circular RNAs (circRNAs) are a class of non-coding RNAs (ncRNAs) which are widely involved in various physiological activities. The intestine is an important digestive and immune organ in mammals, which provides nutrients and energy for the body through digestion, and the maintenance of the intestine barrier is closely related to animal health. It has recently been found that circRNAs play an important regulatory role in various physiological activities, and their regu-latory mechanisms in intestinal barrier function have been gradually revealed. Therefore, this paper describes the discovery, characteristics, classifications, functions and production mechanisms of circRNAs, focuses on reviewing the mechanisms of circRNAs in the mammalian intestinal barrier and looks forward to the application of circRNAs in animal husbandry, in order to provide some reference for the development of green and healthy farming.

Bovine embryonic genome selection (EGS) refers to screening out high-quality early embryos by biopsying the partial trophoblast cells in the early embryo and evaluating the genetic breeding value through the whole genome amplification of micro embryonic cells. The primary steps of this technique include:early bovine blastocysts around day 6 were biopsied and micro trophoblast cells were extracted using a micromanipulation system, followed by whole genomic amplification. Single-nucleotide polymorphism analysis predicts the early embryo production performance, and thus selects the embryos with good genotypes for transplantation. This paper summarizes the biopsy methods and amplification methods commonly used in EGS technology, and the application status of this technology in cattle and the problems of this technology were outlined, so as to provide reference for the development of EGS technology in the future.

Metabolic and microbial homeostasis are critical for the maintenance of host health. The disruption of physiological metabolism and microbial homeostasis may be an important pathogenic factor in various metabolic disorders. The pregnancy is characterized by a series of physiologic, metabolic and microbial changes. Therefore, breeding cycles are the most sensitive periods in maternal physiology and metabolism. During this period, there are significant changes in maternal hormone levels, metabolic status, and microbial composition to fulfil the fetus’s survival in utero and the nutritional needs of subsequent lactation. In recent years, studies of physiological metabolism and microbial changes in the maternal breeding cycles have made some progress. It has been suggested that physiological metabolism and microbial changes are critical for maintaining successful pregnancy and subsequent lactation. In addition, the offspring’s growth and development, microbial colonization and immune system maturation are also susceptible to maternal physiological metabolism and microbial changes. This review summarizes the changes in ruminant physiological metabolism and microorganisms during gestation and lactation and their effects on offspring growth and development, microbial colonization, and the immune system. The aim is to provide new insights into the basic mechanisms of ruminant physiological adaptation and progeny development during gestation and lactation.

Melatonin is an endogenous indole amine synthesized and secreted principally by the pineal gland in mammals. Distinct roles of 5-methoxy and N-acetyl groups determined the melatonin’s specificity and water-lipid solubility. In recent years, melatonin and its metabolites were proved to have an antioxidant, anti-inflammatory, anti-apoptotic and other biological activities, playing important roles in the complex physiological regulation of mammals. In this paper, we reviewed the research progress on biosynthesis and metabolism, antioxidant mechanisms of melatonin and its bio-effects on sperm cryopreservation, which will provide scientific basis for further research on the application of melatonin in in vitro preservation of animal cells.

Fertilization is the basic characteristic of sexual reproduction and forming the foundation of individual development. The maturation of oocytes is a prerequisite for successful fertilization and embryonic development. Oocytes are carefully regulated by a series of molecular mechanisms during maturation and fertilization. The ezrin-radixin-moesin (ERM) proteins act as a bridge between the oocyte membrane and the cytoskeleton, which directly or indirectly mediate many of the signaling pathways found in recent years that regulated mammalian oocyte maturation and fertilization. Therefore, ERM proteins have likewise become the focus of research on such biological events. This paper reviewed the research progress of the ERM protein family in the process of oocyte maturation and fertilization by regulating the formation of microvilli, polar-body extrusion, the exchange of information between oocytes and granulose cells, and sperm-egg fusion. These will provide a theoretical reference for ensuring the success rate of in vitro maturation and in vitro fertilization of mammalian oocytes and improving the reproductive efficiency of female mammals.

Plant polyphenols are secondary metabolites of plants, and plant-derived polyphenols are often classified into flavonoids, non-flavonoids and tannins according to their structure. With the ban of feed antibiotics in livestock and poultry farming worldwide, plant-derived polyphenols have attracted wide interest and attention in the field of livestock production because of their obvious antibacterial, anti-inflammatory, antiviral, anti-stress and antioxidant activities. This paper systematically reviews the research progress of plant polyphenols in poultry field, and provides theoretical references for the scientific application of plant polyphenols in poultry field.

Valine is a functional amino acid which regulates multiple biological processes, including protein synthesis, lipid metabolism, glucose metabolism, antioxidant defense and immunity. Valine supplementation is one of the critical means to develop low protein diets for livestock and poultry, which plays an important role in promoting the growth of livestock and poultry as well as modulating lactation and egg production. This paper summarizes the latest research status at home and abroad, reporting the sources, classifications, metabolic pathways, interactions with other amino acids, biological functions of valine and its application research progresses in the diets of monogastric animal and ruminant. This review also points out the current issues of valine application in the diets of livestock and poultry, and provides the theoretical basis for the scientific, efficient and extensive application of valine in the diets of livestock and poultry.

Under the intensive farming mode, early weaning has become an important measure to promote the development of herbivorous animal husbandry. Studies on humans and other animals have shown that early life stress could lead to many negative consequences, including serious mental disorders, such as depression, anxiety and other mental diseases. Intestinal flora regulates host behavior through brain-gut axis. Inoculation of probiotics can improve the abnormal behavior of the offspring. This paper systematically introduces the influence of early maternal separation on behavior of offspring, and the effects of intestinal flora structure improvement on offspring’s behavior and its mechanism. In order to provide a reference basis for further understanding the impact of early weaning on the behavior of offspring and improving the abnormal behavior of offspring caused by early weaning.

With the rapid development of large-scale and standardized farms, the demand for silage has increased accordingly. Whole corn is an important silage raw material in China. Agricultural production by-products also have high feeding value because they are rich in nutrients such as proteins, vitamins and amino acids, but the level of comprehensive utilization is low due to their usually high moisture content and they are easy to rot at high temperatures. Mixed silage can realize the balance and enhancement of silage nutrient quality through the complementarity of ingredients and microbial interactions, which makes mixed silage necessary from the perspectives of broadening feed source channels, alleviating feed scarcity and improving the added value of agricultural by-products, etc. However, different types of mixed silage have different nutrient values, thus the improvement effects of different types of mixed silage ingredients on the crude protein content and fermentation quality of whole-plant corn are not consistent. Therefore, this paper reviewed the domestic and international research progress of mixed silage of whole plant silage maize with leguminous forage, grass forage and agricultural by-products, analyzed the effect of different mixed silage types on silage fermentation quality, in order to clarify the appropriate mixed silage ratio and characteristics of different mixed silage combinations, and to provide theoretical basis for the efficient utilization of feed resources and silage quality improvement in China.

Antibiotics are currently one of the main means of preventing and treating livestock diseases. With the abuse of antibiotics, the resistance of pathogenic bacteria has increased and antibiotic residues in livestock and poultry products have brought great challenges to food safety and disease prevention. As people’s understanding of the abuse of veterinary antibiotics, more and more attention is focused on how to find alternatives to reduce the use of antibiotics. Lactobacillus rhamnosus is mostly found in human and animal intestinal contents, stool, and vagina, also in milk and dairy products. The use of Lactobacillus rhamnosus can reduce the abuse of antibiotics, reduce the problem of drug resistance of pathogenic bacteria, and also promote the growth of livestock and the balance of gastrointestinal microorganisms. The present article reviews the mechanism of Lactobacillus rhamnosus in regulating the balance of microbial flora, maintaining the integrity of epithelial cells, enhancing immunity, inhibiting inflammation and apoptosis, and inhibiting the growth and adhesion of pathogens. At the same time, the application of Lactobacillus rhamnosus in the prevention of dairy cow mastitis, dairy cow endometritis, piglet gastroenteritis and poisoning was described, aiming to provide reference for the application of Lactobacillus rhamnosus as a potential alternative drug in healthy breeding of livestock.

