Feather pecking is a common and serious act of destruction in the production of laying hens, which can cause damage to the feathers and skin of the pecked chickens, and even results in mortality. Feather pecking not only does negative impact on the health and well-being of laying hens, but also further affects the benefit of farming layers, therefore received extensive attention from the layer industry and research. This review aims to synthesize the existing research results to explore the external influencing factors and genetic regulatory mechanisms of feather pecking behavior of laying hens, so as to promote the in-depth understanding of feather pecking behavior of laying hens, and put forward future research directions. This provides the basis for developing sustainable solutions, improving the welfare of laying hens, and increasing production efficiency.

The development of genomic selection has left a profound mark on beef cattle breeding. In China, the multitude of beef cattle breeds with small population sizes has led to a slow pace in genetic breeding efforts. Most studies indicate that purebred beef cattle populations with large reference groups gain little benefit from multi-breed evaluations, while breeds with smaller reference groups can benefit from such evaluations without adversely affecting the assessment of purebred performance. In the field of beef cattle genetic breeding research, the use of genomic information provides an opportunity to enhance the genetic improvement of beef cattle, thereby determining the value of multi-breed reference groups such as hybrid breeds for beef cattle genetic breeding. Multi-breed genomic assessment, as a beneficial tool for increasing the genetic gain of populations, can evaluate the genomes of beef cattle populations using multi-breed models. This review focuses on the perspective of genomic selection in beef cattle, highlighting the use of genomic selection across multi-breed beef cattle breeds, discussing the mechanisms by which genomic selection is applied in beef cattle, with the aim of providing new insights for research into genomic selection in multi-breed beef cattle and exploring the potential applications of genomic selection.

In livestock and poultry production, oxidative stress is a common physiological phenomenon that can affect their growth, health, and productivity. Mitochondria, as the primary energy-generating centers within cells and the major targets of oxidative stress, play a crucial role in maintaining intracellular redox balance. This article provides a comprehensive review of the research progress on the impact of mitochondrial quality control on oxidative stress in livestock and poultry. The review includes discussions on molecular mechanisms, related regulatory pathways, and potential applications in livestock and poultry production. The aim is to provide valuable insights into oxidative stress management in the livestock and poultry industry.

Canine allergic dermatitis is a common skin disease in the veterinary clinic, and it is affected by several factors, including autogenetic and environmental allergens. These factors cause inflammation and itching in different skin sites of the affected dogs, severely reducing their quality of life and health status. In addition to routine drug treatment and care methods, studies have found that some dietary components in the diet play a role in the treatment of canine skin diseases, and improving skin symptoms through dietary treatment has gradually attracted the attention of veterinarians and pet owners. Therefore, this paper summarizes the common categories, pathogenesis and clinical symptoms of dog allergic skin diseases in dogs, and expounds the research progress of different dietary regulatory substances, including essential fatty acids, hydrolytic proteins, polyphenols, probiotics, vitamins and minerals on dog allergic skin diseases and the improvement effect, aiming to provide reference for the research, diet design and product development of dog allergic skin diseases.

Ferroptosis is an iron and lipid peroxidation-dependent mode of programmed death, and it is triggered when the accumulation of reactive oxygen species reaches a lethal level within the cell. Lipid reactive oxygen species produced by lipid peroxidation act on lipid molecules on cell membranes, resulting in lipid peroxidation and membrane damage, so lipid peroxidation is a prominent feature of ferroptosis. Long-chain acyl-CoA synthetase 4 (ACSL4) plays a crucial role in regulating lipid metabolism, primarily by esterifying polyunsaturated fatty acids and incorporating them into membrane phospholipids, thereby accelerating lipid peroxidation and driving ferroptosis. ACSL4-mediated ferroptosis is mainly regulated at transcriptional, post-transcriptional, and post-translational levels and plays an important role in lipid peroxidation-dependent diseases. The purpose of this study is to elucidate the mechanisms underlying ferroptosis, focusing on the upstream regulation of ACSL4 and consequently mechanism of ferroptosis, providing a theoretical basis for investigation into the mechanisms of ACSL4-mediated ferroptosis.

Henipavirus (HNV) is an important new class of zoonotic pathogens, which can cause respiratory and neurological diseases through contact, oral and nasal transmission, and the mortality rate is as high as 75%. HNV belongs to the negative stranded single-stranded RNA envelope virus of the paramyxoviridae family. With the change of environment, new virus subtypes continue to emerge and the spread of the scope gradually expands, which seriously threatens global public health security, economic development and social stability. However, the pathogenic mechanism of infection is not clear, and preventive vaccines and therapeutic drugs have not been marketed, which has aroused great concern from WHO, and the research and development of vaccines and drugs has been included in the list of blueprints that require urgent research and development. This review summarizes the etiological characteristics, structure and functions of the encoded proteins, and pathogenic mechanism of HNV, so as to provide ideas for the development of drugs and vaccines for effective intervention in HNV infection.

Parasitic diseases are widespread and pose a serious threat to human health and animal husbandry. miRNAs are a class of highly conserved endogenous non-coding single-stranded small molecule RNAs with a length of approximately 19-24 nt. Parasite will express a large number of miRNAs to mediate its infection to the host, and the expression profiles of the host miRNAs will also change. These miRNAs will affect the host's resistance or susceptibility, and miRNAs have become one of the hot areas to study the interaction mechanism between parasites and host. This article reviews the role of miRNAs expressed by different species of parasites in infecting the host and the regulatory effect of host miRNAs on parasites, aiming to provide therapeutic methods of anti-parasitic infection based on miRNAs.

Toxoplasma gondii is an obligate intracellular parasitic protozoan belonging to the phylum Apicomplexa, with a complex life cycle involving multiple hosts and stages. T. gondii has a sexual stage restricted to felid species, while the asexual stage occurs in most warm-blooded animals including humans. About one-third of the world's population is infected with toxoplasmosis, and it can also cause serious economic losses in the livestock industry. T. gondii has a sophisticated gene regulatory network that enables it to timely transcribe its own genes as it adapts to changes in the external environment during specific stages. However, little is known about its potential transcriptional regulatory mechanisms. It has been found that specific transcription factors (TFs) play an important role in eukaryotic transcriptional regulation, especially the apetala 2 (AP2) family of transcription factors, which are involved in T. gondii gene expression during different stages. These factors play a crucial role in the growth and development of parasites. This article reviews the research progress of the Apicomplexan AP2 (ApiAP2) family of proteins in T. gondii, combining recent research results, in order to lay a foundation for further study of the biological characteristics of T. gondii.

This study aimed to investigate the genetic structure of the Beijing black pigs based on runs of homozygosity (ROH) and selection signals|iHS|analysis and to identify candidate genes related to economic traits. The subjects of this study were Beijing black pigs, with an average age of 210 days. After quality control and imputation of the illumina Porcine 50K chip data from 729 Beijing black pigs, the ROH and|iHS|were analyzed. In this study, the threshold for ROH islands was set at the SNPs that constituted the top 1% of ROHs, and regions exceeding this threshold were termed ROH islands. All SNPs in the top 1% of standardized |iHS| values were retained, and the areas extending 200 kb upstream and downstream of these SNPs were considered as the strong selection regions obtained by the iHS. The overlapping areas between the strong selection regions of the selection signals and the ROH islands were defined as the candidate regions for this study. In this study, 724 individuals and 45 585 SNPs were retained, and a total of 10 ROH islands containing 449 SNPs were identified by ROH analysis, and the results of|iHS|analysis showed that a total of 376 strongly selected SNPs were retained after the top 1% SNPs with the highest score were retained. In the end, a total of 18 genes in the overlapping regions of the 5 strongly selected regions of |iHS| and ROH islands were annotated, including some genes known to affect pork quality and growth and development. This study analyzed the distribution of ROH in the Beijing black pigs and revealed potential selected SNPs and candidate genes combined with selection signals. The results provide an important reference for further exploring the population characteristics and genetic mechanisms of economic traits of Beijing black pigs.

The aim of this study was to develop a rapid identification method of pork quality images based on computer vision technology, and to lay a technical foundation for solving the defects of traditional pork quality determination methods and constructing a rapid pork quality determination system. In this study, canny edge detection algorithm, normalization, gamma correction, adaptive histogram equalization and thresholding were used for image processing to simulate a three-dimensional model of porcine dorsal longest muscle using two-dimensional information, and an image-based computer vision method for determining porcine intramuscular fat content was developed. An image-processing-based eye muscle area recognition method was developed using manual depiction and computer vision contour search techniques. The underlying algorithmic programs of each method were implemented using Open CV and C++, and a system for the determination of porcine intramuscular fat content and eye muscle area was developed and tested using 250 test pigs of different breeds. The test results showed that the intramuscular fat content detection module could quickly realize the extraction and prediction of intramuscular fat graphical information, with an average detection time of no more than 2 minutes for a single sample, an accuracy of up to 0.54, and a discrete coefficient of 0.062, which was highly stable. The eye muscle area and backfat thickness detection module can quickly determine eye muscle area and backfat thickness by combining manual and computerized methods. The assay method and software system developed in this study enable rapid detection of intramuscular fat content, backfat thickness and eye muscle area in pigs.

