Baseline cystometric parameters in conscious and anesthetized sheep: experimental data and systematic review.

OBJECTIVE: To characterize cystometry in conscious and anesthetized sheep, including bladder response to sacral root electrical stimulation, thereby providing a baseline set of values. METHODS: Single-fill cystometries were repeated in adult mule ewes both conscious (n = 5) and under general anesthesia (18) using a commercial system. Parameters including bladder capacity, detrusor (bladder) pressure, urethral opening pressure, bladder compliance, number of nonvoiding detrusor contractions, and bladder pressure change in response to electrical stimulation of the sacral roots under general anesthesia are reported. Pubmed, Embase, and Web of Science databases were searched for studies relating to ovine cystometry, and a systematic review was conducted. RESULTS: In awake sheep, mean ± SD bladder capacity was 79.6 ± 32.2 mL, urethral opening pressure was 26.0 ± 10.7 cm H2O, and compliance was 3.5 ± 1.9 mL/cm H2O. Peak detrusor pressures during micturition reached 57.7 ± 28.3 cm H2O. In anesthetized animals, mean bladder capacity (endpoint, 50 cm H2O) was 333 ± 191 mL, and mean bladder compliance was 7.7 ± 4.9 mL/cm H2O. Values for these parameters from our systematic review are presented for comparison and reference. Electrical stimulation of the second and third sacral roots caused a greater increase in detrusor pressure than stimulation of the first and fourth sacral roots. CONCLUSIONS: We present a comprehensive set of data for normal cystometry parameters in sheep, including the first report of detrusor response to sacral root stimulation in anesthetized sheep. CLINICAL RELEVANCE: This report provides a valuable set of baseline values for a potential translational model of value to neurourologic research and may be a useful reference for clinicians.

Tick control prevents carcass condemnations in labs caused by Anaplasma ovis.

Ovine anaplasmosis is causing relevant economic losses in Spain due to icteric carcass condemnation in lambs. Anaplasma ovis infection occurs through grazing sheep that transfer ticks to their offspring. This study compared the efficacy of deltamethrin and cypermethrin pour-on treatments for tick control. A total of 250 PCR A. ovis-positive ewes and their offspring were divided into 5 groups. Group A (50 ewes/50 lambs) was kept as an untreated control group. In groups B (50/50) and C (45/93), the lambs were treated with deltamethrin pour-on and cypermethrin pour-on, respectively, one week after birth. In groups D (50/75) and E (51/68), the ewes were treated with cypermethrin pour-on and deltamethrin pour-on one week before the estimated parturition. External parasite assessment and A. ovis PCR were conducted before treatment and at 21 and 42 days post-treatment. Ewes were checked weekly for tick-detection until weaning. Lamb carcasses were examined at the slaughterhouse. Riphicephalus sanguineus sensu lato ticks were found in ewes throughout the study, with only one tick found in a control group lamb. Three lambs tested positive for A. ovis during the trial, with one condemnation at the abattoir due to jaundice. However, no significant differences were observed between treatment groups. Overall, a significant decrease in infected animals and condemned carcasses was observed compared to previous years, suggesting that deltamethrin and cypermethrin prevent A. ovis transmission from dams to lambs. Further studies are needed to confirm synthetic pyrethroids' effectiveness in controlling tick infestation and averting A. ovis transmission to lambs.

Molecular detection and phylogenetic analysis of ovine herpesvirus-2 in subclinical infections of cattle and sheep.

Ovine herpesvirus-2 (OvHV-2) is the causative agent of malignant catarrhal fever (MCF), a serious and often fatal disease that affects cattle and other ruminants. This study aimed to investigate the molecular epidemiology and genetic diversity of OvHV-2 strains circulating in sheep and cattle populations in the Jammu and Kashmir region of India. Screening of 150 sheep and 57 cattle blood samples revealed the presence of the OvHV-2 polymerase (pol) gene in 8.6% of sheep, 10% of apparently healthy cattle, and 29.7% of cattle exhibiting MCF-like symptoms. The full-length glycoprotein B (gB) gene (2800 bp) and an 875 bp internal fragment were successfully amplified, cloned, and sequenced from pol-positive samples. Comparative sequence analysis of the deduced gB amino acid sequences identified seven substitutions at positions 278, 341, 390, 440, 468, 539, and 566 compared to reference strains. Phylogenetic analysis based on the gB nucleotide sequences clustered the OvHV-2 strains from this study within the Indian clade, distinct from strains reported in the UK and US. These findings provide insights into the genetic diversity of OvHV-2 strains circulating in Jammu and Kashmir, with the identified mutations potentially influencing virus-host interactions. Further investigations into the functional implications of these mutations are warranted to understand their role in viral pathogenesis and tropism.

