Yuanyi Liu

Severe winter nutritional deficiencies may impair reproductive performance in Mongolian mares, yet optimal protein requirements during late gestation remain undefined. This study aimed to determine the effects of varying protein levels in complementary feed on gestational performance, physiology, and gut health. Seventeen late-gestating mares were assigned to three isocaloric diets differing in crude protein (CP)—high (HCP, 13.25%), medium (MCP, 12.04%), and low (LCP, 10.85%)—for 40 days. Statistical analysis was conducted using one-way ANOVA followed by Tukey’s HSD post hoc test. Mares fed the MCP diet tended to show more favorable growth performance and nutrient digestibility relative to the HCP group (p < 0.05). Blood analysis suggested that MCP mares had comparatively lower serum creatinine and creatine kinase concentrations, along with higher antioxidant capacity (catalase) and interleukin-1β levels (p < 0.001). Fecal microbiota sequencing showed that MCP was associated with comparatively higher microbial diversity, while HCP was characterized by enrichment of Proteobacteria, and LCP by enrichment of Bacteroidetes. Metabolomics identified 533 differential metabolites linked to protein metabolism. The MCP diet may help balance immune function, antioxidant status, and microbial homeostasis. These findings suggest that a complementary feed containing 12.04% CP may be associated with favorable effects on maternal health-related indicators in late-gestating Mongolian mares during winter.

Mongolian horses are renowned for their remarkable endurance and ability to adapt to harsh environments. To delve deeper into the molecular mechanisms that underlie these traits, researchers conducted a comprehensive analysis of transcriptomic and proteomic changes in Mongolian horses at three distinct time points: before, immediately after, and 24 h following a 20 km run. The transcriptomic analysis uncovered significant variations in gene expression patterns across these time points. Specifically, 291 differentially expressed genes (DEGs) were identified when comparing pre-exercise to post-exercise conditions, 832 DEGs in the comparison between post-exercise and 24 h post-exercise, and 127 DEGs in the comparison of pre-exercise to 24 h post-exercise. Notably, key genes involved in metabolic activities and cellular proliferation, such as PI3K and LDHA, exhibited significant upregulation immediately after exercise but demonstrated a downward trend 24 h post-exercise. Concurrently, the proteomic analysis revealed 49 differentially expressed proteins (DEPs) in the pre-exercise versus post-exercise comparison, 61 DEPs in the post-exercise versus 24 h post-exercise comparison, and 101 DEPs in the pre-exercise versus 24 h post-exercise comparison. Some proteins, like PDK4 and GLUL, remained upregulated at 24 h post-exercise, whereas others, such as PFKM and LDHA, showed signs of recovery or downregulation. By integrating the transcriptomic and proteomic data, we were able to pinpoint overlapping DEGs/DEPs and implicate crucial signaling pathways, including the HIF-1 signaling pathway and glycolysis, in the molecular response of Mongolian horses to exercise. These findings offer insights into the endurance adaptation mechanisms of the Mongolian horse.

Skeletal muscle satellite cells are muscle stem cells that play an important role in the growth, development, and repair of skeletal muscle as well as in the locomotor performance of the animal body. Lysine is the first limiting amino acid and is involved in multiple metabolic pathways in the organism to maintain overall physiological requirements. In this study, Mongolian horse satellite cells were cultured using lysine culture solution at different concentrations, and the proliferative capacity of satellite cells was detected by the cck-8 assay, and the optimal culture concentration was selected. Then, whole transcriptome sequencing technology was used to determine the differential gene expression and regulatory pathways during the proliferation of lysine-cultured satellite cells after 48 h of culture. Our findings revealed that 0.5 mmol/L lysine is the optimal concentration to increase satellite cell activity in equine muscle. The differential genes involved in satellite cell proliferation were mainly enriched in the cAMPsignaling pathway, calcium signaling pathway, and PPAR signaling pathway. Furthermore, upregulation of PLIN5, ACADL, and FADS2 and downregulation of LOC100052888 regulated the expression of the PPAR signaling pathway. 0.5 mmol/L lysine was the optimal concentration to increase satellite cell activity. Lysine can regulate mitochondrial function and lipid metabolism through the PPAR signaling pathway, and promote the proliferation of equine myosatellite cells.

