【Objective】 This study was aimed to clone the CDS sequence of long-chain acyl-CoA synthetase 1 (ACSL1) gene in Lingqiu Qingbei goats and carry out bioinformatics analysis,and explore the expression pattern of ACSL1 gene in different tissues and the differentiation of subcutaneous fat cells in Lingqiu Qingbei goats. 【Method】 Based on ACSL1 gene sequence of Capra hircus in GenBank (accession No.:XM_018041882.1),specific primers were designed.The CDS sequence of ACSL1 gene was amplified by PCR using the cDNA template of liver in Lingqiu Qingbei goats and cloned and sequenced.The similarity alignment and phylogenetic tree construction were carried out with other species,and the bioinformatics analysis of ACSL1 protein was performed by the online software.The expression of ACSL1 gene in different tissues in Lingqiu Qingbei goats and ACSL1,ACACA,PPARγ and FASN genes at different differentiation stages of subcutaneous fat cells in goats were analyzed by Real-time quantitative PCR. 【Result】 The CDS region of ACSL1 gene in Lingqiu Qingbei goats was 2 100 bp in length,which encoded 699 amino acids.Similarity alignment revealed that the amino acid sequence of ACSL1 protein in Lingqiu Qingbei goats had the highest similarity with Ovis aries,reaching 99.0%.The results of phylogenetic tree showed that Lingqiu Qingbei goats had the closest relationship with Ovis aries and the farthest relationship with Orcinus orca,and the evolutionary process was highly conservative in different species.Bioinformatics analysis showed that the molecular formula of ACSL1 protein in Lingqiu Qingbei goats was C₃₅₂₉H₅₅₆₇N₉₂₉O₁₀₀₀S₃₆,the theoretical molecular weight was 78.2 ku,the theoretical isoelectric point was 7.46,the half-life was 30 h,and the instability coefficient was 31.61.ACSL1 protein was an alkaline hydrophobic protein with a transmembrane structure and no signal peptide.ACSL1 protein had 49 phosphorylation sites,and mainly played a biological function in mitochondria.The secondary structure of ACSL1 protein in Lingqiu Qingbei goats was composed of alpha helix (39.63%),random coil (31.33%),extended chain (20.74%) and beta turn (8.30%).ACSL1 protein might interact with 10 proteins such as FASN,ACACA and LPL.The tissue expression analysis showed that ACSL1 gene was expressed in all tissues of Lingqiu Qingbei goats,with the highest expression in liver,which was significantly higher than that in other tissues (P＜0.05),followed by subcutaneous fat,kidney and heart.The results of temporal expression of genes in goat adipocytes at different differentiation stages showed that,compared with day 0 of differentiation,the expression of ACSL1 gene in goats reached the peak on the 8th day of differentiation (P＜0.05),the expression of ACACA and FASN genes reached the peak on the 10th day of differentiation (P＜0.05),and the expression of PPARγ gene reached the peak on the 6th day of differentiation (P＜0.05). 【Conclusion】 The CDS sequence of ACSL1 gene in Lingqiu Qingbei goats was successfully cloned，and the expression pattern of ACSL1 gene in different tissues and the differentiation of subcutaneous fat cells of goats were clarified.The expression of ACSL1 gene was high in liver and subcutaneous fat.In the process of adipocyte differentiation,the expression of ACSL1,ACACA,PPARγ and FASN genes showed a trend of increasing first and then decreasing.The results provided a theoretical basis for further exploring the molecular mechanism of ACSL1 gene in fat deposition of goats.

【Objective】 This study was aimed to understand the prevalence of viral co-infections in diarrheic pig populations and the alterations in the gut microbiota community structure under viral infection. 【Method】 Seventy-three clinical porcine diarrhea samples were collected and subjected to metagenomic sequencing using single-end 100 bp read length (SE100).The raw data were quality-controlled using FastQC to obtain clean data,and host sequences were removed using BWA to generate unmapped data.Kraken 2 was used to align the unmapped data to an animal pathogen database for species classification annotation and to generate a species classification table.Principal component analysis (PCA) was performed for dimensionality reduction,and the data were normalized using reads per million (RPM).Z-score statistical methods were used to generate heatmaps for differential analysis visualization.MEGAHIT was employed for de novo assembly of viral sequences,and BWA was used to align unmapped data to contigs to assess assembly quality.High-quality contigs were selected and aligned to the NCBI database to find the most similar sequences.The unmapped data were aligned to these sequences to extract consensus sequences,which were used as the viral sequences.Phylogenetic analysis of Porcine epidemic diarrhea virus (PEDV) S gene and Porcine astrovirus (PAstV) ORF1a gene was performed using IQ-TREE. 【Result】 Various viruses were detected in 73 samples of pig diarrhea with the following positivity rates:PAstV 26.03%,Porcine kobuvirus (PKV) 20.55%,Porcine rotavirus (PoRV) 19.18%,PEDV 19.18%,Porcine sapporo virus (PSaV) 6.85% and Porcine deltacoronavirus (PDCoV) 4.11%.The mixed infection situation was complex,mainly consisting of a combination of PEDV and PAstV,accounting for 17.81% (13/73) of all samples and 30.95% (13/42) of mixed infection samples.The gut microbiota structure showed significant changes under different viral infections.The relative abundance of Lactobacillus was higher in PEDV-positive group than that in PEDV-negative group,and the relative abundances of Clostridium and Treponema were higher in PAstV-positive group than that in PAstV-negative group.Two complete PEDV genomes SE18 and SE22 were assembled,belonging to the GⅡa lineage,along with four PAstV ORF1a gene sequences SE18,PE31,PE36 and PE70,of which SE18 belonged to PAstV2 and the other three were closely related to HAstV-HMO-B strain. 【Conclusion】 This study revealed high positive rates and co-infection patterns of PAstV and PEDV in clinically diarrheic pig populations using metagenomic techniques,and also identified significant changes in gut microbiota composition due to PEDV and PAstV infections,providing critical data support for the prevention and control of mixed viral infections in pig diarrhea.

【Objective】 The gene expression differences of longissimus dorsi muscles with different tenderness in Xuzhou cattle were explored to identify the relevant regulatory genes and signaling pathways,providing a theoretical basis for further research on the mechanisms of muscle growth regulation in Xuzhou cattle. 【Method】 This study focused on a distinctive local cattle breed from Jiangsu,known as Xuzhou cattle.After slaughter,the longissimus dorsi muscle was assessed for shear force,dividing the samples into a high-tenderness group (n=6,shear force ＜5.5 kg) and a low-tenderness group (n=4,shear force＞7 kg).Transcriptome sequencing was conducted on muscle tissues from both groups.After filtering,quality control,alignment,and quantification of the sequencing data,differentially expressed genes were identified using the DESeq2 package in R language.Functional enrichment analysis was subsequently performed.Lastly,significantly differentially expressed genes,particularly cystatin B (CSTB),were analyzed for species homology,protein physicochemical properties,and other functional characteristics. 【Result】 ① Transcriptome analysis revealed that compared with the low-tenderness group,94 genes were up-regulated and 37 genes were down-regulated in the high-tenderness group.The top 20 differentially expressed genes included CSTB,VWF,DIRAS3,CDKN1A, CFB, etc. ② GO and KEGG enrichment analysis indicated that these differentially expressed genes were primarily involved in biological processes such as coagulation,immune response,wound healing,and the Wnt signaling pathway related to lipid metabolism.Gene pathway network analysis highlighted that CSTB,PRKG1,and PLAUR were among the differentially expressed genes shared across biological processes and molecular functions.③ The homology analysis of CSTB gene of cattle showed the highest similarity with Ovis aries at 97.96%,followed by Sus scrofa.The protein physicochemical properties analysis indicated that CSTB consists of 98 amino acid residues,with an instability index of 33.17 (＜40),suggesting that it was a stable protein.The prediction of protein secondary structure showed that CSTB was mainly composed of extended chain and random coil.STRING database analysis suggested potential interactions between CSTB and CTSH,WC1-10,and CTSB. 【Conclusion】 In this study,differentially expressed genes influencing the varying tenderness of Xuzhou cattle muscle were identified,including CSTB,VWF,DIRAS3,CDKN1A,and CFB.The results provide a theoretical basis and data support for beef quality research.