Comparative study of the reproductive and growth performance of the Hamra and Rumbi ovine breeds.

Growth and reproductive performance traits are important economic indicators for analyzing the overall performance of breeding systems. This study aims to evaluate the comparative performance of two Algerian sheep (Rumbi and Hamra) in terms of growth and reproductive performance, and the effect of factors such as breed, season of birth, mode of birth and age of the mother on this performance in a semi-intensive breeding system. The reproductive performance of 577 Rumbi ewes and 1328 Hamra ewes bred at the Tiaret and Saïda experimental stations respectively, was analyzed using performance monitoring data. Fertility rates for the Rumbi and Hamra breeds of 87.14% and 78.8% respectively were practically similar (p > 0,05). Litter size at birth and weaning was significantly higher in the Hamra breed than in the Rumbi breed (p < 0,05). Weaning mortality was significantly higher in the Hamra breed than in the Rumbi breed, with an average of 22.60% versus 14.94% (p < 0,05). The effect of factors showed that there was a highly significant effect of the mother's age and season of birth on the reproductive performance of the Hamra and Rumbi breeds with a p < 0.0001 on fertility, litter size at birth, litter size at weaning and fertility. There was a significant effect of the year factor on reproductive performance with p = 0,013 for the Hamra breed and p = 0,031 for the Rumbi breed. The results of this study showed that Rumbi lambs were heavier at birth than Hamra lambs. The values observed were 4,86 kg versus 3,10 kg for the Hamra breed, with a highly significant difference (p < 0,0001), so that the average daily pre-weaning weight gains of Rumbi lambs were higher than those of Hamra lambs, at 0,195 kg/day versus 0,113 kg/day for Hamra lambs, with a high significance (p < 0,0001). The effect of factors showed that there was a significant effect of the mother's age on the ADGs (0-30), (30-70) and (70-90) of the Hamra and Rumbi breeds with a p = 0,034 and p = 0,02 respectively. There was also a highly significant effect of the birth mode effect on ADGs (0-30), (30-70) and (70-90) only for the Hamra breed with a p = 0,004. The effect of the birth weight on ADGs was not significant for both Hamra and Rumbi breeds with a p > 0,05. According to the findings of this study, the Hamra breed had superior reproductive potential and the Rumbi breed had superior growth. The Hamra breed showed better maternal skills in terms of fertility and prolificacy, while the Rumbi breed showed better lamb growth performance. Consequently, these results could be used for selective sheep breeding, taking into account the random effects of the environment and the potential of each breed.

Comparative Analysis of Commercially Available Extracellular Matrix Soft Tissue Bioscaffolds.

Decellularized extracellular matrix (dECM) products are widely established for soft tissue repair, reconstruction, and reinforcement. These regenerative biomaterials mimic native tissue ECM with respect to structure and biology and are produced from a range of tissue sources and species. Optimal source tissue processing requires a balance between removal of cellular material and the preservation of structural and biological properties of tissue ECM. Despite the widespread clinical use of dECM products there is a lack of comparative information on these products. This study provides a comparative analysis of 12 commercially available dECM products. One group of products consisted of materials intended for dermal repair including ovine forestomach matrix (OFMm), porcine peritoneum (PPN), porcine placenta (PPC), and porcine small intestinal submucosa (SISu). The second group, intended for load-bearing reconstruction, consisted of material derived from ovine forestomach matrix (OFMo), porcine urinary bladder matrix (UBM), porcine small intestinal submucosa (SISb and SISz), human dermis (ADM), porcine dermis (PADM), and fetal/neonatal bovine dermis (BADM). A minimally processed product consisting of human placental tissue was included as a control. Products were compared histologically and by agarose gel electrophoreses to assess structural features and decellularization. Structurally, some dECM products showed a well-preserved collagen architecture with a broad porosity distribution, whereas others showed a significantly altered structure compared with native tissue. Decellularization varied across the products. Some materials surveyed (OFMm, PPN, PPC, OFMo, UBM, SISz, ADM, PADM, and BADM) were essentially devoid of nuclear bodies (mean count of <5 cells per high-powered field [HPF]), whereas others (SISu and SISb) demonstrated an abundance of nuclear bodies (>50 cells per HPF). Pathology assessment of the products demonstrated that OFMm, OFMo, and PADM had the highest qualitative assessment score for collagen fiber orientation and arrangement, matrix porosity, decellularization efficiency, and residual vascular channels scoring 10.5 ± 0.8, 12.8 ± 1.0, and 9.7 ± 0.7 out of a maximum total score of 16, respectively. This analysis of commercially available dECM products in terms of their structure and cellularity includes 12 different commercial materials. The findings highlight the variability of the products in terms of matrix structure and the efficacy of decellularization.