The traditional horse industry has undergone a remarkable evolution, with horse racing emerging as a prominent and pivotal economic driver within the sector. Among the various breeds, Mongolian horses, renowned for their exceptional endurance and speed, occupy a significant position in the horse industry. To investigate their homeostasis mechanisms during and after a 20 km endurance exercise and identify novel oxidative-imbalance markers, we selected 12 two-year-old horses and collected blood samples at various time points before, during (at 5, 10, 15, and 20 km), and after the exercise (at 1, 2, 4, and 6 h post-exercise). These samples were analyzed for haematology, blood biochemistry, antioxidant enzyme activities, and liquid chromatography–mass spectrometry (LC-MS) metabolomics. Our results revealed significant changes in heart rate, speed, blood cells, and biochemical markers throughout the exercise. Antioxidant indicators decreased, while malondialdehyde increased, indicating oxidative imbalance post-exercise. Metabolomics analysis identified 122 differential metabolites, including uric acid and L-tyrosine, which were enriched in pathways related to energy metabolism. Uric acid and tyrosine correlated positively with serum creatine kinase, suggesting their potential as markers of oxidative-imbalance injury. These findings elucidate the mechanisms of endurance adaptability in Mongolian horses and provide a theoretical basis for mitigating oxidative imbalance, enhancing horse performance, and promoting the sustainable development of the equine industry.

Colitis in equines has high morbidity and mortality rates, which severely affects the development of the equine-breeding industry. With the issuance of antibiotic bans, there is an urgent need for healthier and more effective alternatives. In recent years, probiotics have been widely used as microbial feed additives in animal husbandry, playing a crucial role in preventing and treating diarrhea and regulating host immune function. In this study, we isolated and screened a strain with rapid and stable acid production using bromocresol purple, litmus milk coloration tests, and acid production performance assessments. Based on morphological characteristics, physiological and biochemical properties, and 16S rDNA identification, the strain was identified as Pediococcus pentosaceus and named M6. The Pediococcus pentosaceus M6 exhibited stable growth and tolerance to high temperatures, acid and bile salt concentrations, and simulated gastrointestinal fluid environments. The M6 strain demonstrated good antibacterial effects against Escherichia coli, Staphylococcus aureus, and Salmonella. The M6 strain did not produce hemolysis zones on Columbia blood agar plates, indicating its high safety, and was found to be insensitive to 12 antibiotics, including cephalexin and neomycin. Additionally, intervention in mice with dextran sulfate sodium (DSS)-induced colitis alleviated weight loss and shortened colon length. To a certain extent, it regulated the expression of inflammatory cytokines and the gut microbiota within the body and reduced inflammatory cell infiltration and intestinal barrier damage. In summary, the isolated Pediococcus pentosaceus M6 strain exhibited excellent probiotic properties and could alleviate DSS-induced colitis in mice, suggesting its potential application value as a probiotic in animal husbandry.

Cryopreservation of semen has advanced significantly with the development of artificial insemination techniques, but post-thawed sperm often exhibit reduced viability, membrane integrity, and acrosome integrity compared to fresh sperm, leading to decreased fertilization capacity. Oxidative stress is a major concern during cryopreservation. This study investigated the use of resveratrol (RSV), a potent antioxidant, in the cryopreservation of Mongolian horse semen. Different concentrations of RSV were incorporated into semen cryopreservation extenders, and the morphological and antioxidant indices of post-thawed sperm were assessed to determine the optimal RSV concentration. The study also employed tandem mass tag (TMT) quantitative proteomics technology to explore differential proteins and their pathways. The results showed that sperm quality parameters were positively correlated with RSV concentration within a certain range (10–40 µmol L⁻¹) and were significantly higher than the control group. RSV also enhanced the antioxidant capacity of sperm, with the optimal effect observed at 40 µmol L⁻¹. Proteomics analysis identified 10 differential proteins between the control and optimal RSV concentration groups, with 7 upregulated proteins primarily involved in antioxidant activity and maintaining intracellular redox balance. These findings were further validated through real-time fluorescent quantitative PCR and protein immunoblotting, suggesting that RSV has potential as an effective antioxidant for improving the cryopreservation of Mongolian horse semen.

Fermented mare’s milk (koumiss), a traditional Central Asian dairy product derived from fermented mare’s milk, is renowned for its unique sour taste and texture. It has long been consumed by nomadic tribes for its nutritional and medicinal benefits. This study aimed to comprehensively analyze the protective effects of koumiss against alcohol-induced harm across behavioral, hematological, gastrointestinal, hepatic, and reproductive dimensions using a mouse model. Optimal intoxicating doses of alcohol and koumiss doses were determined, and their effects were explored through sleep tests and blood indicator measurements. Pretreatment with koumiss delayed inebriation, accelerated sobering, and reduced mortality in mice, mitigating alcohol’s impact on blood ethanol levels and various physiological parameters. Histopathological and molecular analyses further confirmed koumiss’s protective role against alcohol-induced damage in the liver, stomach, small intestine, and reproductive system. Transcriptomic studies on reproductive damage indicated that koumiss exerts its benefits by influencing mitochondrial and ribosomal functions and also shows promise in mitigating alcohol’s effects on the reproductive system. In summary, koumiss emerges as a potential natural agent for protection against alcohol-induced harm, opening avenues for future research in this field.