【Objective】 This study was aimed to clone the mitogen-activated protein kinase 8 (MAPK8) gene sequence in Mashan Black goats,conduct bioinformatic analysis,and construct its eukaryotic expression vector,so as to provide experimental materials for research on goat mammary gland development and the role of MAPK8 gene in transdifferentiation processes. 【Method】 Primers were designed based on MAPK8 gene sequence in Capra hircus (GenBank accession No.：XM_018042429.1).The MAPK8 gene CDS sequence was amplified from Mashan Black goats using PCR and cloned.Sequence alignment and phylogenetic tree construction were performed using DNAStar and Mega 11.0 software.Bioinformatic analysis was conducted using tools such as ProtParam and ProtScale.The eukaryotic expression vector was constructed,and lentiviral packaging was performed to collect viral supernatant,which infected the fibroblasts in Mashan Black goats.The expression of MAPK8 gene were detected using Real-time quantitative PCR in virus-infected and control groups. 【Result】 The sequence of MAPK8 gene CDS in Mashan Black goats was 1 155 bp in length,encoding a protein of 384 amino acids with a molecular weight of 43.98 ku.The molecular formula was C₁₉₆₈H₃₁₁₄N₅₂₈O₅₆₉S₂₂,and the isoelectric point (pI) was 7.13.Similarity alignment results revealed that the amino acid sequence similarity of MAPK8 gene between Mashan Black goats and different species was higher than 85%,indicating that the amino acid sequence of MAPK8 gene was relatively conserved.The phylogenetic tree indicated that the MAPK8 amino acid sequence in Mashan Black goats was most closely related to that of Bos taurus and least related to that of Danio rerio.MAPK8 protein in Mashan Black goats was hydrophilic and did not belong to transmembrane proteins.MAPK8 protein was primarily distributed in cytoplasm (52.2%),mitochondria (26.1%),nucleus (17.4%) and cell membrane (4.3%),and contained a serine/threonine protein kinases,catalytic domain (amino acids 26-321).The secondary structure of MAPK8 protein in Mashan Black goats included random coil,alpha helix, beta turn and extended chain.Protein interaction predictions suggested that MAPK8 protein might interact with MAPK9,JUN,TP53,FOS,JUNB,MAP2K4,MAP2K7,MAPK8IP1 and NFATC3 proteins.The lentiviral eukaryotic expression vector of MAPK8 gene pCDH-CMV-MAPK8-mcherry-Puro was successfully constructed,and transfection into Mashan Black goat fibroblasts resulted in the production of a red fluorescence signal.The expression of MAPK8 gene in experimental group was extremely significantly higher than that in control group (P＜0.01). 【Conclusion】 In this study,the CDS sequence of MAPK8 gene in Mashan Black goats was successfully cloned,and the pCDH-CMV-MAPK8-mcherry-Puro eukaryotic expression vector was constructed,providing important foundational data for future research on the function and application of MAPK8 gene in goats.

Animal infectious diseases are one of the most serious types of diseases that jeopardize the aquaculture industry,not only causing a large number of animal deaths and the loss of their products but also posing a major threat to human health.Therefore,rapid,accurate and inexpensive pathogen detection methods are of great significance for the prevention and control of animal infectious diseases.The clustered regularly interspaced short palindromic repeats (CRISPR) and associated proteins (Cas) system is a sensitive and specific biological system that can rapidly recognize pathogen-specific nucleic acid that plays an important role in the prokaryotic immune system.Pathogen detection methods based on the CRISPR-Cas system have the advantages of high specificity,high sensitivity and convenient operation,and have good prospects for application in the rapid detection of animal pathogenic microorganisms.The authors systematically introduced the type Ⅱ (cas9),type Ⅴ (cas12a,cas12b and cas14a) and type Ⅵ (cas13a) CRISPR-Cas systems,briefly described their working principles and application of NASBA-CRISPR,CAS-EXPAR,CASLFA,DETECTR,CORDS,HOLMESv2,SHERLOCK,SHERLOCKv2 and DETECTR-Cas14 established based on the CRISPR-Cas system in the detection of animal pathogenic microorganisms,and analyzed the problems faced by the CRISPR-Cas system in the detection of animal pathogens,including the impact of factors such as the specificity of the crRNA,the coupling with amplification technology,sample collection and transportation methods on quantitative detection,and proposed some solutions,aiming to provide a more in-depth understanding of the application of CRISPR-Cas technology in the detection of animal pathogenic microorganisms.

Viruses are one of the most important microorganisms causing diseases,which seriously endanger the health and life safety of human beings and animals.With the constant variation and recombination of viruses,such as Influenza virus,Severe acute respiratory syndrome coronavirus 2 and Porcine reproductive and respiratory syndrome virus,the protection provided by vaccines is limited.At the same time,the lack of effective antiviral drugs makes it difficult to treat viral infections.Therefore,it is an urgent need to find a new,safe and effective prevention and control methods to prevent viral infections.Traditional Chinese medicines have been widely used in antiviral research because of their safe composition,low resistance to drugs,and their ability to act on viruses in multiple ways and at multiple targets.Traditional Chinese medicine provides a rich base for antiviral drugs,but traditional experimental methods for antiviral drug development is time-consuming and heavy workload,the development of omics technology provides a new perspective for antiviral drug development,the use of omics data to analyze the relationship between drugs and diseases has become a powerful means of screening,evaluating the efficacy of drugs and discovering new drug targets.Therefore,the authors summarize and analyze the progress of transcriptomics,proteomics,metabolomics and multi-omics integration analysis in the antiviral research of traditional Chinese medicine,and analyze the application of traditional Chinese medicine in antiviral research through different omics perspectives,which not only contributes to an in-depth understanding of the antiviral mechanism of traditional Chinese medicine,but also provides a scientific basis for the research and development and optimization of antiviral drugs.

【Objective】 This study was aimed to clone and obtain the keratin 79 (KRT79) gene from the skin in Hetian sheep,investigate the effects of androgens on the skin structure of Hetian sheep,and understand the role of KRT79 in the process of influencing the skin structure of Hetian sheep through androgens,so as to lay the foundation for in-depth research on the function of KRT79 in sheep skin and the mechanism of androgen on the expression and regulation of KRT79 gene. 【Method】 Fifteen 2-year-old Hetian ewes were randomly divided into five groups with three in each group.Corn oil was injected into Hetian sheep in control group by intramuscular injection,while testosterone at doses of 1,2,3,and 4 mg/kg BW were injected into Hetian sheep in four experimental groups every three days for a total of 42 days.On the 42nd day,the back skin tissue was collected.Total RNA was extracted from the skin of Hetian sheep in control group,and the KRT79 gene CDS sequence was amplified by PCR,cloned and sequenced.The obtained KRT79 gene sequence of Hetian sheep was compared with the corresponding gene sequences of Ovis aries and other species using DNAStar software,and the phylogenetic tree of KRT79 gene of each species was constructed by Mega 5.0 software.The physicochemical property and structural characteristic of KRT79 protein were analyzed by bioinformatics online website.HE staining was used to observe the changes in the skin structure of Hetian sheep treated with testosterone.Real-time quantitative PCR and Western blotting were used to detect and analyze the difference of KRT79 gene and protein expression in the skin of Hetian sheep treated with different concentrations of testosterone.Immunofluorescence staining was used to explore the effect of testosterone on the expression distribution of KRT79 protein in the skin of Hetian sheep. 【Result】 The CDS region sequence length of KRT79 gene in Hetian sheep was 1 614 bp.The similarity of KRT79 gene sequence was 99.9% between Hetian sheep and Ovis aries.Phylogenetic tree analysis demonstrated that KRT79 gene had the closest evolutionary kindred with Ovis aries and the farthest evolutionary kindred with Mus musculus.KRT79 gene encoded 537 amino acids,which was an unstable hydrophilic protein,and the secondary structure of KRT79 protein was mainly comprised of alpha helix and random coil.The results of morphological analysis showed that the area of sebaceous glands in the skin of Hetian sheep expanded after testosterone treatment,and the number raised.Real-time quantitative PCR,Western blotting and immunofluorescence results indicated that the expression of KRT79 gene and protein in the skin of Hetian sheep were significantly higher than that in control group after testosterone treatment (P＜0.05).KRT79 protein was mainly distributed in the sebaceous glands,epidermis,and hair follicle areas of the skin in Hetian sheep. 【Conclusion】 The CDS region of KRT79 gene in Hetian sheep was 1 614 bp,and was an unstable hydrophilic protein.Androgen stimulation could significantly promote an increase in the area and quantity of sebaceous glands in the skin of Hetian sheep,and promote the expression of KRT79 gene and protein in the skin.This results provided a theoretical basis for further exploring the effects and mechanisms of androgens on the skin in Hetian sheep,and also provided a reference for the development of treatment methods for skin lipid metabolism abnormalities and keratin imbalance diseases caused by androgens.