Whole-transcriptome analyses of ovine lung microvascular endothelial cells infected with bluetongue virus.

Bluetongue virus (BTV) infection induces profound and intricate changes in the transcriptional profile of the host to facilitate its survival and replication. However, there have been no whole-transcriptome studies on ovine lung microvascular endothelial cells (OLMECs) infected with BTV. In this study, we comprehensively analysed the whole-transcriptome sequences of BTV-1 serotype-infected and mock-infected OLMECs and subsequently performed bioinformatics differential analysis. Our analysis revealed 1215 differentially expressed mRNA transcripts, 82 differentially expressed long noncoding RNAs (lncRNAs) transcripts, 63 differentially expressed microRNAs (miRNAs) transcripts, and 42 differentially expressed circular RNAs (circRNAs) transcripts. Annotation from Gene Ontology, enrichment from the Kyoto Encyclopedia of Genes and Genomes, and construction of endogenous competing RNA network analysis revealed that the differentially expressed RNAs primarily participated in viral sensing and signal transduction pathways, antiviral and immune responses, inflammation, and extracellular matrix (ECM)-related pathways. Furthermore, protein‒protein interaction network analysis revealed that BTV may regulate the conformation of ECM receptor proteins and change their biological activity through a series of complex mechanisms. Finally, on the basis of real-time fluorescence quantitative polymerase chain reaction results, the expression trends of the differentially expressed RNA were consistent with the whole-transcriptome sequencing data, such as downregulation of the expression of COL4A1, ITGA8, ITGB5, and TNC and upregulation of the expression of CXCL10, RNASEL, IRF3, IRF7, and IFIHI. This study provides a novel perspective for further investigations of the mechanism of the ECM in the BTV-host interactome and the pathogenesis of lung microvascular endothelial cells.

Pearls and Pitfalls of Epicardial Echocardiography for Implantation of Impella CP Devices in Ovine Models.

The Impella CP is a percutaneously inserted temporary left ventricular assist device used in clinical practice and in translational research into cardiogenic shock, perioperative cardiac surgery, acute cardiac failure and mechanical circulatory support. Fluoroscopic guidance is usually used for insertion of an Impella, thus limiting insertion to within catheterization laboratories. Transthoracic, transoesophageal and intracardiac echocardiography have been reported to guide Impella CP implantation with identified specific limitations stemming from the surgical, anatomical and equipment factors. We conducted translational prospective descriptive feasibility investigation as a part of two other hemodynamic Impella studies. It showed the successful application of epicardial echocardiographic scanning for implantation of Impella CP devices in ovine models, from which details of the technique and identified pitfalls are described with practical solutions for future investigators and clinicians. Many described findings are relevant to any other echocardiographic techniques when adequate imaging of the Impella and relevant anatomical structures is achievable.

Retroviral coinfection (Jaagsiekte and Maedi-Visna viruses) in sheep with pulmonary tumors in Transylvania (Romania): retrospective study on 82 cases.