The aim of this study was to investigate the imprinting status of the MKRN3 gene and its DNA methylation level in wild type and cloned pigs. The imprinting status of the MKRN3 gene in the 3 wild-type crossbred pigs, which were born at full term, were examined using interspecies single nucleotide polymorphism(SNP) present in Western (Duroc) and local (Bama or Rongchang) pig breeds. CpG islands near the MKRN3 promoter region were predicted using the MethPrimer website, and CpGs were verified as differentially methylated region (DMR) in oocyte and sperm genomes. The genomes of the 3 wild-type hybrid and 2 cloned pigs were sequenced after bisulfite transformation to detect the methylation status of MKRN3-DMR in wild-type and cloned pigs, and to analyze the relationship between methylation status and expression. The results showed that a single nucleotide polymorphism (SNP) existed in the coding region of the MKRN3 gene between Western (Duroc) and local (Bama and Rongchang) pig breeds: A/G; RT-PCR sequencing showed that MKRN3 was bi-allelic expressed in the heart tissue of one of the wild-type individual (offspring of a cross between Duroc pig and Bama pig: DB2), and monoallelic expressed in organs such as liver, spleen, lungs, and brain tissues, and all of them expressed the allele from paternal origin. MKRN3-DMR showed hypomethylation (0%) in spermatozoa and showed hypermethylation (70.9%) in oocytes. The average methylation levels of MKRN3-DMR in the six tissues of hybrid pigs were: heart (43.1%), liver (46.2%), spleen (48.4%), lung (45.6%), kidney (48.5%), and brain (44.3%), respectively. In most tissues of the newborn cloned pigs, MKRN3 was expressed as the allele of paternal origin, and the level of MKRN3-DMR methylation was similar to that of the wild-type crossbred pigs. While MKRN3-DMR methylation assay results showed that the methylation levels were 79.0% and 80.1% in spleen and spleen of NT201 and NT207, respectively, SNP sequencing results also indicated that the imprinted state was no longer maintained in the two cloned pig spleens. It is suggested that MKRN3 imprinting status was abnormal in cloned pig spleen tissues. In summary, MKRN3 was maternally imprinted and paternally expressed in liver, spleen, lung, kidney and brain tissues of wild-type pigs, and was in a non-imprinted state in the heart; MKRN3 imprinted expression and methylation status were abnormal in some tissues of the cloned pigs. The expression of MKRN3 was regulated by the DMR of the promoter.

The aim of this study was to investigate the effects of miR-127 on the skeletal myoblast proliferation and differentiation in sheep, and to screen for transcription factors that regulate the expression of miR-127 by identifying its upstream core promoter region. In this study, primary skeletal muscle myoblasts of small-tailed Han fetal sheep were used as experimental materials. After overexpression or inhibition of miR-127, the RT-qPCR, EdU staining, flow cytometry analysis, and immunofluorescence staining were used to detect the effects of miR-127 on the proliferation, apoptosis and differentiation of sheep myoblasts. The bioinformatics analysis and dual luciferase reporting assay were used to predict and identify the sheep miR-127 core promoter region and its transcription factors. The results showed that overexpression of miR-127 in sheep myoblasts promoted the expression of cell proliferation related genes PCNA and CDK4 (P < 0.01), and inhibited the expressions of cell apoptosis related genes Caspase3 and BAX (P < 0.05). EdU results showed that the positive rate of sheep myoblasts was significantly increased after miR-127 overexpression (P < 0.05). Flow cytometry analysis showed that overexpression of miR-127 significantly increased the proportion of S and G2 phase myoblasts and decreased the apoptosis of myoblasts. In the cell differentiation assay, overexpression of miR-127 significantly increased the mRNA expression levels of myoblast differentiation related genes MYOD1 and MYHC (P < 0.05), and significantly increased the MYHC positive myotube area (P < 0.05). The opposite result was found after miR-127 inhibition. In order to further reveal the regulatory factors regulating the expression of miR-127, the dual luciferase activity assay showed that the 1 500-1 800 bp (miR-127-P6) region upstream of miR-127 had the highest activity, which was inferred to be the core promoter region of miR-127. Bioinformatics predictions revealed a site in the core promoter region of miR-127 that bound to the transcription factor PAX3. Overexpression of the transcription factor PAX3 in sheep myoblasts significantly increased the promoter activity and the expression of miR-127 (P < 0.01). This study showed that sheep miR-127 significantly promoted the proliferation and differentiation of skeletal muscle myoblasts and reduced their apoptosis, which participated in their development process. Further studies showed that 1 500-1 800 bp upstream was the core promoter region of sheep miR-127, and the transcription factor PAX3 positively regulated the transcription of miR-127. This study provided a theoretical reference for further exploring the molecular mechanism of sheep muscle growth and development.

The study aimed to evaluate the conservation effect of Nanyang cattle by analyzing genetic diversity and population structure. In this study, based on the whole genome resequencing data of 30 healthy Nanyang cattle, single nucleotide polymorphism (SNP) information was obtained through mutation detection. The genetic diversity, population structure, phylogenetic relationship and runs of homozygosity (ROH) distribution characteristics were analyzed comprehensively to evaluate the conservation effect of Nanyang cattle. The results showed as follows: 1) The total number of high quality SNPs sites was 25 929 389; 2) The conservation population was rich in genetic diversity, nucleotide diversity was 0.002 9, polymorphism marker ratio was 0.888 7, minimum allele frequency was 0.186 1, expected heterozygosity was 0.274 9, observed heterozygosity was 0.255 7; 3) The effective population size was 2 834 before 1 000 generations and 149 before 20 generations, which showed a decreasing trend year by year; 4) The results of principal component analysis showed that there was no obvious stratification in Nanyang cattle conservation population; 5) The genetic distance between individuals ranged from 0.80 to 0.89, and the average genetic distance was 0.83±0.02; 6) The 30 Nanyang cattle were divided into 7 families, and the bulls were divided into 5 families; 7) A total of 4 992 ROH fragments were detected, the average length of ROH fragments per Nanyang cattle was about 74.41 Mb, the total length was 2.18 Gb, the average inbreeding coefficient based on ROH was 0.031, and the maximum proportion of ROH fragments below 0.5 Mb was 75.72%, the proportion of ROH fragments of 2-4 Mb was at least 0.16%. In summary, the genetic diversity of the Nanyang cattle conservation population is rich, there is no obvious stratification, the inbreeding level is low, but there are still some individuals with high inbreeding. Therefore, the future conservation work should strengthen the management of seed selection and mating, in order to promote the sustainable development of the population.

The aim of this study was to investigate the mechanism of action of quercetin in repairing lipoteichoic acid (LTA)-induced tight junction damage in mammary alveolar cells-large T antigen (MAC-T) of dairy cows. MAC-T was used as the research object, and different concentrations of LTA group (0, 0.1, 1, 10 μg·mL^-1), different concentrations of quercetin group (0, 5, 10, 20 μmol·L^-1), and blank wells were set up to detect the effects of different concentrations of LTA and quercetin on the viability of MAC-T cells; A control group (without any treatment), low, medium and high LTA concentration groups (0.1, 1 and 10 μg·mL^-1) were set up to screen for the optimal concentration of LTA action; A control group (without any treatment), a high concentration of LTA+low concentration of quercetin (5 μmol·L^-1), a high concentration of LTA+medium concentration of quercetin group (10 μmol·L^-1), and a high concentration of LTA+high concentration of quercetin group (20 μmol·L^-1) were set up to screen for the optimal action concentration of quercetin. In the study of the relationship between autophagy and tight junctions, the cells were divided into a control group (without any treatment), a high-concentration LTA group, a high-concentration LTA+medium-concentration quercetin group, and a high-concentration LTA+autophagy inhibitor chloroquine (CQ) group (50 μmol·L^-1). Each group was subjected to 3 replications, and both quercetin and chloroquine were added before the action of LTA, the cells were incubated with quercetin and chloroquine for 3 h respectively, and then 10 μg·mL^-1 LTA was added to continue the incubation for 12 h. The effects of different concentrations of LTA and quercetin on the viability of MAC-T were detected by CCK-8 assay; the expression levels of cellular tight junction proteins (Occludin, ZO-1, Claudin-1) and autophagy-associated proteins (Beclin-1, LC3, P62) were detected by Western blot and immunofluorescence. The results showed that the MAC-T cell activity was maintained at 90% with the increase of LTA concentration, and 5-20 μmol·L^-1 quercetin had no significant effect on MAC-T viability (P>0.05), and the optimal action concentration was further screened by a follow-up experiment on the basis of CCK-8 results. The expression of tight junction proteins of MAC-T was reduced and the level of autophagy was elevated after LTA induction; the expression of tight junction proteins of the cells was elevated and the level of autophagy was reduced after the action of quercetin on MAC-T, the expression of tight junction proteins was elevated and the autophagy level was reduced after CQ treatment. LTA can lead to over-activation of MAC-T autophagy and disruption of tight junction function, whereas quercetin can restore tight junction function by inhibiting autophagy. The results of this study provide new research ideas and theoretical basis for the treatment of mastitis in dairy cows.