【Objective】 The aim of this study was to explore the effects of different concentrations of stearic acid on the viability and milk fat synthesis of goat mammary epithelial cells (GMECs). 【Method】 Firstly,GMECs were cultured in vitro and treated with different doses of stearic acid (0,12.5,25,50,100 and 200 μmol/L) for 36 h,the effect on cell viability was detected by CCK-8 method,and the effect on cell triglyceride content was detected by cell triglyceride detection kit.The maximum concentration of stearic acid that had no inhibitory effect on cell viability was chose to treat cells,the effect of stearic acid on lipid droplet accumulation of GMECs were detected by oil red O staining.The mRNA expression levels of genes related to milk fat synthesis were detected by Real-time quantitative PCR. 【Result】 When the concentration of stearic acid was in the range of 0-100 μmol/L,it had no significant effect on cell viability (P>0.05),but when the concentration of stearic acid was 200 μmol/L,the activity of GMECs was significantly lower than that of the control group (P＜0.05).Compared with the control group,the triglyceride content and lipid droplet accumulation in GMECs of the 100 μmol/L stearic acid group were significantly or extremely significantly increased (P＜0.05 or P＜0.01).The Real-time quantitative PCR results showed that compared with the control group,after treatment with 100 μ mol/L stearic acid,the mRNA expression levels of cluster of differentiation 36 (CD36) and diacylglycerol O-acyltransferase homolog 1 (DGAT1) were extremely significantly or significantly increased (P＜0.01 or P＜0.05),The mRNA expression levels of heart-type fatty acid binding protein 3 (FABP3),stearoyl-CoA desaturase 1 (SCD1),adipose triglyceride lipase (ATGL) and forkhead box transcription factor O1 (FoxO1) were extremely significantly or significantly reduced (P＜0.01 or P＜0.05),while the mRNA expression levels of fatty acid synthase (FASN) and sterol-regulatory element binding protein 1 (SREBF1) genes were not significantly affected (P＞0.05). 【Conclusion】 100 μmol/L stearic acid could promote the synthesis of triglycerides and lipid droplet secretion in GMECs by regulating the expression of genes related to milk fat metabolism.This study provided a reference for exogenous addition of long-chain fatty acids to regulate milk fat synthesis and metabolism,which was of great significance for further improving the lactation performance and milk quality of dairy goats.

Goat meat has the characteristics of tender meat,low fat and cholesterol content,and is loved by consumers.Skeletal muscle is an important part of the animal body,which greatly affects the meat yield and meat quality of goats.Many genes,signaling pathways and molecules are involved in the regulation of skeletal muscle growth and development,such as myogenic regulatory factor family (MRFs),pair-box gene family (PAX),MAPK signaling pathway,PI3K-Akt signaling pathway,etc.Non-coding RNA (ncRNA),including small RNA (miRNA),long non-coding RNA (lncRNA),circRNA,etc.,play an important role in the growth and development of skeletal muscle by regulating these genes and signaling pathways.For example,miR-495-3p,miR-101a,miR-27b and lncR-125b can promote the differentiation of skeletal muscle satellite cells,and miR-99b-3p can promote the proliferation of skeletal muscle satellite cells.Some lncRNA act as miRNA sponges to regulate the expression of target genes and the growth and development of skeletal muscle.The study of ncRNA involved in regulating the development of skeletal muscle in goats is helpful to understand the growth and development process of skeletal muscle in goats,and also plays an important role in the improvement of meat quality.The author gives a brief introduction of miRNA,lncRNA and circRNA related to skeletal muscle development in goats and their related regulatory mechanisms,providing some references for further studies on the regulation of ncRNA on skeletal muscle development in goats.

【Objective】 Nitrogen utilisation by ruminant organisms is an important factor affecting the efficiency of farming,while their metabolites can cause some pollution to the environment.This study was aimed to investigate the effects of supplementation nicotinamide (NAM) on rumen fermentation parameters,microbial protein production and microbial community in lactating dairy cows,and explore the modulation of rumen fermentation and microflora in dairy cows by supplementation nicotinamide to improve the efficiency of nitrogen utilisation in the organism. 【Method】 Forty healthy mid-lactation Holstein dairy cows with similar age at lactation (170 d±50 d),litter size (2.23±0.62) and milk yield (36.17 kg±7.40 kg) were selected and randomly divided into four groups of 10 dairy cows each,dairy cows in control group were fed a total mixed ration (TMR) with 50 mL of tap water,and dairy cows in NAM groups (NAM7,NAM11 and NAM15) were given 7,11 and 15 g/d of nicotinamide on top of TMR, respectively.The trial period was 75 d,of which the pre-trial period was 15 d,and the trial period was 60 d.Rumen fluid samples were collected before morning feeding on the 30th and 60th days of the trial period and urine samples on days 0-2,28-30 and 58-60 of the trial period for the determination of pH,volatile fatty acids such as acetic and propionic acids,rumen microbial protein production and rumen microflora,respectively. 【Result】 ① Compared with control group,the rumen pH of dairy cows in NAM7 group was significantly increased (P＜0.05),and the acetic acid/propionic acid value of dairy cows in NAM groups were extremely significantly decreased (P＜0.01).The acetic acid/propionic acid value of dairy cows in NAM7 group was significantly or extremely significantly lower than that in NAM11 and NAM15 groups (P＜0.05 or P＜0.01).The interaction effect between trial treatment and trial period was not significant (P＞0.05).② The urinary allantoin,PD derivative concentration and rumen microbial protein content of dairy cows in NAM7 group were significantly higher than that in control group (P＜0.05),and the uric acid concentration was significantly higher than that in control,NAM11 and NAM15 groups (P＜0.05).The interaction effect between trial treatment and trial period was not significant (P＞0.05).③ The rumen Chao1 index and the number of species observed of dairy cows in NAM groups were significantly higher than that in control group (P＜0.05),and the relative abundance of Spirochaetes in NAM7 and NAM11 groups was significantly lower than that in control group (P＜0.05).The relative abundance of Succiniclasticum in NAM7 and NAM15 groups was significantly higher than that in control group (P＜0.05).The relative abundance of Shuttleworthia in NAM7 and NAM15 groups was significantly lower than that in control group (P＜0.05). 【Conclusion】 Under the conditions of this trial,nicotinamide could increase rumen pH,microbial protein production of dairy cows,and the relative abundance of Bacteroidetes,Proteobacteria and Ruminococcus, and decrease the acetic acid concentration,acetic acid/propionic acid value,and the relative abundance of Firmicutes and Prevotella.The recommended nicotinamide supplementation rate was 7 g/d.

【Objective】 The study aimed to investigate the effects of dietary supplementation with non-starch polysaccharide (NSP) enzymes on the growth performance,slaughter performance,nutrient metabolizability,and nitrogen emission of meat ducks reared in three-dimensional cages. 【Method】 A 2×3 factorial experiment was designed,with two levels of dietary NSP enzyme supplementation (0 and 500 mg/kg) and three cage positions (upper,middle,and lower),corresponding to heights of 1.8,1.2,and 0.6 m above the ground.A total of 840 healthy 21-day-old Pekin ducks of similar body weight were randomly assigned to 6 treatment groups,with 10 replicates per group and 14 ducks per replicate (equal numbers of males and females).The experimental period lasted from 21 to 42 days of age.After feeding,the body weight and feed intake of 42-day-old Pekin ducks (fasting for 6 h) were recorded,and the average body weight and average daily gain,average daily feed intake and feed to gain ratio (F/G) of 21 to 42 days old ducks were calculated.The breast muscle,leg muscle and abdominal fat of 42-day-old Pekin ducks were collected and weighed,and the breast muscle percentage,leg muscle percentage and abdominal fat percentage were calculated.The excreta of the ducks at the 41 and 42 days of age was collected and the apparent metabolic rate of nutrients was calculated. 【Result】 ① As the cage position decreased,the body weight at 42-day-old,average daily gain,and daily feed intake of meat ducks from 22 to 42 days of age were significantly decreased (P＜0.05).The average daily feed intake and F/G of meat ducks from 22 to 42 days of age were significantly reduced when NSP enzymes were added to the feed (P＜0.05).② Neither dietary NSP enzyme supplementation nor cage location significantly affected the weight or ratio of breast muscle,leg muscle,and abdominal fat (P＞0.05).③ As the cage location decreased,crude protein metabolizability were extremely significantly decreased (P＜0.01).The metabolizability of energy,crude protein,and dry matter were extremely significantly improved by dietary NSP enzyme supplementation (P＜0.01).There was a significant interaction effect between dietary NSP enzyme supplementation and cage location on crude protein metabolizability (P＜0.05).④ As the cage location decreased,crude protein and nitrogen intake were extremely significantly decreased (P＜0.01),while nitrogen excretion was extremely significantly increased (P＜0.01).The crude protein intake and nitrogen excretion were extremely significantly reduced by dietary NSP enzyme supplementation (P＜0.01). 【Conclusion】 In three-dimensional cage rearing of meat ducks,dietary NSP enzymes supplementation could reduce average daily feed intake and F/G,improve apparent metabolizability rate of dry matter,energy and crude protein and reduce crude protein intake and nitrogen emission of meat ducks in the fattening stage.Cage position significantly affected body weight,average daily gain,average daily feed intake,metabolic rate of crude protein nutrients,crude protein intake,nitrogen intake and nitrogen excretion of 42-day-old meat ducks.

