The 13th Five-Year National Key Research and Development Program has established a key project of "Prevention and Control of Major Animal Diseases, Efficient and Safe Husbandry Technology Research and Development" (Animal Project), which supported scientific and technological innovation research in the field of animal epidemic prevention and control, efficient and safe breeding and breeding environment treatment. This project carried out the design of "whole chain design and integrated implementation" according to basic research, key technology research and development and integrated demonstration to solve the important basic theory and technical bottleneck of animal breeding in China. Based on the method of bibliometric, a statistical analysis was conducted of the papers supported mainly by the project to master the research progress and hot spots of the special project in basic research and frontier theory. Moreover, the future key research direction and development trend in the field of animal husbandry and veterinary medicine was discussed in combination with the layout of animal husbandry and veterinary related projects in the 14th Five-Year Plan. The results showed that this special funded papers had achieved breakthrough research in the basic research fields of major animal diseases and zoonotic diseases such as the COVID-19, Zika virus and African Swine Fever Achievements:Agriculture-related universities and scientific research institutes cooperate closely and have made great contributions; International cooperation is not only with the United States and other developed countries, but also closely cooperated with developing countries such as Pakistan and Egypt related to the "Belt and Road" initiative. The probability of publishing high-quality papers which cooperated with scientific research teams in developed countries has increased significantly; Research hotspots mainly focus on epidemiology, pathogen replication and evolution, drug resistance, pathogen and host interaction and network regulation, immune and pathogenic mechanisms, cross-species transmission,etc.The livestock and poultry special project focuses on the research direction of the prevention and control of major livestock and poultry diseases and efficient and safe breeding, and has made important research progress in major basic theories, supporting the research and application demonstration of key core technologies. The 14th Five-Year National Key Research and Development Program will make a comprehensive layout in the field of animal seed industry innovation, prevention and control of animal diseases, purification and eradication, nutrition regulation and efficient breeding, waste resource utilization and green breeding, breeding equipment and intelligent breeding.

Structural variation (SV) is widely distributed in the genome and mainly occurs in the form of deletion, insertion, duplication, inversion and translocation. SV can affect the gene dosage directly or indirectly through different mechanisms, thereby causing phenotypic variation and even disease in livestock and poultry. With the development of molecular biology and the advancement of new genomic technologies, SV has been increasingly studied in the pig genome, including reproductive traits, meat quality traits, growth traits, coat color, diseases, etc. In this paper, the definition, classification, formation mechanism, detection method and research status of SV for pig genomes were reviewed based on relevant research reports from home and abroad. The problems existing in the SV research were suggested and the future research trends were prospected.

The quality of skeletal muscle not only affects the exercise ability and health state of human or animal, but also affects the production and quality of muscle in livestock and poultry. With the in-depth exploration of microbial functions, gut-brain axis, gut-liver axis, gut-lipid axis and other signaling pathways mediated by microorganisms and their metabolites have been confirmed to participate in the body's energy metabolism. In recent years, microbiota-gut-muscle axis has also been confirmed. Therefore, regulating the metabolism of skeletal muscle by regulating intestinal flora or its metabolites provides a novel insight to improve muscle production and quality. This review mainly summarizes the potential role and preliminary mechanism of intestinal microorganisms and their key metabolites in skeletal muscle function and glucose and lipid metabolism, and briefly summarizes the potential means of regulating flora to control skeletal muscle function, which provides a certain theoretical reference and new ideas for improving meat quality in animal husbandry production.

Temperature is an important non-biological environmental variable that drives the adaptive trajectory of animal lineages and the composition of animal communities. Ambient temperature, as one of the many factors affecting the changes of intestinal microbiota, can affect the composition and abundance of gut microbiota, and thereby regulate the biological process and functions of the host growth, development, reproduction and immunity. The composition of gut microbiota and its metabolites vary significantly at different temperatures, which have been reported in monogastric animals, ruminants and so on. Extreme temperature can affect host phenotypes mainly by inducing structural and functional differences in intestinal microbiota. At present, the understanding about how temperature affects the intestinal flora of animals is still very limited. In this paper, the differences in the structure and function of intestinal microbiota under different ambient temperatures were summarized and reviewed. Further discussion and exploration of the relationship between the gut microbiota and host adaptation mechanisms caused by ambient temperature, including the effects on mechanisms of heat production, digestive system and immune system of host, will provide references and ideas for the regulation of intestinal microflora on host health.

Alpha herpesvirus has a wide range of hosts, and can infect mammals, amphibians and poultry. It mainly invades the skin, mucous membrane and nerve tissue of the host and latently infects the nerve tissue of the host. Once infected, it is difficult to be eradicated. gC is one of the envelope glycoproteins of alpha herpesvirus, which plays an important role in the process of viral infection and replication. gC binds to receptors on the cell to help the virus adsorb to the surface of the host, mediates the invasion of the virus into epithelial cells at low pH, and affects the replication of the viral genome. In addition, gC helps the virus evade the neutralization of complement and antibodies, and promotes the absorption and invasion of the virus. In this review, the related functions of gC affecting viral infection and replication were reviewed to provide reference for the study of gC and the life cycle of the alpha herpesvirus, as well as the research of gC subunit vaccine and mRNA vaccine.

The study aimed to accelerate the progress of lean pig breeding research in China and to develop economic weight that meet the current status of lean pig breeding in China. This study was conducted to select target traits suitable for the current Duroc-Landrace-Large White crossbreeding system in China based on the current breeding status of Duroc-Landrace-Large White crossbreeding pigs in China. The production process of pigs was simulated based on the bio-economic model, and the cost and income at each stage of the production cycle were calculated. The marginal benefits of the target traits were first calculated using the difference method, and then the economic weight of each breeding target trait was obtained by correcting for the genetic standard deviation of each trait. The results showed that it mainly included litter size born alive, sow weaning interval, feed conversion efficiency, days at 100 kg body weight, and backfat thickness at 100 kg body weight in the reproduction, growth and carcass quality traits for lean pig breeding in China at present. Under the existing production level and market conditions in China, the marginal benefits of the above traits were 19.52, -1.07, -286.95, -8.41 and -13.20 yuan, respectively. By calculating the economic weight of different breeds, the relative economic weight of feed conversion efficiency, days at 100 kg body weight, and backfat thickness at 100 kg body weight of Duroc were obtained as 50.42%, 34.50%, and 15.08%, respectively. And the relative economic weight for litter size born alive, sow weaning interval, feed conversion efficiency, days at 100 kg body weight, and backfat thickness at 100 kg body weight for the Landrace and Large White groups were 16.82%, 0.22%, 39.56%, 31.42%, 11.98% and 32.22%, 0.41%, 33.22%, 24.43%, 9.17%, respectively. At present, feed utilization efficiency should be the main target trait for breeding in the breeding process of Chinese lean pigs, and the most suitable trait should be selected for different breeds.

The objective of this study was to investigate the effect of genomic methylation on the difference of gene expression in liver at different developmental stages through the analysis of the genome-wide methylation difference in liver between pre-laying and peak-laying hens. In this study, genomic DNA (DNA pools of 3 in each group) isolated from livers of Lushi blue-shelled hens in pre-laying (20-week-old) and peak-laying (30-week-old) were scanned by whole genome bisulfite sequencing (WGBS) method for genome-wide methylation analysis. Integrative analysis of pre-existing liver mRNA transcriptome data and the WGBS data were conducted to explore the effect of genomic methylation on gene expression differences at different physiological stages. The results showed that about 4% cytosine (C) were methylated(mC) in the whole genome. The overall methylation level of two physiological stages was basically the same. A total of 670 differentially methylated regions (DMRs) and 356 related differentially methylated genes (DMGs) were detected. The gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analyses revealed that hypermethylated DMGs were significantly enriched in positive regulation of growth, regulation of cell morphogenesis, VEGF signaling pathway, regulation of actin cytoskeleton, focal adhesion and gap junction etc, while hypomethylated DMGs were significantly enriched in embryonic digestive tract morphogenesis, positive regulation of mesenchymal cell proliferation, starch and sucrose metabolism, Wnt signaling pathway etc. The methylation levels in different functional regions of genes were correlated with gene expression levels. The methylation levels in the promoter and gene body regions of genes were significantly negatively correlated with gene expression levels, the methylation levels in the other regions (intron, 3' UTR) of genes were not obviously correlated with gene expression levels. In addition, 4 candidate genes, RASD1, HAO1, UBE2O and MSRB3, related to liver lipid metabolism were regulated by methylation. This study provided the genome-wide methylation atlas of Lushi blue-shelled hens at different physiological periods. The role of DNA methylation in regulating gene expression was illustrated with mRNA transcriptome data, and genes regulated by methylation in different physiological periods were identified. The results provided reference information for the epigenetic regulation mechanism on liver metabolism at different physiological stages in laying hens.