The aim of this study was to investigate the subcellular localization and function of high density lipoprotein binding protein (HDLBP), and its relationship with the formation of goose fatty liver using in vivo and cellular models. Fourteen 70-day-old healthy Landes male geese were selected and raised in single cages. They were randomly divided into the control group (average weight 3.72 kg, ad libitum feeding) and the treating group (average weight 3.71 kg, overfed for 20 d) for in vivo experiment. Hepatocytes were isolated from 23-day-old Landes goose embryos and overexpressed with HDLBP gene for cellular experiment. Firstly, the subcellular localization of HDLBP protein in goose primary hepatocytes was determined by immunoblotting and immunofluorescence analyses. Secondly, the protein abundance of total HDLBP (wHDLBP) and mitochondrial HDLBP (mHDLBP) in the liver of the overfed geese and the control geese was determined by immunoblotting analysis. Then, HDLBP was overexpressed in goose primary hepatocytes, which was followed by determining the effects of HDLBP overexpression on the protein abundance of mHDLBP, the content of malondialdehyde (MDA), the activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX), the level of reactive oxygen species (ROS), and mitochondrial membrane potential. Finally, the differentially expressed genes (DEGs) and related signaling pathways affected by HDLBP overexpression were identified by transcriptome sequencing analysis, and some DEGs were verified in the in vivo model by quantitative polymerase chain reaction (PCR). The results showed that HDLBP could bind to mitochondria; the protein abundance of wHDLBP and mHDLBP in the overfeeding group was significantly lower than that in the control group (P < 0.01); overexpression of HDLBP in goose primary hepatocytes significantly increased the protein abundance of mHDLBP (P < 0.05), increased the levels of MDA (P < 0.01) and ROS (P < 0.05), and decreased the mitochondrial membrane potential (P < 0.05) and the activities of T-SOD (P < 0.05) and GSH-PX (P < 0.05). The up-regulated DEGs affected by HDLBP overexpression were mainly enriched in immune/inflammation-related pathways. In addition, compared with the control group, the expression of inflammation-related genes including IL1R1, TNFSF10, LTC4S, NCF1, SFTPA1, and KDR in the overfeeding group might be significantly reduced via HDLBP regulation (P < 0.05, 0.01 or 0.001). HDLBP can bind to mitochondria, and overfeeding significantly reduced the protein levels of wHDLBP and mHDLBP in goose liver. Overexpression of HDLBP leads to mitochondrial dysfunction, oxidative stress and increased expression of inflammatory factors. Therefore, HDLBP may provide protection for goose fatty liver by affecting mitochondrial function, regulating oxidative stress and inflammatory response.

The aim of this study was to investigate the genetic diversity of Lion-head geese and to perform the genome-wide association study of body weight and size traits. In this study, the 111 lion-head geese (20 males and 91 females) were randomly selected. They are two years old and off-season. The phenotypes detection of body weight and size traits and the second-generation genome sequencing (5×) for these geese were performed. SNPs from the sequencing data was called, the genetic diversity indexes was calculated and the association between SNPs and body weight and size traits was performed using the single SNP regression mixed model. The Bonferroni correction was used, i.e., the genome-wide threshold (0.05/a total of SNPs) and the chromosome-wide threshold (0.05/number of SNPs on each chromosome) to define the significant SNPs. The gene annotation was performed based on the 50 kb upstream and downstream of chromosome-wide significant SNPs. By the quality control, a total of 7 577 552 SNPs was obtained for the further analysis. The analysis of genetic diversity found that effective population size, minor allele frequency, polymorphic information content, observed heterozygosity, expected heterozygosity and inbreeding coefficient were 234, 0.25, 0.34, 0.26, 0.34 and 0.22, respectively. A total of 6 164 runs of homozygosity was detected, the high proportion (74.4%) of which ranged from 1.0 Mb to 2.0 Mb. We found 38 chromosome-wide significant SNPs by the association between SNPs and body weight and size traits, and these significant SNPs were involved in 90 genes. Among these genes, D2HDH, THAP4, ESPNL, EPT1, TNPO3, MCF2L and AIP1 were previously reported to affect the growth and development.In this study, by using the second generation genome sequencing data, we found a certain degree of inbreeding phenomenon for the Lion-head geese population and detected 7 candidate genes affecting the body weight and size traits, which can provide important references for the subsequent conservation of the Lion-head geese, the study of gene function and the application of molecular breeding.

The aim of this study was to construct a molecular pedigree for the Jilin sika deer conservation herd using SNP loci obtained by genome resequencing technology, and to analyse the genetic structure of the population. The 10 mL of blood from Jilin sika deer of the conservation herd (n=425) during the antler-sawing period was collected, including 132 adult bucks, 208 adult does and 85 fawns, and extracted the DNA for whole genome resequencing. The kinship relationship of Jilin sika deer was analysed by calculating the blood homology coefficient (IBD), and the genetic structure of the Jilin sika deer conservation population was analysed based on the observed heterozygosity (Ho), the expected heterozygosity (He), the polymorphic information content (PIC), the phylogenetic tree and the population differentiation index (Fst). The 25 548 601 high-quality SNPs were screened by whole genome resequencing, and 425 samples comprised a total of 90 100 pairs of kinship relationships, with an average kinship coefficient of 0.435 1. A total of 195 pairs of paternity and 143 pairs of maternity were derived, which accounted for 92% of the original genealogical records of the sampled populations, and the error rate of the original genealogical records was detected to be 2.2%, and the errors of the original records were corrected to be 8, with a high accuracy and reliability. The group differentiation index (Fst) was calculated, and the Dongfeng-type Jilin sika deer was farther away from the Yitong-type; the phylogenetic tree was drawn, and the Jilin sika deer population was divided into 17 families; the average observed heterozygosity of the SNP markers was 0.456, the average expected heterozygosity was 0.277, and the average polymorphic information content was 0.627. The average inbreeding coefficient was 0.078, and there was weak inbreeding. The present study established the molecular genealogy and analysed the population genetic structure of the Jilin sika deer conservation herd, which is crucial for the conservation of genetic diversity of the Jilin sika deer and for the planning of the subsequent selection and breeding programme of the conservation herd.

The aim of this study was to investigate the effect of vitrification on gene expression in porcine parthenogenetic activation (PA) blastocysts. In this study, porcine PA blastocysts were divided into fresh, vitrification group Ⅰ and vitrification group Ⅱ according to the experimental treatments, and then 3 well-morphologised blastocysts were selected from each group and analysed by transcriptome sequencing using Smart-seq2 single-cell full-length transcriptome sequencing technology. As a result, compared with the fresh group, a total of 772 differential expression genes (DEGs) were identified in the vitrification group Ⅰ. GO and KEGG enrichment analysis results showed that these DEGs were related to cellular lipid metabolic process, cell glucose homeostasis, MAPK signaling pathway, PI3K-Akt signaling pathway, etc. Compared with the fresh group, a total of 1 613 DEGs were identified in the vitrification group Ⅱ, which mainly related to gluconeogenesis, metabolic pathways, biosynthesis of amino acids, etc. Compared with the vitrification group Ⅰ, 822 DEGs were identified in the vitrification group Ⅱ, which mainly involved in pyruvate metabolic process, N-Glycan biosynthesis, cellular senescence, etc. In summary, this study revealed the effects of vitrification on the expression of genes related to lipid metabolism, energy metabolism, MAPK signalling pathway and other related genes in porcine PA blastocysts based on Smart-seq2 single-cell full-length transcriptome sequencing technology.

This study aimed to investigate the potential function of FKBP5 in ovine ovarian granulosa cells (GCs). GCs were isolated from the ovaries of twenty approximately 2-year-old sexually mature Altay sheep obtained from the Hualing slaughterhouse in Urumqi. The experiment was divided into 4 groups: GC (blank control), GC+NC (transfected with siRNA-NC), GC+siFKBP5 (transfected with siRNA-FKBP5), and GC+siFKBP5+LH (treated with luteinizing hormone and transfected with siRNA-FKBP5). Immunofluorescence was used to detect the localization of FKBP5 protein in GCs. Its effects on cell proliferation and apoptosis were examined using EdU, Tunel assays, and Western Blot analysis. Its impacts on the AKT and ERK signaling pathways were assessed by Western blot, while the levels of E2 and P4 were measured by ELISA. FKBP5 was found to be expressed in the cytoplasm of GCs. Its expression increased with the increasing concentration of LH, reaching a peak at 5 IU·mL^-1 LH after 4 h of treatment (P < 0.001). Knockdown of FKBP5 significantly inhibited cell proliferation, as evidenced by a reduction in PCNA protein expression (P < 0.001). It also significantly promoted cell apoptosis, with an increase in BAX expression and a decrease in Bcl-2 expression (P < 0.001). Additionally, FKBP5 knockdown markedly suppressed the activation of the AKT and ERK signaling pathways and the secretion of E2 and P4 (P < 0.001). LH treatment partially mitigated the effects of FKBP5 knockdown on GCs (P < 0.05). The results indicate that FKBP5 influences the proliferation and apoptosis of ovine GCs, as well as the activation of the AKT and ERK signaling pathways and the secretion of E2 and P4. Its function is modulated by LH. These findings provide a theoretical basis for further research on the role of FKBP5 in ovine follicular development.

This study aimed to investigate the effects of different FecB genotypes on the BMP/SMAD signaling pathway activity and protein expression in sheep follicles, and explored the differences in BMP/SMAD signaling pathway activity and protein expression between mature large follicles and small follicles. Firstly, TaqMan method was used to screen ewes with different genotypes of FecB. Secondly, after estrus synchronization, mature follicles in follicular phase and small follicles in luteal phase were sampled, and the pathway activity and the protein expression of BMP/SMAD pathway were determined by Western blot. The result showed that, for the small follicle group, the expression of bone morphogenetic protein receptor type 1B (BMPR1B) in FecB mutant follicles was significantly higher than that in wild-type follicles (P<0.05), but the expression of SMAD family member 4 (SMAD4) and the phosphorylation levels of SMAD1/5/9 were significantly lower than those in wild-type follicles (P<0.05). For the mature large follicle group, the expression of FKBP prolyl isomerase 1A (FKBP1A) and SMAD4 in FecB mutant follicles was significantly lower than that in wild-type follicles (P<0.05), and there was no significant difference in the protein expression of type Ⅰ receptor (BMPR1B) and type Ⅱ receptor (BMPR2) and the phosphorylation levels of SMAD1/5/9 between the two genotypes. On the other hand, when comparing FecB mutant small follicles with mature large follicles, the protein expression levels of BMPR1B and SMAD4 and the phosphorylation level of SMAD1/5/9 in mature large follicles were significantly higher than those in small follicles (P<0.05). The results indicated that due to the decrease in the expression of SMAD4, the FecB mutant large and small follicles have relatively fewer SMAD4-SMAD1/5/9 protein complexes bound to the genomic target regions, which means a reduction in pathway activity. Moreover, due to the lower phosphorylation level of SMAD1/5/9 in small follicles, its pathway activity was lower. Additionally, after the development and maturation of the mutant sheep follicles, the activity of the BMP/SMAD pathway was significantly enhanced.