【Objective】 This experiment was conducted to study the effects of different levels of cassava meal on production performance,serum biochemical parameters,and immune indexes of Wenchang chickens. 【Method】 A total of 600 eighty-one-day-old healthy female Wenchang chickens were randomly divided into 5 groups with 6 replicates per group and 20 chickens per replicate.Chickens were fed diets supplementing 0(CM0),5％(CM5),10％(CM10),20％(CM20),and 25％(CM25) cassava meal,respectively.The trial period lasted for 40 days.The experimental chickens were weighted on the end of the experiment and the growth performance was calculated. Two chickens’ serum in per replicates were collected for the measurement of serum biochemical indicators and serum immune indexes,and slaughter performance and organ coefficients were measured after slaughter. 【Result】 ①Compared with CM0 group,daily gain of Wenchang chickens in CM10,CM20 and CM25 groups was significantly increased (P＜0.05),while the ratio of feed to gain were significantly decreased (P＜0.05).②Supplementing different levels of cassava meal had no significant effects on slaughtering performance and organ coefficients of Wenchang chickens (P＞0.05).③Compared with CM0 group,serum glucose levels of Wenchang chickens in CM20 and CM25 groups were significantly increased (P＜0.05);Serum glutathione peroxidase content of Wenchang chickens in CM20 group was markedly increased in comparison to CM0 group (P＜0.05). Compared with CM0 group,the serum immunoglobulin A content of Wenchang chickens in CM5 group was significantly increased (P＜0.05),but serum tumor necrosis factor-α content of CM25 group was significantly decreased (P＜0.05). 【Conclusion】 Supplementing appropriate amount of cassava meal could improve production performance of Wenchang chickens,and improve the glyco metabolism as well as antioxidant properties.Therefore,it was recommended that the appropriate level of cassava meal in the diets of Wenchang chickens aged from 81 to 120 days was 20％.

【Objective】 The purpose of this study was to study the effects of Aspergillus niger on rumen fermentation in vitro,methane emission and microflora of dairy cows,and provide theoretical basis for the rational application of Aspergillus niger as a feed additive in dairy cow production. 【Method】 In vitro rumen fermentation device was used to divide into four groups:Group A (control group),groups B,C and D.0,15,20 and 25 mg of Aspergillus niger (spore concentration ≥1.0×10⁹ /g) were added to the fermentation bottle (including artificial feed and culture medium) of each group,respectively.Each treatment was repeated 3 times,and 3 blank groups were set up to correct the gas and methane content (blank group did not contain feed,only culture medium).Gas and methane production were measured at 3,6,9,12 and 24 h after the beginning of culture.After 24 hours of culture,the pH,ammonium nitrogen (NH₃-N),microbial protein (MCP),volatile fatty acid (VFA) and microbial community diversity of rumen were analyzed. 【Result】 Compared with group A,the pH of rumen fermentation fluid of groups B,C and D were significantly increased (P＜0.05),while the NH₃-N content was significantly decreased (P＜0.05).The MCP content in groups C and D was significantly higher than that in group A (P＜0.05),while that in group B was significantly lower than that in the other three groups (P＜0.05).There were no significant differences in VFA content,acetic acid/propionic acid ratio and TVFA content among all groups (P＞0.05).The ratio of CH₄ production to total gas production in group A was significantly higher than that in groups B,C and D (P＜0.05).16S rRNA sequencing showed that there was no significant difference in rumen microbial Alpha and Beta diversity index between groups B and A (P>0.05).Among the top 10 bacteria in rumen at phylum level,Proteobacteria and Bacteroidetes were the dominant bacteria in rumen of dairy cows,and there was no significant difference between groups A and B (P＞0.05).Spirochaetota had a significant negative correlation with PA and NH₃-N content (P＜0.05).Fibrobacterota was positively correlated with pH (P＜0.05),and negatively correlated with VA,BA,AA,CH₄ and NH₃-N contents (P＜0.05).Among the top 10 bacteria in rumen at genus level,Prevotella and Rikenellaceae_RC9_gut_group were the dominant bacteria in the rumen of dairy cows.Compared with group A,the relative abundance of Succinivibrio in group B was significantly decreased (P＜0.05).Rikenellaceae_RC9_gut_group was positively correlated with NH₃-N content (P＜0.05).There was a significantly positive correlation between the contents of VA,BA,AA,CH₄ and NH₃-N with Bacteroidales_RF16_group (P＜0.05).Compared with group A,the absolute content of bacteria and methanogens in group B was significantly increased (P＜0.05).The absolute content of protozoa in group B was significantly reduced (P＜0.05). 【Conclusion】 Besides improving the rumen fermentation environment of dairy cows,the addition of Aspergillus niger affected the production of VFA,NH₃-N,MCP and methane emission by regulating the microbial community structure in rumen,revealing the potential complex mechanism of microbial intervention to improve the health and production efficiency of dairy cows.

Tryptophan (Trp) is one of the essential functional amino acid.Tryptophan and its bacterial metabolites are crucial for maintaining host intestinal homeostasis,promoting growth performance and metabolism.Tryptophan produces various beneficial bacterial metabolites through metabolic processes such as indole,kynurenine and 5-hydroxytryptamine pathways.Tryptophan and its metabolites can promote the expression of tight junction proteins in intestinal epithelial cells,increase the synthesis and secretion of mucins in the intestinal mucosal barrier.In addition,tryptophan and its metabolites promote the colonization of beneficial bacteria in the intestinal microbiota,inhibit the proliferation of pathogenic bacteria,and maintain the stability and diversity of the microbiota.The positive effects of tryptophan and its bacterial metabolites on the growth performance of livestock and poultry include increasing feed intake,daily weight gain,alleviating growth barriers,and improving the quality of livestock and poultry products.However,there is currently a lack of systematic research on the mechanism of action of tryptophan bacterial metabolites in the intestinal health,nutritional metabolism and growth performance of livestock and poultry.Future research should focus on how tryptophan metabolites influence microbial colonization and mediate different signaling pathways to regulate intestinal barrier function.The authors summarize recent findings on the role of tryptophan and its metabolites in enhancing the intestinal mucosal barrier,growth performance,and immune response,aiming to provide new ideas and methods for the application of tryptophan bacterial metabolites in livestock and poultry production.

【Objective】 This study was aimed to enhance the nutritional value and mitigate adverse effects by investigating the effects of different supplementing complex bacteria on the composition of fermentation products from black soldier fly larvae meal. 【Method】 The experiment was divided into four distinct treatments.Treatment TB was inoculated with Bacillus subtilis and Lactobacillus plantarum,treatment TF was inoculated with Aspergillus Niger and Saccharomyces cerevisiae,and treatment TM was inoculated with a mixture of four bacteria，all as fermentation treatment.Treatment CK served as a non-inoculated control.Each fermentation treatment was inoculated with a bacterial suspension at a ratio of 10% (V/W) into the meal of black soldier fly larvae,with the control group receiving an equal amount of sterile water.Aerobic solid fermentation was conducted at 30 ℃ for 5 d.After fermentation,samples were dried to determine crude fat,crude protein,chitin,crude ash,fatty acid profiles and amino acid spectra. 【Result】 ①In terms of fermentation product composition of black soldier fly larvae meal,compared with CK,TM treatment significantly increased crude fat content (P＜0.05),while other fermentation treatments had no significant impact on the crude fat content (P＞0.05).Each fermentation treatment led to a reduction in crude protein content to varying degrees,with TF treatment exhibiting a significant level (P＜0.05).Each fermentation treatment significantly reduced chitin content (P＜0.05),with TM treatment showing the greatest reduction,followed by TB treatment.No significant effect was observed for each fermentation treatment on crude ash content (P＞0.05).②In terms of fatty acid composition of fermentation products from black soldier fly larvae meal,compared with CK,TB treatment resulted in a notable increase in the proportion of short and medium chain fatty acids,accompanied by a significant reduction in the content of unsaturated fatty acids (P＜0.05).The n-6/n-3 ratio in polyunsaturated fatty acids (PUFA) remained largely unaffected.TF and TM treatments demonstrated a significant increase in the proportion of n-6 PUFA and a significant decrease in the proportion of n-3 PUFA and saturated fatty acids (P＜0.05).③In terms of amino acid composition of fermentation products from black soldier fly larvae meal,compared with CK,the fermentation treatments significantly reduced the content of non-essential amino acids,essential amino acids and total amino acids (P＜0.05).The only exception was TF treatment,which significantly increased the content of the first limiting amino acid methionine (P＜0.05).TF treatment exhibited the highest protein scores among the fermentation treatments,followed by TB treatment. 【Conclusion】 The complex bacteria had the potential to optimize the composition of fermentation products from black soldier fly larvae meal and enhance their nutritional value. The composition of fermentation products from different complex bacteria combinations exhibited significant differences.

