The purpose of this experiment was to study the effects of oregano essential oil (OEO) on the performance, intestinal morphology and intestinal flora of fattening Sewa sheep. Sixty 20-month-old Sewa sheep with similar body weights (BWs) and in good health were randomly divided into four groups. The groups were fed a diet containing 0 mg/kg OEO (group A), 150 mg/kg (group B), 300 mg/kg (group C) or 450 mg/kg (group D). Daily gain, slaughter rate and other production performance parameters were analysed in the test sheep (mean ± standard error). Intestinal morphology was analysed by tissue sectioning, and intestinal flora was analysed by 16S rRNA genome sequencing. The indexes, including average daily gain (ADG), slaughter rate, villus length of the small intestine and number of beneficial bacteria in the intestinal flora, in group C were significantly higher than those in the other groups. Supplementation with 300 mg/kg OEO concentrate in the diets can improve the growth performance of Sewa sheep by changing their intestinal morphology and modifying their intestinal flora structure. Conclusively, these encourage to further verifying in practice positive evidence in improving growth performance of OEO supplementation in the diets for Sewa sheep.

To illuminate the mechanisms underlying the high-altitude tolerance of Tibetan pig spermatozoa, proteomes of spermatozoa from Tibetan pigs raised in high and low altitudes were compared using a tandem mass tag (TMT)-labeled quantitative proteomics approach. A total of 77 differentially expressed proteins (DEPs) were identified. Gene Ontology (GO) analysis revealed DEPs that were predominantly associated with the actin cytoskeleton, the tricarboxylic acid (TCA) cycle, and adenosine triphosphate (ATP) metabolism, and were from 12 enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Three subnetworks were significantly enriched and 10 centric proteins were identified by protein-protein interaction (PPI) network analysis. Relative expression levels of the proteins (ATP5H, CYCS, MYH9 and FN1) were confirmed using Western blotting. Our study is the first to use a tandem mass tag (TMT) approach to analyze Tibetan pig spermatozoa, and provides a foundation to understand the mechanisms underlying the reproductive adaptations of Tibetan pigs to high-altitude environments.

Background: Tibetan pigs (TP) exhibit heritable adaptations to their hypoxic environments as a result of natural selection. However, candidate proteins that affect the sperm quality of boars on plateaus have not yet been clearly investigated. Methods: In this study, to reveal the candidate proteins that affect the quality of spermatozoa of boars on plateaus, we analyzed the sperm quality using computer-assisted semen analysis (CASA) system and reactive oxygen species (ROS) levels. We also compared the proteomes of sperm proteomes between TP and Yorkshire pigs (YP) raised at high altitudes using the isobaric tags for relative and absolute quantitation (iTRAQ) in combination with the liquid chromatography-tandem mass spectrometry (LC–MS/MS) proteomic method, and confirmed the relative expression levels of the four proteins by western blotting. Results: The sperm quality of the TP was superior to that of the YP on plateaus. Of the 1,555 quantified proteins, 318 differentially expressed proteins (DEPs) were identified. Gene ontology (GO) analysis revealed that the DEPs were predominantly associated with the sorbitol metabolic process, removal of superoxide radicals, cellular response to superoxide, response to superoxide and regulation of the mitotic spindle assembly. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were mainly enriched in pathways involved in the regulation of the actin cytoskeleton, glutathione metabolism, oxidative phosphorylation, and estrogen signaling. Based on the protein–protein interaction (PPI) network analysis, we identified 8 candidate proteins (FN1, EGF, HSP90B1, CFL1, GPX4, NDUFA6, VDAC2, and CP) that might play important roles and affect the sperm quality of boars on plateaus. Moreover, the relative expression levels of four proteins (CFL1, EGF, FN1, and GPX4) were confirmed by western blot analysis. Conclusions: Our study revealed 8 candidate proteins (FN1, EGF, HSP90B1, CFL1, GPX4, NDUFA6, VDAC2, and CP) that affect the sperm quality of boar on plateaus and provide a reference for further studies on improving sperm quality and the molecular breeding of boars on plateaus.