This study aimed to estimate the genetic parameters of fertility traits in different regions, and to test the effect of genotype by environment interactions (G×E) across regions. The raw fertility data were collected from 2 064 Holstein dairy farms in 6 regions of China, including records from 2005 to 2022. A total of 1 787 590 and 2 476 422 phenotypic records were derived from the raw data for age at first calving (AFC), and calving interval (CI). Meanwhile, these phenotypes data were quality controlled and separated into different datasets for subsequent analysis. The statistical models used in this study were all incorporated in the airemlf90 module of BLUPF90. Univariate animal (and repeatability) models were used for estimating genetic parameters for these 2 traits in 6 regions, while bivariate animal (and repeatability) models were used to estimate genetic correlations between the regions, which are the indicators of G×E. The results indicated that the proposed quality control steps could filter abnormal phenotypes records. The heritabilities of AFC were relatively high and varied across regions (0.06-0.40), whereas the heritabilities of CI were low but remained similar across regions (0.02-0.04). Significant G×E effect (P<0.05) was observed across most of the regions for both traits. In conclusion, the genetic parameters of the same fertility trait varied across the regions in China, and significant G×E effect was detected for the trait in partial regions. Therefore, it is highly recommended to consider the impacts of regional difference and G×E effect on genetic advance when breeding for fertility traits of dairy cattle in China.

The aim was to investigate the effect and mechanisms of melatonin on the mitochondrial dynamics of bovine endometrial epithelial cells (BEECs) induced by palmitic acid (PA). BEECs were used as the research subjects and divided into 3 groups: control group, PA group, and melatonin group. The control group was supplemented with 0.2 mmol·L^-1 BSA as the solvent, the PA group was supplemented with 0.2 mmol·L^-1 PA, and the melatonin group was supplemented with both 0.2 mmol·L^-1 PA and 100 nmol·L^-1 melatonin. The experiments included: assessing cell viability and apoptosis using the CCK8 method (n=4) and Annexin V-FITC/PI double staining method (n=3); detecting the ROS levels in mitochondria using flow cytometry(n=3); further analyzing mitochondrial respiration-related indicators such as oxygen consumption rate, basal respiration, ATP production capacity using Seahorse XFe96 cellular metabolism analysis system (n=4); measuring the mRNA expression changes of mitochondrial dynamics-related genes MFN1, DRP1 and PGC1-α were detected by qRT-PCR (n=3); finally, the protein expression changes of mitochondrial dynamics-related proteins MFN1, p-DRP1, DRP1 and PGC1-α were detected by Western-Blot (n=3). The results showed that: compared with the PA group, 1) the melatonin significantly reduced the mitochondrial ROS level of BEECs, increased cell viability, and decreased apoptosis rate significantly (P<0.05); 2) Seahorse results indicated that melatonin significantly increased mitochondrial basal respiration, ATP production, and maximum oxygen consumption (P<0.05), suggesting that melatonin could improve mitochondrial function, promote aerobic respiration, and increase ATP production; 3) qRT-PCR results showed that the melatonin significantly reduced the mRNA expression of MFN1 and DRP1, while significantly increasing the mRNA expression of PGC1-α(P<0.05); 4) Western-Blot analysis revealed a significant decrease in MFN1 protein expression and a significant increase in p-DRP1/DRP1 and PGC1-α protein expression in the melatonin group (P<0.05). In conclusion, the study suggests that melatonin may alleviate PA-induced mitochondrial oxidative stress and improve mitochondrial respiration by improving mitochondrial dynamics of BEECs, which ultimately enhances the viability of BEECs and reduces apoptosis. This study preliminarily explored the mechanism by which melatonin mitigates PA-induced injury in BEECs, offering a theoretical foundation for improving the low reproductive capacity of severe NEB cows.

The objective of this study was to investigate the accuracy and additivity of digestible energy (DE), metabolizable energy (ME) and net energy (NE) predicted from simulated digestion method in feed for growing pig, which will provide a reference for quickly determining effective energy in feed. A single factorial completely randomized design was adopted for the determination of enzymatic hydrolysate gross energy (EHGE) of 12 energy feed ingredients, 9 protein feed ingredients and 17 diets formulated by the above 21 feed ingredients.Each treatment contained 5 replicates with 1 digestive tube per replicate. The DE, ME and NE were predicted by EHGE combined with crude protein (CP) and acid detergent fiber (ADF). The difference and correlation between the predicted effective energy (DE, ME and NE) values and the in vivo values estimated by gross energy (GE) multiplied by energy utilization coefficients in the GB/T 939235—2020 of 17 feed ingredients with the same name as this study were calculated to verify the accuracy of effective energy predicted from simulated digestion method. The difference between the weighted values of effective energy calculated by individual value of feed ingredients and the values predicted by the mathematical model of effective energy from EHGE in the diets were compared to validate the additivity of effective energy predicted from simulated digestion method. The results showed that the coefficients of determination (R²) of the linear regression model of in vivo DE, ME and NE calculated from GB/T 939235—2020 against effective energy predicted from EHGE combined with CP and ADF of 17 feed ingredients were 0.774, 0.778 and 0.870, respectively. Regression diagnostic analysis indicated that rice bran, wheat bran and corn germ meal deviated from other 14 feed ingredients in the linear relationship between the in vivo and predicted values (DFFITS>$ 2 \sqrt{\frac{p}{n}} $). Excluding the above 3 samples, the R² of the linear regression of in vivo effective energy calculated from GB/T 939235—2020 on predicted values were greater than 0.93. The linear regression of determined EHGE on weighted calculation values and the predicted DE, ME and NE on weighted calculation values were consistent to the line of Y=X (R²>0.95, P < 0.01). These results indicate that the simulated digestion method can accurately predict the effective energy of 14 feed ingredients, but underestimate the effective energy of rice bran and wheat bran, whereas overestimate the DE and ME of corn germ meal. The EHGE determined by simulated digestion method and the DE, ME, NE which predicted from EHGE all have good additivity.

The aim of this study is to investigate the effects of three rearing systems on the growth performance, immune function, intestinal morphology, and cecal microbiota of Lueyang black-bone chickens. In this study, ninety 70-day-old healthy Lueyang black-bone chickens from the same batch of chicken flocks were randomly divided into 3 groups: cage rearing (CR), net-flat rearing (NF), and free-range rearing (FR) groups, each group had 5 replicates with 6 chickens per replicate (half of male and female). A one-week pre-experiment was conducted, and all experimental chickens were fed the same basic diet and had free access to feed and water. The body weight was collected every 7 days, the experimental chickens were raised to 119 days old, total feed consumption was recorded to calculate the average daily feed intake (ADFI), average daily gain (ADG) and feed to gain raito (F/G). Samples including serum, small intestine and intestinal mucosa (duodenum, jejunum, and ileum), and cecal contents were collected. The results showed that the average body weight of male and female chickens in NF and CR groups was significantly higher than FR groups (P < 0.01), the body weight of CR hens in the later stage of the experiment (105 to 119 day-old) was significantly higher than NF and FR groups (P < 0.01). The average daily feed intake (ADFI) and average daily gain (ADG) of NF and CR chickens were higher than FR chickens (P < 0.001, P=0.005), and the ratio of feed to gain (F/G) of FR chickens is significantly higher than CR and NF groups (P=0.002). The results of immune performance testing using ELISA kits showed that there was no significant difference in immunoglobulin A (IgA), immunoglobulin M (IgM), immunoglobulin G (IgG) and secretory immunoglobulin A (sIgA) among the roosters under the three rearing systems (P>0.05), while serum IgA of NF hens was significantly higher than CR and FR hens (P < 0.05). The results of intestinal morphology showed that the villus height of duodenum, jejunum, and ileum, as well as the ratio of villus height to crypt depth, were significantly higher in the NF and CR groups than FR group (P < 0.05). The 16S sequencing results of cecal contents indicated that the FR group increased the relative abundance of Proteobacteria, Epsilonbacteraeota, and Spirochaetes and decreased Bacteroidetes and Firmicutes at the phylum level. The NF group increased the relative abundance of Actinobacteria, Verrucomicrobia, and Chloroflexi. The CR group increased the relative abundance of Bacteroidetes and Firmicutes. At the genus level, the relative abundance of Escherichia-Shigella, Helicobacter, Enterococcus and Campylobacter increased, while Faecalibacterium, Bacteroides, and Akkermansia decreased in the FR group. The CR group increased the relative abundance of Bacteroides and Rikenellaceae_RC9_gut_group. In summary, the growth performance and intestine of Lueyang black-bone chickens were better under cage rearing and net-flat rearing, and net-flat rearing can improve immune performance. Therefore, net-flat rearing is a more proper rearing system for Lueyang black-bone chickens.