The purpose of the study was to explore the biological characteristics and expression regulation of chicken microsomal triglyceride transfer protein like gene (MTTPL), and lay a foundation for further studying its biological function in lipid metabolism of chicken liver. In this study, firstly, PCR and sequencing were used to clone MTTPL cDNA sequence. Online softwares were used to analyze the structural domain, three-dimensional structure of MTTPL and construct phylogenetic tree. Overexpression vector pcDNA3.1-MTTPL-EGFP was constructed, and co-transfected chicken hepatocellular carcinoma (LMH) with DsRed-λ vector, which expressed endoplasmic reticulum marker protein, for MTTPL subcellular localization. Then tissue samples were collected from Lushi blue-shelled chickens at different weeks of age (8 chickens for 1 day old, 1 week old, 10 week old, 30 week old, respectively). The spatial and temporal expression profiles of chicken MTTPL gene and microsomal triglyceride transporter (MTTP) gene were analyzed by real-time quantitative PCR (qPCR). Then, the effects of estrogen on the expression of MTTPL and MTTP in chicken liver were estimated, twenty hy-line brown chickens in each group were treated with 17β-estradiol at 0.5, 1 and 2 mg·kg^-1 body weight for 12 and 24 h, respectively. Lastly, the regulation mechanism of estrogen on the expression of MTTPL and MTTP were studied, 1, 50 and 100 nmol·L^-1 17β-estradiol and estrogen receptor antagonist were used to treat chicken embryo hepatocytes, respectively. The results showed that chicken MTTPL CDS region was 2 646 bp in length, encoding 881 amino acids, and sharing a common ancestor with human and chicken MTTP. MTTPL was located in endoplasmic reticulum. Chicken MTTPL and MTTP had the same functional domains as human MTTP, and the similarity deviation of three-dimensional structure with human MTTP were 0.090 and 0.064, respectively. MTTPL was highly expressed in liver and kidney tissues of chicken. MTTP was highly expressed in chicken liver, kidney and small intestine. With the growth development of chickens, the expression levels of ApoB and MTTPL in liver were significantly up-regulated (P<0.05), while the expression levels of MTTP in liver was significantly increased before 10-week-old (P<0.05), but no significant change between 10-week-old and 30-week-old chickens (P>0.05). After estrogen treatment for 12 and 24 h, the expression levels of MTTPL and ApoB in chicken liver were significantly up-regulated (P<0.05). MTTP was significantly down-regulated in high concentration group (P<0.05), while no significant change in low concentration group. Compared with the control, estrogen could significantly up-regulate the expression level of ApoB and MTTPL in chicken embryo hepatocytes (P<0.05), while MTTP was not significantly changed. Compared with estrogen treatment group, the expression level of MTTPL gene was significantly decreased in estrogen and ERα antagonist MPP co-treated group (P<0.05). Compared with MPP and ERα antagonist co-treated group, no significant change of MTTPL expression level in ERα and ERβ receptor antagonist ICI or TAM and estrogen co-treated group was observed. In conclusion, chicken MTTPL was located in endoplasmic reticulum, and had the same functional domains as human MTTP. Both MTTPL and MTTP were highly expressed in chicken liver. Compared with pre-laying stage, MTTPL expression in liver of chicken at laying stage was significantly up-regulated, while no significant difference was observed in MTTP expression. Estrogen could regulate the expression of MTTPL via binding with ERα receptor, but MTTP was not affected. It was showed that MTTPL may play an important role in liver lipid metabolism of chicken at the egg-laying stage.

The purpose of this study was to screen some SNP markers that can be used for paternity identification of Tan sheep, which is of great significance for the conservation and reproduction of sheep. A total of 159 Tan sheep in the Yanchi area of Ningxia was selected as the research object. The 600K gene microarray was used for SNP determination. The genetic background of the sample was explored through principal component analysis. The family lineage was divided according to the phylogenetic tree. A paternity test was conducted. The results showed that most of the Tan sheep had similar genetic backgrounds, and the phylogenetic tree divided them into 5 major lineages; The 211 high-quality SNPs were screened, and the single parent cumulative exclusion probability (CPE) exceeded 99.99%, with high accuracy and reliability. The results of paternity identification show that at the 95% confidence level, the observed identification rate was 79%, and under the 80% confidence level, the observed identification rate reached 87%. In the results, most of the real parents were found in the suspected male parents, that is, the male parents with no pedigree records, indicating that the pedigree management should be strengthened in the field to avoid errors as much as possible.

The aim of the current study was to establish a fluorescent qPCR technology for rapid, efficient and precise detection of the FecB mutation. This will provide technical support for Tan sheep multi-lamb performance research, population improvement and breeding of improved prolific and meat-producing Tan sheep strains. In this study, a method for detecting the FecB mutation in Tan sheep based on fluorescence qPCR was developed by designing specific primer pairs. Genomic DNA samples of 85 healthy and reproducible Tan ewes with known FecB genotypes were genotyped by PCR-based Sanger sequencing, TaqMan probe and fluorescence qPCR, respectively. Subsequently, the accuracy of the 3 methods was detected. Additionally, the FecB genotyping of 939 Tan sheep was carried out by the developed fluorescent qPCR method. Furthermore, the lambing rates of primiparous ewes with different FecB genotypes were recorded. TaqMan probe, PCR-based Sanger sequencing and the developed fluorescence qPCR method were used to detect the FecB mutation in samples with known genotypes. The results showed that the accuracy of the developed fluorescent qPCR method for the identification of each FecB genotype was 100%, which was higher than the other two methods. The results of genotyping the FecB mutation in 939 healthy and reproducible Tan ewes showed that 6 ewes were homozygous (BB), 57 ewes were heterozygous (B+), and 876 ewes were wild type (++). The genotype frequencies of BB, B+ and ++ Tan sheep were 0.64%, 6.07% and 93.29%, respectively, of which the B allele frequency was 0.04 and the + allele frequency was 0.96. The lambing of the ewes was monitored, it was found that the lambing rate of Tan sheep with FecB mutant homozygous was 166.67%, the lambing rate of Tan sheep with mutant heterozygous was 153.12%, and the lambing rate of wild-type Tan sheep was 105.78%. The lambing rate of the ewes with mutant homozygous and heterozygous was significantly higher than that of the wild-type Tan sheep (P<0.01).Compared with TaqMan and PCR-based Sanger sequencing methods, the developed fluorescence qPCR method in this study has the advantages of simplicity, low cost, and effectiveness. Thus, it has potential application value for molecular breeding. Therefore, the established fluorescent qPCR detection method provides a solid technical support for detecting the FecB genotypes in sheep. Furthermore, it is confirmed that the mutation of FecB can significantly improve the lambing rate of local sheep breeds.

The purpose of this study was to explore the molecular mechanism of wool bending during growth of Zhongwei goat, and to explore the key genes affecting the curvature of wool at different developmental stages. The skin tissues of 3 Zhongwei goats at 45 days old (curved hair) and 365 days old (straight hair) were collected for transcriptome sequencing (RNA-seq). Hub gene was identified by WGCNA and GSEA analysis. Taking P-value<0.05 and log₂FoldChange ≥ 1 as the screening criteria for differentially expressed genes, a total of 1 252 significant differentially expressed genes were screened, the age of 45 days as the control group and 365 days as the experimental group, including 812 up-regulated genes and 440 down-regulated genes. A total of 14 modules were obtained based on WGCNA analysis, among which yellow and turquoise modules were related to the curved phenotype of coat. Network analysis indicated 20 core genes affecting wool curvature were screened using String and Cytoscape. GSEA results showed that Hedgehog signaling pathway, JAK/STAT signaling pathway, TGF/BETA signaling pathway and other regulatory pathways involved in hair follicle development were significantly enriched. Based on the results of KEGG, WGCNA, molecular network construction and GSEA analysis, the genes CCL27, IL7 and WNT2 were screened, and it was inferred that these genes played a key role in regulating hair follicle development. This study provides a theoretical basis for further elucidating the molecular mechanism of animal hair bending.