Ovine pulmonary adenocarcinoma (OPA) is an important viral-induced neoplasia in sheep caused by exogenous Jaagsiekte sheep retrovirus (exJSRV). Coinfection of exJSRV and Maedi-Visna virus (MVV) is reported in OPA cases, but its worldwide distribution and significance on lung pathology is not yet completely understood. This study aimed to investigate the MVV coinfection rate in 82 exJSRV-related OPA cases, and their pathological effects on lung parenchyma in slaughtered sheep in Transylvania (Romania). On gross examination, classical form of OPA was identified in 92.7%; no changes consisting with MVV interstitial pneumonia were identified in the included cases. The most common histological type of OPA was acinar (58.5%) and the myxoid growths were found in 18 cases. The exJSRV and MMV coinfection rate in examined sheep was 47.6% (39/82). The assessment of perineoplastic areas from coinfected animals, revealed interstitial lymphoplasmacytic infiltrates in all cases, lymphoid hyperplasia in 60.6% cases (20/33) and fibromuscular hyperplasia in 63.7% (21/33). This is the first report providing new data on distribution of OPA coexisting with MVV infection in slaughtered sheep in Romania. We consider that the OPA and MVV coinfection may play an important role on the severity of ovine chronic pulmonary diseases and further studies are needed to confirm this hypothesis.

The effects of simultaneous respiratory infections on the nasal shedding of Mycoplasmopsis bovirhinis in dairy calves.

Although there are several studies that described the possible participation of Mycoplasmopsis bovirhinis (formerly, Mycoplasma bovirhinis) in respiratory disease in calves worldwide, none of these evaluated the effects of concomitant infections on the shedding of this organism. Accordingly, this study evaluated the effects of simultaneous respiratory infections in dairy calves on the nasal shedding of M. bovirhinis. A statistical two-step model, using univariable and multivariable with logistic regression was developed to investigate and predict the possible effects of simultaneous infections by Histophilus somni, Mannheimia haemolytica, Pasteurella multocida, bovine coronavirus (BCoV), and ovine gammaherpesvirus 2 (OvGHV2) in dairy calves on the nasal shedding of M. bovirhinis. The multivariable analysis demonstrated that dairy calves infected with OvGHV2 have 2.59 times likelihood of nasal shedding of M. bovirhinis relative to calves not infected by OvGHV2, while the odds of nasal shedding of M. bovirhinis was 3.46 times higher in dairy calves infected by M. haemolytica. In contrast, simultaneous respiratory infections in dairy calves by H. somni, P. multocida, and BCoV had no direct effect on the nasal shedding of M. bovirhinis. Consequently, infections by OvGHV2 and M. haemolytica may be possible risk factors for the nasal shedding of M. bovirhinis in dairy calves. These results demonstrated the importance of disease modeling in veterinary medicine to predict and understand the complex outcomes of associations in animals concomitantly infected by several disease pathogens.

Lesion Localization and Pathological Diagnosis of Ovine Pulmonary Adenocarcinoma Based on MASK R-CNN.

Ovine pulmonary adenocarcinoma (OPA) is a contagious lung tumour caused by the Jaagsiekte Sheep Retrovirus (JSRV). Histopathological diagnosis is the gold standard for OPA diagnosis. However, interpretation of traditional pathology images is complex and operator dependent. The mask regional convolutional neural network (Mask R-CNN) has emerged as a valuable tool in pathological diagnosis. This study utilized 54 typical OPA whole slide images (WSI) to extract 7167 typical lesion images containing OPA to construct a Common Objects in Context (COCO) dataset for OPA pathological images. The dataset was categorized into training and test sets (8:2 ratio) for model training and validation. Mean average specificity (mASp) and average sensitivity (ASe) were used to evaluate model performance. Six WSI-level pathological images (three OPA and three non-OPA images), not included in the dataset, were used for anti-peeking model validation. A random selection of 500 images, not included in the dataset establishment, was used to compare the performance of the model with assessment by pathologists. Accuracy, sensitivity, specificity, and concordance rate were evaluated. The model achieved a mASp of 0.573 and an ASe of 0.745, demonstrating effective lesion detection and alignment with expert annotation. In Anti-Peeking verification, the model showed good performance in locating OPA lesions and distinguished OPA from non-OPA pathological images. In the random 500-image diagnosis, the model achieved 92.8% accuracy, 100% sensitivity, and 88% specificity. The agreement rates between junior and senior pathologists were 100% and 96.5%, respectively. In conclusion, the Mask R-CNN-based OPA diagnostic model developed for OPA facilitates rapid and accurate diagnosis in practical applications.