Protoparvovirus (PtPV) is a type of virus that infects various animals or humans and causes a wide range of pathological reactions. During PtPV infection,its capsid protein and non-structural protein play important roles. The capsid protein interacts with receptors on the host cell membrane,allowing PtPV to enter the host cell. Non-structural proteins,on the other hand,play a role in replication within the host cell. PtPV’s non-structural protein NS1 is a key protein that not only plays a role in virus replication but also has oncolytic and lytic properties. Studies have shown that NS1 protein can inhibit cell proliferation and induce cell apoptosis,making ectopic expression of NS1 protein a potential anti-tumor strategy. PtPV’s capsid protein also has a wide range of potential applications as a carrier in gene therapy and drug delivery: the capsid protein assembles into virus-like particles that can load foreign genes or drugs and deliver them to host cells through PtPV’s infection pathway. This virus-based gene or drug delivery system has been widely studied and applied in clinical treatment. Although the key factors and effects of PtPV infection are understood,its molecular mechanisms are not fully understood. Studies have shown that PtPV may involve the regulation and activation of multiple signaling pathways,including inflammatory responses,DNA damage responses,and cell apoptosis. Although PtPV may cause a variety of diseases,there are currently drugs and vaccines available to prevent or treat PtPV infection,and its capsid protein and non-structural protein have important applications in biotechnology and medicine. In the future,through further research and understanding of PtPV,it may be possible to apply it to new fields and better address the challenges of its infection and related diseases.

The study aimed to analyze the polymorphism and genetic effects of -868 locus of FSHR gene in Langya chickens. Genotyping of the -868 locus of FSHR gene were performed by PCR amplification and electrophoresis on 382 Langya hens that were raised with the same feed management and were recorded individually for egg performance, and the correlation between the locus and egg laying traits was analyzed. Quantitative real-time PCR (qRT-PCR) and Western blotting were used to compare mRNA and protein expression levels of chicken FSHR. The results showed that, the polymorphism of -868 locus in FSHR 5' regulatory region in the Langya chicken population was found, I^- was the dominant allele, and this population deviated from the Hardy-Weinberg equilibrium (P<0.05). The egg number at 47 weeks (E47) and the egg number at 134 days after molting (134D) were both significantly higher for hens with I⁺I⁺ than those with I^-I^- (P<0.05). The maximum clutch size (MCS) was significantly higher for hens with I⁺I⁺ and I⁺I^- than those with I^-I^- (P<0.01). The expression of FSHR mRNA in pre-hierarchical follicles was significantly higher for hens with genotype I⁺I⁺ than those with I^-I^- (P<0.05). The expression of FSHR protein in the ovary was significantly higher for hens with genotype I⁺I^- than those with I^-I^-(P<0.05). There were polymorphism at the -868 locus of FSHR gene in Langya chickens, the genetic effect of genotypes on E47, MCS and 134D was significant and hens with genotype I⁺I⁺ exhibited higher expression level of FSHR. In Langya chicken breeding, egg laying performance is expected to increase by decreasing the allele frequency of I^-.

The study aimed to explore the regulatory effect of the Indian hedgehog (IHH) gene on the proliferation and differentiation of chicken primary chondrocytes. The eukaryotic overexpression vector (OV-IHH) was constructed according to the sequence information of the IHH gene in this study. The OV-IHH vector was identified by double enzyme digestion and sequencing, and transfected into chicken primary chondrocytes. The cell proliferation was detected by CCK-8 method, and the cell cycle and apoptosis were detected by flow cytometry. The chondrocytes were induced to differentiate into osteoblasts for 21 d. The ALP activity of cells was detected by the ALP kit. The results showed that the IHH eukaryotic overexpression vector was successfully constructed. Compared with the control group and the empty vector group (OV-NC), the mRNA expression of the IHH gene in the overexpression group was significantly increased (P<0.01), and the overexpression efficiency was increased about 2 700 times. Moreover, the overexpression of IHH promoted the transformation of the cell cycle from G1 to S phase, thereby promoting proliferation and inhibiting apoptosis, increasing ALP activity, and promoting cell differentiation. In conclusion, the IHH gene significantly affects the growth and development of chicken chondrocytes, which provides a theoretical basis for further analysis of the mechanism of the IHH gene regulating the creeper trait at the cellular level.

The aim of this study was to detect genomic selection signals in the Yongdeng Qishan sheep population and to mine valuable germplasm trait genes. A total of 40 individuals from 4 sheep populations (Yongdeng Qishan sheep, Minxian black fur sheep, Lanzhou fat-tailed sheep, Tan sheep) were used as study subjects to detect genome-wide single nucleotide polymorphism sites (SNPs) using specific-locus amplified fragment sequencing (SLAF-seq). Based on SNPs data, elgensoft software was used for principal component analysis (PCA), gene flow events were analyzed by Treemix software. Selective sweep analysis was performed using population genetic differentiation index (Fst) and nucleotide diversity ratio (π ratio) and the intersection of top 5% Fst and π ratio was taken to identify selected genomic regions. The GO and KEGG enrichment analysis of candidate genes was performed. A total of 1 658 596 population SNPs were obtained; Principal component analysis (PCA) found that Yongdeng Qishan sheep were able to independently group, gene flow showed that there was weak gene exchange between Yongdeng Qishan sheep and Lanzhou fat-tailed sheep. Yongdeng Qishan sheep were used as the experimental group, and Minxian black fur sheep, Lanzhou fat-tailed sheep and Tan sheep were used as the reference group for selection sweep analysis. The 424, 294 and 301 candidate genes were detected in the selected regions of the 3 comparison groups; GO and KEGG analyses showed that the candidate genes were significantly enriched in 65, 79 and 41 GO terms and 15, 22 and 10 KEGG pathways, respectively (P＜0.05). In addition, SNP datas from 3 populations of Minxian black fur sheep, Lanzhou fat-tailed sheep and Tan sheep were combined into one dataset for comparison with Yongdeng Qishan sheep and 466 candidate genes were significantly enriched to 124 GO terms and 7 KEGG pathways (P＜0.05).Functional genes BMP2, GRM1, and ALDH1A1 related to important economic traits were screened from Yongdeng Qishan sheep. The research shows that the selection signal detection in the whole genome of Yongdeng Qishan sheep can identify candidate genes related to growth and development and fat tail evolution, providing reference for molecular genetic marker mining of Yongdeng Qishan sheep.

The aim of this study was to mine the candidate genes related to nutrient contents of longissimus lumborum in Pingliang red cattle, so as to improve the meat quality. Forty steers with 30-months-old slaughter age and 750 kg weight under the same feeding conditions were selected, and the contents of 3 conventional nutrients were measured, i.e., protein, fat, and moisture. The high and low groups with extreme differences in phenotypic data were selected, respectively, with 3 replicates each group. Principal component analysis and comparative transcriptome analysis were used to screen significant factor loading genes (SFLGs) and differentially expressed genes (DEGs), and these genes were subjected to enrichment analysis. Weighted gene co-expression network analysis (WGCNA) was performed using all sample transcriptome data and phenotype data to screen target gene modules (r>0.35 and P<0.05) and hub genes (HGs) related to phenotypes. The 91, 81, and 80 SFLGs (the first principal component PC1 and the second principal component PC2) and 18, 85, and 338 DEGs were identified for protein, fat, and moisture content traits, respectively. Among them, 8, 4, and 3 SFLGs were shared in PC1 and PC2, and 1, 3, and 2 DEGs showed significant factor loading, respectively. The enrichment analysis results were related to the corresponding phenotype. WGCNA screened 2 target gene modules respectively as well as 10, 14, and 26 HGs for protein, fat, and moisture contents, and all identified key candidate genes such as MYADML2 and ZBTB14, which might play important roles in influencing the proportional relationship among 3 nutrients. In this study, key genes related to meat quality traits were found by identifying candidates affecting 3 conventional nutrients contents. The research result will provide a theoretical basis for the breeding work of Pingliang red cattle and also provide reference for the quality breeding of other beef cattle.