This study aimed to purify the cathay topotype of foot-and-mouth disease virus (FMDV) type O and prepare monoclonal antibody to provide biological materials for the study of novel cathay strain of foot-and-mouth disease. The antigen of cathay strain of FMDV type O was purified by PEG precipitation method and immunized BALB/c mice. Hybridoma cells were prepared by fusion of spleen cells and SP2/0 cells. Positive cells were screened by indirect ELISA and subcloned by limited dilution method. Two hybridoma cells, named 10E6 and 11C7, which were able to secrete monoclonal antibodies specifically against O-type FMDV Cathay strain were obtained. Additivity assay showed that the additivity rate of the two mAbs was 49.45%, and different epitopes were identified.Indirect ELISA and IFA showed that the two strains had good reactivity with O-type FMDV Cathay strain. The results of monoclonal antibody detection showed that the two monoclonal antibodies could specifically recognize Cathay FMDV strains and did not cross-react with other FMDV strains. The results of antibody subtype identification showed that the light chain of 10E6 monoclonal antibody was Kappa chain, the light chain of 11C7 monoclonal antibody was Lamda chain, and the heavy chain type of both strains was IgG2a. The results showed that two monoclonal antibodies specifically binding to O-type FMDV Cathay topological strain were successfully prepared in this study. Both monoclonal antibodies had good reactivity and specificity. Two monoclonal antibodies were used to establish a double antibody sandwich ELISA method for detecting O-type FMDV Cathay strain. The ELISA method had good specificity, repeatability and sensitivity, which laid a foundation for the rapid diagnosis, control and research of O-type foot and mouth disease virus Cathay strain.

This study was designed to establish an antibody detection method for porcine rotavirus (PoRV). We utilized the truncated VP6* (aa149-332) protein of PoRV as the detection antigen to develop an indirect ELISA detection method for PoRV antibodies. The truncated recombinant VP6* (aa149-332) exists in two forms: inclusion bodies and soluble, with a size of 22.5 ku. The optimized reaction conditions of the ELISA were as follows: the optimal coating antigen concentration, coating time and temperature were found to be 25 ng per well, and left overnight at 4 ℃; the plates were blocked with 5% skimmed milk at 37 ℃ for 2 hours; the optimal dilution of test serum and the secondary antibody were found to be 1 ∶400 and 1 ∶24 000, respectively. The optimal incubation time and temperature for test serum and the secondary antibody were 30 minutes and 37 ℃, respectively, and the color development time was 15 minutes. Testing 30 negative sera determined the cutoff value at OD_{450 nm}=0.418, the maximum dilution of detectable antibodies is 1 ∶3 200. The intra-batch and inter-batch coefficient of variation were both less than 10%, and it exhibited good specificity. The agreement rate with Western Blot results for 28 sera was 96.42%. The correlation coefficient (R²) between ELISA OD_{450 nm} values and neutralizing antibody log2 values was 0.878 5. In summary, the indirect ELISA established in this study for detecting porcine rotavirus antibodies has high specificity and sensitivity, making it applicable for clinical sample testing of porcine rotavirus.

In order to understand the genetic variation characteristics of the newly emerged H3N3 subtype avian influenza virus (AIV), we conducted whole-genome sequence analysis of H3 subtype AIV isolated during 2022-2023, and analyzed antigenic differences among representative strains. A total of 15 strains of H3N3 subtype AIV from poultry origin and 1 strain from wildfowl origin were isolated and identified. Phylogenetic analysis of the whole genome revealed that all 16 isolates belonged to the Eurasian lineage, with the HA gene derived from H3N8 subtype AIV, sharing a nucleotide homology of 97.3% to 99.2% when compared to human H3N8 subtype AIV isolates. The NA gene was derived from H10N3 subtype AIV, with a nucleotide homology of 98.1% to 98.4% when compared to human H10N3 subtype AIV isolates. The internal gene segments were all derived from H9N2 subtype AIVs. The cleavage sites of the HA gene of the isolates are consistent with the molecular characteristics of low pathogenic AIV. The isolated strains have multiple mutation sites that can enhance the adaptability and pathogenicity of the virus in mammals, such as the A588V and E627V mutations in the PB2 protein, the I368V and S375N mutations in the PB1 protein. Antigenic difference analysis showed that the isolates had HI antibody titers 1 log2-3 log2 different from those of earlier circulating strains in East China. Therefore, all 16 strains of H3N3 AIVs in this study are triple-recombinant viruses, with H9N2 AIV serving as the donor for all internal genes, and they harbor multiple amino acid mutations that enhance their adaptability and pathogenicity in mammals. These strains have already spread to wildfowl. This study reveals the genetic characteristics, variation and multi host distribution of the novel H3N3 AIVs, providing theoretical support for the prevention and control of avian influenza.

To investigate the effect of Rab32 on the replication of avian metapneumovirus type C (aMPV/C), confocal images were obtained and co-localization coefficients were analyzed by Image J software after infected with A549 cells by aMPV/C. Furthermore, the plasmids of pCMV-Flag-Rab32 or pCMV-Flag as well as siRab32 or siNC RNA sequences were transfected into A549 cells before aMPV/C infection, respectively. The transcription level of aMPV/C N gene, the expression level of aMPV/C N and Rab32 proteins, and the viral titers in collected samples were detected by quantitative real-time PCR (qPCR), Western blot, and the half tissue culture infective dose (TCID₅₀) method, respectively. Then, the plasmids of pCMV-mcherry-Rab32 and GFP-tagged aMPV/C proteins were co-transfected into A549 cells before conducting confocal imaging, respectively. Subsequently, the plasmids of pCMV-Flag-Rab32 and GFP-tagged aMPV/C proteins were co-transfected into HEK293T cells before collecting cell samples at 36 h post-transfection and conducting the co-immunoprecipitation assay. The results showed that obvious co-localized fluorescent signals of Rab32 and aMPV/C were observed in the cytoplasm. The co-localization coefficients of Rab32 and N proteins were significantly higher than that of mock-infected group. The transcription level of the N gene, the expression level of Rab32 and N proteins, and the viral titers were significantly increased (P<0.01) after overexpression of Rab32, respectively. On the contrary, the transcription level of the N gene, the expression level of Rab32 and N proteins, and the viral titers were significantly decreased (P<0.01) after knockdown expression of Rab32, respectively. Obvious co-localized fluorescent signals of Rab32 and aMPV/C proteins (N, F, M, G, SH, P, M2-1, M2-2, L1, L2, and L4) were observed in the cytoplasm, while scarcely co-localized signals of Rab32 and L3 protein were found. Specific bands of N and M2-2 proteins were found in immunoprecipitation samples while no bands of other GFP-tagged aMPV/C proteins were found. These results indicating that Rab32 interacts with aMPV/C N and M2-2 proteins. In summary, Rab32 might affect aMPV/C replication by interacting with multiple viral proteins (N and M2-2). The relevant results can provide the basis for elucidating the mechanism of Rab32 regulating aMPV/C replication via protein interaction.

A strain of pigeon paramyxovirus-1(PPMV-1) was isolated from the dead pigeon tissue in Tianjin region. To provide scientific basis for the development of PPMV-1 vaccines, the genetic evolution, biological characteristics, and pathogenicity of the virus were analyzed. The pathogens were identified by RT-PCR, virus isolation, purification by chicken embryos, genetic evolution analysis, pathogenicity analysis, and animal regression tests. A strain of PPMV-1 was isolated from the dead pigeons and named Pigeon/TJ/CH/020/2020 (TJ20). Sequence analysis and homology analysis of the virus F gene showed that the strain belonged to sub-genotype Ⅵ.2.1.1.2.2(Ⅵk), and the amino acid residues of the cleavage site were ¹¹²R-R-Q-K-R-F¹¹⁷, which were consistent with the molecular characteristics of NDV virulent strains. Hemagglutination inhibition revealed a noticeable difference between TJ20 and LaSota. The values of TCID₅₀, EID₅₀, MDT and ICPI were 10^-8.64·0.1 mL^-1, 10^-8.38·0.1 mL^-1, 62 h, 1.19. The animal infection experiment found that pigeons showed clinical symptoms on 4 dpc (day 4 post-challenge). The incidence rate and mortality were 100%, and the cloacal detoxification rate could reach 100% on 5 dpc. TJ20 was highly pathogenic to pigeons. This study successfully isolated a highly pathogenic sub-genotype Ⅵ.2.1.1.2.2(Ⅵk) TJ20 strain from samples of dead pigeons, providing important biological materials for the research and development of vaccine of PPMV-1 in the future.

Bacteriophages can specifically lyse target bacteria and are usually considered as effective alternatives to antibiotics. In order to screen for bacteriophages that are efficient to lyse Salmonella, and provide experimental data and reference for exploring the prevention and control method of Salmonella. In this study, Salmonella phage was induced and purified by mitomycin C. Phage was evaluated by plaque and electron microscopy observation, host spectrum determination, biological characterization and whole genome sequencing analysis. A broad-spectrum Salmonella long-tail phage was successfully induced, named SP18-108, which could lyse at least 14 different serotypes of Salmonella. The activity is stable at 30-40℃ and pH 4-12.The whole genome analysis showed that the length of the phage was 43 250 bp, and the GC content was 49.96%, the proportion of known coding sequences (CDS) was 52%. Phylogenetic tree analysis showed that phage SP18-108 belonged to the (Siphoviridae). In summary, in this study, we isolated a broad-spectrum Salmonella bacteriophage without lysogenic genes, which providing a good material for further research on Salmonella antibacterial agents.

This study aimed to establish a rapid method for the detection of Listeria monocytogenes. Listeria monocytogenes (LM) internalin G (InlG) gene was amplified by PCR, pET-32a-InlG recombinant expression vector was constructed, and recombinant protein of InlG was obtained by induced expression, which was purified and immunized to mice (100 μg per mouse). Three positive hybridoma cell lines were obtained by cell fusion, cloning, and screening, and were designated as 1D2, 1D2-1 and 2H10. The subtypes of the antibodies were identified as IgG₁. Using the prepared 1D2-1 as the capture antibody and the Listeria monocytogenes rabbit-derived polyclonal antibody as the detection antibody, a preliminary double-antibody sandwich ELISA method for detecting Listeria monocytogenes was established. WESTERN BLOT results showed that all three monoclonal antibodies (mAb) reacted specifically with InlG. The results of the specificity test of the method showed that there was not reaction to Salmonella, Escherichia coli, Bacillus subtilis, Staphylococcus albicans and Staphylococcus citreus. The results of the sensitivity test showed that the limit of the method for the detection of LM pure cultures was 1.0×10⁶ CFU·mL^-1. The results of the reproducibility test showed that the coefficients of variation for each group ranged from 5%-10% (< 10%). In conclusion, this study established a double antibody sandwich ELISA method using anti-internalin G protein mAb and rabbit polyclonal antibody. The method showed good specificity, sensitivity and repeatability, and can be used for rapid diagnosis and detection of Listeria monocytogenes infection.