Identification of concurrent infection with Jaagsiekte sheep retrovirus and maedi-visna virus in China.

IMPORTANCE: Ovine pulmonary adenomatosis (OPA) and maedi-visna disease (MVD) are chronic and progressive infectious diseases in sheep caused by Jaagsiekte sheep retrovirus (JSRV) and maedi-visna virus (MVV), respectively. OBJECTIVE: To investigate the pathological changes and conduct viral gene analysis of OPA and MVD co-occurrence in Inner Mongolia, China. METHODS: Using gross pathology, histopathology, immunohistochemistry, ultrastructural pathology, PCR, and sequence analysis, we investigated the concurrent infection of JSRV and MVV in 319 Dorper rams slaughtered in a private slaughterhouse in Inner Mongolia, in 2022. RESULTS: Of the 319 rams included, 3 showed concurrent JSRV and MVV infection. Gross lung pathology showed diffuse enlargement, consolidation, and greyish-white miliary nodules on the lung surface; the trachea was filled with a white foamy fluid; hilar and mediastinal lymph nodes were significantly enlarged. Histopathology results revealed typical OPA and MVD lesions in the lung tissue. Immunohistochemical results were positive for JSRV envelope protein (Env) in the tumor cells and MVV CA in alveolar macrophages. Transmission electron microscopy showed several virions and autophagosomes in the lung tissue, severely damaged mitochondria, and the induced mitophagy. Nucleotide sequences obtained for JSRV env and MVV gag showed the highest homology with the Inner Mongolian strains of JSRV env (JQ837489) and MVV gag (MW248464). CONCLUSIONS AND RELEVANCE: Our study confirmed that OPA and MVD co-occurrence and identified the pathological changes in Inner Mongolia, China, thereby providing references for the identification of concurrent JSRV and MVV infections.

Impact of Nebulized BromAc® on Mucus Plug Clearance in a Mechanically Ventilated Ex Vivo Ovine Lung Model of Obstructive Respiratory Conditions.

Mucus plugging of the respiratory tract occurs in airway diseases, including asthma, chronic obstructive pulmonary disease, and cystic fibrosis. It can cause blockage of the airways, leading to breathlessness and lung failure. Here, we used a ventilatory setup to demonstrate the effect of BromAc® in dissolving mucus plugs in a novel ex vivo ovine obstructive lung model. Mucus simulant was filled into the trachea of freshly slaughtered ovine lungs and ventilated via an endotracheal tube (ETT) using Continuous Mandatory Ventilation. Predetermined single or repeated doses of Bromelain, Acetylcysteine (Ac), BromAc®, and saline control were administered via an Aerogen® vibrating nebulizer and ventilated for 30 or 60 min. Ventilatory recording of resistance, compliance, and tidal volume was conducted, and rheology pre- and post-treatment were measured. A significant decline in airway resistance (p < 0.0001) compared to the saline control was observed when treated with Bromelain, Ac, and BromAc®, with the latter showing a stronger mucolytic effect than single agents. The decline in resistance was also effective in shorter time points (p < 0.05) at lower doses of the drugs. Changes in compliance, peak pressure, and tidal volume were not observed after administration of the drugs. Rheology measurements revealed that BromAc®TM significantly reduced the viscosity of the mucin at the end of 30 min and 60 min time points (p < 0.001) compared to the saline control. BromAc® showed complete dissolution of the respiratory mucus simulant and improved ventilatory airflow parameters in the ex vivo ovine model.

Transmission patterns of malignant catarrhal fever in sheep and cattle in Karnataka, India.

