Eunice Oba

Gestational success in ruminants depends on the maintenance of a dynamic maternal–foetal microenvironment, resulting from complex interactions among the conceptus, extraembryonic membranes, maternal tissues, and gestational fluids. This study performed a comparative and longitudinal proteomic characterization of allantoic and amniotic fluids throughout pregnancy in sheep, aiming to elucidate the molecular mechanisms involved in maternal–foetal communication and embryonic development. Samples of allantoic and amniotic fluids aseptically collected from extraembryonic compartments after uterine opening following animal slaughter and allocated into three gestational groups according to foetal development: early gestation (0–50 days; n = 6), mid gestation (50–100 days; n = 3) and late gestation (100–150 days; n = 5). After centrifugation and protein quantification using the Bradford method, standardized aliquots were subjected to in‐solution protein digestion and analysed by nano‐LC–ESI‐Q‐TOF mass spectrometry. A total of 201 proteins were identified in the allantoic fluid and 159 proteins in the amniotic fluid, with five proteins showing significant differences across gestational stages. In the allantoic fluid, differentially abundant proteins included alpha‐2‐macroglobulin, gelsolin, basement membrane–specific heparan sulphate proteoglycan core protein and alpha‐globin chain. In the amniotic fluid, changes were observed in peroxiredoxin‐2, mucin‐5 AC, fetuin‐B, cystatin domain–containing protein and globin domain–containing protein. Multivariate analyses revealed progressive remodelling of the foetal extraembryonic microenvironment, associated with proteolytic control, tissue remodelling, redox homeostasis, epithelial protection and metabolic processes. Collectively, these findings reinforce the active role of foetal extraembryonic fluids in gestational physiology and highlight their potential as sources of biomarkers associated with reproductive success in sheep.

Electroejaculation (EE) is a practical and effective method for semen collection in domestic animals; however, it may cause pain and stress when performed without prior anesthesia. This study evaluated two local anesthetic block protocols and two hypogastric nerve access routes as alternatives to reduce discomfort and stress associated with EE in male goats. Six healthy Anglo-Nubian bucks were subjected to five semen collection treatments (n=3 collections/treatment): T1, control; T2, ventral hypogastric block with lidocaine; T3, ventral block with lidocaine plus fentanyl; T4, perineal block with lidocaine; and T5, perineal block with lidocaine plus fentanyl. Semen samples were evaluated for motility, volume, morphology, concentration, and plasma membrane integrity. Serum cortisol and creatine kinase (CK) concentrations were determined, and stress responses were assessed through blood pressure, heart rate (HR), respiratory rate (RR), and the occurrence of recumbency, ataxia, and vocalization. Data were analyzed using a general linear model (GLM-SAS®). No treatment effects were observed for HR or the occurrence of vocalization and ataxia (P > 0.05). Lower RR values were observed when fentanyl was included in the anesthetic protocol, regardless of the access route (P = 0.01). Most semen parameters were unaffected by treatments; however, total sperm concentration per ejaculate was higher in treatments combining lidocaine and fentanyl (P = 0.005). Serum cortisol concentrations increased after EE in all treatments but were lower in fentanyl-treated animals (P = 0.0007). In conclusion, pre-EE administration of lidocaine hydrochloride combined with fentanyl citrate improved control of stress-related responses and increased sperm concentration in male goats.

Diego Gouvêa de Souza, Fernanda Nunes Marqui, Sabrina Cruz Tfaile Frasnelli, Andressa Vilas Boas Nogueira, Alicio Martins Jr., Ana Carolina Monteirinho Lobo, Claudio Willian de Oliveira Delfes-Camargo, Luan Sitó-Silva and Eunice Oba. J Anim Reprod Biotechnol 2026;41:2-12. https://doi.org/10.12750/JARB.41.1.2

Boar semen cryopreservation is limited by high sperm sensitivity, with the cooling extender and holding time representing critical steps. However, the interplay between transport and freezing extenders remains poorly elucidated. This study evaluated the main effects and the interaction between two cooling extender (BTS and BSUI®) and two freezing extenders (TRIS® and BBB®) on post-thaw boar semen quality. Ejaculates from 10 boars were processed in a 2x2 factorial design (BTS/TRIS, BTS/BBB, BSUI/TRIS, BSUI/BBB). Sperm kinetics (CASA) and plasma membrane integrity (PMI) were assessed at pre-centrifugation, post-centrifugation, and post-thaw time points. At the post-thaw evaluation, no significant interaction was observed between transport and freezing extenders (P > 0.05), indicating that these factors act independently. Regarding the main effects, the BSUI® cooling extender resulted in superior kinetic performance compared to BTS (P < 0.05). Independently, the TRIS® freezing extender yielded higher motility and membrane integrity than BBB® (P < 0.05). Consequently, the sequential combination of BSUI/TRIS presented the highest absolute kinetic values (Total Motility 63.3%; Progressive Motility 36.1%) due to the cumulative effect of the most efficient extenders. In conclusion, the cooling extender influences post-thaw quality independently of the freezing extender. The BSUI/TRIS sequence optimized post-thaw kinetics through an additive effect. Therefore, protocol optimization should focus on selecting the most efficient extender for each isolated stage of the process.