This study aimed to compare different methods for genomic predictions of fertility traits in Chinese Holstein cows, and to select the optimal method and combination of scaling factors (τ and ω) for practical breeding program. The raw fertility data were collected from 33 Holstein dairy farms in Beijing, covering the period from 1998 to 2020. The data included a total of 98 483 to 197 764 phenotypic records for the traits of interval from calving to first service (ICF), number of services for heifers (NSH) and number of services for cows (NSC). Meanwhile, genotypes of 8 718 cows and 3 477 bulls were collected. Both bull validation population and cow validation population were generated based on the structure of populations with genotypes data. Afterwards, best linear unbiased prediction (BLUP), genomic best linear unbiased prediction (GBLUP) and single-step genomic best linear unbiased prediction (ssGBLUP) were used for the predictions of the 3 target traits by using AIREMLF90 and BLUPF90 modules in BLUPF90 software. Prediction accuracy and unbiasedness were calculated to evaluate the effect of predictions. The results indicated that all 3 traits had low heritability (0.03-0.08), and weights of each trait information matrix in ssGBLUP methods had impacts on prediction accuracy and unbiasedness. The optimal combination of scaling factors for ICF, NSH and NSC were τ=1.3 and ω=0, τ=0.5 and ω=0.4, and τ=0.5 and ω=0, respectively based on cow validation population, while the combinations were τ=1.5 and ω=0, τ=1.3 and ω=0.8, and τ=0.5 and ω=0, respectively for bull validation population. The accuracy of the ssGBLUP method based on the best weight was 0.10-0.39 and 0.08-0.15 higher than that of the BLUP and GBLUP methods, respectively, and the unbiasedness was closest to 1. In conclusion, ssGBLUP with optimized weights produced the most accurate and unbiased predictions, thus it is suggested to be used in practical genomic selection program for fertility traits of Chinese Holstein cattle.

The purpose of this study was to explore the changes of body condition score (BCS) in early lactation and its effects on production performance and productive lifespan of Holstein cows. In this study, the BCS, culling records and dairy herd improvement (DHI) of 7 811 Holstein cows in early lactation from January 2018 to December 2020 were collected from a large farm in Jiangsu province. The effects of days in milk (DIM), parity and calving season on BCS, and the impacts of BCS changes on early lactation performances and productive life span of Holstein cows were analyzed by multivariate analysis of variance. Using Cox regression to draw the survival curve of Holstein cows with different BCS in early lactation, and the culling reasons of dairy cow with different BCS were tested by chi-square test. The results showed that the average BCS of Holstein cows in early lactation was (2.95±0.32). Parity, calving season and DIM had extremely significant effects on BCS in early lactation (P<0.01). The BCS of cow at the first parity and calving in summer was the highest in early lactation. The BCS of cows during 5-30 DIM, 31-60 DIM and 61-100 DIM gradually and significantly decreased. BCS of cows in early lactation had extremely significant effects on milk yield, milk fat percentage, milk protein percentage, somatic cell score(P<0.01). Milk yield and peak milk yield decreased significantly with the increase of BCS (P<0.01). In early lactation, BCS was significantly correlated with milk yield and peak milk yield (with the negative coefficient), and correlated with milk protein percentage (with the positive coefficient) (P<0.01). The changes of BCS in cows during early lactation had significant effects on SCS and peak milk yield (P<0.05). BCS in early lactation had extremely significant effect on culling parity and age (P<0.01). The survival curve showed that the cows with BCS of 2.75 had the highest survival probability. BCS had a highly significant effect on the distribution of cows culling at parity 2 and 4, and calving in winter (P<0.01). The distribution of BCS culling in early lactation of low-yielding culled cows was significantly different (P<0.01). Holstein cows with BCS of 2.75 in early lactation had the better production performance and the lowest culling risk. This study provides a reference for feeding and management of Holstein cows during early lactation of large-scale cattle farms.

The study aimed to explore the structural characteristics of specificity protein 1 (SP1) and its effect on milk fat synthesis of Chinese Holstein dairy cows. According to the SP1 gene sequence of Bos taurus published by NCBI (NM_001078027.1), the SP1 sequence conservation, physical and chemical properties, protein hydrophilicity, protein structure and interaction proteins of the encoded protein were analyzed by bioinformatics softwares. The CDS region of SP1 gene was amplified and cloned by PCR. Then, 6 healthy Holstein dairy cows were used to study the effect of SP1 on milk fat synthesis. The mammary tissues of lactating cows and dry cows were collected, and the expression of SP1 in mammary tissue at different stages was detected by real-time quantitative PCR and Western blot. Next, the mammary epithelial cells were isolated and purified from the lactating cows and the effect of SP1 on milk fat synthesis were investigated by SP1 overexpression and RNAi. Each experiment was preformed triplicate. The results showed that the sequence of SP1 gene was highly conserved among different species, and had the highest similarity with goat (98.94%). The CDS region of SP1 gene in dairy cows was 2 361 bp, encoding 786 amino acids. The molecular weight of the protein was 80 902.17 u and the theoretical isoelectric point was 6.942. The average hydrophobic index of SP1 was -0.438, which was an unstable hydrophilic protein. The SP1 contained 3 zinc finger structures, and the secondary structure of SP1 protein was mainly random coil (52.29%). The results of STRING protein interaction analysis showed that SP1 interacted with transcription factor AP-1 (JUN), estrogen receptor α (ERα), MYC proto oncogene protein (MYC), TATA box binding protein (TBP) and other proteins. Real-time quantitative PCR and Western blot results showed that the mRNA and protein levels of SP1 in mammary tissues of lactating cows were significantly higher than those in dry cows (P<0.01). Overexpression of SP1 in mammary epithelial cells of dairy cows significantly increased the triglyceride content (P<0.01), while knockdown of SP1 expression significantly decreased the intracellular triglyceride content (P<0.01). These results suggest that SP1 positively regulate the milk fat synthesis. The study on the structure and function of SP1 gene provides a theoretical basis for further study on the regulatory mechanism of SP1 on milk fat synthesis in lactating dairy cows.

The study aimed to study the effect of DNA oxidative damage induced by cobalt chloride (CoCl₂) on the proliferation of porcine follicular granulosa cells. Porcine follicular granulosa cells were used as experimental materials, and hypoxia model was established by treating porcine follicular granulosa cells with chemical hypoxia model inducer CoCl₂. In the previous study, the optimal treatment concentration of CoCl₂was determined. Porcine follicular granulosa cells were treated with 200 μmol·L^-1 CoCl₂ for 12 h, and the cultured passage cells were divided into 4 groups for treatment, as follows:control group, CoCl₂-induced hypoxia treatment group, GSH treatment group, GSH+CoCl₂ combined treatment group. Cells in control group was cultured in complete medium for 12 h; Cells in CoCl₂-induced hypoxia treatment group was cultured in medium with final concentration of 200 μmol·L^-1 CoCl₂ for 12 h; Cells in GSH treatment group was treated with GSH at a concentration of 2 mmol·L^-1 for 12 h; Cells in the GSH+CoCl₂ combined treatment group was treated with 200 μmol·L^-1 CoCl₂ and 2 mmol·L^-1 GSH for 12 h. After 12 h, the proliferation activity, ROS level, γH2AX protein activity and Oxo-8-G level of each group were detected. CCK-8 assay was used to detect its proliferation activity. ROS levels were determined by 2', 7'-dichlorofluorescin diacetate (DCFH-DA). Western blot was used to detect the protein activity of γH2AX, and FITC fluorescent mouse monoclonal antibody was used to detect Oxo-8-G. In order to further clarify the relationship between CoCl₂-induced granulosa cell proliferation arrest and DNA oxidative damage, this experiment added antioxidant GSH on the basis of CoCl₂ treatment for 12 h to detect cell proliferation, ROS level, DNA oxidative damage and other related indicators. Compared with the control group, the proliferation activity of porcine follicular granulosa cells treated with 200 μmol·L^-1 CoCl₂ was significantly decreased (P<0.000 1), and the ROS level, γH2AX protein expression and Oxo-8-G level in hypoxia group were significantly increased (P<0.000 1). Compared with the hypoxia group, the levels of ROS, Oxo-8-G and γH2AX were significantly decreased by adding GSH on the basis of CoCl₂ treatment (P<0.000 1), and the proliferation activity of cells was significantly recovered by adding GSH (P<0.000 1). CoCl₂ can inhibit the proliferation activity of porcine follicular granulosa cells, and the mechanism is related to the damage of DNA induced by oxidative stress.

