, Spain (2021), were positive for the virus clone responsible for the severe disease outbreak despite several weeks of quarantine. These findings shed light on the genetic diversity and transmission dynamics of the virus and significantly contribute to better understanding of the epidemiology of EHV-1 in Sweden and globally.

Use of OODEV® in Improving the Reproductive Performance of Male Yellow Rasbora Fish Rasbora lateristriata (Bleeker, 1854)

A local commodity, Yellow rasbora fish Rasbora lateristriata (Bleeker, 1854), can potentially be used as a food resource by the Kulon Progo community. Added to that, cultivation or aquaculture is known to optimize this potential. Furthermore, Aquaculture will also prevent illegal fishing in nature, where yellow rasbora fish are listed as vulnerable species in the IUCN Red list. This study induced male yellow rasbora fish using the hormone OODEV® injection, which comprises the hormone Pregnant Mare Serum Gonadotropin (PMSG) and anti-dopamine. PMSG is a hormone that contains FSH as well as LH in it. Yellow rasbora fish were nurtured to the age of six months and treated with four different treatments (dose) for a month, namely 0 mL/Kg, 0.25 mL/Kg, 0.5 mL/Kg, and 0.75 mL/Kg. Observed parameters included motility (movement and duration) as well as sperm count, sperm viability, sperm morphology, sperm morphometry, gonadosomatic index (GSI), and survival rate (SR). Data obtained were analyzed using SPSS with the One-way ANOVA test and continued with Duncan's test if the results were significant. The obtained results had no significant effect on the IGS value (p&gt;0.05), with the highest value found at a dose of 0.75 mL/Kg. In addition, administration of OODEV® also improved sperm quality with the best results at 0.75 mL/Kg in terms of motility with the highest progressive movement compared to other doses but not significant (p&gt;0.05) compared to the control, and significantly (p&lt;0.05) longest movement duration compared to other doses, while in terms of morphometry it had the second widest middle piece area but not significant (p&gt;0.05) compared to other doses, widest tail area but not significant (p&gt;0.05) compared to other doses except with 0.25 mL/Kg, longest tail length (p&gt;0.05) but not significant with other doses except with 0.25 mL/Kg , and significantly (p&lt;0.05) had the longest sperm total length. Every dose showed a 100% percentage of survival rate.

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 known ovulation dates, every two weeks from 240- days of gestation until parturition. P1 was imaged in 69 % of the examinations. Inability to image P1 was due to obstructive positioning such as carpal or fetlock flexion, or posterior presentation of the fetus. Advancing fetal age did not affect visibility of P1. P1 length correlated significantly with days of gestation and a correlation equation was established: y = 0.3837x -69.55 where y is the predicted value of P1 length and x is the day of gestation (with day 0 being the day of ovulation). When P1 length was equal to or larger than the width of the ultrasound image (52.5 mm), 90 % of mares (9/10) were above 300- days of gestation. Ossification of the proximal and distal epiphysis of P1 typically appeared between 277- and 303 -days of gestation (mean: 288 days). The proximal epiphysis did not close before parturition whereas the distal one closed between 306- and 333-days of gestation (mean: 320 days). P1 epiphyseal appearance and closure occurred chronologically reflecting bone maturation. Radiographic findings at birth and prenatal ultrasound findings were in agreement, apart from timing of P1 distal epiphyseal closure. In conclusion, P1 length can be used as a new fetal biometric parameter to assess fetal age and growth after 240- days of gestation. The knowledge of P1 bone maturation process in utero as a marker for fetal bone development, may also be valuable in clinical decision-making when considering inducing parturition in the mare.

Obesity and gestation in Criollo mares: endocrine and metabolic profiles

The aim of this study was to determine the effect of body condition score (BCS) on metabolic and endocrine parameters in pregnant Criollo mares (n=41), which were categorized according to their BCS as obese (7 to 9 BCS, n=26) or normal (5 to 7, n=15). Blood samples were taken during gestation in 3 periods: between 3.5 and 5 months (I), 8 and 9 months (II) and in the last month of gestation (III). The data was analyzed in the statistical model by mixed procedures, including BCS, gestational period and their interaction as fixed effects. BCS was only different in period I, as normal mares increased their BCS in the later periods. Leptin concentrations were greater in obese mares when compared to non-obese mares during all sampling periods (P<0.01), while glucose concentrations were also greater in the former group (P<0.01) but only during the first sampling period. Insulin concentrations and homeostatic model assessment for insulin resistance (HOMA-IR) index were greater also in obese mares in periods I and III (P<0.05). Adiponectin concentrations in period I were lower in obese mares (P<0.05). Cholesterol concentrations increased during gestation, and obese mares tended to have greater concentrations than nonobese mares (P<0.1). Triglyceride concentrations were not affected by group or gestational period. This study revealed adaptations in carbohydrate and lipid metabolism during gestation in mares. Several parameters are dependent on the degree of body fat reserves, which are reflected in the concentrations of biomarkers such as leptin and adiponectin. Insulin concentration in obese mares was higher than non-obese mares at the end of gestation, a similar profile was observed for HOMA-IR although cutoff values are yet still to be validated.