The aim of this study was to analyze the transcriptomic expression profile of the cerebral cortex in newborn and adult yaks, and screen the candidate genes affecting cerebral cortex development. The newborn yaks (1-7 days of age (NYB), n=3) and adult yaks (3-4 years of age (AYB), n=3) were selected and slaughtered, then the cerebral cortex was collected. Moreover, transcriptome sequencing and analysis were performed using Illumina HiSeq platform, and differen-tially expressed genes (DEGs)were screened. On this basis, the differential genes were performed by GO functional annotation and KEGG enrichment analysis, and verified by real-time fluorescence quantification PCR (qRT-PCR). The results showed 4 790 DEGs (P<0.05), including 2 670 up-regulated DEGs and 2 120 down-regulated DEGs. Nine differentially expressed genes were randomly selected for qRT-PCR verification, and their expression trend was consistent with the transcriptome sequencing results, indicating that the sequencing results were reliable. GO analysis showed that the most DEGs were enriched in regulation of transcription, positive regulation of transcription by RNA polymerase II, protein binding and ATP binding, which were related to protein synthesis and ATP utilization. Moreover, the most DEGs according to analysis based on KEGG database were mainly enriched in the axon guidance signaling pathway that regulate axon development and remodeling; MAPK signaling pathway which related to glial cell proliferation; in addition neuroactive ligand-receptor interactions, PI3K-AKT, calcium signaling and phospholipase D signaling pathways were related to synaptic transmission; and Toll-like receptor pathways were related to immune defense, and HIF signaling pathways related to hypoxic adaptive regulation. From the enrichment pathway, Slit2, SEMA5A, BDNF, Rab3a, FGF18, HIF1α, HIF2α, NGF, VEGFA, CaMK2A, PLD1, TLR1 and TLR4 might be candidate genes affecting the cerebral cortex development in yaks. These results suggest that synapse development, plasticity, transmission, immune defense may be more active in the cerebral cortex of adult yaks. And hypoxic adaptation of the cerebral cortex in adult yaks might be more perfect. It provided the reference for further exploring the potential molecular mechanism of brain development in yaks.

The study aimed to study the internal relationship between cardiac structure and function parameters of Yili horses with different body sizes and improve the efficiency of sports horse selection. In this study, the cardiac structure and function parameters of 30 healthy 2-year-old Yili horses were measured by color Doppler ultrasound system. The correlation between body height, body length, thoracic circumference, pipe circumference and cardiac structure and function parameters of Yili horses was analyzed and the linear model was fitted. The results showed that the weight, body surface area, body length and thoracic circumference of Yili horses were positively correlated with LADd (P<0.01). Body weight, body surface area, thoracic circumfere-nce were positively correlated with MVD and PAd (P<0.05). Body length was positively correlated with MVD (P<0.01), LVFWs and LVM (P<0.05). Body height was positively correlated with LVLD (P<0.01). Pipe circumference was positively correlated with LADs and MVD (P<0.05). There was no significant correlation between other body size and cardiac structure (P> 0.05). Body weight, body surface area, body length, thoracic circumference were positively correlated with EDV and ESV (P<0.05). Body surface area and thoracic circumference were negatively correlated with EF (P<0.05). Body height was positively correlated with EDV,SV (P<0.01) and CO (P<0.05). Pipe circumference was negatively correlated with LV MASS-I (P<0.05). A total of 12 linear regression equations were fitted, and the R² values (coefficient of determination) were all higher than 0.9, reaching the extremely significant level, which could be used in production practice. The body length and body height of Yili horses have great influence on the cardiac structure and function parameters. Conducting correlation and regression analysis of cardiac structure and function parameters among Yili horses of different body sizes can provide theoretical basis for cardiac evaluation of horses.

The experiment aimed to study the key genes affecting lambing traits in East Friesian and Hu crossbred sheep and select the mutation loci of the key genes for validation, to provide molecular markers for the selection and breeding of multiple lambing traits in East Friesian and Hu crossbred sheep. In this study, 168 healthy and disease-free East Friesian and Hu crossbred sheep were collected from the Jinchang Milk Sheep Experimental Demonstration Base of Northwest Agriculture and Forestry University for whole-genome resequencing, genome-wide association study was performed by GEMMA and SnpEff softwares, enrichment analysis of annotated genes was conducted by KOBAS 3.0 database, and analysis of the chain region around the most significant SNPs with LDBlockShow software. Linkage disequilibrium analysis was performed on the linkage regions around the SNPs by LDBlockShow. SNPs were typed in the GRID2 gene using kompetitive allele-specific PCR (KASP), and the genetic diversity parameters of the two polymorphic loci of the gene were counted and analyzed in association with lambing traits. The results showed that genome-wide association analysis identified 1 163 SNP loci at the significance level on chromosome 6, and candidate genes BMPR1B, PDLIM5, PDHA2, UNC5C, GRID2, NFKB1, TSPAN5, STPG2, and PPP3CA were identified as associated with lambing traits through the annotation of the candidate loci. The two SNPs on GRID2 (g.35685218A>G and g.35685499C>T) were also selected as candidate loci by combining the existing reports and annotations of the most strongly associated regions. Statistical analysis revealed that both loci involved in this study were in Hardy-Weinberg equilibrium at P>0.05, indicating that neither locus had been subjected to over-selection and that both loci were significantly associated with lambing traits in East Friesian and Hu crossbred sheep, with wild-type being dominant at both loci and the means of the two loci increasing with the increasing parities. In summary, the two SNPs in the GRID2 gene have significant effects on lambing number traits in East Friesian and Hu crossbred sheep and can be used as candidate loci for molecular marker-assisted selection. This study provides a solid theoretical basis for improving the lambing rate of East Friesian and Hu crossbred sheep and promoting the progress of genetic breeding of milk sheep.

This study aimed to provide important reference for the development of silent estrus identification technology based on the fact that male and female cows communicate through sex pheromone. The 25 healthy Holstein cows aged 3 to 5 weeks from Shijiazhuang Tianquan Good Breed Dairy Co. Ltd. were pre-selected, which were 15 to 35 d postpartum, and artificial observation, activity monitoring, rectal examination and B-ultrasound detection and other methods were used to identify the estrus of Holstein cows, and distinguish between normal estrus and silent estrus. The saliva samples of a total of 4 normal estrus and 5 silent estrus cows were collected at different stages of estrus. The Solid Phase Micro-extraction Gas Chromatography-Mass Spectrometry (SPME-GC-MS) was used to identify and analyze the volatile compounds in these saliva samples, and compare the differences between different estrus states and different estrus stages. The results showed that 40 compounds were found in the saliva of all cows, and 23 compounds with significantly higher content during estrus than before estrus (P<0.05) were screened out by paired analysis, among which 13 compounds (1-Pentanol, pyrrole, 1-Hexanol, 3-hexen-1-ol, Phenethyl alcohol, 6-methyl-2-heptanone, 6- (2,2,2-trichloro-1-hydroxyethyl)-1-methyl Cyclohexene and 2-pentylfuran, 2-methyl-1- pentanol,2,6,6-trimethyl-2-neneneba cyclohexene 1,4-dione, 3-methyl-1-butanol, Methylsulfonylmethane, Sulfonyl group bismethane) showed an increasing trend in all cows during estrus. These compounds can be used as estrus candidate markers for cow estrus identification, and their content is small in difference between normal estrus and silent estrus cows, providing important reference for simultaneous identification of normal estrus and silent estrus.

The study aimed to understand the morphological changes of testicular tissue and responding gene profile of male rabbits in heat stress environment to reveal the mechanism of heat stress of the decline of semen quality of male rabbits. In this study, six 8-month-old New Zealand male rabbits with the same feeding level and similar body condition and weight were selected. By establishing a heat stress model, 3 rabbits in the heat stress group (August, HS ) and 3 rabbits in the non-heat stress group (May, NHS ) were obtained. The testis and semen of the two groups were collected, respectively. HE staining was used to compare the differences in testicular tissue structure under different conditions, and Illumina Hiseq high-throughput sequencing technology was used to analyze the transcriptome sequencing of sperm. GO and KEGG enrichment analysis of differentially expressed genes between the two groups of samples were performed by bioinformatics methods, and the transcriptome sequencing data were verified by RT-qPCR method. The results of testicular tissue sections of male rabbits showed that, compared with the NHS group, the central part in testis of the HS group showed obvious vacuolization and tearing, the spermatogenic epithelium was thinner, the damage was significant, and the number of sperm cells decreased. With log₂FoldChange>1 and P<0.05 as the threshold, a total of 1 676 differentially expressed genes related to sperm heat stress response were screened, including ATP5MC1, MDH2, ALDH7A1, GAPDHS, PRPS1, etc. Among them, 894 genes were up-regulated and 782 genes were down-regulated. GO analysis result showed that differentially expressed genes was enriched in stress response, protein metabolic process, catalytic activity and other related items, and KEGG result showed that differentially expressed genes was enriched in MAPK, PI3K-AkT, Toll-like receptor, Ras and other signaling pathways. RT-qPCR verified the expression levels of ATP5MC1, MDH2, PRPS1, ALDH7A1 and GAPDHS, which were consistent with the trend of transcriptome results. In summary, heat stress can regulate the expression of spermatogenesis-related genes and affect related signaling pathways and biological functions. The results of this study provide clues for the molecular regulation mechanism of spermato-genesis and provide a theoretical basis for the breeding of rabbits under high temperature environment.