In equine reproduction, determining foetal sex is of economic and strategic importance, but currently available methods are often invasive, costly, or require specialised expertise. This study aimed to assess whether plasma progesterone concentrations could serve as a predictive tool for foetal sex determination in Criollo mares between the 4th and 8th months of gestation and to determine whether these measurements could identify foetal sex. Blood samples were collected at 30‐day intervals from 17 Crioula mares between 114 days and 240 days of gestation. Maternal plasma progesterone concentrations were determined by radioimmunoassay and the sex of the foals was confirmed at birth. Analysis of Variance (ANOVA) was made to verify the variation in maternal progesterone concentrations according to foetal sex and month of gestation. In mares carrying male foetuses ( n = 7), there was a significant difference in progesterone concentrations between months 4 and 8, as well as between months 7 and 8. In mares carrying male foetuses ( n = 7), progesterone concentrations were higher ( p = 0.028) during the 4th month of gestation and lower at the 8th month ( p = 0.020), compared to the values in mares with female foetuses ( n = 10). In the 8th month of pregnancy, the sensitivity and specificity of progesterone concentrations for the predicted sex were 80% and 100%, respectively. A limit value of progesterone (12.45 ng/mL) was established through the ROC (receiver operating characteristic) Curve. Prediction values were 78.8% and 100% for males and females, respectively. Detection rates were 100% and 80% for males and females, respectively. The diagnostic accuracy for both sexes was 88.2%. It is concluded that foetal sex influences plasma concentrations of progesterone in pregnant mares.

In this study, thirty female dogs, aged one to five years and varying in weight, in the last week of gestation were evaluated. The animals were divided into two groups: GC, which comprised twenty-two bitches undergoing elective cesarean section, and GD, which consisted of eight dogs requiring therapeutic cesarean section as a treatment to dystocia. We found that cortisol levels in the amniotic fluid were significantly higher in pups delivered via elective cesareans (mean: 9.86 ng/mL) compared to those from therapeutic c-sections (mean: 4.11 ng/mL). This observation contrasted with previous studies that reported lower cortisol levels in elective procedures, suggesting complexities in the physiological responses to different delivery methods that warrant further investigation. Notably, our study observed no significant association between amniotic fluid meconium presence and other distress markers, indicating that meconium may be more closely associated with fetal maturation rather than distress (p > 0.05). Neonatal viability (Apgar score) revealed that 92.86% of the neonates from elective procedures demonstrated no distress shortly after delivery, contrasting with 56.25% in therapeutic c-section. Fetal distress can be a direct consequence of dystocia caused by various stressors, such as pain and hypoxia. These factors can impair the fetus’ ability to adapt to extrauterine life, often leading to lower Apgar scores. Notably, neonatal weight was directly related to fetal cortisol levels, while no significant associations were noted between the litter size or birth order and cortisol concentrations, irrespective of the delivery type. These findings underscore the need for ongoing investigation into the relationships between cesarean delivery types, maternal and neonatal stress markers, and resultant health outcomes, aiming to enhance care strategies for expectant canine mothers and their puppies.

The objective was to evaluate the influence of nonsteroidal anti-inflammatory drugs on the duration of the luteal phase, progesterone concentrations and pregnancy rates in buffaloes undergoing embryo transfer. Twenty-nine buffaloes were synchronized. After estrus detection, the recipients were divided into three groups: Control (uterine manipulation), Flunixum Meglumine (manipulation + administration) and Firocoxib (manipulation + administration). Ultrasound evaluations and hormonal dosages were performed on days 6, 12 and 18 to determine the plasma concentration of P4 and the functional duration of the corpus luteum. The control group presented a larger CL area on day 0 than the FM group, there was a significant increase in plasma progesterone concentration between D6 and D12 (P < 0.05), and a significant decrease between D6-D18 and D12-D18. Additionally, 8 buffalo cows underwent in vitro embryo transfer and were divided into three groups: CONT (manipulation of the reproductive tract), FM group (manipulation + administration) and FIRO group (manipulation + administration). Pregnancy diagnosis was performed at 30 and 60 days. No statistically significant differences in pregnancy rates were observed between groups. It was concluded that a single application of FM and FIRO at the time of embryo transfer did not significantly increase conception rates.