Background: Proteins related to sperm motility and sperm morphology have an important impact on sperm function such as metabolism, motility and fertilisation etc. An understanding of the key proteins related to semen quality in Niangya yaks would help to provide support for breeding. However, the key proteins that affect semen quality in Niangya yaks remain unclear. Methods: Herein, we applied tandem mass tag (TMT) labeling and liquid chromatography-tandem mass spectrometry (LC‒MS/MS) to analyze the expression levels of sperm proteins in groups of high- and low-quality semen from Niangya yaks. And fifteen differentially expressed proteins (DEPs) were randomly selected for expression level validation by parallel reaction monitoring (PRM). Results: Of the 2,092 quantified proteins, 280 were identified as DEPs in the high-quality group versus the low-quality group. Gene Ontology (GO) analysis revealed that in terms of biological pathways, the DEPs were mainly involved in metabolic processes, cell transformation processes, and single organism metabolic processes. In terms of cell composition, the DEPs were mainly located in the cell membrane, organelle, molecular complex. In terms of molecular functions, the most abundant functions of the DEPs were catalytic activity, binding activity, transport activity, and enzyme regulation activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the DEPs were mainly involved in the cytokine and cytokine receptor interaction, notch signaling pathway, lysine biosynthesis, renal function-related protein and proteasome pathway. From protein-protein interaction (PPI) analysis of DEPs involved in important pathways, 6 related proteins affecting the semen quality of Niangya yaks were identified. And the results of the PRM and TMT analysis were consistent. Conclusions: The differential sperm proteomic analysis of high- and low-quality semen from Niangya yaks, revealed 6 proteins (PSMC5, PSMD8, PSMB3, HSP90AA1, UGP2 and HSPB1), were mainly concentrated in energy production and metabolism, might play important roles in semen quality, which could serve as candidates for the selection and breeding of Niangya yaks.

This study was aimed to evaluate the effects of the substitution of oregano essential oil (OEO) for antibiotics in the plateau-broiler diet. Partridge Shank chicken is a broiler breed which has stronger adaptability and disease resistance compared with commercial broiler strain. It is generally slaughtered at 75 -d-old. Here, after a 12-d pre-experiment, 144 57-d-old healthy Partridge Shank chickens were randomly divided into three groups, and fed a basal diet supplemented with OEO (group OEO), a basal diet supplemented with aureomycin (group aureomycin), or a basal diet alone (group control) for 28 days. At the end of the experimental period, production performance, mortality ratio, carcass traits, nutrient digestibility, serum antioxidant performance, intestinal morphology, and intestinal flora structure were determined in each group of broilers. We found that the chickens in group OEO and group aureomycin were improved in average daily gain, average daily feed intake, thigh yield, breast yield, and digestibility of crude protein, reduced in mortality ratio compared with group control (p < 0.05), while there were no significant differences in these indices between these two groups (p > .05). Besides, dietary supplementation with OEO improved serum antioxidant activity and intestinal morphology in the plateau broilers, as well as the richness of beneficial bacteria in the intestine. Thus, OEO improved production performance, nutrient digestibility and reduced mortality ratio of Partridge Shank chickens in the plateau by improving intestinal flora structure. Conclusively, it is practicable that use of OEO to replace growth-promoting antibiotic additives in the plateau-broiler diet.

DNA methylation plays an important role in reproduction. Tibetan pigs maintain high sperm motility, even under extreme conditions at high altitudes. However, the DNA methylation mechanisms underlying testicular plateau adaptations in Tibetan pigs remain unclear. We determined the genomic DNA methylation level in the testicular tissues of Tibetan pigs living at high altitudes (TP) and of Yorkshire pigs that migrated to high altitudes (YP) using the fluorescence method. Quantitative real-time PCR and western blots were used to measure the gene and protein expression levels, respectively, of three DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B) and hypoxia-inducible factor 2α (HIF2α). We found that the genomic DNA methylation level and the mRNA and protein expression levels of the four genes were all significantly lower in the testicular tissues of TP than YP. In short, compared with YP, the downregulation of DNA methyltransferases in the TP testes led to lower levels of genomic DNA methylation, which would facilitate higher sperm motility. Meanwhile, HIF2α expression in the TP testes was down-regulated, which might contributes to TP testes’ adaption to the plateau environment. This study provided new insights into the DNA methylation mechanisms underlying plateau adaptations in TP testicles.