The study aimed to investigate whether dihydrotestosterone (DHT) regulates sheep uterine function through progesterone (P₄), oestrogen (E₂) and apoptosis, and to reveal its potential role in sheep reproductive physiology. In this experiment, female Small Tailed Han sheep about 1.5 years old were used as experimental animals to detect the expression changes of DHT synthase and androgen receptor (AR) in the uterus during follicular phase, luteal phase and pregnant phase. Subsequently, sheep uterus endometrial epithelial cells were cultured in vitro and treated with DHT (10^-10-10^-7mol·L^-1) and AR antagonist flutamide (Flu, 10^-8mol·L^-1, n=3). P₄ and E₂ levels, synthase and receptors expression were detected by enzyme-linked immunosorbent assay, cellular immunofluorescence, Western blot and real-time fluorescent quantitative PCR. In addition, after treatment with DHT and Flu, the expression of apoptosis factor B cell lymphoma protein 2 (Bcl-2), Bcl-2 associated X protein (Bax), caspase 3 (CASP3) and active-caspase 3 (Act CASP3) in sheep endometrial epithelial cells were detected. The results showed that there were differences in DHT synthesis and AR expression in sheep uterus at different stages. The DHT synthesis and AR expression in uterus at pregnant phase were significantly lower than those at follicular and luteal stages (P<0.05). After 10^-10-10^-7 mol·L^-1 DHT treatment, the level of P₄ significantly up-regulated (P<0.05), P₄ synthesis significantly increased at 10^-8-10^-7 mol·L^-1DHT (P<0.05), the expression of progesterone receptor protein significantly increased at 10^-10-10^-8 mol·L^-1DHT (P<0.05), but the expression of progesterone receptor protein significantly decreased at 10^-7mol·L^-1 DHT (P<0.05). The expression of E₂ synthase and the level of E₂ significantly decreased at 10^-8-10^-7 mol·L^-1 DHT (P<0.05), E₂ receptor ERα protein was significantly down-regulated at 10^-9 and 10^-7 mol·L^-1 DHT (P<0.05). ERβ and GPER significantly increased at 10^-10-10^-7 mol·L^-1 DHT (P<0.05). The regulation of P₄ and E₂ by DHT was partially relieved after Flu treatment. In addition, 10^-10-10^-7 mol·L^-1 DHT significantly promoted apoptosis of endometrial epithelial cells (P<0.05). This study confirmed that DHT at least partially regulates P₄ and E₂ synthesis and receptors expression through AR, affects cell apoptosis to participates in the regulation of uterine function, which provides a new basis and relevant data for further elucidating the role of androgens in the regulation of uterine function.

The aim of this study was to investigate the effects of procyanidins (PC) on the growth, proliferation, antioxidant properties and hormone secretion of yak granulosa cells after oxidative damage induced by zearalenone (ZEA). In this experiment, healthy yaks of 3-5 years old (n=3) were selected to complete the isolation and culture of ovarian granulosa cells, and immunofluorescence staining was performed to identify the purity of granulosa cells. The effects of different concentrations of ZEA (0 (Control group), 5, 10, 20, 40, 60, 80 and 100 μmol·mL^-1), different concentrations of PC (0 (Control group), 0.05, 0.5, 2.5, 5, 10, 50 and 100 μg·mL^-1) and the combined treatment of 50 μmol·mL^-1 ZEA+5 μg·mL^-1 PC on the activity of yak granulosa cells were compared by CCK-8 assay. The levels of reactive oxygen species (ROS) and estradiol (E₂) in granulosa cells of yaks Control group (without ZEA and PC), 50 μmol·mL^-1 ZEA and 50 μmol·mL^-1ZEA+5 μg·mL^-1PC groups were measured by ELISA. The expression levels of genes related to proliferation and growth, apoptosis, antioxidant and E₂ synthesis in different groups of granulosa cells were detected by real-time fluorescence quantitative PCR. The results showed that, cells isolated and cultured in this study expressed granulosa cell marker protein FSHR, which had high purity and could meet the requirements of subsequent experiments. After adding different concentrations of ZEA, the viability of granulosa cells decreased obviously with the increase of ZEA concentration (P<0.05). In a certain concentration range (0-5 μg·mL^-1), PC could significantly improve the viability of granulosa cells with the increase of concentration (P<0.05), and the effect was most obvious when the concentration was at 5 μg·mL^-1. Compared with ZEA treatment group, the combined treatment of ZEA+PC significantly increased the number of granulosa cells and cell viability(P<0.05). The expression of proliferation- and growth-related genes PCNA and IGF-II, as well as anti-apoptotic genes XIAP and BCL-2, significantly increased(P<0.05). On the contrary, the expression of pro-apoptotic genes BAX and CASP3 significantly decreased(P<0.05). Meanwhile, the combined treatment of ZEA+PC could significantly reduce the level of reactive oxygen species and promote the secretion of E₂ in yak granulosa cells(P<0.05). The expression of antioxidant-related genes SOD2, GPX1 and CAT, as well as E₂ synthesis-related genes STAR, CYP11A1 and HSD3B significantly up-regulated in granulosa cells(P<0.05). The above results suggest that PC promotes the growth and proliferation of granulosa cells after ZEA treatment, up-regulates the viability of granulosa cells, improves the antioxidant capacity, reduces the level of ROS, and increases the secretion level of E₂. In conclusion, PC has a protective effect on ZEA-induced oxidative damage in yak granulosa cells. This study provides some research data and theoretical support for the prevention and treatment of ZEA toxicity and the application of PC in animal husbandry.

This experiment was conducted to study the changes of rumen microbe and milk fatty acid composition during early lactation. In this study, 50 Holstein cows with similar parity, lactation days and milk yield were selected from a dairy farm in Jiangsu province. Milk samples and rumen fluid samples from 7 days of lactation (d7) and 30 days of lactation (d30) were collected. Feed intake, milk yield, milk composition and milk fatty acid content were detected. Meanwhile, the composition of rumen microbes was analyzed by 16S rRNA sequencing technology. The results showed that dry matter intake (15.79 kg·d^-1) and milk yield (26.81 kg) of d7 were significantly lower than those of d30 (dry matter intake:18.87 kg·d^-1; milk yield:37.47 kg)(P<0.01). Milk fat percentage, milk protein percentage and somatic cell score of d7 were extremely significantly higher than those of d30 (P<0.01). The contents of C6:0, C8:0, C10:0, C12:0, C14:0, C14:1trans9, C14:1cis9, C15:1trans10, medium chain fatty acids (MCFA) and saturated fatty acids (SFA) of d7 were significantly lower than those of d30 (P<0.05), on the contrary, the proportion of C17:0, C17:1cis10, C18:1trans6, C18:1trans11, C18:1cis9, C18:1cis11, C19:1trans10, C22:5cis4,7,10,13,16, long chain fatty acids (LCFA), monounsaturated fatty acids (MUFA) and trans fatty acids (TRANS) were significantly higher than those of d30 (P<0.05). 16S rRNA sequencing results showed that rumen bacterial richness and diversity of dairy cows during early lactation were not significantly changed (P>0.05). At the genus level, the abundance of Ruminiclostridium_1, Ruminococcaceae_UCG_014, Ruminococcaceae_UCG_005, Clostridium_sensu_stricto_1 and Dialister in rumen of d7 were significantly lower than those of d30 (P<0.05), while the abundance of Sphaerochaeta, Campylobacter and Eubacterium_saphenum_group were significantly higher than those of d30 (P<0.05). In addition, the association analysis between milk fatty acids and rumen microbiome data showed that rumen microbes had little influence on milk MCFA content, while cellulose-degrading bacteria (Ruminiclostridium_1, Ruminococcaceae_UCG_005) were significantly negatively correlated with the contents of C17:0, C18:1trans6, C18:1trans11 and C19:1trans10 in milk. In conclusion, changes in physiology and feed intake of dairy cows in early lactation lead to changes in rumen microbial composition, which lead to changes in microbial metabolites and metabolic pathways, and ultimately lead to changes in milk production and milk composition. The current study provides a scientific basis for analyzing the mechanism of rumen microorganisms regulating milk fat metabolism, and also provides a theoretical basis for regulating postpartum dairy cow nutrition and improving the quality of raw milk.

This experiment aimed to investigate the characterization of perirenal adipose tissue metabolomics of captive meat sheep with different typical odor and flavor levels. The experiment was divided into four groups with 15 lambs each, of which each test group was fed with Allium mongolicum Regel powder(AMR), Allium mongolicum Regel water extract (AWE), and Allium mongolicum Regel ethanol extract (AFE), respectively, and the control group (CK) was fed with the basal diet. At the end of the experiment, six sheep were randomly selected from each group for slaughter, and samples of perirenal adipose tissue (PF), tail adipose tissue (TF), dorsal subcutaneous adipose tissue (DF), and omental adipose tissue (GF) were collected to measure the deposition of 4-alkyl branched-chain fatty acids (BCFA), which were used as a basis for screening samples with extremely high and low odor and flavor. LC-MS was used to investigate the characterization of perirenal adipose tissue metabolomics of captive meat sheep with different typical odor and flavor levels. The results showed that, the addition of AMR, AWE, or AFE to the sheep diet reduced the content of 3 kinds of BCFA in the DF, PF, and GF to different degrees except for TF, and AFE had a stronger influence in terms of its effect on PF (MOA P<0.001; MNA P=0.044; EOA P<0.001, respectively). Metabolomics revealed that the histidine metabolism, glycerophospholipid metabolism, arginine and proline metabolism, linoleic acid metabolism, and their related metabolites might be related to the synthesis of typical odor and flavor-related substances. In conclusion, AFE may improve the typical odor and flavor of lamb by modulating the fatty acid and amino acid metabolic pathways in the body of captive meat sheep, which further affects the synthesis of 4-alkyl branched-chain fatty acids.