【Objective】 This study aimed to investigate the effects of curcumin (CUR) on growth performance,apparent digestibility of nutrients and serum biochemical indexes of breeding cattle under heat stress condition,and to explore the appropriate curcumin supplementation level in beef cattle diets under heat stress condition. 【Method】 Thirty-two healthy Yanbian Yellow breeding cattle,weighing 286.36 kg±3.95 kg,were randomly divided into four groups,with eight replicates in each group and one cow in each replicate.The curcumin supplemental levels for each group were set at 0,100,200 and 300 mg/kg DM diet respectively，named as control group,100 CUR,200 CUR,and 300 CUR groups.The prefeeding period was 7 days and the test period was 30 days.During the experiment,the temperature and relative humidity of the cowshed were measured at different time points every day,and the temperature and humidity index (THI) was calculated.During experimental period, THI≥72,the experimental cattle were considered to be in a state of heat stress.On the morning of the 31st day,the experimental cattle were weighed and their body size was assessed.Blood was drawn from the jugular vein to test serum biochemical indicators.The total fecal collection method was used to collect fresh feces for the measurement of apparent digestibility of feed nutrients. 【Result】 Compared to control group,cattle in 200 CUR group exhibited significant improvements in average daily weight gain,body depth,and chest circumference (P＜0.05),alongside a notable reduction in feed-to-gain ratio (P＜0.05).The apparent digestibility of crude fat,neutral detergent fiber and acid detergent fiber were significantly enhanced (P＜0.05),serum albumin and thyroid hormone levels were markedly elevated (P＜0.05),whereas activities of glutamate-oxaloacetic transaminase and glutamate-pyruvic transaminase as well as triglyceride content were significantly diminished (P＜0.05),furthermore,malondialdehyde levels showed a significant decrease (P＜0.05) in 200 CUR group.Compared to control group,the body height,crude protein digestibility,serum total protein and globulin contents were significantly increased (P＜0.05),the levels of heat shock protein 70 and cortisol were significantly decreased (P＜0.05) in three experimental groups.Serum immunoglobulin A was significantly increased in 100 CUR group (P＜0.05).The activities of superoxide dismutase,glutathione peroxidase,and total antioxidant capacity in bovine serum were significantly elevated in 200 CUR and 300 CUR groups (P＜0.05). 【Conclusion】 Adding 200 mg/kg DM curcumin to the diet of Yanbian Yellow breeding cattle during heat stress could improve their growth performance,apparent digestibility of feed nutrients,and antioxidant capacity.

Plant essential oil (PEO) is one of the main types of natural plant extracts,which has good antibacterial,antioxidant,anti-inflammatory,immune-enhancing and other functions.PEO is recognized as a non-toxic,pure natural green new plant additive because of its fast degradation,short half-life and no accumulation in the body.PEO plays an antibacterial role by hyperpolarizing the cell membrane and destroying the cell homeostasis.It can improve the body’s antioxidant capacity by scavenging free radicals,inhibiting cell membrane lipid peroxidation,and enhancing antioxidant enzyme activity.It can also reduce the risk of inflammation and alleviates inflammation by inhibiting the expression of pro-inflammatory cytokines,reducing the content of NO,prostaglandin E₂ and reactive oxygen species synthesis.In terms of chicken production performance,PEO can increase feed intake,body weight gain,feed utilization rate,and reduce feed to gain ratio.In terms of egg quality,PEO can increase the thickness and strength of egg shell,egg weight and egg mass,egg yolk color score and Haugh unit.In terms of chicken quality,PEO can significantly reduce the content of saturated fatty acid in serum and thigh,significantly increase the content of polyunsaturated fatty acid in serum and thigh,and significantly reduce the drip loss of chicken.In terms of intestinal flora and intestinal morphology of chickens,PEO can significantly increase the number of probiotics in the intestinal tract of chickens,significantly reduce the number of pathogenic bacteria,and significantly increase the villus height,crypt depth and villus/crypt ratio of duodenum,ileum and cecum of chickens.In terms of chicken serum biochemical and immune performance,PEO can improve the body’s metabolic level,increase the body’s cellular immune response and humoral immune response.In this paper,the biological function and mechanism of PEO were firstly reviewed,then the application and mechanism of PEO in chicken production were expounded,in order to provide more theoretical reference for the practical application of PEO in chicken production.

【Objective】 The effects of different doses of Bacillus subtilis on the growth performance,intestinal mucosa morphology,serum biochemistry and immune indexes of nursery pigs were studied to explore the optimal dose of Bacillus subtilis in nursery pig breeding,and to provide a reference for the efficient application of Bacillus subtilis. 【Method】 Two hundred and forty nursery pigs with similar body condition were selected and equally divided into four groups with six replicates per group and ten pigs per replicate.Piglets in control group were fed a basal diet,and in the three experimental groups were fed a basal diet supplemented with 200,400 and 800 mg/kg Bacillus subtilis (the viable counts were 2.0×10⁹,4.0×10⁹ and 8.0×10⁹ CFU/kg),respectively.The experiment lasted for 60 days.At the end of the experiment,one pig was randomly selected from each replicates,and serum,jejunal and ileal samples were collected.Growth performance,intestinal mucosal morphology,serum biochemical and immune indexes of nursery pigs were measured. 【Result】 Compared with the control group,the addition of 400 and 800 mg/kg of Bacillus subtilis to the diets significantly increased the final body weight and average daily gain of nursery pigs in the experimental period (P＜0.05),and significantly reduced the feed-to-gain ratio (P＜0.05),significantly increased the villus height and the ratio of villus height to crypt depth of the ileum and jejunum of nursery pigs (P＜0.05),and significantly decreased the crypt depth of the ileum and jejunum (P＜0.05),significantly increased albumin,total protein,immunoglobulin A,immunoglobulin G,and interleukin-2 contents in serum of nursery pigs (P＜0.05),and significantly decreased tumor necrosis factor-α content of serum (P＜0.05).The addition of 200 mg/kg Bacillus subtilis had no significant effect on growth performance,intestinal mucosa morphology,serum biochemistry and immunity indexes of nursery pigs (P＞0.05) 【Conclusion】 Adding Bacillus subtilis to nursery pig diets could improve their growth performance,optimize the intestinal mucosal structure,and improve the level of protein turnover metabolism and immune function of the body.Taking all factors into consideration,the appropriate dosage for addition was 400 mg/kg (viable cell count was 4.0×10⁹ CFU/kg).

Inosine monophosphate (IMP)，as an intermediate product of purine metabolism，is involved in intracellular energy metabolism and signal transduction.Meanwhile，IMP is a key flavor precursor in livestock and poultry muscle.It has complex interactions with amino acids,sugars and other substances to produce aroma compounds，which significantly improves the umami and aroma of livestock and poultry muscle.IMP content is an important evaluation index for meat flavor and a significant factor affecting the economic value of livestock and poultry muscle products.Therefore，the impact of IMP on meat quality and the genetic regulatory mechanisms of IMP deposition have garnered significant attention.The synthesis and metabolism of IMP are regulated by a network of numerous genes.With the development of modern molecular biology techniques，researchers have delved into the synthesis and metabolic pathways of IMP，revealing several key enzymes and regulatory genes.Currently，multi-omics technologies have been widely applied to elucidate the genetic mechanism underlying important economic traits in livestock and poultry，and further breakthroughs are expected in understanding the regulatory mechanism of IMP deposition in livestock and poultry muscle.This article provides an overview of the research progress on IMP in livestock and poultry muscle，introduces the structure and detection methods of IMP，outlines its impact on meat quality，reviews the mechanism of IMP synthesis and metabolism，and analyzes the main factors affecting IMP synthesis and metabolism.This review serves as a theoretical reference for further research on the synthesis and metabolism mechanism of IMP，the regulation mechanism of meat flavor in livestock and poultry，and the genetic improvement of livestock and poultry breeding.

【Objective】 The aim of this study was to investigate the effects of oleoresin capsicum (OC) on serum biochemical,immune and antioxidant indexes of fattening cattle,so as to provide a theoretical basis for the application of OC in fattening cattle rearing and production. 【Method】 Forty-eight Simmental crossbred cattle in good condition,of similar age (15.5±0.5) and weight (484.73 kg±48.42 kg) were selected and divided into four groups of 12 replicates each with one cattle per replicate in a randomized block design.The cattle in control group were fed with the original diet of cattle farm,and cattle in groups Ⅰ,Ⅱ and Ⅲ were fed with adding 4,8 and 12 g/d OC to the original diet of cattle farm,respectively.The pre-test period was 7 d,and the test period was 90 d.Blood samples were collected at the end of the test to determine serum biochemical,immune and antioxidant indexes. 【Result】 Compared with control group,① The levels of total protein (TP) and albumin (ALB) in serum of cattle in group Ⅱ were significantly increased (P＜0.05),whereas the urea nitrogen (BUN) level was significantly decreased (P＜0.05).②The immunoglobulin A (IgA) content in serum of cattle in groups Ⅰ,Ⅱ and Ⅲ were significantly increased (P＜0.05),and the contents of interleukin-1 (IL-1),IL-2 and tumor necrosis factor-α (TNF-α) were significantly decreased (P＜0.05).The contents of IgM and IL-4 in serum of cattle in groups Ⅰ and Ⅱ was significantly increased (P＜0.05),and the interferon-γ (IFN-γ) content was significantly decreased (P＜0.05).The IgG content in serum of cattle in group Ⅱ was significantly increased (P＜0.05),while the contents of IgG,IgM,IL-4 and IFN-γ in group Ⅲ showed no significant changes (P＞0.05).③The total antioxidant capacity (T-AOC),superoxide dismutase (SOD) and catalase (CAT) activities in serum of cattle in groups Ⅰ and Ⅱ were significantly increased (P＜0.05),while the malondialdehyde (MDA) content was significantly decreased (P＜0.05).The glutathione peroxidase (GSH-Px) activity in serum of cattle in group Ⅱ was significantly increased (P＜0.05),whereas there was no significant changes of various antioxidant indexes in group Ⅲ (P＞0.05). 【Conclusion】 Dietary supplementation of appropriate OC could improve the antioxidant capacity and immunity of fattening cattle to a certain extent.Under the conditions of this experiment,the supplementation of 8 g/d OC in diet of fattening cattle had the best effect on improving antioxidant capacity and immunity.