Malignant catarrhal fever (MCF) presents a sporadic yet significant threat to livestock and wildlife. A comprehensive investigation in Karnataka, India into the prevalence and transmission patterns of sheep-associated MCF (SA-MCF) was conducted. A total of 507 sheep peripheral blood leukocyte samples from 13 districts along with 27 cows and 10 buffalo samples from various regions in Karnataka were tested for SA-MCF infection i.e. Ovine gammaherpesvirus 2 (OvHV-2) using heminested PCR. Furthermore, serum samples collected from 73 cows and 15 buffalo suspected of MCF were tested using a commercially available ELISA kit. Additionally, histopathological examinations of affected tissues and phylogenetic analysis of viral tegument protein sequences were conducted. Our findings indicated a 20.11%, 33.33% and 20% positivity for OvHV-2 in sheep, cows and buffalo respectively by PCR. Statistical analysis revealed a significant association between the age of sheep and the detection of OvHV-2. Seven cows and one buffalo serum samples tested positive for ELISA. Clinical findings in bovids were consistent with typical MCF signs, and histopathological results revealed multi-organ involvement characterised by necrotising vasculitis and lymphoid hyperplasia. The nucleotide pairwise identity matrix revealed 99.5% identity between the sequences obtained in the study with sequences from other states. The phylogenetic analysis of partial tegument protein sequences from bovid and sheep samples suggested a close genetic relationship between the local OvHV-2 strains and those from various global regions. Crucially, this study underscores the widespread presence of SA-MCF in Karnataka, with significant implications for both livestock management and wildlife conservation.

High genetic diversity of Anaplasma ovis in sheep from Bosnia and Herzegovina.

BACKGROUND: Ovine anaplasmosis (sensu stricto) is a rickettsial blood disease caused by the tick-borne species Anaplasma ovis. The disease is characterized by mild anemia, fever, and icterus. A more severe clinical presentation is possible in non-endemic areas. There is no existing data on the presence of Anaplasma ovis in Bosnia and Herzegovina. However, given the country's location within the Mediterranean Basin and the recent molecular detection of Babesia ovis, it is plausible that sheep in the region could naturally be infected with this tick-borne pathogen. METHODS AND RESULTS: Blood samples from 81 sheep in the Podrinje and Herzegovina areas were examined by PCR. PCR positivity was found in 38 (46.9%) cases indicating a high number of infected sheep. Mixed infections with Babesia ovis and A.ovis were observed in 63.3% of cases. A higher number of positive sheep was recorded in the area of Herzegovina. Phylogenetic analysis of the gltA, groEL, and msp4 genes of A. ovis revealed numerous genotypes and significant genetic variability. This diversity was not related to geographic origin, tick-borne infection status, or sheep breeding practices in Podrinje and Herzegovina. CONCLUSIONS: The data obtained in this study suggest that the emergence of new genotypes and the high genetic variability of A. ovis are driven by specific local and micro-environmental factors.

Anti-Müllerian hormone as a promising novel biomarker for litter size in Romanov sheep.

Anti-Müllerian hormone (AMH) is a hormone produced by growing preantral and antral follicles of the ovary. AMH is accepted as an important biomarker for fertility and superovulation parameters in livestock species. This study aimed to evaluate changes in serum AMH level in the oestrous cycle, repeatability of AMH, the effect of age on serum AMH level and the effects of AMH on litter size in Romanov sheep. In the study, a total of 36 Romanov sheep were used as animal material. First blood samples (0th day) were collected from 36 ewes to evaluate AMH and progesterone levels. Second blood samples were collected randomly from 20 ewes 9 days after first sampling to compare AMH levels at two different periods of the oestrous cycle in Romanov ewes. The ewes were categorized into three groups as low, medium and high AMH based on their first AMH levels. Results indicated that serum AMH level did not change during the oestrous and dioestrous phases of the oestrous cycle and two random time points of the oestrous cycle (p > .05). Pearson correlation analysis revealed that there is a high (r = .95) and significant (p < .001) correlation between AMH levels at the 0th (AMH-1) and 9th (AMH-2) days. The effect of AMH level on litter size was found to be significant. Litter size was significantly higher in the high AMH group than in the low AMH group (p < .05). In addition, the age of ewes did not affect serum AMH levels (p > .05). ROC analysis indicates that AMH cut-off value >320 pg/mL with 70% sensitivity and 100% specificity can be used for litter size in Romanov ewes. In conclusion, AMH is highly repeatable and its serum AMH level did not change during the oestrous cycle in Romanov sheep. In addition, AMH affects litter size and can be reliably used as a marker for litter size in Romanov sheep.

Effect of lactose on the in vitro development of sheep secondary follicles.