This experiment aimed to explore the effects of dietary energy level on rumen fermentation characteristics and microbial composition of Hu Sheep. Forty-eight Hu sheep (body weight (17.77±1.15) kg) were randomly divided into two groups:1) Control group (C group), metabolizable energy (ME)=8.83 MJ·kg^-1; 2) High energy group (H group), ME=10.84 MJ·kg^-1, with 6 replicates per group and 4 sheep in each replicate. The experiment lasted for 105 days, including 15 days of pre-experiment and 90 days of formal experiment. At the end of experiment, rumen fluid was collected to determine rumen fermentation characteristics, and 16S rRNA high-throughput sequencing was performed on V3-V4 region of microbial bacteria to detect rumen microbial composition. Results were showed as follows:1) There were no significant differences in rumen pH, total volatile fatty acids, acetate, propionate, isobutyrate, butyrate, isovalerate, valerate, acetate to propionate ratio, ammonia nitrogen, and microbial crude protein concentrations between H and C groups (P>0.05); 2) Alpha diversity showed that Chao 1, Observed species, PD whole tree, and Shannon index were lower in H group than those in C group (P<0.05); 3) Taxonomic annotations showed that Bacteroidetes and Firmicutes accounted for the highest proportion, whereas no significant differences were observed between H and C groups regarding these two phyla (P>0.05). The relative abundances of Ruminococcus and Anaerovibrio were higher in H group than those in C group (P<0.05). These results indicate that under the condition of the current experiment, the increased dietary energy level did not alter rumen fermentation characteristics significantly, but reduced the richness and evenness of rumen bacteria, as well as variations in relative abundances of some bacteria.

This study aimed to investigate the effects of hydrogen sulfide (H₂S) exposure on redox status and endogenous H₂S metabolism in nursery pigs. Twelve 35-day-old healthy Large White pigs with similar body weight ((11.61±1.51) kg) were randomly divided into two artificial environmental cabins with 6 pigs in each group, half male and half female per group. Pigs in the experimental group were exposed to 30 mg·m^-3 H₂S for 28 days, while pigs in the control group were kept without H₂S. Serum and liver samples were collected from each pig at the end of the experiment to detect the indexes related to redox and H₂S metabolism. The results showed that compared with the control group:1) In serum, the content of ROS increased extremely significantly (P<0.01) and MDA increased significantly (P<0.05); The activity of the antioxidant enzyme T-SOD decreased significantly (P<0.05), the activity of CAT and GPX decreased extremely significantly (P<0.01); The contents of non-enzymatic antioxidant GSH and GSSG did not change significantly (P>0.05). 2) In liver, the activities of T-SOD and GPX increased extremely significantly (P<0.01); the ability of scavenging ·OH improved significantly (P<0.05); The contents of ROS, H₂O₂, PC, MDA, GSH and GSSG showed no significant difference (P>0.05). 3) In liver, the mRNA expression of Keap1 was significantly down-regulated (P<0.05) and Nrf2 was significantly up-regulated (P<0.05); The mRNA expression of the antioxidant-related gene (SOD2, GPX1, GPX2, GPX4 and GSR) were significantly up-regulated (P<0.05). 4) The concentration of H₂S in serum and liver decreased significantly (P<0.05); The mRNA expressions of endogenous H₂S synthase CSE and CBS in the liver were significantly down-regulated (P<0.05) while that of 3-MST was not significantly different (P>0.05), and the mRNA expressions of H₂S catabolic enzyme SQR and SUOX showed no significant change either (P>0.05). The results indicated that 30 mg·m^-3 H₂S exposure caused damage to the serum antioxidant system of nursery pigs, but the activation of the Nrf2/Keap1 signaling pathway in liver protected the liver from oxidative damage. In addition, H₂S exposure inhibited the anabolism of endogenous H₂S in nursery pigs.

With the aim of exploring the potential factors of strong fibre degradation ability for Tibetan pigs, this experiment was conducted to study the digestion of dietary cellulose and hemicellulose and their correlation with the faecal bacteria of Tibetan pigs. The apparent digestibility of dietary fibre to grazing Tibetan pigs, captive Tibetan pigs and commercial pigs[Duroc×Landrace×Yorkshire (DLY) pigs] at 150 days of age was determined by digestion test. Faecal samples were collected, and the full-length sequence of the 16S rRNA gene of faecal bacteria was determined by single molecule real-time sequencing technology. The structure and diversity of faecal bacterial community were analysed. Spearman correlation analysis was used to determine the correlation between apparent digestibility of dietary fibre and faecal bacterial community. Results showed that the apparent digestibility of dietary cellulose and hemicellulose of grazing Tibetan pigs was significantly higher than that of captive Tibetan pigs and DLY pigs (P<0.05). A total of 15 phyla, 26 classes, 48 orders, 87 families, 190 genera and 419 species of bacteria were identified from faeces of grazing Tibetan pigs, captive Tibetan pigs and DLY pigs. Furthermore, there were 1 phylum (Fibrobacteres), 3 genera (Alloprevotella, Fibrobacter, and Succinivibrio) and 3 species (Alloprevotella rava, Fibrobacter intestinalis, and Succinivibrio dextrinosolvens) which relative abundance in grazing Tibetan pigs were significantly higher than those of captive Tibetan pigs and DLY pigs (P<0.05), which were significantly positively correlated with apparent digestibility of dietary fibre (P<0.05). In conclusion, grazing Tibetan pigs have strong ability of fibre digestion, which was closely related to the fibre-degrading bacteria in faeces.

The aim of this study was to investigate the effect of yeast selenium addition in the diet on mitochondrial oxidative damage and apoptosis during postmortem aging of white-feathered chickens. The breasts of chickens fed diets supplemented with different levels of yeast selenium were used as the research objects to determine the degree of mitochondrial oxidative damage, antioxidant enzyme activity, Caspase-3 and Caspase-9 activities, meat tenderness of chicken during postmortem aging. The results showed that during the postmortem aging process, reactive oxygen species (ROS) content, mitochondrial permeability transition pore (MPTP) opening degree, mitochondrial membrane permeability and the activities of Caspase-3 and Caspase-9 were significantly lower than those of the control group (P<0.05). Selenium content, cytochrome c (Cyt-c) reduction level, mitochondrial membrane potential and glutathione peroxidase (GSH-Px) activity were significantly higher than those of the control group (P<0.05). The total antioxidant capacity (T-AOC) of the yeast selenium-fed groups were significantly higher than that of the control group during early stage of postmortem aging (P<0.05), while it increased at other time points, but the difference was not significant (P>0.05). Moreover, the myofibrillar fragmentation index (MFI) of the yeast-selenium-fed groups was significantly lower than that of the control group during the postmortem aging process, and the corresponding shear force was significantly higher than that of the control group (P<0.05). Thus, yeast-selenium feeding inhibited cell apoptosis by decreasing oxidative damage to chicken mitochondria and ultimately weakened myofibril protein degradation.

Avian influenza virus (AIV) is an important zoonotic pathogen, which severely restricts the healthy development of the poultry industry and poses a great threat to public health. Among them, highly pathogenic avian influenza (HPAI) caused by H5 (H5N1, H5N2, H5N6, H5N8, etc.) and H7N9 subtypes of highly pathogenic avian influenza virus (HPAIV) have great harm to China's poultry industry. Through the implementation of compulsory immunization, the epidemic has been controlled, but there are still outbreaks in poultry flocks, and the prevention and control situation are still severe. This article summarizes all the official outbreaks and surveillance data of poultry infected with H5 and H7N9 subtypes of HPAI as of September 2021, and analyzes their epidemic characteristics intending to provide a reference for the early warning, prevention and control of avian influenza.

Avian leukemia (leukosis) virus subgroup E (ALV-E) refers to endogenous retroviral genomic DNA or fragments present in chicken chromosomes. ALV-E with transcriptional activity will not only have a negative impact on chicken production performance (body weight and egg production), but also interfere with the differential diagnosis of exogenous ALV at the antibody level. In order to isolate and identify an avian leukosis virus RT-PCR positive disease material in a chicken farm in Heilongjiang Province and analyze its genome characteristics and genetic evolution, the virus culture was identified and analyzed by molecular biology, virus morphology and whole genome sequencing. Results showed that the virus could be stably subcultured to the nine generation in CEF cells. Virus particles with approximate spherical shape, diameter of about 80 nm, capsule and fiber structure could be observed using electron microscopy. It was named HLJE2020 strain. Sequence analysis showed that gag and pol genes in the whole genome sequences were relatively conserved. LTR and env genes belong to the same evolutionary branch with ALV-E, while gp85 gene had high homology with ALV-E and ALV-B. Genetic evolution analysis combined with the analysis results of RDPv.4 and SimPlot software showed that there was a separate branch between ALV-E and ALV-B. It is speculated that the gp85 gene of this virus may be recombined with subgroup E AF229 and subgroup B SDAU09C1. This study can provide data for understanding the genetic evolution of avian leukemia virus genome, and provide references and basis for ALV prevention and control.