As a probiotic,Rhodopseudomonas palustris is not only metabolically robust but also rich in a variety of amino acids,vitamins,carotenoids,coenzyme Q,and other bioactive substances.It exhibits numerous biological functions.On the one hand,Rhodopseudomonas palustris can purify water by degrading and assimilating nitrogen,phosphorus,and other compounds through the production of specific metabolic enzymes.On the other hand,it promotes the growth of aquatic animals by providing essential nutrients,enhancing digestive enzyme activities,and increasing the abundance of beneficial intestinal bacteria.Moreover, Rhodopseudomonas palustris boosts the disease resistance of aquatic animals by enhancing the activity of immune-related enzymes to strengthen non-specific immunity,modulating signaling pathways to activate specific immunity,and producing antimicrobial substances or competing for ecological niches to inhibit the growth of pathogenic bacteria.Given the context of intensive aquaculture practices and the feed additive restrictions,Rhodopseudomonas palustris is widely utilized in aquaculture as a water purifier and feed additive due to its critical functions of improving water quality,enhancing animal growth performance,and strengthening immunity.The authors systematically reviewed the research progress on Rhodopseudomonas palustris in aquaculture,offering insights into future research directions and serving as a reference for further studies on its application in this field.

【Objective】 The experiment was aimed to investigate the effects of compound bacteria culture on growth performance,immune function and vaccine antibody titer of Mongolian-Han crossbred mutton sheep. 【Method】 Forty 1.5-month-old Mongolian-Han crossbred male lambs with good health and similar body weight were randomly divided into 2 groups,control group and experimental group,with 4 replicates in each group and 5 lambs in each replicate.The lambs in control group was fed with basal diet,and the lambs in experimental group was fed with additional 30 g/d of compound bacterial culture per sheep on the basis of the basal diet.On the 16th day of the experiment,each lamb was injected with type A foot-and-mouth disease and sheeppox vaccines.The pre-trial period was 7 days and the formal period was 90 days.On the 0th,30th,60th and 90th day of the experiment,the lambs were weighed,blood was collected and serum was separated before morning feeding,and the growth performance,immune and antioxidant indexes were measured.On the 15th,30th and 45th day of the experiment,blood was collected and serum was separated to determine the antibody titers of type A foot-and-mouth disease and sheep pox vaccine. 【Result】 On the 90th day of the experiment,compared with control group,the average body weight of mutton sheep in experimental group were significantly increased (P＜0.05).From 0 to 90 days of the experiment,there was no significant difference in the average daily feed intake (ADFI) and feed to gain ratio (F/G) of mutton sheep between experimental group and control group (P＞0.05),but the average daily gain (ADG) of mutton sheep in experimental group was significantly increased compared to control group (P＜0.05).On the 90th day of the experiment,compared with the control group,the activity of lysozyme (LZM),contents of interleukin-1β (IL-1β),transforming growth factor-β (TGF-β),tumor necrosis factor-α (TNF-α),activities of catalase (CAT) and glutathione peroxidase (GSH-Px),and total antioxidant capacity (T-AOC) in serum of mutton sheep in experimental group were significantly increased (P＜0.05),while the content of malondialdehyde (MDA) was significantly decreased (P＜0.05).On the 45th day of the experiment,compared with control group,the antibody titer of the sheeppox vaccine of mutton sheep in experimental group was significantly increased (P<0.05),while the antibody titer of the foot-and-mouth disease type A vaccine was not significantly different (P＞0.05). 【Conclusion】 The addition of compound bacteria culture could significantly improve the growth performance,immune function and antioxidant function of Mongolian-Han crossbred mutton sheep,and increase the titer of vaccine antibody.

【Objective】 Oocytes collected by ovum pickup (OPU) in Japanese Black cattle (Wagyu) were matured in vitro (IVM) in medium supplemented with different sources of follicle-stimulating hormone (FSH) and luteinizing hormone (LH),and the in vitro and in vivo developmental potentials were studied after in vitro fertilization (IVF) and in vitro culture (IVC). 【Method】 According to the 3×2 experimental design,OPU oocytes were matured in 6 groups of IVM media in combinations with 3 FSH (NIH-FSH,NB-FSH and CA-FSH,0.13 IU/mL) and 2 LH (NIH-LH and NB-LH,23 IU/mL) for 22-24 h.The blastocyst developmental rate was compared after IVF and IVC.The pregnancy rate was examined by ultrasound 40 days after embryo transfer (ET) to the synchronized recipients. 【Result】 The best combination was supplementing 0.13 IU/mL NIH-FSH and 23 IU/mL NIH-LH in IVM medium,and the blastocyst development rate was up to 47.3%.The pregnancy rate of blastocysts (62.6%-64.0%) derived from OPU oocytes cultured for 6 days(IVC 6D)post IVM and IVF was not significantly different from that of in vivo embryos (P＞0.05),but significantly higher than that of embryos cultured for 7 days (IVC 7D) (44.2%-47.1%) (P＜0.05).The pregnancy rate of blastocysts transferred into heifer recipients was as high as 67.1%,and open recipients after pervious ET cycle could be used for next ET treatment,but the pregnancy rate was significantly lower when ET was repeated 4 times compared with 0 and 1 times (P＜0.05). 【Conclusion】 This study demonstrated that different sources of FSH and LH in combinations in IVM medium had a significant effect on the embryonic development potential of OPU-IVF oocytes.The pregnancy rate of blastocysts from IVC 6D was significantly higher than that from IVC 7D.The optimized OPU-IVF-ET system could effectively cultivate excellent Wagyu breed and rapidly expand its production population.

【Objective】 The aim of this study was to investigate the biological function of cysteine and glycine-rich protein 3(CSRP3) gene in sika deer and its expression patterns in different muscle tissues. 【Method】 The longissimus dorsi muscle tissues of sika deer were used as experimental sample.The cDNA sequence of CSRP3 gene was cloned and sequenced,followed by sequence similarity alignment,construction of a phylogenetic tree,and bioinformatics analysis of CSRP3 protein. The expression differences of CSRP3 gene in longissimus dorsi muscle,gluteus maximus,intercostal muscle and quadriceps of sika deer was studied by Real-time quantitative PCR technology. 【Result】 The CSRP3 gene of sika deer was successfully cloned,and its coding region was 585 bp in size,encoding 194 amino acids.The BLAST comparison showed that CSRP3 gene of sika deer had the highest similarity with Cervus elaphus,at 99.83%,and the similarity with Odocoileus virginianus,Bos taurus,and Ovis aries were also over 95%,indicating that CSRP3 gene in sika deer had a high degree of conservation in evolution.The phylogenetic tree was constructed based on CSRP3 gene,and the results showed that sika deer was most closely related to that of Cervus elaphus and most distantly related to that of Panthera tigris and Orcinus orca.The molecular formula of CSRP3 gene-encoded protein was C₉₀₃H₁₄₀₃N₂₆₃O₂₇₅S₁₉,and the relative molecular mass was 20 952.81,the theoretical isoelectric point (pI) was 8.89,the fat coefficient was 43.81. The secondary structure of the protein was mainly random coil. Subcellular localization prediction indicated that the protein was located in the nucleus.Real-time quantitative PCR results showed that CSRP3 gene was expressed in different muscle tissues of sika deer.The expression level of this gene was the highest in the intercostal muscle of sika deer,with significant differences compared with the longissimus dorsi muscle,gluteus maximus,and quadriceps (P＜0.05),while the expression of CSRP3 gene in the longissimus dorsi muscle,gluteus maximus,and quadriceps were not significantly different (P＞0.05). 【Conclusion】 The CSRP3 gene of sika deer was successfully cloned in this study,which encoded a protein located in the nucleus of the cell.The CSRP3 gene was differentially expressed in different muscle tissues of sika deer.The results provided a data basis for investigating the regulatory mechanism of CSRP3 gene in sika deer meat quality.

The physical dimensions and weight data of livestock are one of the primary parameters for assessing production and breeding characteristics,and provide essential reference data for the selection of superior breeds.Traditional methods of measuring livestock dimensions and weight are time-consuming and labor-intensive,and are subject to significant interference from subjective factors,which can severely compromise the welfare of the animals.With the advancement of modern scientific and technological levels,the rapid development of automatic measurement technology for livestock dimensions and weight has achieved remarkable research progress.The author summarizes the current mainstream methods for dimension measurement and weight estimation,comprehensively elaborating on data collection and processing methods,the current state of research on livestock dimension measurement and weight prediction,the characteristics of the methods,as well as their strengths and weaknesses.By understanding efficient modern technological means,this study aims to accurately measure the dimensions and estimate the weight of livestock,thereby assisting breeders in better managing their herds,predicting growth trends,assessing the health status of the animals,and improving production efficiency.Furthermore,the author also forecasts the current state and development trends in the field of basic automatic measurement,with the intention of providing a reference for the study of livestock dimension measurement technology.