Considering that follicular development is an energy-dependent process, supplementation of the culture medium with energy substrates, such as lactose, would improve follicle viability and growth. Thus, the aim of this study was to evaluate the effect of lactose on morphology, development, glutathione (GSH) concentration, mitochondrial activity, DNA fragmentation, and meiotic resumption of oocytes from sheep secondary follicles cultured in vitro. Secondary follicles were isolated from the cortex of ovine ovaries and cultured individually for 18 days in α-MEM supplemented with bovine serum albumin (BSA), insulin, glutamine, hypoxanthine, transferrin, selenium and ascorbic acid (control medium: α-MEM+) or in α-MEM+ plus different concentrations of lactose (0.025, 0.05 and 0.1 M). After culture, some of the oocytes were subjected to TUNEL assay and in vitro maturation (IVM). Follicular morphology, glutathione (GSH) concentration and mitochondrial activity were evaluated at the end of the culture. At the day 18, the percentage of morphologically normal follicles was greater (P<0.05) in the treatment of 0.025 M lactose (92.5 %) compared to the control group (75.55 %). In addition, GSH concentrations increased (P<0.05) in treatment containing 0.025 M lactose compared to the other treatments. Furthermore, oocytes cultured in 0.025 M lactose had greater (P<0.05) mitochondrial activity levels than in α-MEM+ and 0.1 M lactose. The group α-MEM+ presented a increase of TUNEL-positive oocytes (35.09 %) compared to 0.025 lactose (9.09 %). The percentage of meiotic resumption was greater (P<0.05) in oocytes from secondary follicles cultured in 0.025 M lactose (54.5 %) than in α-MEM+ (45.5 %). In conclusion, 0.025 M lactose improved survival, GSH and active mitochondria levels and meiotic resumption of oocytes from in vitro cultured secondary follicles. Supplementation of the culture medium of preantral follicles with lactose can gradually provide energy to follicular cells, potentially enhancing the production of viable oocytes for biotechniques such as IVM and in vitro fertilization.

MicroRNA-148a Targets DNMT1 and PPARGC1A to Regulate the Viability, Proliferation, and Milk Fat Synthesis of Ovine Mammary Epithelial Cells.

In this study, the expression profiles of miR-148a were constructed in eight different ovine tissues, including mammary gland tissue, during six different developmental periods. The effect of miR-148a on the viability, proliferation, and milk fat synthesis of ovine mammary epithelial cells (OMECs) was investigated, and the target relationship of miR-148a with two predicted target genes was verified. The expression of miR-148a exhibited obvious tissue-specific and temporal-specific patterns. miR-148a was expressed in all eight ovine tissues investigated, with the highest expression level in mammary gland tissue (p < 0.05). Additionally, miR-148a was expressed in ovine mammary gland tissue during each of the six developmental periods studied, with its highest level at peak lactation (p < 0.05). The overexpression of miR-148a increased the viability of OMECs, the number and percentage of Edu-labeled positive OMECs, and the expression levels of two cell-proliferation marker genes. miR-148a also increased the percentage of OMECs in the S phase. In contrast, transfection with an miR-148a inhibitor produced the opposite effect compared to the miR-148a mimic. These results indicate that miR-148a promotes the viability and proliferation of OMECs in Small-tailed Han sheep. The miR-148a mimic increased the triglyceride content by 37.78% (p < 0.01) and the expression levels of three milk fat synthesis marker genes in OMECs. However, the miR-148a inhibitor reduced the triglyceride level by 87.11% (p < 0.01). These results suggest that miR-148a promotes milk fat synthesis in OMECs. The dual-luciferase reporter assay showed that miR-148a reduced the luciferase activities of DNA methyltransferase 1 (DNMT1) and peroxisome proliferator-activated receptor gamma coactivator 1-A (PPARGC1A) in wild-type vectors, suggesting that they are target genes of miR-148a. The expression of miR-148a was highly negatively correlated with PPARGC1A (r = -0.789, p < 0.001) in ovine mammary gland tissue, while it had a moderate negative correlation with DNMT1 (r = -0.515, p = 0.029). This is the first study to reveal the molecular mechanisms of miR-148a underlying the viability, proliferation, and milk fat synthesis of OMECs in sheep.

Tracking Ovine Pulmonary Adenocarcinoma Development Using an Experimental Jaagsiekte Sheep Retrovirus Infection Model.