The aim of this study was to establish an inflammation model of yak rumen epithelial cells induced by lipopolysaccharide (LPS), and to investigate whether there is intracellular complement C3 activation in rumen epithelial cells as non-immune cells, and its influence on the production of adenosine triphosphate (ATP). To provide experimental basis for nutrition regulation techniques of rumen health. Different concentrations of LPS were used to treat yak rumen epithelial cell line. Cell viability was determined by CCK-8 method. ELISA kit was used to determine the concentrations of C3 activation products C3a and C3b in cells and the concentrations of interleukin-1β (IL-1), interleukin 6 (IL-6), tumor necrosis factor (TNF-α) in the cell culture; The intracellular ATP concentration was detected by chemical method, and the number of mitochondria and membrane potential were detected by mitochondrial red fluorescent probe and flow cytometry. The relative expression of IL-1β, IL-6, TNF-α, complement C3, cathepsin B (CTSB), cathepsin L (CTSL), and ATP synthase subunits (ATP5A and ATP5C1) were determined by q-PCR. The results showed that: 1) After different concentrations of LPS treatment, the activity of yak rumen epithelial cells was significantly decreased (P<0.01), and the gene expression and concentration of proinflammatory factors, such as TNF-α, IL-1β and IL-6 were significantly increased (P<0.01). The inflammatory model of yak rumen epithelial cells was established successfully when the concentration of LPS was 10 μg·mL^-1; 2) Under inflammation, the gene expression of complement C3 and its key activating enzyme CTSB increased significantly in yak rumen epithelial cells (P<0.01), and the concentration of activated complement fragments C3a and C3b increased significantly (P<0.01); 3) Under inflammation, the ATP content (P<0.01) and mitochondrial membrane potential (P<0.01) in yak rumen epithelial cells decreased significantly, and the gene expression of ATP synthase subunits ATP5A and ATP5C1 decreased significantly with the increasing of LPS concentration (P<0.01). In summary, the inflammation model of yak rumen epithelial cells was established by LPS. The LPS stimulation can activate the intracellular complement C3, and inhibit the gene expression of mitochondrial ATP synthase subunits ATP5A, ATP5C1 and key enzyme ME1 of aerobic respiration, thus reducing mitochondrial membrane potential and inhibiting ATP production in the yak rumen epithelial cells. LPS-induced inflammation can inhibit ATP production of rumen epithelial cells, leading to rumen health problems.

The purpose of this experiment was to investigate the effects of Bacillus subtilis (BS) on intestinal immunity, intestinal tissue morphology, and intestinal barrier of broilers challenged with lipopolysaccharide (LPS). A total of 240 one-day-old healthy AA broilers (males and females in half) were randomly divided to 4 treatments as a 2×2 factorial design. The main factors were diets (a basic diet or a experimental diet added with 200 g·t^-1 BS) and LPS stress (oral administration of LPS solution or saline),and randomly divided into: 1) The basal diet+normal saline group; 2) The basal diet+LPS group; 3) The experimental diet+ normalsaline group; 4) The experimental diet+LPS group, respectively, a total of 4 groups, each group composed of 6 replicates with 10 broilers per replicate. The trial lasted for 28 days, and the experimental period was divided into three stages, including pre-stress (1 to 14 days), LPS stress (15 to 21 days) and recovery (22 to 28 days). The results showed as follows: l ) On the 21st day, there was a significant interaction between BS diet and LPS stress on the expression of IL-1β and TLR4 mRNA in duodenum(P<0.05), MyD88 mRNA in jejunum(P<0.05), and TNF-α mRNA in ileum(P<0.05). Without LPS stress, none of the above indicators were significantly affected by BS diet (P>0.05). Under LPS stress, BS significantly down-regulated the mRNA expression levels of those genes(P<0.05).2)On the 21st day, there was an significant interaction between BS and LPS on VH and V/C ratio in duodenum and CD in jejunum (P<0.05). BS diet significantly increased VH and V/C ratios with or without LPS stress in duodenum. Without LPS stress, BS diet significantly reduced CD of jejunum (P<0.05); Under LPS stress, BS diet had no significant effect on CD of each intestinal segment(P>0.05). On the 28th day, there existed significant interaction between BS and LPS on VH and V/C ratio in jejunum. Without LPS stress, BS diet has no significant effect on VH or V/C ratio of jejunum (P>0.05); Under LPS stress, the BS diet significantly increased jejumum VH and V/C ratio (P<0.05).3)LPS stress significantly reduced the mRNA expression of Claudin-1, Occludin, ZO-1 and MUC2 in the intestine at 21 days. BS diet significantly increased the expression of Occludin and ZO-1 mRNA in duodenum, as well as Occludin, ZO-1 and MUC2 mRNA in jejunum. The results showed that dietary BS supplementation significantly decreased the expression of intestinal proinflammatory cytokines, increased the expression of tight junction proteins Claudin-1, Occludin, ZO-1 and MUC2 mRNA, increased intestinal VH and V/C ratio, effectively alleviated the damage of immune stress on intestinal morphological structure, and promoted the growth and development of small intestine,maintains intestinal health. Dietary BS can alleviate the damage of intestinal morphology and structure caused by LPS stress, promote the growth and development of small intestine, and maintain intestinal barrier.

This experiment was conducted to investigate the regulatory effects of lauric acid (LA) on slaughter performance, muscle quality, conventional nutrients and antioxidant properties of broilers. A total of 480 1-day-old AA broilers were randomly divided into 4 groups with 8 replicates per group and 15 broilers per replicate. Broilers were fed with basal diet (control group), basal diet supplemented with 75 mg·kg^-1 aureomycin (antibiotic group) and 500 mg·kg^-1 lauric acid (low-dose lauric acid group, LA500), and 1 000 mg·kg^-1 lauric acid (lauric acid high-dose group, LA1 000), respectively. The experiment lasted for 42 days. The results showed that compared with the control group, dietary supplementation of 500 mg·kg^-1 lauric acid increased the red (a^*) value, yellow (b^*) value, pH at 24 h and the contents of organic matter, ether extract and crude protein in breast muscle, also increased the level of total antioxidant capacity (T-AOC), up-regulated the expression levels of SOD1, CAT, GPX1, Nrf2 and HO-1 genes, decreased the brightness (L^*) value at 24 h, moisture content, drip loss at 48 h and cooking loss of breast muscle in broilers (P<0.05). Dietary supplementation of 1 000 mg·kg^-1 lauric acid increased slaughter percentage and evisceration percentage, enhanced the subcutaneous fat thickness and intermuscular fat width, increased pH, a^*, b^* values at 24 h and the contents of ether extract in breast muscle, increased the levels of T-AOC, total superoxide dismutase (SOD) and glutathione peroxidase (GPX), up-regulated the gene expression levels of SOD1, SOD2, CAT, GPX1, Nrf2 and HO-1, decreased drip loss at 48 h, L^* value at 24 h and cooking loss, and reduced the content of malondialdehyde (MDA) in breast muscle of broilers (P<0.05). Compared with antibiotic group, dietary 500 mg·kg^-1 lauric acid increased the 24 h a^* and b^* values, decreased the L^* value at 24 h of breast muscle in broilers (P<0.05). Dietary supplementation with 1 000 mg·kg^-1 lauric acid increased subcutaneous fat thickness, increased the pH, a^*, b^* values at 24 h and T-AOC levels, decreased the L^* value at 24 h of breast muscle in broilers (P<0.05). In conclusion, lauric acid could improve slaughter performance, muscle quality and antioxidant capacity of broilers, and activate the related genes expression of Nrf2 signaling pathway, and the optimal dose of lauric acid is 1 000 mg·kg^-1 in the diet of broilers.