【Objective】 This study was aimed to analyze the effects of polymorphisms in endothelin receptor B subtype 2 (EDNRB2) gene on skin color traits in Chishui Black-bone chickens,and screen the key polymorphism loci of EDNRB2 gene in regulating skin color of Chishui Black-bone chickens,in order to provide new genetic markers for a thorough examination of the intrinsic mechanism regulating melanin deposition in silky fowls and the optimization and improvement of skin color traits in Chishui Black-bone chickens. 【Method】 Chishui Black-bone chickens were used as the research subject in this study.The nine exons of EDNRB2 gene were sequenced after PCR amplification,the single nucleotide polymorphism (SNP) of EDNRB2 gene were identified by comparison,and the genetic diversity of EDNRB2 gene were analyzed.The mRNA secondary structure before and after the mutation of EDNRB2 gene SNPs was analyzed by RNAfold web server.The chain disequilibrium,haplotype and diplotype of EDNRB2 gene SNP were analyzed using SHEsis online website.The correlation between EDNRB2 gene SNP and skin color traits in Chishui Black-bone chickens was analyzed by SPSS 27.0 software. 【Result】 Five SNPs were identified in exons 3 and 9 of EDNRB2 gene in Chishui Black-bone chickens,of which two SNPs of g.11120193 T＞C and g.11120382 C＞T were found to exist in exon 3,and of which three SNPs of g.11125882 G＞A,g.11125917 T＞A and g.11125931 C＞A were found to exist in exon 9.There were three genotypes of TT,TC and CC in g.11120193 T＞C,and there were two genotypes of CC and CT in g.11120382 C＞T,which belonged to samesense mutation.There were three genotypes of GG,AG and AA in g.11125882 G＞A,which belonged to missense mutation (Gly→Glu).There were three genotypes of TT,AT and AA in g.11125917 T＞A,which belonged to missense mutation (Phe→Ile).There were three genotypes of CC,AC and AA in g.11125931 C＞A,which belonged to nonsense mutation.Five SNPs of EDNRB2 gene had a total of 10 haplotypes and 24 diplotypes,with H4 and H4H4 being the dominant haplotype and diplotype,respectively.The results of association analysis showed that the cockscomb △a value of CC genotype of EDNRB2 gene in g.11120193 T＞C was significantly higher than that of TC genotype (P＜0.05),the back △a value was significantly lower than that of TT genotype (P＜0.05).The cockscomb △L value of CC genotype of EDNRB2 gene in g.11125931 C＞A was significantly higher than that of AC genotype (P＜0.05).At the remaining SNPs,there were no significant variations in skin color parameters across individuals with different genotypes (P＞0.05).The most noticeable effects on the skin color traits in Chishui Black-bone chickens were caused by haplotypes H5H5 and H7H7. 【Conclusion】 EDNRB2 gene had five SNPs in exons 3 and 9,with g.11120193 T＞C and g.11125931 C＞A showing a substantial correlation with the skin color of cockscomb and back in Chishui Black-bone chickens.The haplotype H5H5 significantly impacted the cockscomb △L and △a values,back △b value,and underwing △b value.EDNRB2 gene could be utilized as a potential gene for breeding selection of skin color traits in Chishui Black-bone chickens.

Follicular development is an important factor in determining ovulation rate and lambing number，it directly affects the reproductive function and fecundity of maternal animals.With the development of omics technology in recent years,microRNA (miRNA) and long non-coding RNA (lncRNA) have played an important regulatory role in the dynamic development of follicle in ruminants.miRNA can participate in the regulation of granulosa cell function,oocyte maturation and follicular development by silencing or inducing the expression of target genes.lncRNA acts as a molecular sponge for miRNA and indirectly regulates gene expression by competitive binding to miRNA,affecting germ cell development and ovarian function within the follicle.The authors review the molecular function and mechanism of miRNA and lncRNA in follicle development of ruminants,and summarize the competitive endogenous RNA (ceRNA) interaction networks among miRNA,lncRNA and gene,in order to provide a reliable genetic resources and theoretical reference for excavating key genes for reproductive traits of maternal animals and carrying out molecular breeding work.

【Objective】 The purpose of this study was to express and obtain recombinant protein p22 of African swine fever virus (ASFV) using the prokaryotic expression system,and further prepare and identify the monoclonal antibody against recombinant protein p22. 【Method】 PCR was used to amplify the ASFV p22 protein coding gene and construct the recombinant expression plasmid pET-28a(+)-p22，and induced to express p22 protein by IPTG.The purified recombinant protein was immunized to mice,and the spleen cells of immunized mice were fused with SP2/0 myeloma cells to prepare monoclonal antibody.The specificity of monoclonal antibody was determined by Western blotting,and the titer of ascites was determined by ELISA. Online software was used to predict the distribution of p22 protein epitopes and synthesize overlapping peptides,and the epitopes recognized by antibodies were identified by Dot blotting. 【Result】 In this study,the prokaryotic expression plasmid of p22 recombinant protein was successfully constructed,and the recombinant protein p22 expressed in the prokaryotic system was obtained with a molecular mass of about 22 ku.After immunizing mice with purified p22 protein as immunogen,4 monoclonal hybridoma cell lines were successfully screened，which was 1G3D7G11,2G5H6H8,6D10G7D6 and 8F6F8B9,and the ascites titer reached 1∶500 000.Western blotting results showed that 4 monoclonal antibodies could react specifically with p22 protein.The identification results of monoclonal subtypes showed that the heavy chains of monoclonal antibodies of 1G3D7G11,2G5H6H8 and 6D10G7D6 were IgG1,the heavy chain of monoclonal antibody of 8F6F8B9 was IgG2a,and the light chains of the 4 monoclonal antibodies were Kappa.Dot blotting test results showed that the epitopes of the recognition antigen of monoclonal antibodies 1G3D7G11 and 2G5H6H8 were located at amino acid 58-89.The epitope of monoclonal antibody 8F6F8B9 was located at amino acid 126-150. 【Conclusion】 In this study,4 monoclonal antibodies against ASFV p22 protein were successfully prepared,and the B cell epitope interval recognized by the monoclonal antibody was preliminarily identified.The results provided a reference for the study of biological function of p22 protein and serological detection of ASFV.

【Objective】 The experiment was to investigate the role of long non-coding RNA (lncRNA) in the infection of Porcine epidemic diarrhea virus (PEDV) in porcine small intestine epithelial cells (IPEC-J2). 【Method】 The cytopathic model was constructed using PEDV-infected IPEC-J2 cells with a multiplicity of infection (MOI) of 1.lncRNA sequencing was performed by RNA-Seq to screen out key lncRNA affecting PEDV replication.lncRNA expression and cell localization were detected by Real-time quantitative PCR and karyoplasmic separation.RNA interference vector was constructed and transfected with IPEC-J2 cells，then the effect of lncRNA expression on PEDV replication level was detected by virus copy number assay,Western blotting,50% tissue culture infectious dose (TCID₅₀) and indirect immunofluorescence assay (IFA). 【Result】 When PEDV infected IPEC-J2 cells for 24 h,the cytopathosis was most obvious,and the cytopathosis model was successfully constructed.Compared with control group,61 lncRNAs were differentially expressed in the PEDV infected group,among which 19 were up-regulated and 42 were down-regulated.lncRNA with significantly up-regulated and difference multiple was screened out—lncMSTRG.10733.2.Real-time quantitative PCR results showed that the expression of lncMSTRG.10733.2 was significantly up-regulated after PEDV infection with IPEC-J2 cells compared with control group (P＜0.05).lncMSTRG.10733.2 was mainly distributed in the cytoplasm of IPEC-J2 cells.lncMSTRG.10733.2 transient interference IPEC-J2 cells were successfully constructed,and the interference efficiency was 45.9%.Real-time quantitative PCR and Western blotting results showed that the relative mRNA expression level of PEDV-M gene and PEDV N protein expression level were significantly increased after lncRNA interference (P＜0.05).The results of TCID₅₀ showed that the virus titer of PEDV increased extremely significantly after lncRNA interference (P＜0.01).IFA results showed that the fluorescence distribution of PEDV N protein in IPEC-J2 cells was significantly increased after lncRNA interference. 【Conclusion】 In this study,one lncRNA closely related to PEDV infection was screened and identified at the cellular level based on high-throughput sequencing，and its up-regulated expression level was conducive to improving the resistance of pigs to PEDV infection.This study revealed the important role of lncRNA in the process of PEDV infection in the host,which laid a foundation for the development of PEDV resistance breeding strategies and the screening of molecular markers of PEDV in the future.