The aim was to evaluate the immune protective effect of a trivalent inactivated vaccine prepared from virulent strains of clinically isolated Streptococcus suis serotype 2, 3 and 9 on mice. One virulent strain each of S. suis serotype 2, 3 and 9 were screened from clinical isolates using Galleria mellonella and mice infection models(SS1803, SS1803024, SS1696), and the growth curves and virulence genes were tested. The strains were separately inactivated and mixed inactivated and mixed with adjuvants. 4×10⁷ CFU, 8×10⁷ CFU SS1803, 2×10⁸ CFU, 5×10⁸ CFU SS1803024, 1×10⁸ CFU, 5×10⁸ CFU SS1696, and trivalent inactivated vaccine (2×10⁷ CFU SS1803+1.5×10⁸ CFU SS1803024+3×10⁷ CFU SS1696) were used to immune the BALB/c mice in two rounds, serum was collected to detect the levels of specific antibodies and the immune protection rates of the mice were observed after challenge with lethal doses of the three strains respectively. Then, a sub-lethal dose were used to challenge the trivalent immunized group, the bacterial loads in blood, brain, lung and spleen and the levels of cytokines IL-6 and IL-12 of mice were measured, and the histopathological changes in brain, lung, spleen and kidney were also observed. The virulence genes of the three vaccine candidate strains were identified as: SS1803: gapdh⁺/sly⁺/fbps⁺/orf2⁺/mrp^-/89K^-/gdh⁺/epf⁺, SS1803024: gapdh⁺/sly⁺/fbps⁺/orf2⁺/mrp^-/89K^-/gdh⁺/epf^-, SS1696: gapdh⁺/sly^-/fbps⁺/orf2⁺/mrp^-/89K^-/gdh⁺/epf^-. Both monovalent and trivalent vaccine immune groups induced IgG antibodies corresponding to the immunized serotypes, with the production of IgG1 antibodies predominating. The trivalent group provided 83.3%, 66.7% and 66.7% protection against serotype 2, 3 and 9 strains, respectively. It also effectively reduced the bacterial loads in the tissues, and reduced the levels of serum inflammatory factors and the degree of tissue lesions of mice after infection. In this study, highly virulent strains of serotype 2, 3 and 9 with high clinical prevalence were screened. Trivalent inactivated vaccine were prepared, which provided good immune protection in mice challenge model. These studies provided new materials for the development of multivalent vaccine of Streptococcus suis.

In this study, the effect of a patent-protected strain, Lactobacillus salivarius XP132, on the gut microbiota of healthy white feathered broiler breeders was evaluated using 16S rDNA sequencing. Twelve 6-month-old white-feathered broilor breeders were selected and randomly divided into control growp and experimeat group, with 6 broilers in each group. Lactobacillus salivarius XP132 fermentation broth with 1×10⁹ CFU was fed to broiler breeders in experiment group per day for 4 weeks, while broiler breeders in the control group were fed with PBS. Gut microbiota were determined by 16S rDNA sequencing. The results showed that after feeding Lactobacillus salivarius XP132 the species richness was higher in the experimental group than that in the control group using α diversity analysis. At the genus level of microbial composition, there was an increase in the abundance of beneficial species such as Laehnospiraceae NK4A136 spp., Clostridium spp., Paramycetes spp., and Rhodococcus spp. in the gut microbiota of the experimental group compared to the control group. While at the species level, there was a significant increase in the abundance of beneficial species such as Lactobacillus spp., Anaplasmatales spp., and Lactobacillus rhamnosus spp. in the gut microbiota of the experimental group. The results showed that feeding Lactobacillus salivarius XP132 changed the richness of intestinal microbiota and increased the species abundance of beneficial bacteria in white-feathered broilers.

To elucidate the impact of interferon regulatory factors (IRFs) on the proliferation of porcine pseudorabies virus (PRV), this study utilized shRNA technology to establish a PK15 cell line with the targeted knockdown of IRF1-9 genes. The knockdown efficiency was verified, and the proliferation of PRV subsequent to the knockdown was assessed using flow cytometry and titration assays. Additionally, the mRNA expression levels of PRV-gB, IFN-β, ISG-15, and IL-6 in PRV-infected cells were quantified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The expression of the gB protein in PRV-infected cells was analyzed by Western blotting. The knockdown efficiency assay demonstrated a significant reduction in the expression of IRF1-9 mRNA in PK15 cells. The results from flow cytometry and titration assays indicated that the knockdown of IRF1-9 genes facilitated the proliferation of PRV. Furthermore, RT-qPCR and Western blot results revealed a significant increase in the mRNA and protein expression levels of PRV-gB following the knockdown of IRF1-9 genes. The analysis of mRNA expression levels of cellular inflammatory factors showed that the knockdown of IRF1-9 inhibited the PRV-induced expression of IFN-β, ISG-15, and IL-6 at the mRNA level. In conclusion, these findings suggest that IRF1-9 serves as a host restriction factor, limiting the replication of PRV within PK-15 cells.

The aim of this study is to use lentiviral packaging knockdown technology to construct lentiviral plasmids for knocking down tumor susceptibility gene 101 (TSG101) and stably transfect PK15 cell lines, and to verify the impact of this knockdown cell line on PRV infection. A recombinant lentivirus was successfully constructed and screened for the TSG101 gene, and PK15 cells were infected with the obtained recombinant lentivirus. Puromycin was used for screening to obtain PK15 cell lines that knocked down the TSG101 gene. Perform editing efficiency testing on the constructed cell line using Real time PCR and Western blot methods; Use CCK-8 method to detect cell viability and growth status of the selected cell lines; Verify the effect of this cell line on PRV replication through flow cytometry, Real time PCR, Western blot, and progeny virus titer methods; Finally, experiments were conducted on the adsorption, entry, and replication stages of PRV to explore the impact of knocking down the TSG101 gene on PRV infection. The results showed that: 1) the expression of TSG101 was significantly reduced in the cell line constructed in this study, and the cell line was named sh-TSG101 cell line; 2) The results of cell viability testing showed that knocking down the TSG101 gene had no significant effect on cell viability and growth; 3) Using PRV-GFP and PRV-QXX to infect sh-TSG101, in vitro experiments have shown that knocking down TSG101 has a significant inhibitory effect on PRV proliferation. 4) The adsorption, entry, and replication experiments of the virus have shown that knocking down TSG101 has a significant inhibitory effect on the replication stage of PRV. In summary, this study successfully constructed PK15 cell lines with TSG101 gene knockdown. Knocking down TSG101 in vitro can significantly inhibit PRV proliferation, providing new ideas for the prevention and control of DNA viral diseases such as PRV, and laying a foundation for further exploring the molecular mechanism of TSG101 regulating PRV infection.

The purpose of this study was to investigate the clinico-histopathological traits (age, sex, breed, sterilization, number of necrotic lesions, number of hemorrhagic lesions) of canine mammary tumors in Wuhan area and to analyze their correlation with benign and malignant tumors. Two hundred and eight cases cases of canine mammary tumors were clinically collected and clinical information such as breed, gender, age, and sterilization status were collected. Pathological methods were used for histological diagnosis, and the number of necrotic and hemorrhagic lesions was counted. Correlation analysis was performed using SPSS 27.0. The results showed that 208 cases of mammary tumor in dogs in Wuhan area were all females, with an onset age ranging from 1 to 15 years old, with an average onset age of 9.7 years old. The most susceptible breeds were Poodle and hybrid dogs, and unsterilized dogs were more susceptible to the disease. The pathological diagnosis results show that the benign to malignant ratio of mammary tumors is close to 1∶1. The high incidence types of benign tumors are mixed tumors and complex tumors, while the high incidence types of malignant tumors are ductal cancer and mixed tumors. Bleeding and necrosis are more common in malignant tumors. After correlation analysis, it was found that the age of the affected dog was correlated with the type of malignant tumor (P=0.016), the number of bleeding lesions (P < 0.01), and the number of necrotic lesions (P < 0.01). The number of bleeding lesions was correlated with the number of necrotic lesions (P < 0.01). Age, number of necrotic lesions, and multifocal bleeding can be independent influencing factors for the malignancy of canine mammary tumors. Older dogs are prone to necrosis and bleeding when developing mammary tumors. Age, number of necrotic lesions, and multifocal bleeding can serve as clinico-histopathological traits for diagnosing malignant tumors, providing a certain reference for clinical diagnosis.

The aim of this study was to prepare altrenogest (ALT) solid dispersion, improve the solubility and bioavailability of altrenogest, and provide a reference for its application in actual production. ALT solid dispersion was prepared by freeze-drying method with polyvinyl pyrrolidone k30 (PVPK30) as the drug carrier and tert-butanol as the lyophilized solvent. X-ray diffraction (XRD), simultaneous thermal analysis (TG-DSC), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and other methods were used to characterize the properties. The results showed that the optimal preparation process of tetraene estrone solid dispersion was as follows: drug loading ratio of 1∶8, tert-butanol concentration of 50%, and ultrasonic time of 60 min. The equilibrium solubility of the solid dispersion in pH 5.0 buffer was 5.91 times that of the active pharmaceutical ingredient (API), 3.65 times that of the 1∶8 mixture, the cumulative dissolution rate of the solid dispersion in vitro for 6 h was 89.09%, and the cumulative dissolution rates of the ALT active ingredient and the physical mixture were 32.94% and 28.93%. In summary, the solid dispersion prepared by this method can effectively improve the solubility of altrenogest API.