This study was conducted to establish a fluorescence detection method of recombinase polymerase amplification (RPA) combined with CRISPR/Cas12a for rapid, sensitive and visual detection of dermatophytes in dogs and cats. Taking Microsporum canis, Nannizia gypsea and Trichophyton mentagrophytes as research objects, specific RPA primers and CRISPR RNA (crRNA) were designed and synthesized in the internal transcribed spacer region. A fluorescence detection method for simultaneous and separate detection of the dermatophytes was established, and the limit of detection was evaluated. The sensitivity and specificity of the method were evaluated by detecting clinical samples. Under the condition of 37 ℃, the limit of detection (LOD) for three kinds of dermatophytes can be as low as a single copy in 30 min. Twenty-four clinical samples were tested, and the results of fungal culture and colony sequencing were taken as standard results. The sensitivity and specificity of this assay were 100% when using the dermatophyte crRNA (crRNA-DM) that can simultaneously detect M. canis, N. gypsum and T. mentagrophytes, and the Microsporum canis crRNA (crRNA-Mc) that can specifically detect M. canis in the RPA-CRISPR/Cas12a reaction. The RPA-CRISPR/Cas12a established in this study can detect M. canis, N. gypsum and T. mentagrophytes simultaneously and separately. This technique required short time, visualization, high sensitivity and specificity, did not need expensive instruments, and was suitable for rapid clinical diagnosis.

Mare’k disease (MD) is caused by the infection of Marek’s disease virus (MDV) and is regarded as one of the most serious immunosuppressive and neoplastic diseases of the poultry. Development of specific monoclonal antibodies (mAbs) against MDV is crucial for providing key reagents for the studies on gene functions, pathogenesis and diagnostic techniques. The NE-PER^TM Nuclear and Cytoplasmic Extraction Reagents was used to prepare the nuclear and plasma proteins from the chicken embryo fibroblasts (CEF) cultures infected with vvMDV (very virulent MDV) strain Md5, and then were concentrated by tangential flow ultrafiltration to make the immunogen and immunize female BALB/c mice at age of 6 to 8 weeks. The hybridomas were produced by conventional cell fusion. Through the screening of positive supernatants by indirect immunofluorescence assay (IFA), a total of 31 purified monoclonal hybridomas stably secreting mAbs specific for MDV were obtained, of which 27 hybridomas secret MDV-1 specific mAbs and the other four hybridomas secret conserved mAbs recognizing MDV-1, MDV-2 and herpesvirus of turkey (HVT). Furthermore, the J-1F3-C6 was identified as a specific mAb against MDV glycoprotein B (gB) thorough the IFA staining of 293T cells over-expressing gB protein. The titer of mAb J-1F3-C6 in ascites is 1∶25 600 determined by IFA, and the light chain and IgG subtype was characterized as Kappa and IgG2a, respectively. The cross reaction experiments have shown that the J-1F3-C6 specifically recognized the gB proteins from all the tested strains of MDV-1, MDV-2 and HVT, but for Western blot analysis it can only recognize MDV-1 and HVT strains. In conclusion, we have developed a pool of mAbs against MDV and identified a mAb specific for gB protein, providing a solid foundation for future research.

The objective of this study was to identify the differentially expressed circRNAs in A549 cells upon influenza A virus infection. The findings will provide a basis for future researches on the regulatory roles of circular RNAs (circRNAs) in influenza A virus replication. RNA extracted from IAV-infected A549 cells and PBS-treated control cells were subjected to whole transcriptome sequencing. Bioinformatic analysis was performed to identify the circRNAs expressed in the cells. Comparing with uninfected control samples, differentially expressed circRNAs in cells before and after infection were screened using the EdgeR package with the selection criteria of log₂FC≥1 and P value<0.05. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted on the parental genes of the differentially expressed circRNAs using the ClusterProfiler package. Finally, the differential expression of some circRNAs before and after viral infection was verified by fluorescence quantitative PCR, exonuclease treatment, and Sanger sequencing. The abundance and varity of circRNAs were found to increase upon influenza virus infection. By RNA sequencing, a total of 1 101 and 676 circRNAs were identified in the infected and uninfected groups, respectively. These circRNAs were widely distributed across all chromosomes, with approximately 60% ranging in length from 300 nt to 1 000 nt, and around 20% of circRNAs being longer than 2 000 nt. Furthermore, 75%-82% of circRNAs were derived from exons, while 12%-17% were classified as sense overlapping, and a small fraction (1%-4%) originated from intronic, intergenic, or antisense transcripts. Differential expression analysis identified 54 up-regulated and 18 down-regulated circRNAs in response to viral infection. These differentially expressed circRNAs were mainly distributed on chromosomes 5 and 19. Gene ontology (GO) enrichment analysis revealed that the parent genes of differentially expressed circRNAs were significantly enriched in RNA localization, cytoplasmic membrane, and single-stranded DNA binding. Additionally, KEGG pathway analysis demonstrated that these circRNAs were mainly enriched in pathways related to amino acid degradation and FoxO signaling. Finally, the differential expression of three circRNAs (SNUPN:has_circ_0104558, DCBLD1:hsa_circ_0077717, and EIF4G3:hsa_circ_0000025) was verified by RT-qPCR, RNase R digestion, and Sanger sequencing, which confirmed that they were back spliced from the corresponding source sequences and were resistant to RNase R digestion. The circRNA expression profiles in A549 cells upon influenza A virus infection were obtained using transcriptome sequencing and bioinformatics analysis. The length, chromosome distribution, source classification of these circRNAs, and the potential pathways they probably involved in were analyzed. We identified differentially expressed circRNAs upon viral infection, which lays a foundation for further investigations on the potential roles of circRNAs in influenza virus infection.

The purpose of this experiment was to study the regulatory effect of MID2 on porcine reproductive and respiratory syndrome virus (PRRSV) replication. Firstly, MARC-145 cells were infected with BJ-4 strain of PRRSV, and then the mRNA and protein expression level of MID2 were detected by RT-qPCR and Western blot. It was found that PRRSV infection could up-regulate MID2 expression. To further evaluate the effect of MID2 on PRRSV replication, this study overexpressed or knocked down the expression level of MID2 protein, and then inoculated PRRSV. It was found that MID2 could inhibit the replication of PRRSV by detecting the transcription level of PRRSV ORF7 and the expression level of N protein. Furthermore, the pCMV-Flag-MID2 and pGL3-IFN-β-Luc plasmid were co-transfected into HEK293T cells, the result of double luciferase assay showed that MID2 could positively regulate the type I interferon signaling pathway. Finally, the plasmid of MID2 and RIG-I were co-transfected into HEK293T cells, the result of Co-IP assay indicated that MID2 could interact with RIG-I, and MID2 could promote the protein expression level of RIG-I in a dose-dependent manner and enhance RIG-I mediated I-IFN signaling pathway. These results suggested that MID2 could activate the type I IFN signaling pathway through interacting with RIG-I and promoting RIG-I expression, lead to inhibiting PRRSV replication. In this study, we found for the first time that MID2 can positively regulate the type I interferon signaling pathway and inhibit PRRSV replication.

In order to establish a specific, sensitive, rapid and simple detection method for bovine viral diarrhea virus (BVDV), four loop-mediated isothermal amplification (LAMP) specific primers and one DNA probe labeled with fluorescein isothiocyanate were designed according to the conserved segment of BVDV 5'UTR sequence by combining loop-mediated isothermal amplification (LAMP) with lateral flow dipstick(LFD). By optimizing the reaction temperature, reaction time, ratio of internal and external primer concentrations, Bst DNA 2.0 polymerase concentration, dNTP Mix concentration, Mg²⁺ concentration, etc., the specificity and detection sensitivity of this method were analyzed, and 52 clinical samples were tested. A LAMP-LFD method for detecting BVDV was established. LAMP-LFD detection technology can specifically detect BVDV, but foot-and-mouth disease virus, bovine epidemic fever virus, and bovine herpesvirus type 1 have not been detected. The sensitivity of LAMP-LFD is high, and the minimum detection concentration is 1.9×10¹ copies·μL^-1. Both LAMP-LFD and PCR detection methods detected 5 positive samples, with a coincidence rate of 100%. The LAMP-LFD method for rapid detection of BVDV was successfully established in this experiment. The detection method has the advantages of short detection time, strong specificity, simple operation and high sensitivity, and can be used as a new detection method for grassroots detection.