This work aimed at investigating the genetic evolution and pathogenicity of feline parvovirus (FPV). From 2018 to 2020, 54 fecal samples suspected of cat distemper were collected in Shandong province, and the VP2 gene was sequenced by PCR and VP2 gene cloning. In order to analyze the genetic variation, the phylogenetic tree was constructed and the amino acid sequence was deduced and compared with the vaccine strain. A strain named FPV-QDC20 was isolated and cultured on F81 cells. Its characteristics were studied by electron microscopy, indirect immunofluorescence, hemagglutination assay, TCID₅₀, complete gene sequencing and animal challenge test. VP2 gene of 16 samples was sequenced successfully, of which 15 were FPV and 1 was canine parvovirus (CPV) from cat. Phylogenetic tree construction showed that the strain in this study was in the same branch, and was closely related to the published strains in other regions of China, but far related to the European strain and the vaccine strain. Amino acid sequence analysis showed that mutations in some key sites may change host range and infectivity, which may lead to immune failure. Interestingly, the variation of conserved loci 80, 93 and 103 appeared in the QDBL2 strain, which may be related to coinfection and gene recombination of canine and feline parvovirus. The animal challenge test showed that the FPV-QDC20 strain was highly pathogenic, and the cats showed typical clinical symptoms and pathological changes, and finally died. In this study, the genetic evolution of FPV strains in China was investigated to provide reference for future disease control and vaccine research.

The purpose of this study was to investigate the optimal time and concentration of bovine infectious rhinotracheitis virus (IBRV)-induced mitochondrial damage in MDBK cells. 0.5, 1.0, 1.5 and 2.0 MOI IBRV were used to infect MDBK cells for 6, 12, 24, 36 and 48 h. Electron microscopy and flow cytometry were used to detect the MMP and abnormal opening of MPTP. The results showed that when MDBK cells were infected with different MOI IBRV for 12 h, the MPTP decreased significantly in the Infection group compared with the control group, and decreased with the increase of exposure dose except 2.0 MOI;The MMP started to decrease significantly after 1.5 MOI; When the MDBK cells were infected with 1.5 MOI IBRV for 6, 12, 24 and 36 h respectively, compared with the control group, the MPTP and MMP in the Infection group were significantly decreased from 6 h, and decreased with the prolongation of the virus infection;The results of transmission electron microscopy showed that MDBK cells infected with IBRV could cause mitochondrial damage and partial vacuolization after 6 h, complete vacuolization of mitochondria after 24 h, and virus particles could be seen around mitochondria. The results show that IBRV infection can induce mitochondrial damage in MDBK cells, and infecting MDBK cells at 1.5 MOI for 6-24 h is the best time and concentration to induce cell mitochondrial damage. This time and concentration can be used for IBRV-related drug research, and provide a theoretical basis for further research on mitochondrial damage.

To elucidate the genetic and evolutionary differences of Haemonchus contortus with morphological differences in the vulval flap, in this study, fresh worms were isolated from the abomasum of infected goats. The morphological characteristics of the vulval flap of 71 female worms were observed by microscope. Based on the ITS-1, ITS-2 and nad4 gene loci, PCR was used to amplify H. contortus with morphological differences in the vulval flap, and phylogenetic analysis was performed by comparing the sequences of multiple loci. Morphological observation showed there existed three morphologic types of vulval flap for female H. contortus isolated in this study, namely linguiform, spheroid-shaped and ligule-spheroid form, and statistical analysis showed that the proportion of the three types of the vulval flap was 45.07% (32/71), 50.70% (36/71) and 4.23% (3/71), respectively. The body length and the length from the vulva to the posterior of 43 females (20 linguiform, 20 spheroid-shaped and 3 ligule-spheroid form) were measured and analyzed. Statistical analysis showed that there was no significant difference among the body length of the H. contortus with different vulval flap (P>0.05), but a significant difference was found in the length from the vulva to the posterior of the nematode with spheroid-shaped vulval flap compared with the other two types (P<0.05). Sequence analysis of the ITS-1, ITS-2 and nad4 genes of H. contortus showed there existed different levels of base differences at the three gene loci among 9 samples with different vulval flaps, that there were 10, 13 and 43 polymorphic sites, and the nucleotide diversity was 0.85%, 1.34% and 1.97%, respectively. The phylogenetic analysis based on ITS-1 and ITS-2 suggested that the samples here and reference sequence of H. contortus in GenBank were grouped into the same evolutionary branch, indicating that the parasites isolated here belonged to H. contortus. The morphological difference on vulval flap of female H. contortus was observed here and these parasites, on ITS-1, ITS-2 and nad4 gene locus, shown different degrees of base mutation. The results of this study should provide reference data for species identification and molecular epidemiological studies of H. contortus.

To investigate the function of LncRNA NR_003508 in regulating Bacillus Calmette-Guérin (BCG)-induced necrosis of mouse macrophages, small interfering RNA for LncRNA NR_003508 were transfected into RAW264.7 cells alone or combined with BCG infection. Western blot, immunofluorescence and flow cytometry were used to detect the expression level of MLKL (mixed lineage kinase domain-like protein) and cell necrosis rate; The target binding of LncRNA NR_003508 and miR-483-3p was predicted and verified by bioinformatics and dual-luciferase report assay. The results showed that after BCG infection of macrophages, the expression level of LncRNA NR_003508 was significantly increased (P<0.01); After transfection of siRNA-LncRNA NR_003508, the protein expression of MLKL was significantly down-regulated (P<0.01), and the rate of macrophage necrosis was also significantly reduced (P<0.05). LncRNA NR_003508 adsorbed miR-483-3p through sponge effect, and interference of LncRNA NR_003508 significantly up-regulated the expression of miR-483-3p (P<0.01), while overexpression of miR-483-3p significantly inhibited the expression of MLKL (P<0.01) and macrophage necrosis. Our results indicated that LncRNA NR_003508 promoted BCG-induced macrophages necrosis by sponging miR-483-3p and targeting the expression of MLKL.

The study aimed to explore the mechanism of brain tissue injury caused by Enterococcus faecalis, a brain injury model from the mice infected with E. faecalis was constructed. Pathological observation and transcriptomic difference analysis for different period of infection were conducted. In this experiment, a strain of E. meningitidis was selected. Mice were used as infected animals. After being infected with E. faecalis, the brain tissues of mice were collected in time periods:at 2, 4, 6, 12, 24, 36, 60 and 72 h, separately. Then, the degree of brain tissue damage were observed. Three time points:early stage, obvious stage and prognosis stage, were selected to analyze differentially expressed genes by transcriptomic sequencing, and fluorescent quantitative PCR was used to verify the transcriptomic data. After 12 h, lesions occurred in the brain tissues of the mice infected. Histopathological observation showed that the meninges presented and brain tissue blood vessels were congested successively in the mouse brain tissue. The perivascular space was widened, and the brain tissue presented grid gap due to edema. Microthrombosis and inflammatory cell occurred. For transcriptomic differential gene analysis, the GO enrichment results showed that the main enrichment was the response to interferon-β, the response of cells to interferon-β, the defense response to other organisms, the response to interferon-γ, the response to bacteria, response, extrinsic apoptosis signaling pathway, regulation of extrinsic apoptosis signaling pathway, neuronal apoptosis process, endothelial cell migration and other biological processes. KEGG enrichment results showed that differential signaling pathways were mainly enriched relative signal paths related to brain tissue damage:peroxisome, NOD-like receptor signaling pathway, oxidative phosphorylation, calcium metabolism signaling pathway, PI3K-Akt signaling pathway, Wnt signaling pathway, MAPK signaling pathway, GnRH secretion, VEGF signaling pathway, tight junction and some other related pathways. After the infection of mice, E. faecalis affected the brain tissue peroxisome, NOD-like receptor signaling pathway, oxidative phosphorylation, calcium metabolism signaling pathway, PI3K-Akt signaling pathway and other pathways. These are related to protein phosphorylation, the occurrence of inflammation and the change of the permeability of the blood-brain barrier. The study conclusion provides a research direction and theoretical basis for further research on the mechanism of brain tissue damage caused by E. faecalis.