This study aimed to further explore the effect of taraxasterol on liver tissue oxidative stress cauesed by aflatoxin B₁ (AFB₁) in broiler chickens. One hundred and twenty broilers were randomly divided into six groups: normal group, model group, taraxasterol low-, medium- and high-dose groups (25, 50, 100 mg·kg^-1 BW) and positive group (300 mg·kg^-1 silibinin). Except the normal group, which was fed a basal diet, the other groups were fed a diet containing 0.5 mg·kg^-1 AFB₁ for 21 consecutive days to establish a liver injury model, the corresponding concentrations of medication were administered daily in drinking water during this period to each group. The body weight of broilers in each group were recorded and the feed-to-gain ratios were calculated; Liver function indexes asaspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), total bilirubin (TBIL), alkaline phosphatase (ALP) in broilers were determined by kits. The contents of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) in broiler liver tissues were determined by kits. The expression of nuclear factor erythroid2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1) and heme oxygenase-1 (Heme Oxygenase-1), NAD(P) H: Quinone oxidoreductase-1 (NQO1) mRNA and protein in brolier liver were determined by RT-qPCR and Western blot. The results showed that the body weight was increased (P < 0.05) and the feed-to-weight ratio was decreased (P < 0.05) in broilers with AFB₁-induced liver injury at 14 and 21 days in the high dose group of taraxasterol. After 21 days, it was shown by the results that the activities of ALT (P < 0.05), AST (P < 0.01), GGT (P < 0.01), TBIL (P < 0.01), and ALP (P < 0.01), which are indicators of hepatic function, were reduced in the serum of broilers with AFB1-induced liver injury in the high dose group of taraxasterol. ROS and MDA content were inhibited (P < 0.01), while SOD (P < 0.01), CAT (P < 0.05) and GSH (P < 0.05) activities were increased in the liver of broilers with AFB1-induced liver injury in the high dose group of taraxasterol. The mRNA and protein expression levels of Nrf2 (P < 0.05), NQO1 (P < 0.01) and HO-1 (P < 0.05) were up-regulated. The mRNA (P < 0.05) and protein expression levels of Keap1 were down-regulated in the livers of broilers with AFB₁-induced liver injury in the high dose group of taraxasterol. In conclusion, taraxasterol can inhibit the overproduction of ROS and MDA and increase the content of antioxidants SOD, CAT, and GSH in broiler liver by regulating the Nrf2/Keap1 signaling pathway, enhance the hepatic antioxidant function, and significantly improve the liver function and growth performance, which can have a significant inhibitory effect on the oxidative damage caused by the induction of AFB₁.

The anti-inflammatory effect of essential oils from Citrus reticulata Blanco was investigated based on lipopolysaccharide (LPS)-induced RAW264.7 cell model. The level of Nitric oxide (NO) secretion was detected by Griess method, and the mRNA expression levels of tumor necrosis factor (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) were determined by real-time PCR method. The results showed that essential oils from Citrus reticulata Blanco significantly decreased the level of NO released from LPS-induced RAW264.7 cells and inhibited the expression of iNOS, COX-2, IL-1β, IL-6 and TNF-α mRNA. In conclusion, essential oils from Citrus reticulata Blanco can inhibit the secretion and expression of inflammatory factors, and thus alleviate the inflammatory response induced by LPS in RAW264.7 cells effectively.

This experiment mainly aimed at isolating and identifying lactic acid bacteria from the gut of healthy Hyline brown laying hens, and detected the effect of the isolated lactic acid bacteria on intestinal health of laying hens in early brood period. Bacterial culture, 16S rRNA and Oxford Cup diffusion methods were used to isolate, screen and identify Lactobacillus strains that could producing bacteriocins. The tolerance to high temperature, pH and bile salt was assessed. Two hundred and forty healthy one-day-old Hyline brown laying hens with similar body weight were randomly divided into four groups: control group (C), low dose Lactobacillus salivarius CL09 group (L), medium dose Lactobacillus salivarius CL09 group (M) and high dose Lactobacillus salivarius CL09 group (H). The effects of this strain on growth performance, immune organ index and intestinal health were analyzed. The experiment lasted for 21 days. The results showed that the isolated strain was a bacteriocin-producing Gram-positive bacteria, identified as Lactobacillus salivarius CL09 based on 16S rRNA identification. The cell-free supernatant of Lactobacillus salivarius CL09 demonstrated inhibitory effects on the growth of Escherichia coli, Salmonella, Staphylococcus aureus and Listeria. The resistant temperature of Lactobacillus salivarius CL09 was 60 ℃, and possessed the characteristics of acid and bile salt tolerance. The results of animal testing showed the Lactobacillus salivary CL09 supplementation could improved body weight and immune organ weight, with noticeable decreases in crypt depth of duodenum and jejunum observed in the H group, and significant increase in villus height of duodenum observed in L and M groups. The intestinal villi in the group H showed a wavy trend. Additionally, the mRNA levels of intestinal stem cell marker genes Lgr5 and Bmi1 were significantly increased in the M and H group(P < 0.001), while the mRNA level of mucosal barrier genes Zo-1 and Ocln was significantly increased in the H group(P < 0.01). Lactobacillus salivarius CL09 supplementation also led to the increasing of mRNA levels of Pan's cell marker gene Lyz and goblet cell marker gene Muc (P < 0.01). In summary, Lactobacillus salivary CL09 isolated from the gut of healthy Hyline brown laying hens, has the potential to enhance villi length and crypt depth by promoting differentiation of intestinal stem cells into Paneth and goblet cells, thereby increasing the mucosal surface area in the intestine. Lactobacillus salivary CL09 exhibits favorable characteristics for regulating the intestinal health of chicks in the early brood period, and could be considered as a candidate probiotic strain.

The purpose of this study is to investigate the changes in mitochondrial function and energy metabolism in the liver during the entire process of insulin resistance by establishing a mouse model. A total of 60 male C57BL6 mice were randomly selected and divided into three groups: a control group (Con group) fed with normal maintenance feed; a high-fat diet group (HFD group) fed with high-fat feed. The model was established by randomly selecting six mice from each group at weeks 4, 6, 8, 10, and 12 of feeding. The successful establishment of the whole-process model of insulin resistance was confirmed by insulin resistance assessment and histopathological examination. At the 8th and 12th weeks of the experiment, blood was collected from the tail of the mice for IGTT and ITTs. At weeks 4, 6, 8, 10, and 12 of the experiment, serum and liver tissue samples were collected from the mice for testing: 1) fasting blood glucose and serum content were measured; 2) The contents of Srebp-1c enzyme, PFK1, and COX-I in liver tissues were detected by ELISA. 3) Biochemical detection of ALT and AST levels in serum; 4) Western blot was used to detect expression level of PI3K, Akt, P-Akt, GLUT4, GSK-3β, P-GSK-3 β, FOXO1, P-FOXO1, SIRT1, AMPK, P-AMPK, and PGC-1 α protein in liver tissue; 5) Transmission electron microscopy, HE staining, oil red O staining, and PAS staining were used to detect changes in the pathological organization and structure of the liver. The results showed that: 1) 12 weeks of high-fat diet caused obesity and increased HOMA-IR in mice, and oil red O staining showed significant fat deposition, successfully inducing a model of insulin resistance in the entire mouse. During insulin resistance, the levels of ALT and AST in mice increased, and HE results showed significant lipid droplet vacuoles and structural disorder of liver cells. 3) After the fourth week of feeding a high-fat diet, the upstream signaling of insulin in the liver began to be affected; Compared with the Con-6 group, the expression of GLUT4 protein and the ratio of P-FOXO1/FOXO1 as well as the content of PFK1 in the liver of HFD-6 group mice significantly decreased (P < 0.01); Compared with the Con-4 group, the GSK-3β expression in the liver of the HFD-4 group mice Phosphorylation and Srebp-1c enzyme levels gradually decreased (P < 0.05); The PAS results showed that from the 8th week, the glycogen content in the liver cells of HFD mice decreased; Compared with the Con-4 group, the AMPK, P-AMPK, and SIRT1 contents in the liver of the HFD-4 group significantly decreased (P < 0.01 and P < 0.001); 6) In the HFD group, the expression of Mfn2 in the liver increased at week 10, while the expression of Drp1 protein showed a trend of decrease first and then increase. Compared with the HFD-6 group, the PINK1 and Parkin proteins in the liver of the HFD-6 group mice decreased significantly (P < 0.05). In summary, the liver, as the main organ of metabolism, undergoes selective insulin resistance after feeding 60% high-fat feed. After resistance, overall energy catabolism decreases, mitochondrial damage increases, and autophagy, which clears damaged mitochondria, weakens. In addition, there is a brief increase in mitochondrial biogenesis and fusion at weeks 8 and 10, indicating a temporary compensatory effect due to energy deficiency in the liver. This study explains the characteristics and regularities of energy metabolism in hepatic insulin resistance from the perspective of the entire process, providing a reference for further studying the mechanism of excess nutrients affecting cellular energy metabolism.