The aim of this study was to investigate the effects of exosomes (Exo) from different milk sources on macrophage polarization. Ten milk samples were collected aseptically and the properties of the milk samples were determined by somatic cell count (SCC) and bacteriological identification; the bovine milk-derived exosomes were enriched and purified by differential ultracentrifugation; exosomes were identified by nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and western blot (WB); the fluorescent tracer method was used to detect whether exosomes could be internalized by macrophages (Raw264.7); real-time fluorescent quantitative PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect changes in mRNA levels of pro-inflammatory cytokines, anti-inflammatory cytokines and protein levels after the action of bovine milk-derived exosomes on Raw264.7 cells. According to SCC, there were 4 normal milk samples and 6 inflammatory milk samples. Four strains of pathogenic bacteria were isolated from milk samples of inflamed cows and their biological characteristics were consistent with Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae respectively; the exosomes were separated by ultracentrifugation and different bovine milk-derived exosomes were internalized by Raw264.7 after co-culture with it for 6 h. Compared with the control group (Con), compared with the control (Con) group, both the low somatic cell count source exosomes (L-Exo) and high somatic cell count source exosomes (H-Exo) groups significantly increased Raw264.7 cell tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 mRNA and protein expression levels (P<0.05), nitric oxide synthase (iNOS) and macrophage mannose receptor CD206 protein expression were significantly increased (P<0.05), IL-10, transforming growth factor (TGF)-β mRNA and protein levels were decreased (P<0.05), arginase (Arg)-1 mRNA expression levels were decreased (P<0.05). During the inflammatory response in the mammary gland of cows, mastitis bovine milk-derived exosomes can promote the polarisation of macrophages towards M1 type, express high levels of pro-inflammatory cytokines and promote the inflammatory response, while exosomes secreted in the healthy state of the mammary gland can mediate the polarisation of macrophages towards M2 type, express high levels of anti-inflammatory cytokines, participate in the immune regulation of the body and have certain anti-inflammatory effects, this demonstrates that milk-derived exosomes can influence the process of macrophage polarization.

This study was conducted to investigate whether the expression of glucocorticoid receptor (GR) and FK-506 binding protein 5 (FKBP5) in hippocampus and hypothalamus of broiler chickens is related to stress sensitivity. Arbor Acres (AA) and Rugao yellow (Rugao) broiler chickens at 35 days of age were injected subcutaneously with corticosterone (CORT) for 10 consecutive days to establish a chronic stress model. The body weight, feed intake, behavior and plasma biochemical indexes of the two lines of chickens were detected, and the differences in stress sensitivity were compared. The expression of GR and FKBP5 in hippocampus and hypothalamus were detected by qPCR and Western blot, and their correlation with plasma CORT levels was analyzed. The results showed as follows: 1) After CORT treatment, the body weight of AA decreased significantly, the tonic immobility (TI) duration and plasma CORT level increased significantly, but there was no significant change in Rugao. CORT treatment resulted in increased heterophil/lymphocyte (H/L) ratio in blood of both AA and Rugao, yet H/L ratio was significantly higher in AA than in Rugao. 2) The basal level of GR protein expression in hippocampus and hypothalamus was significantly higher in Rugao than that in AA; The protein expression of GR was significantly down-regulated after CORT treatment, but Rugao still showed significantly higher GR protein than AA after stress. 3) CORT significantly up-regulated FKBP5 expression at both mRNA and protein levels in hippocampus and hypothalamus of AA, while the FKBP5 up-regulation in hippocampus and hypothalamus of Rugao only occurred at the protein level. FKBP5 protein expression was significantly in AA than in Rugao after stress. 4) Plasma CORT level was negatively correlated with GR protein expression in hippocampus and hypothalamus, and positively correlated with FKBP5 protein expression. GR was negatively correlated with FKBP5 protein expression in hippocampus and hypothalamus. These results indicate that AA and Rugao have different stress sensitivity, and the expression levels of GR and FKBP5 in hippocampus and hypothalamus are related to stress sensitivity.

To investigate the magnetic resonance imaging (MRI) characteristic of acute edematous pancreatitis (AEP) in canines, ten local adult canines were used to establish AEP models by sodium taurocholate and trypsin retrograde perfusion. MRI was performed before and after perfusion. FSE-T2WI-TRIG and FSE-T2WI-FS-TRIG images preferred best for subjective and objective analysis through MRI multi-sequence scanning and contrast enhanced scans can be performed if necessary. Pancreas was found diffuse enlargement with an irregular shape. Pancreatic parenchyma was also found hyperintense uneven signal and high signal was found compared with the same liver layer in T2WI. With extracellular fluid surrounding and irregular pancreatic margins, hyperintense stripe signal was also found in T2WI. The Gad-enhanced images showed inhomogeneous enhancement in pancreas parenchyma of AEP canines, and the average enhancement peak time was 60-90 s after injection of Gad medium delayed enhancement was found. Our research integrated these selected sequences can be used for clinical examination of AEP canines. MRI characteristic of AEP canines provided important reference for the diagnosis of AEP canines.

This study aimed to investigate the effects of administration intramuscularly of alfaxalone with or without dexmedetomidine, on the sedative effect and echocardiographic measurement in healthy cats. Baseline values of echocardiography and physiological indicators were determined before the experiment. Eight cats were intramuscularly injected with alfaxalone (5 mg·kg^-1, ALF), dexmedetomidine (5 μg·kg^-1 DEX) or both (DEX+ALF). The washout period was 2 weeks. Physiological indicators were measured immediately after anesthesia 0 (T0), 5 (T5), 10 (T10), 15 (T15), 20 (T20), 25 (T25) and 30 (T30) mins after the sedation effect was achieved. Echocardiography was performed at T15. After T30, the DEX and DEX+ALF groups were intramuscularly injected with atipamezole (25 μg·kg^-1). Times for cats to head-lift (LH), sternal recumbency (SRr), and standing position (ST) were recorded. The recovery time of DEX+ALF was shorter. Compared with the baseline value, alfaxalone decreased the respiratory rate and increased the heart rate of the cats, but did not significantly affect the echocardiographic results. The use of dexmedetomidine significantly reduced respiratory rate and heart rate, depressed the cardiovascular system, and affected the results of echocardiography significantly. The results of the DEX+ALF group were similar to the DEX group. All 3 kinds anesthesia methods could achieve sedative effect. Alfaxalone alone did not significantly affect echocardiographic parameters, but dexmedetomidine strongly depressed cardiovascular function even combined with alfaxalone it was not suitable for anesthesia before echocardiography.

This study aimed to establish the defect model of mandibular first molar and to investigate the long-term effect of immediate implantation in repairing the defect of teeth in dogs. Three healthy adult dogs were selected, and the right mandibular first molars were surgically extracted, and the implants were implanted into the mandibular alveolar by immediate implantation. Dental radiographs were taken at 30 d intervals for 120 days after surgery. Bone absorption, mobility, gingival index around the implants and basic physiological indicators were evaluated. The results showed that the dogs could successfully implant the implants in good physical health, and the implant was stable after implantation. Some of the implants showed gingival inflammation, increased bone absorption and slight mobility.In conclusion, the immediate implantation technique has good effect and application prospect for the treatment of dog molar defect. The key to the success of implantation lies in the surgical technique and later nursing.

The objective of this study was to investigate the role of endoplasmic reticulum stress (ERS) on citrinin-induced intestinal barrier dysfunction. Twenty-four 7-week-old Kunming mice weighed (27.8±1.5) g were divided into 4 groups randomly: control group(5% ethanol), citrinin of low-(1.25 mg·kg^－1), medium-(5 mg·kg^－1) and high-(20 mg·kg^－1) dose groups. After conventionally raised for one week, the mice in control group were administrated orally by 5% ethanol according to 0.1 mL·10 g^－1 body weight and the mice in toxin groups were exposed to different dosage of citrinin for 14 days. At the end of the experiment, the blood was collected, the serum was separated, the length of small intestine was measured and the jejunum samples were collected. The pathological changes of intestine were observed by HE staining, while the content of diamine oxidase (DAO), D-lactic acid(D-LA) and endotoxin (ET) were detected by ELISA. Besides, the activities of antioxidative enzymes and the release of reactive oxygen species (ROS) of jejunum were examined. In order to explore the role of ERS on citrinin-induced intestinal injury, 32 Kunming mice were randomly divided into 4 groups: control group(5% ethanol), medium-dose citrinin group (5 mg·kg^－1), 4-PBA group (240 mg·kg^－1) and citrinin + 4-PBA group. The mice were exposed to citrinin after intraperitoneal injection of 4-PBA for 1 h. The pathologic injury, oxidative damage, apoptosis and the expression of ER stress related proteins in jejunum were tested after 14 days. Besides, Spearman correlation analysis was used to determine the correlation between ERS signaling pathway and intestinal oxidative stress as well as intestinal barrier dysfunction. The results showed that different dosage of citrinin could trigger intestinal damage, oxidative stress and intestinal barrier dysfunction. Pretreated with 4-PBA up-regulated total antioxidant capacity (T-AOC) and the activities of catalase (CAT), total superoxide dismutase (T-SOD), decreased the production of ROS and malondialdehyde (MDA), inhibited cell apoptosis and ERS, down-regulated the content of DAO, D-LA and ET, increased the mRNA expression of ZO-1, Occludin and Claudin-1, finally relieved the damage of jejunum caused by citrinin. In addition, the endoplasmic reticulum stress signaling pathway was significantly correlated with intestinal oxidative stress and intestinal barrier dysfunction. In summary, the study indicated that ERS plays an important regulatory role in citrinin-caused barrier dysfunction of jejunum.