Placental abnormalities associated with Leptospira interrogans infection in naturally infected mares

The reproductive features of equine leptospirosis are often neglected. Equine genital leptospirosis is characterized as a silent chronic syndrome, and besides abortions, leads to placental abnormalities, stillbirths, and birth of weak foals. This study aimed to study the occurrence of placental abnormalities associated with Leptospira interrogans infection in naturally infected mares under field conditions. The studied herd had a high occurrence of placentitis and abortions. Ten pregnant mares, eight with placental abnormalities on ultrasonography and were selected. Serum and cervicovaginal mucus (CVM) samples were collected for serology and PCR, respectively. Positive samples in lipL32-PCR were submitted to the sequencing of the secY gene. In lipL32-PCR of CVM, five out of 10 (50%) mares were positive and all were characterized as Leptospira interrogans. Our results highlight the presence of placental abnormalities in the reproductive subclinical leptospirosis syndrome. We encourage field veterinarians to include leptospirosis testing in their reproductive management.

Complete abdominal wall rupture in a late‐term pregnant mare with pre‐existing prepubic tendon rupture

SummaryA 15‐year‐old multiparous Quarter Horse mare with a pre‐existing (&gt;1 year) prepubic tendon rupture was presented pregnant (approximately 310 days gestation) with mild signs of generalised discomfort and an advanced degree of cervical relaxation. The foal was declared to be the priority in an emergency situation; therefore, intravenous dexamethasone (0.1 mg/kg bwt i.v. q24h) was administered in an attempt to mature the fetus in case urgent induction of parturition was required. Within 36 h of admission, the mare developed a complete rupture of the caudoventral body wall and skin, from the anus to the cranial aspect of the mammary gland. Because eventration had occurred, the mare underwent immediate euthanasia and terminal caesarean section via a modified approach. The colt foal was euthanised on humane grounds, due to an inability to breathe without a ventilator, following 72 h of intensive care. Rebreeding mares with prepubic tendon rupture is not recommended, this case report presents important evidence that rebreeding mares with this condition can have fatal consequences.

Pregnancy rates according to follicle diameter and uterus edema in different age groups in two consecutive ovulations in Arabian mares

The study aimed to evaluate the pregnancy rates of mares in different age groups based on follicle diameter and uterine edema during two consecutive ovulations in three breeding seasons. Thirty Arabian mares were divided into two groups: below and equal to 10 years (Group A=54) and above 10 years old (Group B=36). Throughout the breeding season, the diameters of ovulatory follicles and uterine edema were recorded. After the first ovulation, when the follicle diameters of all mares in both Group A and Group B were analyzed independently of age, and compared between pregnant and non-pregnant mares, no differences were found (P&gt;0.05). The differences between the agerelated groups were insignificant (P&gt;0.05). Follicle diameters between pregnant and non-pregnant mares at the second ovulation were significantly different (P0.05). Differences between uterine edema values determined in mares that were pregnant and nonpregnant in two consecutive ovulations were found to be insignificant in terms of pregnancy (P&gt;0.05). As a result, although preovulatory diameter is not a reliable marker for pregnancy detection, it remains an important parameter for determining ovulation and artificial insemination timing. Uterine edema is only useful for determining the timing of insemination and is not associated with pregnancy. Moreover, since similar pregnancy rates were observed among different age groups, age alone is not a sufficient parameter for assessing reproductive efficiency in mares.

Effect of Pregnant Mare Serum Gonadotropin and Antidopamine on the gonads of female bileh fish (Rasbora maninjau)

Bileh fish (Rasbora maninjau) still have difficulty spawning in a controlled manner in aquaculture containers because the maturation of female fish gonads is slow and takes a long time. Internal factors, including the hormonal system, strongly influence the maturation of fish gonads. This study aims to determine the effect of Pregnant Mare Serum Gonadotropin (PMSG) and antidopamine on female gonads of bileh fish. The research used an experiment with a CRD (Completely Randomized Design) experimental design. The experiment consisted of four treatments and three repetitions. The treatments were the administration of PMSG and antidopamine hormones at different doses through feed, namely: 0 ml/kg feed (P1), 0.5 ml/kg feed (P2), 1 ml/kg feed (P3) and 2 ml/kg feed (P4). The research procedures included container and fish preparation, hormone, and feed preparation, fish rearing, and data collection. The test parameters evaluated were weight gain (Wg), gonadosomatic index (GSI), and gonadal maturity level (GML). Data on test parameters were analyzed with statistics (Anova). The research results showed that the administration of PMSG hormones and antidopamine through feed had a significant effect on weight gain, gonadosomatic index and gonad maturity level of bileh fish (P<0.05). Effective and best treatment at P3 (1 ml/kg feed) with Wg 0.22grams, GSI 8.58%, and GML IV 60%.