The purpose of the present study was to evaluate the effects of Lactobacillus salivarius on growth performance and lung injury of broiler chickens challenged with Mycoplasma gallisepticum (MG). Total of 240 one-day-old broiler chickens were randomly distributed into 6 groups, including control group (Con), low dose Lactobacillus salivarius group (L), high dose Lactobacillus salivarius group (H), MG infection group (MG), MG infection+low dose Lactobacillus salivarius group (MG+L), MG infection+high dose Lactobacillus salivarius group (MG+H). Broilers in Con group and MG group were fed control diet during experiment period; broilers in L group and MG+L group were fed control diet supplemented with Lactobacillus salivarius of 10⁸ CFU·kg^-1 feed during experiment period; broilers in H group and MG+H group were fed control diet supplemented with Lactobacillus salivarius of 10⁹ CFU·kg^-1 feed during experiment period; broilers in MG, MG+L and MG+H group were challenged with MG at 1 week of age. The effects of Lactobacillus salivarius supplementation on the body weight, feed conversion ratio, lung histopathology change, pulmonary MG colonization, pulmonary inflammatory injury related proteins expression and pulmonary pro-inflammatory cytokines content were determined after 42 d of feeding. The results showed that the Lactobacillus salivarius supplementation could improve growth performance and feed conversion ratio of broilers challenged with MG (P<0.01). In addition, the Lactobacillus salivarius supplementation could promote MG clearance in lung and alleviate lung injury caused by MG which were characterized by the significant decreased TLR2, HMGB1, p-p65/p65, NLRP3, Pro-Caspase-1/Caspase-1 expression levels (P<0.01) and significant decreased TNF-α, IL-1β, IL-6, IL-8 contents (P<0.01). These results suggested a tremendous potential of Lactobacillus salivarius as a feed additive in the poultry feed to against MG infection.

The action mechanism of antimicrobial peptide tachyplesin Ⅰ(TP Ⅰ) and its analogue TP Ⅰ-Y4 targeted the cell membrane of Escherichia coli have been studied by exploring the action mode of both peptides on the liposome membrane, the effect on the bacteria surface potential, hydrophobicity, the permeability of inner and outer membrane, and ion leakage after two peptides treated E.coli. The results showed that TP Ⅰ/TP Ⅰ-Y4 induced the increase of surface potential and hydrophobicity of E.coli. TP Ⅰ-Y4 caused a slightly higher potential and hydrophobicity enhancement than TP Ⅰ. Both peptides could disturb the liposome membrane causing the calcein leakage during peptides crossing phospholipids bilayer, TP Ⅰ-Y4 caused more fluorescein leakage, but it did not completely collapse the liposome membrane. TP Ⅰ/TP Ⅰ-Y4 obviously increased the inner and outer membrane permeability of bacteria, in contrast, TP Ⅰ-Y4 induced stronger outer membrane permeability, greater damage to the plasma membrane, causing more leakage of ions and intracellular macromolecules. TP Ⅰ-Y4 had a greater destructive effect on E.coli cell membrane, which may be the main reason for the significant improvement of its antibacterial activity compared with TP Ⅰ.

The purpose of this study was to investigate the antiviral effect of phenylpyridinone derivative JIB-04 on porcine deltacoronavirus (PDCoV), and explore the possible mechanism. Cell viability after treatment with different concentrations of JIB-04 was detected by CCK-8, and the 50% cytotoxic concentration (CC₅₀) and 50% effective concentration (EC₅₀) were calculated. TCID₅₀ method was used to detect the effects of JIB-04 pretreatment and co-treatment on PDCoV replicationand the effect of JIB-04 treatment on virus attachment and penetration. Finally, qRT-PCR, TCID₅₀ and Western blot methods were used to detect the effect of JIB-04 on virus replication at different times post infection. The results showed that JIB-04 did not affect the cell viability of LLC-PK cells at all tested concentrations, and CC₅₀>640 μmol·L^-1, EC₅₀=0.216 μmol·L^-1, and SI index is greater than 2 963. Compared with untreated virus infection group, JIB-04 treatment significantly reduced the virus titer (P<0.001), but it had no effect on attachment or penetration of PDCoV. At 6 h post infection, compared with untreated virus infection group, virus titer in JIB-04 treatment group was significantly decreased (P<0.01). At 12 and 24 h post infection, virus titer, genome copy number, and N protein expression level all significantly decreased (P<0.01). JIB-04 has a low cytotoxicity and a high selective index, and can protect against PDCoV infection in vitro, making it a potential antiviral drug. JIB-04 can inhibit synthesis of viral RNA, protein and PDCoV replication.

The pharmacokinetics of enrofloxacin soluble powder in the drinking water were investigated in chicks of various ages and the PK/PD model combined with Monte Carlo simulation (MCS) was used to evaluate the rationality of enrofloxacin soluble powder administration by the recommended regimen. Chicks were given 75 mg·L^-1 of enrofloxacin soluble powder (calculated by enrofloxacin) at 1, 7 and 14 days of age. At predefined time intervals, blood samples were obtained, the plasma concentration of enrofloxacin was measured by HPLC, and pharmacokinetic parameters were calculated. PK/PD parameters were calculated by combining the pharmacokinetic parameters with the breakpoint (0.25 μg·mL^-1) of enrofloxacin against Escherichia coli in poultry obtained by Clinical and Laboratory Standards Institute (CLSI), and the target attainment rate (TAR) of the current administration regimen under different MIC ranges of Escherichia coli was obtained by MCS. The results showed that C_max of chicks at 1, 7 and 14 days of age were 0.561, 0.564 and 0.550 μg·mL^-1 on day 0 of administration, and AUC_0-24 were 8.85, 9.85 and 9.27 μg·h·mL^-1, respectively. C_max of chicks at 1, 7, and 14 days of age on day 4 of administration were 0.599, 0.550 and 0.487 μg·mL^-1, C_avg were 0.513, 0.493 and 0.432 μg·mL^-1; AUC_0-24were 12.31, 11.82and 10.37 μg·h·mL^-1; C_max/MIC were 2.40, 2.20 and 1.95; C_avg/MIC were 2.05, 1.97 and 1.73; AUC_0-24/MIC were 49.24, 47.28 and 41.48, respectively. When the MIC of enrofloxacin against clinical isolates of Escherichia coli within 0.25 μg·mL^-1, TAR varied from 75.01 percent to 76.11 percent at 1, 7, and 14 days of age. The results revealed that enrofloxacin soluble powder failed to achieve the PK/PD parameter ratio and TAR of sensitive bacteria as expected by the currently suggested regimen, which not only limited bactericidal effect, but also easy to induce bacterial drug resistance.

The misuse of antibiotics on farms has caused the emergence of a variety of drug-resistant bacteria. MRSA isolated from dairy meat products are increasing year by year, leading to a great threat to food safety in the farming industry. In this paper, berberine hydrochloride (BBR), a natural product with combined inhibition effect of MRSA with levofloxacin, was screened, and the synergistic inhibition effect and combined inhibition mechanism of BBR with its effect on MRSA were investigated. The results showed that BBR could effectively inhibit the growth of MRSA and improve the sensitivity of MRSA to levofloxacin, and the combination could reduce the MIC of the latter up to 1/16. The synergistic mechanism of combination was mainly up-regulation of ribA and down-regulation of mec A and msc L expression levels, disrupting the cell wall and increasing the permeability of the cell membrane, thus achieving synergistic bacterial inhibition. This thesis helps to lay the foundation for reducing the use of antibiotics in livestock farming and improving the food safety of meat and milk.

This study aimed to investigate the regulation mechanism of (2, 8, 16 μmol·L^-1) sodium butyrate to the LPS-induced lipid metabolism disorder model of bovine mammary epithelial cell line (MAC-T), explore its regulation mechanism on cell lipid metabolism and repair inflammation damage effect. After stimulating MAC-T cells with 1 000 ng·mL^-1 LPS for 9 h, the lipid droplet area and the cell triglyceride (TG) content were measured respectively. After stimulating MAC-T cells with different concentrations of sodium butyrate for 12 h. MAC-T cells were added with different concentrations of sodium butyrate, and the apoptosis rate was detected by flow cytometry. Subsequently, the experiment was divided into 5 groups:control group, LPS treatment group, 2 μmol·L^-1 sodium butyrate + LPS treatment group, 8 μmol·L^-1 sodium butyrate +LPS treatment group and 16 μmol·L^-1 sodium butyrate+LPS treatment group. Cell TG content, AMPK signaling pathway protein, key genes of lipid metabolism and related inflammatory factors were detected. Results:LPS will cause a significant decrease in the total lipid droplet area of MAC-T cells (P<0.05), and extremely significant decrease in TG content (P<0.01). Different concentrations of sodium butyrate had no effect on the apoptosis rate of MAC-T cells. Compared to the control group, LPS treatment group significantly decreased the content of TG (P<0.01), significantly increased the expression level of P-AMPK (P<0.05), lipid anabolism related genes ACC, SCD-1 and FAS mRNA expression levels were significantly (P<0.05) or extremely significantly decreased (P<0.01), lipid catabolism-related genes CPT-1, CPT-2 and ACO mRNA expression levels of were significantly increased (P<0.05), and contents of inflammatory factors TNF-α and IL-6 were significantly increased (P<0.05). Compared with LPS treatment groups, (2, 8, 16 μmol·L^-1) sodium butyrate +LPS treatment groups increased TG content, decreased P-AMPK expression level, increased lipid anabolism related gene expression level, decreased lipid catabolism related gene expression level, and decreased inflammatory factors TNF-α and IL-6 content. This study shows that sodium butyrate activates lipid anabolism through the AMPK pathway, regulates TG synthesis, and alleviates the inflammatory damage in MAC-T cells.