Testicular development and spermatogenesis are tightly regulated by both coding and non-coding genes, with mRNA and lncRNA playing crucial roles in post-transcriptional gene expression regulation. However, there are significant differences in regulatory mechanisms before and after sexual maturity. Nevertheless, the mRNAs and lncRNAs in the testes of Mongolian horses have not been systematically identified. In this study, we first identified the testicular tissues of sexually immature and sexually mature Mongolian horses at the tissue and protein levels, and comprehensively analyzed the expression profiles of mRNA and lncRNA in the testes of 1-year-old (12 months, n = 3) and 10-year-old (n = 3) Mongolian horses using RNA sequencing technology. Through gene expression analysis, we identified 16,582 mRNAs and 2128 unknown lncRNAs that are commonly expressed in both sexually immature and sexually mature Mongolian horses. Meanwhile, 9217 mRNAs (p < 0.05) and 2191 unknown lncRNAs (p < 0.05) were identified as differentially expressed between the two stages, which were further validated by real-time fluorescent quantitative PCR and analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). The analysis results showed that genes in the sexually immature stage were mainly enriched in terms related to cellular infrastructure, while genes in the sexually mature stage were enriched in terms associated with hormones, metabolism, and spermatogenesis. In summary, the findings of this study provide valuable resources for a deeper understanding of the molecular mechanisms underlying testicular development and spermatogenesis in Mongolian horses and offer new perspectives for future related research.

This study aimed to investigate differences in testicular tissue morphology, gene expression, and marker genes between sexually immature (1-year-old) and sexually mature (10-year-old) Mongolian horses. The purposes of our research were to provide insights into the reproductive physiology of male Mongolian horses and to identify potential markers for sexual maturity. The methods we applied included the transcriptomic profiling of testicular cells using single-cell sequencing techniques. Our results revealed significant differences in tissue morphology and gene expression patterns between the two age groups. Specifically, 25 cell clusters and 10 cell types were identified, including spermatogonial and somatic cells. Differential gene expression analysis highlighted distinct patterns related to cellular infrastructure in sexually immature horses and spermatogenesis in sexually mature horses. Marker genes specific to each stage were also identified, including APOA1, AMH, TAC3, INHA, SPARC, and SOX9 for the sexually immature stage, and PRM1, PRM2, LOC100051500, PRSS37, HMGB4, and H1-9 for the sexually mature stage. These findings contribute to a deeper understanding of testicular development and spermatogenesis in Mongolian horses and have potential applications in equine reproductive biology and breeding programs. In conclusion, this study provides valuable insights into the molecular mechanisms underlying sexual maturity in Mongolian horses.

Interspecific hybridization often shows negative effects on hybrids. However, only a few multicellular species, limited to a handful of plants and animals, have shown partial genetic mechanisms by which hybridization leads to low fitness in hybrids. Here, to explore the outcome of combining the two genomes of a horse and donkey, we analyzed the whole-genome sequences from an Equus parent-offspring trio using Illumina platforms. We generated 41.39× and 46.21× coverage sequences for the horse and mule, respectively. For the donkey, a 40.38× coverage sequence was generated and stored in our laboratory. Approximately 24.86 million alleles were discovered that varied from the reference genome. Single nucleotide polymorphisms were used as polymorphic markers for assigning alleles to their parental genomic inheritance. We identified 25,703 Mendelian inheritance error single nucleotide polymorphisms in the mule genome that were not inherited from the parents through Mendelian inheritance. A total of 555 de novo single nucleotide polymorphisms were also identified. The rate of de novo single nucleotide polymorphisms was 2.21 × 10⁻⁷ in the mule from the Equus parent-offspring trio. This rate is obviously higher than the natural mutation rate for Equus, which is also consistent with the previous hypothesis that interracial crosses may have a high mutation rate. The genes associated with these single nucleotide polymorphisms are mainly involved in immune processes, DNA repair, and cancer processes. The results of the analysis of three genomes from an Equus parent-offspring trio improved our knowledge of the consequences of the integration of parental genomes in mules.