In this study, Echinacea purpurea extract and sulfasalazine were used to treat intestine damp-heat syndrome rats, to explore the efficacy of integrated traditional Chinese and Western Medicine on Intestine Damp-heat syndrome rats, and to provide scientific basis for the treatment of Intestine Damp-heat syndrome diseases. The rats were randomly divided into 5 groups. Except the control group, the rest of the rats were treated with "internal and external Damp-heat + Escherichia coli" to establish Damp-heat syndrome rat model. Then Echinacea purpurea extract group, sulfasalazine group and integrated traditional Chinese and Western medicine group were given 1 g·kg^-1 Echinacea purpurea extract, 0.1 g·kg^-1 sulfasalazine, 1 g·kg^-1 Echinacea purpurea extract and 0.1 g·kg^-1 sulfasalazine, respectively. The disease model was evaluated by clinical symptom score. The serum inflammatory factors and the proportion of Th17/Treg cells in PBMCs were measured. The results showed that after modeling, the rats had poor spirit, decreased dietary intake, reduced amount of exercise, rough and yellowish hair, and excreted yellowish brown soft stool. After 6 days of administration, the spirit, dietary intake and appearance of rats in Echinacea purpurea extract group, sulfasalazine group and integrated traditional Chinese and Western medicine group returned to normal. Compared with the control group, the levels of IL-17 and IL-23 in serum in the model group were significantly higher (P<0.05), and the level of TGF-β, IL-10 in serum decreased significantly (P<0.05). In PBMCs of model group, the proportion of Th17 cells increased significantly (P<0.05), the proportion of Treg cells decreased significantly (P<0.05), and the proportion of Th17/Treg increased significantly (P<0.05) compared with the control group. Compared with the model group, the levels of IL-17 and IL-23 in serum in Echinacea purpurea extract group and integrated traditional Chinese and Western medicine group were significantly lower (P<0.05), and the levels of TGF-β in serum increased significantly (P<0.05). The proportion of Th17 cells decreased significantly (P<0.05), the proportion of Treg cells increased significantly (P<0.05), and the proportion of Th17/Treg decreased significantly (P<0.05). In conclusion, Echinacea purpurea extract combined with sulfasalazine can reduce the unbalanced Th17/Treg ratio in Intestine Damp-heat syndrome model rats by regulating related cytokines, so as to alleviate Intestine Damp-heat syndrome in rats.

The purpose of this study was to analyse the effect of Macleaya cordata extract and its combination with antibiotics on the Mycoplasma synovia natural infection in breeding hens. Eighty breeding hens of Hy-line Brown Parent with 124-day-old were randomly divided into Macleaya cordata extract group (G1), non-treated group (G2), doxycycline hydrochloride + Macleaya cordata extract group (G3), linco-spectin+ Macleaya cordata extract group (G4), tylosin tartrate + Macleaya cordata extract group (G5), tylvalosin + Macleaya cordata extract group (G6), temicoxacin phosphate + Macleaya cordata extract group (G7), and tiamulin fumarate + Macleaya cordata extract group (G8), respectively. G2 hens were treated normally, Macleaya cordata extract were added to the feed throughout the experiment in all groups except G2, antibiotics were added to the drinking water in the group 3, 4, 5, 6, 7, 8 for 5 days, and added for another 5 days after 3 days withdrawal. The swabs of the cleft palate before treatment, on day 17, 24, 38 and 59 after treatment, the swab of the magnum and the uterus of the oviduct on day 59 after treatment were collected for MS detection by fluorescent quantitative PCR. The blood before treatment, on day 17, 31 and 59 after treatment was collected for the MS antibody detection. On day 59 after treatment, the morbidities of the air sacculitis, foot pad swelling and salpingitis were counted by dissection, and the trachea, the magnum and the uterus of the oviduct were harvested, fixed and sujected to histopathological observation. After delivery, the average daily egg production per week for each group was counted for 6 weeks, and egg quality was measured at the 4th, 5th and 6th week. The results showed that: 1) Results of MS antigen dectection: MS loads of cleft palate swabs in G4 on day 17 and 24 after treatment were extremely significantly and significantly lower than those of G2 (P＜0.001 and P＜0.01), respectively, and MS loads of cleft palate swabs in G6 and G7 on day 17 after treatment were significantly lower than that of G2 (P＜0.01); MS positive rate of cleft palate swabs in the treatment groups (except G3 and G5) decreased on the 17th or 24th day after treatment, and increased to the level before treatment (except G4, G6 and G8) on the 59th day; The positive rate of MS antigen of the magnum of the oviduct in G2 and G8 was 20%, in G4, G5 and G7 was 10%, no MS antigen was found in the the magnum in G1, G3 and G6 and none in uterus of all groups. 2) Results of MS antibody detection: The average titer of MS antibody in G1 and G4 decreased by about 60% on the 59th day after treatment compared with those before treatment. 3) Results of pathological lesions observation: Varying degrees of infiltrating inflanmatory cells were found in the trachea before and after treatment, and no histopathological lesions were observed in the ovduct. 4) Results of egg quality: The average daily egg production per week of G1, G3, G4 and G6 was higher than G2 group; The average daily egg production per week of G8 was significantly lower than that of G2 at the 4th week after delivery (P＜0.01), no significant difference was found in the egg weight and egg quality between groups at other time points; The proportion of medium egg (53＜n≤63) of G4 was higher than other groups at the 6th week (60%) after laying. In conclusion, for the MS natural infection, the use of Macleaya cordata extract alone or Macleaya cordata extract in conjunction with antibiotics before delivery, and the continuous use of Macleaya cordata extract after delivery could decrease the antigen loads, the positive rates of the cleft palate swabs and the average titer of MS antibody in serum, and also increase the average daily egg production per week. Furthermore, the use of Macleaya cordata extract in conjunction with antibiotics also improve the relative abundance of medium egg. Therefore, the medical treatments used in the current study could do some extent improve to the early production performance of breeding hens.

This study aimed to investigate the inhibitory effect of baicalin on IBV and its underlying mechanism. Firstly, baicalin (125 μg·mL^-1)was added into cells (H1299 and Vero) before or after IBV infection to analyze the inhibitory effect of baicalin on IBV replication, and then baicalin was diluted into different concentrations to observe the inhibitory effect of different concentrations of baicalin on IBV replication. Furthermore, the experiment was divided into normal group, IBV group, pre-treatment group and post-treatment group, qRT-PCR and Western blot were used to detect mRNA and protein expressions of IFN pathway related signaling molecules in each group. At the same time, the sensitivity of IBVs to IFN treatment was analyzed after treatment with recombinant human IFN-α and the nuclear translocation of p-STAT1 was detected by indirect immunofluorescence in IBV group and dosed groups. Finally, the effect of STAT1 silencing on IBV replication was analyzed by gene silencing assay. The results showed that baicalin had an inhibitory effect on IBV replication in a dose-dependent manner. Baicalin treatment up-regulated the expressions of IFN pathway signaling molecules P-IRF3, IFN-β, p-STAT1 (P<0.05), down-regulated the expression of JAK-STAT signaling pathway negative regulator SOCS3 and SOCS3 stimulator IL-6 (P<0.05). Simultaneously, baicalin could increase IFN-mediated translocation of p-STAT1 and increase the sensitivity of IBV to IFN treatment. Further experiments revealed that silencing STAT1 decreased the inhibition effect of baicalin on IBV replication. The results showed that baicalin can inhibit IBV replication and reduce the pathological effect of viral infection on host cells by inducing type Ⅰ IFN production.