The aim of this study was to investigate the effects of selenium on dendritic cells (DCs) and macrophages. Selenium was cultured with bone marrow derived dendritic cells (BMDCs) and peritoneal macrophages, respectively. Flow cytometry was used to detect phagocytosis activity of immature BMDCs and macrophage, as well as the phenotype MHCⅡ, CD86, CD80 and CD40 expression on BMDCs, and the ability of BMDCs treated with selenium to stimulate the proliferation and antigen presenting of allogenic lymphocytes. The cytokines (IL-12, IL-1β, IFN-γ, IL-6, IL-10, TNF-α, NO) in the supernatant of BMDCs and macrophages were detected by ELISA. The results showed that when the concentration of selenium was 0.18-0.09 mg·L^-1, the phagocytic activity of BMDCs and macrophages were significantly enhanced(P<0.05), and the expression levels of MHCⅡ, CD86 and CD80 on BMDCs were significantly increased(P<0.05), and the ability to stimulate the proliferation and antigen presentation of allogeneic lymphocytes was also significantly increased (P<0.05). The contents of IFN-γ, IL-12 and IL-10 were significantly increased in the supernatant of BMDCs(P<0.05), while the contents of IFN-γ, TNF-α and NO were significantly increased in the supernatant of macrophages(P<0.05). The results indicated that proper concentration of selenium could enhance the function of DCs and peritoneal macrophages, and it was worth further exploring the effect of selenium on immune function.

The aim of this study was to evaluate the alleviation effect of N-acetyl-L-cysteine (NAC) on cadmium (Cd) exposure-induced the apoptosis of lung cells and the damage of lung tissue in the ovariectomized rats. Forty adult female Sprague-Dawley (SD) rats were randomly divided into sham operation group (Control), Cd group, NAC group (NAC), and NAC+Cd group (NAC+Cd). Each group contained 10 rats. After feeding for 18 months, the lung tissue of the rat was separated for further tests. The pathological change of lung tissue was observed after the HE staining and the Masson staining. The content of Cd in lung tissue was detected by atomic absorption analyzer. The mRNA levels of lung tissue fibrotic key proteins (Col-I and Col-III) were analyzed by the qRT-PCR. In addition, the expression of key apoptosis proteins (Bcl-2, Bax, and cleaved caspase-3) and p53, and Akt phosphorylation were evaluated by Western blot. The results showed that the disappearance of alveolar structure and the hyperplasia of fibrous tissue, the content of Cd was significantly (P<0.01) increased, the mRNA levels of Col-I and Col-III were significantly (P<0.01) up-regulated, and the ratio of Bax/Bcl-2, the expression of cleaved caspase-3 and p53 were increased in lung tissue of Cd group compared with Control group, but the phosphorylation of Akt was inhibited. The pathological change, the content of Cd, the mRNA levels of Col-I and Col-III, and the ratio of Bax/Bcl-2, the expression of cleaved caspase-3 and p53 were decreased in lung tissue of NAC+Cd group compared with Cd group, but the phosphorylation of Akt was increased. These results indicated that NAC has a certain alleviating effect on Cd-induced the damage of lung tissue and the apoptosis of lung cells in rats.

Astragalus polysaccharide (APS) has been widely recognized as a key medicine for supplementing qi and its role in regulating natural immunity. However few studies were related with the immunoregulation effect and molecular mechanism of APS on chicken macrophages. The purpose of this study was to evaluate the protective effect of APS on HD11 cell injuryed by LPS and the recognition of sensitive TLRs in the signaling pathway. The optimal concentration of LPS-injuryed HD11 cells and the working concentration of APS were decided by CCK-8 method. The effect of APS on LPS-injuryed HD11 cells was evaluated by microscopic observation, nitric oxide (NO) detection and lactate dehydrogenase (LDH) detection. The regulation of APS on inflammatory cytokines and mRNA expression of TLR1, TLR2, TLR4 and TLR15 in LPS-injuryed HD11 cells was detected by real-time fluorescence quantitative PCR (RT-PCR). The results showed that the proliferation activity of HD11 cells cultured in the complete medium of 2% chicken serum +1% penicillin-streptomycin decreased significantly and the changes of inflammatory damage were obvious when LPS concentration was greater than 9.76 μg·mL^-1. The proliferation activity of HD11 cells continued to increase when APS concentration was greater than 50 μg·mL^-1, and there was a positive correlation between APS dosage and proliferation activity. 100 μg·mL^-1 APS significantly increased the release of NO and LDH in HD11 cells (P<0.05), but extremely significantly (P<0.01) and significantly (P<0.05) decreased the release of NO and LDH in HD11 cells induced by 9.76 μg·mL^-1 LPS. 100 μg·mL^-1 APS significantly increased the mRNA levels of pro-inflammatory factors (IL-1β, TNF-α and iNOS) (P<0.05) and extremely significantly inhibited the mRNA levels of IL-10 (P <0.01) in HD11 cells, but extremely significantly inhibited the increasing of mRNA levels of IFN-α、TNF-α、IL-10 (P<0.01) and significantly inhibited the increasing of mRNA levels of IL-6, IL-1β, iNOS (P<0.05) in LPS-injuryed HD11 cells. 100 μg·mL^-1 APS significantly decreased the expression of TLR2, TLR4 and TLR15 mRNA transcription levels in HD11 cells (P<0.01), but significantly inhibited the ascending of TLR2 mRNA transcription levels (P<0.01), and significantly inhibited the expression of TLR4 and TLR15 mRNA transcription levels in LPS-induced injury HD11 cells were significantly (P<0.05). However the expression of TLR1 mRNA transcription levels in HD11 cells and LPS-injuryed HD11 cells were not significantly affected by APS. In conclusion, APS had a wide range of safe concentrations on HD11 cells. APS can promote reduce excessive inflammatory response to injuryed HD11 cells by recognizing TLR2, TLR4 and TLR15 mRNA levels, and play a bidirectional immune regulatory role.

The purpose of this experiment was to reveal the relationship between the intramuscular fat content and lipidomics in Beijing black pig. In this experiment, 11 samples of high intramuscular fat group and 19 samples of low intramuscular fat group were selected from 400 210-day-old Beijing black pigs, and the average intramuscular fat content was 3.89% and 0.81%, respectively. For the selected individuals in high and low groups, 60 mg muscle samples were taken for lipid extraction, and finally non-targeted lipidomics detection was carried out. According to the test results, the two groups were analyzed by diversification, and the markers were screened by T test, difference multiple and partial least squares discriminant analysis. A total of 104 fatty acids, including 3 acylcarnitine (AcCa), 4 diglycerides (DG), 23 triglycerides (TG), 8 ardiolipin (CL), 21 phosphatidylcholine (PC), 29 phosphatidylethanolamine (PE), 3 phosphatidylglycerol (PG), 6 phosphatidylinositol (PI) and 7 phosphatidylserine (PS) were detected. The 33 kinds of lipids were preliminarily screened by T-test (P<0.05), of which TG were 23, AcCa were 2, DG were 4 and PE were 4. Further screening by VIP value (VIP>1) and FC value (FC>2 or FC<0.5),there were 22 kinds of lipids, including 21 TG and 1 DG. The results showed that lipidomics could be used as a method to distinguish the intramuscular fat content of Beijing black pig. The lipid difference substances affecting intramuscular fat content mainly concentrated in TG and DG.

This study was conducted to investigate the inhibitory effect of the African swine fever virus (ASFV) MGF360-14L on type Ⅰ interferon (IFN) and its mechanism. The effects of MGF360-14L on MAVS-induced IFN-β promoter activity were detected by dual luciferase assay, and the interaction between MGF360-14L and MAVS was examined by co-immunoprecipitation and indirect immunofluorescence assays. The results showed that the viral non-structural protein MGF360-14L inhibited interferon β (IFN-β) promoter activity induced by MAVS signaling. MGF360-14L interacted with MAVS and inhibited the phosphorylation of TBK1 and IRF3 induced by MAVS and TRIM21. In addition, MGFF360-14L competed with TRIM21 to bind MAVS and inhibit the TRIM21-mediated ubiquitination of MAVS, thereby reducing IFN-β levels. In conclusion, MGF360-14L may inhibit TRIM21-mediated ubiquitination of MAVS by competitively binding MAVS, thus down-regulating the production of type Ⅰ interferon. These findings provide new insights into the mechanisms underlying ASFV immune evasion.