Ovine pulmonary adenocarcinoma (OPA) is an infectious, neoplastic lung disease of sheep that causes significant animal welfare and economic issues throughout the world. Understanding OPA pathogenesis is key to developing tools to control its impact. Central to this need is the availability of model systems that can monitor and track events after Jaagsiekte sheep retrovirus (JSRV) infection. Here, we report the development of an experimentally induced OPA model intended for this purpose. Using three different viral dose groups (low, intermediate and high), localised OPA tumour development was induced by bronchoscopic JSRV instillation into the segmental bronchus of the right cardiac lung lobe. Pre-clinical OPA diagnosis and tumour progression were monitored by monthly computed tomography (CT) imaging and trans-thoracic ultrasound scanning. Post mortem examination and immunohistochemistry confirmed OPA development in 89% of the JSRV-instilled animals. All three viral doses produced a range of OPA lesion types, including microscopic disease and gross tumours; however, larger lesions were more frequently identified in the low and intermediate viral groups. Overall, 31% of JSRV-infected sheep developed localised advanced lesions. Of the sheep that developed localised advanced lesions, tumour volume doubling times (calculated using thoracic CT 3D reconstructions) were 14.8 ± 2.1 days. The ability of ultrasound to track tumour development was compared against CT; the results indicated a strong significant association between paired CT and ultrasound measurements at each time point (R2 = 0.799, p < 0.0001). We believe that the range of OPA lesion types induced by this model replicates aspects of naturally occurring disease and will improve OPA research by providing novel insights into JSRV infectivity and OPA disease progression.

Complete Thoracic Ectopia Cordis in Two Lambs.

Cardiac congenital defects related to inheritance and teratogenesis have been reported in veterinary species and humans worldwide. Among these, ectopia cordis (EC), characterized by an externalized heart through a cleft, is extremely rare in sheep. This report presents the diagnostic features of two cases of complete thoracic EC in newborn lambs. Clinical findings in the lambs, aside from the EC, were unremarkable. Both animals exhibited exteriorized hearts without pericardial coverage, delineated in the thoracic cleft by a fibrous ring of the pericardium and adjacent skin. Histologically, the epicardium was thickened by fibrous tissue in both lambs, with one animal also showing marked edema, hemorrhage, and neutrophilic inflammatory infiltration. The prognosis of EC in the lambs of this study was poor, with fatal outcomes despite attempts at surgical correction.

Mechanobiological Strategies to Enhance Ovine (Ovis aries) Adipose-Derived Stem Cells Tendon Plasticity for Regenerative Medicine and Tissue Engineering Applications.

Adipose-derived stem cells (ADSCs) hold promise for tendon repair, even if their tenogenic plasticity and underlying mechanisms remain only partially understood, particularly in cells derived from the ovine animal model. This study aimed to characterize oADSCs during in vitro expansion to validate their phenotypic properties pre-transplantation. Moreover, their tenogenic potential was assessed using two in vitro-validated approaches: (1) teno-inductive conditioned media (CM) derived from a co-culture between ovine amniotic stem cells and fetal tendon explants, and (2) short- (48 h) and long-term (14 days) seeding on highly aligned PLGA (ha-PLGA) electrospun scaffold. Our findings indicate that oADSCs can be expanded without senescence and can maintain the expression of stemness (Sox2, Oct4, Nanog) and mesenchymal (CD29, CD166, CD44, CD90) markers while remaining negative for hematopoietic (CD31, CD45) and MHC-II antigens. Of note, oADSCs' tendon differentiation potential greatly depended on the in vitro strategy. oADSCs exposed to CM significantly upregulated tendon-related genes (COL1, TNMD, THBS4) but failed to accumulate TNMD protein at 14 days of culture. Conversely, oADSCs seeded on ha-PLGA fleeces quickly upregulated the tendon-related genes (48 h) and in 14 days accumulated high levels of the TNMD protein into the cytoplasm of ADSCs, displaying a tenocyte-like morphology. This mechano-sensing cellular response involved a complete SOX9 downregulation accompanied by YAP activation, highlighting the efficacy of biophysical stimuli in promoting tenogenic differentiation. These findings underscore oADSCs' long-term self-renewal and tendon differentiative potential, thus opening their use in a preclinical setting to develop innovative stem cell-based and tissue engineering protocols for tendon regeneration, applied to the veterinary field.