Hydroxytyrosol is a kind of natural polyphenolic compound with strong antioxidant activity. This experiment was conducted to investigate the effects of dietary hydroxytyrosol supplementation on growth performance, organ indexes, serum antioxidant performance, short-chain fatty acids, and intestinal inflammatory factors expression of broilers, in order to provide data support for the selection of green additives instead of antibiotics. A total of 126 1-day-old Arbor Acres (AA) broilers with the initial body weight of (46.0±1.0) g were randomly divided into 3 groups with 6 replicates per group and 7 broilers per replicate. Broilers in control group (CON) were fed normal basal diet, and those in experimental groups were fed experimental diets supplemented with 100 mg·kg^－1 aureomycin (ANT) and 500 mg·kg^－1 hydroxytyrosol (HT), respectively. The experiment lasted for 21 days. The weight gain and feeding consumption of broilers were recorded during the experiment. At 21 days of age, one broiler was randomly selected from each replicate of CON, ANT and HT groups for slaughter and sampling to detect the relevant indexes. The results showed as follows: 1) Compared with CON, BW of broilers in HT and ANT groups was increased by 3.70% and 4.17%, respectively, but the difference did not reach a significant level. The ADFI of broilers fed hydroxytyrosol was 57.17 g, which was significantly higher than that in CON and ANT groups (P=0.007). The data of feed to gain ratio of broilers in the three groups showed a different trend (P=0.069), and were 1.39 (CON group), 1.34 (ANT group) and 1.48 (HT group), respectively. 2) Compared with CON, the activity of catalase (CAT) was significantly increased (P<0.01) in serum of broilers in HT group. The total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) in serum of broilers in ANT and HT groups were numerically improved, but the differences were not statistically significant. The content of malondialdehyde (MDA) in ANT group and HT group was significantly lower than that in control group (P<0.01). 3) Compared with CON and ANT groups, the supplementation of HT significantly decreased the expression level of TLR-4 transmembrane protein in the TLR4/NF-κB inflammatory response pathway in jejunum mucosa (P<0.05). Compared with CON group and ANT group, supplementation of HT could reduce the expression levels of cytokines IL-1β, IL-6 and TNF-β at varying degrees (P<0.05),but the expression of anti-inflammatory cytokine TGF-β was decreased(P<0.05). The expression level of TNF-α was not significantly different between HT and ANT groups, but were both significantly lower than that of CON group (P<0.05). 4) Short-chain fatty acids (SCFA) such as acetic acid, propionic acid, butyric acid, isobutyric acid, valerate acid, isovalerate acid in cecal digesta were analyzed. No statistically significant difference was found in the contents of these SCFA among three treatment groups. In conclusion, hydroxytyrosol has significant antioxidant and anti-inflammatory effects, which can improve the growth performance of broilers. Its specific mechanism and application prospects need further investigation.

In order to investigate the innate immune response and antiviral response of host cells at the early stage of infection, infectious bronchitis virus (IBV) Beaudette strains was used to infect chicken macrophage HD11 cells. After 2 h, total RNA was extracted from the cells into cDNA, and high throughput transcriptomic sequencing was performed by Illumina. The results showed that 1 363 up-regulated genes and 653 down-regulated genes were screened out in the infection group. According to GO and KEGG analysis, it was found that in the early stage of the infection of IBV-infected HD11 cells, the differentially expressed genes were mostly related to immune response and antiviral effect. The enriched signaling pathways mainly focus on the cytokine-cytokine receptor interaction, viral protein interaction with cytokine and cytokine receptor, TNF signaling pathway, MAPK signaling pathway, etc. Ten randomly selected genes related to immune response and antiviral were verified by RT-qPCR, and the results were consistent with the transcriptome sequencing analysis. This study lays a foundation for further investigation of the pathogenesis of IBV and host cell immune response in the early stage of infection.

To investigate the prevalence and biological characteristics of swine influenza virus (SIV) in Jilin,the nasal swab samples were collected from swine farm in Jilin and inoculated into SPF chicken embryos for virus isolation. The isolated virus was identified using hemagglutination test and RT-PCR. Whole genome amplification, genetic evolutionary analysis, analysis of functional amino acid mutations, and selection pressure analysis were performed on the isolated strain. RT-PCR analysis confirmed that the isolated strain belonged to the H1N1 subtype of SIV. Genetic evolutionary analysis revealed that all eight gene segments of the strain belonged to the classical lineage of SIV H1N1. No gene rearrangements among different genotypes of influenza viruses were observed. Analysis of functional amino acid sites indicated that the strain had mutations at sites associated with increased pathogenicity, virulence, and replicability of SIV. Mutations in the NA gene were found at sites associated with resistance to neuraminidase inhibitors. Moreover, the HA and NA genes of SIV in Jilin province displayed evidence of autonomous mutations, with higher mutation rates observed in the NA gene compared to the HA gene. Whole genome sequence analysis of the H1N1 subtype SIV isolates in this study provides valuable insights for epidemiological investigations of SIV and future vaccine development.

In order to investigate the effects of transmissible gastroenteritis virus (TGEV) infection on the immune organs of piglets, ten healthy 5-day-old piglets were randomly divided into control group and TGEV-infected group (n=5). After 5 days of TGEV infection, the piglets were euthanized and the thymus, spleen, tonsil, inguinal lymph nodes, mesenteric lymph nodes, inferior iliac lymph nodes, superficial cervical lymph nodes and mandibular lymph nodes were collected. The pathological changes of various tissues and organs were observed by hematoxylin-eosin (HE) staining. The distribution of TGEV in various immune organs was also detected by immunohistochemistry (IHC). HE results showed TGEV infection enlarged the thymic lobules, and reduced immune cells in piglets. The red pulp was increased and filled with large numbers of blood cells. The margin between splenic cord and splenic sinus was unclear. Tonsil lymph follicles were decreased. Blood cell infiltrated in the superficial cortical area under the capsule of lymph nodes. IHC results showed that TGEV distributed in a variety of immune organs. The virus load in spleen was the highest, followed by superficial cervical lymph nodes and inguinal lymph nodes, and was least in the thymus. The above results indicate that TGEV infection affect the immune system of piglets, and cause damage to the immune system. This study provides a theoretical basis for the immune pathogenesis of TGEV.

The aim of this study was to investigate the phylogenetic grouping, drug resistance, virulence and resistance gene carriage and pathogenicity of Salmonella spp. carried by diseased pigeons in a region of Guangdong, and to propose a basis for the prevention and control of Salmonella spp. diseases in the region. In this study, 72 samples of diseased pigeon tissues were isolated, purified and identified. We determined the strain type by 16S rRNA sequencing, serotype identification, and PCR identification of Salmonella typhimurium-specific primers, and detected the drug resistance, resistance gene, and virulence genes of isolated bacteria, and carried out animal pathogenicity tests using mice. We found that the morphology, biochemical indexes, 16S rRNA sequence ratio, serotype identification and specific primer PCR results of the 12 isolates were consistent with the characteristics of Salmonella typhimurium; Resistance results showed that 12 strains were resistant to nalidixic acid and rifampicin, and highly sensitive to trimethoprim, co-trimoxazole, enrofloxacin, florfenicol, ampicillin, and meropenem; We found that 15 drug resistance gene test results showed that 7 strains contained tetA, 5 strains contained sul-11, and other resistance genes were not detected. The results of 17 virulence gene tests showed that the virulence gene carrier rate of 5 strains was 100%, and the virulence gene carrier rate of the remaining strains was also high; In addition, we found that in the animal pathogenicity test, the body weight and feed intake of mice in the experimental group decreased significantly, HE staining observed that the number of liver withered cells increased, the number of jejunal goblet cells decreased, and VH/CD decreased. The 12 strains isolated in this study all belonged to Salmonella typhimurium, all of which showed multi-drug resistance and high virulence gene carrier rate. Animal tests have observed that pathogenic bacteria can cause strong inflammatory damage to animal body organs and are highly pathogenic. We recommend the use of highly sensitive drugs such as trimethoprim for the treatment of salmonellosis in pigeons, or treatment with antibiotic substitutes, regular detection of bacterial resistance, and timely adjustment of treatment regimens.