The aim of this study is to explore the mechanism of Limosilactobacillus reuteri (LR) improving intestinal ischemia-reperfusion injury (IR) using ROS/NLRP3 inflammasome as a starting point. The IR cell model was constructed using hypoxia/reoxygenation methods, and the rat IR model was constructed using microarterial clamping/perfusion methods. The cell experiment was divided into four groups: control group, IR group, LR pre-treatment group (LR+IR group), and LR group. The animal experiment was divided into three groups (10 rats in each group): sham surgery group (S group), IR group, and LR gavage treatment group (LR+IR group). The level of ROS, the expression of NLRP3 inflammasome related proteins (NLRP3, ASC, Caspase p10, and GSDMD), the levels of inflammation-related indicators, and the content of oxidative stress related indicators in each group were detected. Histopathological evaluation was also performed. The results showed that: 1) LR attenuates IR induced oxidative stress and NLRP3 inflammasome activation. 2) LR alleviates NLRP3 inflammasome activation by attenuating ROS expression. 3) LR could alleviate intestinal injury and the expression of inflammatory factors induced by IR. In summary, LR can alleviate intestinal IR and oxidative stress in rats, and its mechanism of action is related to the inhibition of ROS dependent NLRP3 inflammasome, providing experimental basis for the veterinary clinical treatment of LR in intestinal related diseases.

In currently study, LC1 and CX1 of Riemerella anatipestifer type 11 were isolated and purified from the brain and liver tissue of 10-day-old ducks, The aim of this study was to isolate, purify, identify and analyze the pathogenicity of the strains from the disease material of Muscovy ducks which suspected to be infected with infectious serositis from a farm in Putian, Fujian Province, China. Brain and liver tissues of 10-day-old diseased Muscovy ducks were collected for strain isolation and purification, and 16S rDNA PCR identification and serotyping were conducted, respectively. The isolates were subjected to 16S rDNA sequencing and genetic evolutionary analyses, and their drug resistance and pathogenicity to ducklings were determined. The 16S rDNA sequence sequencing and genetic evolution of these isolates were analyzed, and their drug resistance and pathogenicity to ducklings were further determined. (Results) The results showed that 2 strains of Riemerella anatipestifer type 11 were obtained and named as LC1 and CX1. The 16S rDNA sequences of LC1 and CX1 showed that the isolates were in the same evolutionary branch as the reference strains of Riemerella anatipestifer Fujian strain RAf115 and Shanghai strain Yb2, with 99.9% similarity. The isolates were sensitive to β-lactams, chloramphenicol, and tetracyclines, but less sensitive to macrolides and aminoglycosides. The pathogenicity assay indicated that the mortality of the two strains (1.3×10⁶ CFU·mL^-1) was 100%, and the lethal ducks showed the typical Riemer's disease with pericarditis, perihepatitis, and enlarged spleen.The pathology results of the HE staining showed that the red-white medullary boundary of the spleen of the lethal ducks disappeared, and a large number of necrotic foci were presented. In addition, myocardial fibers of lethal ducks from the two isolates showed tear-like lesions. These datas demonstrated that two strains of Riemerella anatipestifer type 11 LC1 and CX1 were isolated and characterized, MLST to be ST111 and ST114, respectively, which provide reference basis for the prevention and control of Riemerella anatipestifer disease and subsequent research.

The purpose of this study was to determine the pathogen and its drug sensitivity of rabbits who died in a large-scale rabbit farm in Henan province. In this study, the dead rabbits in a large-scale rabbit farm in Henan province were dissected, three rabbits' diseased tissues were collected, the pathogen causing the disease in the rabbit farm and its drug sensitivity were determined by asking questions, combining with the incidence, clinical manifestations, autopsy changes, bacterial isolation and culture, biochemical tests, 16S rRNA PCR identification, phylogenetic tree construction and drug sensitivity tests. The results showed that two strains of Gram-negative Brevibacterium (named LY-01 and LY-02, respectively) with different sizes were obtained by bacterial isolation and culture, which accorded with the biochemical characteristics of Escherichia coli and Proteus mirabilis, respectively. It was found by PCR that the 16S rRNA gene fragments of LY-01 and LY-02 were 833 bp and 1 500 bp, respectively. The homology of LY-01 and OR717622.1 was 99.88%. The homology of LY-02 and CP042907.1 was 99.93%. After coccidiosis examination, it was found that there were a large number of coccidia eggs in their feces, and their OPG values were 0.64×10⁴, 0.62×10⁴ and 0.68×10⁴, respectively, which all reached the infection standard of enterococcidia. The results of drug sensitivity test showed that Escherichia coli and Proteus mirabilis were sensitive to both penicillin and ceftriaxone. To sum up, this study provides a theoretical basis for the prevention and treatment of mixed infection of Escherichia coli, Proteus mirabilis and coccidia in rabbit breeding.

The aim of this study was to investigate the antiviral effect of resveratrol on porcine rotavirus (PoRV) infected porcine intestinal epithelial cells(IPEC-J2). In this experiment, IPEC-J2 cells were used as research object. Firstly, the effect of different concentration of resveratrol on the cell viability of IPEC-J2 was determined. Then experimental groups including negative control group, PoRV-infected group and PoRV-infected group with the addition of resveratrol at different time points were set up depending on whether the IPEC-J2 cells were treated with PoRV or resveratrol (100 μmol·L^-1). The replication and proliferation of PoRV in IPEC-J2 cells were detected by real-time fluorescence quantitative PCR, viral titer assay and Western blot. The results showed that: 1) The addition of resveratrol (100 μmol·L^-1) significantly inhibited PoRV replication and infection at the late and full phases of viral infection of PoRV infection with IPEC-J2 (P < 0.05); 2) Compared with the PoRV-infected group, the addition of resveratrol (100 μmol·L^-1) during the full phase of PoRV-infected IPEC-J2 extremely significantly suppressed the levels of inflammatory cytokines IL-1β, IL-10, TNF-α and IFN-β in the supernatant fluid of IPEC-J2 cells (P < 0.01), while significantly suppressed the IL-10 and IFN-β levels during the late phase (P < 0.05); Extremely significantly suppressed the relative expression of immune-related factors MDA5, RIG-I, TRIF, MAVS, LGALS9, EIF2AK2, IRF9 and IFI44L in IPEC-J2 cells (P < 0.01) during late and full phases; Extremely significantly suppressed the relative mRNA expression of variable splicing factors SRPK1, SRPK2, HNRNPC and HNRNPR in IPEC-J2 cells (P < 0.01) during late and full phases; 3) Compared with the negative control group, PoRV infection significantly promoted exon jumps in exon 5 of LGALS9 and exon 2 of EF2AK2 in IPEC-J2 cells, while the addition of resveratrol (100 μmol·L^-1) significantly inhibited the exon skipping of target genes in the late and full phases of PoRV infection IPEC-J2 cells. In conclusion, this study confirmed that the addition of 100 μmol·L^-1 resveratrol could inhibit the infection and replication of PoRV in IPEC-J2 cells and play a role in the late phases of PoRV replication, which can provide a new basis and reference for the prevention and treatment of viral diarrhea in piglets.

This experiment was conducted to establish a rapid nucleic acid detection method for African swine fever virus (ASFV) based on enzymatic recombinase amplification (ERA). We designed ERA probes and primers specific for the conserved sequence of ASFV B646L gene, and optimized the reaction conditions in order to establish an ERA method for the detection of ASFV DNA under isothermal conditions. The ERA method for ASFV demonstrated high specificity and no cross-reaction with other pathogens; the CV was less than 10%, indicative of good reproducibility. The lowest detection limit for the ERA method is 85 copies·μL^-1; comparison with the World Organization for Animal Health (WOAH) recommended qPCR diagnostic method for African swine fever (ASF) demonstrated a Kappa value of 0.961, suggestive of high identity with African swine fever qPCR diagnostic method. ERA-based method for the detection of ASFV can be used for the rapid detection of ASFV in the field.

In 2023, some goslings at a Longde Goose Farm in Kunming showed symptoms of soft neck accompanied by sporadic deaths, with the pathology suspected to be hydropericardium syndrome(HPS).The purpose of this study was to carry out molecular virological diagnosis and pathogenicity research on the etiology of gosling. Liver samples from diseased goslings were collected and inoculated with leghorn male hepatocellular cells(LMH). 1) The cytopathic effect (CPE) was observed. The culture medium was negative stained and the morphology of virus particles was observed by electron microscope. 2) The hexon gene encoding the capsid protein of the target serotype 4 fowl adenovirus (FAdV-4) was subjected to PCR diagnosis, followed by genetic evolutionary analysis of the amplified gene sequence. 3) At a dose of 5×10^5.5 TCID₅₀ per bird, subcutaneous injection was administered to healthy 10-day-old Taizhou geese for animal retroinfection to confirm its pathogenicity. The results showed that, after the inoculation of LMH cells with the supernant of disease material for 48 to 72 hours, clear cytopathic effects are observed, characterized by cell rounding, increased intercellular spaces, subsequent fragmentation, gradual detachment. Under electron microscopy, non-enveloped icosahedral viral particles were observed. The PCR test result showed positivity for FAdV-4, the virus was isolated and purified, and named strain YNKM2023;Genetic evolution analysis of the hexon gene revealed a high similarity (99.8%~99.9%) with domestically prevalent chicken and duck FAdV-4 strains, and a similarity of 99.5%~99.6% with strains isolated from India. After being infected, Taizhou geese did not exhibit severe characteristic clinical symptoms, but began to show characteristic lesions of HPS three days post-infection, with neutralizing antibodies detected six days post-infection. In conclusion, this study successfully isolated the goose-origin FAdV-4/YNKM2023 strain, which is highly homologous to the existing chicken and duck epidemic strains in the country, with no apparent genetic drift occurring. The isolated strain can infect geese, replicate in goslings causing tissue organ lesions, and trigger an immune response, showing a certain pathogenicity to geese. This contributes to understanding the prevalence of FAdV-4 in goose populations and its pathogenicity to goslings.