【Objective】 The aim of this study was to explore the bioinformatics characteristics of bile salt activated lipase (EgBAL) in Echinococcus granulosus and perform prokaryotic expression to detect the immunogenicity of EgBAL recombinant protein,provide theoretical basis for antigen screening of cystic echinococcosis vaccine. 【Method】 EgBAL gene sequence (GenBank accession No.:HM748917) of Echinococcus granulosus was obtained from NCBI database,specific primers were designed,and EgBAL gene was amplified and cloned by PCR using the cDNA of Ecanococcus granulosus as template.Phylogenetic tree was constructed by NJ method using Mega 7.0 software.The physical and chemical properties and structural characteristics of EgBAL protein were predicted and analyzed by bioinformatics softwares.Recombinant pET-22b plasmid containing EgBAL gene was constructed and transformed into Escherichia coli BL21(DE3) competent cells to induce expression of EgBAL recombinant protein.The protein expression was detected by SDS-PAGE and purified.The immunogenicity of the recombinant protein was analyzed by Western blotting. 【Result】 The fragment size of the EgBAL gene in Echinococcus granulosus was 1 020 bp.The phylogenetic tree showed that the EgBAL protein was in the same branch as the EgBAL protein of the Tupaia belangeri with a close evolutionary distance and a similarity as high as 99.60%.Bioinformatics analysis revealed that the EgBAL gene was 1 014 bp in length,encoding 337 amino acids.The molecular weight of EgBAL protein was 37 089.59 u,with a theoretical isoelectric point of 4.77,an instability index of 44.72,indicating an unstable protein,a fat coefficient of 66.11,a hydrophilicity of －0.429,a hydrophilic protein with no transmembrane region or signal peptide.EgBAL protein had 14 potential B-cell epitopes,and the secondary structure included alpha helix,extended chain,beta turn and random coil,accounting for 27.90%,12.76%,12.76% and 56.08%,respectively.In addition,EgBAL protein contained 35 phosphorylation sites,including 12 serine phosphorylation sites,16 threonine phosphorylation sites and 7 tyrosine phosphorylation sites.In this study,the recombinant pET-22b-EgBAL plasmid was successfully constructed,and the size of EgBAL recombinant protein was about 38 ku.Western blotting results showed that the recombinant protein could be recognized by the positive sera of Kunming mice and dogs infected with Echinococcus granulosus,and had good immunogenicity. 【Conclusion】 This study successfully cloned the EgBAL gene of Echinococcus granulosus,expressed the recombinant EgBAL protein,and preliminarily confirmed the recombinant EgBAL protein had good immunogenicity,suggesting its potential as a vaccine or diagnostic candidate antigen for cystic echinococcosis.These findings provided a foundational scientific basis for further investigation into the functional role of the EgBAL protein.

【Objective】 This study was aimed to clarify the pathogen,which caused mass mortality of snakehead fish in Nanyang city,Henan province,in September 2021. 【Method】 This study identified pathogens through methods such as surface detection,microscopic observation,bacterial isolation,PCR detection,phylogenetic tree analysis,cell culture,transmission electron microscopy observation,artificial infection,and pathological section observation. 【Result】 No noticeable lesions and blooding points was observed on the surface of diseased fish.No parasite in the gills or on the body surfaces was found,and no pathogenic bacterium was isolated.PCR detection result showed that the diseased fish was positive for Snakehead fish vesiculovirus (SHVV).The similarity analysis of SHVV G gene sequence showed that the isolate had the highest similarity with the Foshan isolate HSHRV-MS2021,reaching 99.85%.The phylogenetic tree showed that the isolated strain was clustered into the same branch as SHVV-2019,SHVV-YL01 and HSHRV-MS2021 strains,belonging to the Siniperhavirus genus,and was most closely related to the HSHRV-MS2021 strain.The tissue homogenate of diseased fish could cause obvious cytopathic effect in EPC and GS cells.Transmission electron microscopy observations showed that abundant bullet shaped virus particles scattered on the surface of diseased EPC cells.Artificial infection experiments showed that infected fish exhibited symptoms similar to those of naturally diseased fish,with a mortality rate as high as 100%.Observation of tissue slices showed that the microvilli in the intestinal tract of the fish with recurrent infection disappeared,and the hemolymph in the liver and spleen increased. 【Conclusion】 In this study,a strain of SHVV was isolated from snakehead fish cultured outside Guangdong province and named SHVV-NY01.A large number of deaths of snakehead fish in this farm were caused by SHVV.The results of this study provided a reference for the epidemiological investigation and control of this virus.

【Objective】 The objective of this study was to investigate the prevalence of Feline panleukopenia virus (FPV) and the genetic variation of FPV VP2 gene in Baoding. 【Method】 The feces and nasal secretions samples of 20 cats suspected to be infected with feline panleukopenia (FP) were randomly collected from several pet hospitals in Baoding,and the FPV VP2 whole gene sequence was obtained by PCR amplification and sequencing.The phylogenetic tree was constructed by Mega 7.0 software,and the nucleotide sequence similarity and key amino mutation sites were analyzed by MegAlign software. 【Result】 16 FPV VP2 specific bands with length of 1 755 bp were amplified from the fecal samples of 20 cats,and the sequence analysis showed that the full length of FPV VP2 gene was 1 755 bp.The isolated FPV belonged to G1 subtype,which was closely related to Japanese strain V211 (accession No.:AB054227) and far related to FPV standard strain CU-4 (accession No.:M38246).The nucleotide sequence similarity among 16 FPV VP2 genes was 99.1%-100%.13 key amino acid sites of 16 VP2 protein sequences were the same.Compared with FPV standard strain CU-4,there was an I-T mutation at amino acid 101.Compared with the key amino acid sites of 5 reference strains CPV VP2,only the 101 amino acid site was the same,and other sites had different degrees of variation. 【Conclusion】 G1 FPV was predominant in Baoding area,and the VP2 gene had strong genetic stability.The results enriched the epidemiological data of FPV and provide a theoretical basis for the prevention of FPV in Baoding area.

Porcine circoviruse (PCV) is one of the fastest single-stranded DNA viruses known to evolve,and can be classified into four genotypes (PCV1 to PCV4),of which PCV2 has an evolutionary rate of 1.2×10^-3 substitutions/sites/year,which is close to that of RNA viruses.PCV4 is a newly identified genotype with 43.2% to 51.5% similarity to the genomes of other PCVs.PCV1 is not pathogenic,and the remaining genotypes can infect pigs of all ages,causing immunosuppression-related diseases with various clinical manifestations,which has become one of the most important factors constraining the development of contemporary pig farming.Available studies have shown that PCVs are widespread and highly contagious in swine and frequently detected in ruminants,rodents,canines,arthropods and other species,posing a risk of cross-species transmission and warranting great attention.To gain a deeper understanding of the evolution,origin and cross-species transmission potential of PCVs,the authors summarize the detection of PCVs in different species and the potential transmission pathways,which will provide a reference for revealing their evolution,host adaptation studies and prevention and control strategies.

【Objective】 The objective of this experiment was to investigate the co-infection and genetic evolution of Avian leukosis virus (ALV) and Marek’s disease virus (MDV) in free range local chickens in Xinyang area. 【Method】 Pathological autopsy was performed on the chickens suspected to be co-infected with ALV and MDV,and PCR amplification was performed using specific primers.The ALV-J subgroup (ALV-J) gp85 gene and MDV meq gene were amplified and sequenced,and the nucleotide and amino acid sequences similarity and amino acid variation sites were analyzed by MegAlign software.The phylogenetic tree of gp85 and meq amino acid sequences was constructed with Mega 11.0 software. 【Result】 The chickens were examined for enlargement of the gland,stomach and spleen,and diffuse enlargement of the liver with grayish white nodules.PCR results of ALV-J gp85 and MDV 132-bpr genes were positive, and 545 and 317 bp target bands were obtained, respectively. Sequencing results showed that the amplified sequences were highly similar to the gp85 gene of ALV-J strain GX12NN04 (accession number: KT598488) and the meq gene of MDV-1 strain YLO40920 (accession number: DQ174459), and the similarity was 94.6% and 99.9%, respectively. The isolates were initially identified as ALV-J and MDV,and named as HN23XY01-ALV and HN23XY01-MDV,respectively.Nucleotide sequence analysis showed that the nucleotide sequence similarity between HN23XY01-ALV gp85 gene and 13 ALV-J reference strains was 92.1%-94.6%，and the nucleotide sequence similarity between HN23XY01-MDV meq gene and 14 MDV reference strains was 99.3%-99.9%.The amino acid sequence analysis showed that the amino acid sequence similarity between HN23XY01-ALV gp85 and 13 ALV-J reference strains was 87.4%-91.4%,and the amino acid sequence similarity between HN23XY01-MDV and 14 MDV reference strains was 97.9%-99.7%.Phylogenetic tree results showed that HN23XY01-ALV and ALV-J were closely related and in the same evolutionary branch.HN23XY01-MDV was in the same branch with Guangxi isolates GXY2,YLO40920 and GX20NN2，and Henan isolate HNSC105,and was distantly related to vaccine strains CVI988,814 and CU-2.Analysis of amino acid variation sites showed that HN23XY01-ALV had mutations at D(E)65Y,Q(K/R)75L,A(T)76S,R(T)119K and T(M/A)219K.HN23XY01-MDV had K77E,D80Y,T139A,P176R and P217A amino acid mutations，and contained site 193 (proline) that was missing from the vaccine strains,which was consistent with the characteristics of MDV-1 virulent strains. 【Conclusion】 In this study,co-infection of ALV-J and MDV was detected in free range local chickens in Xinyang area，and the results provided important references for the study of the co-pathogenic mechanism of ALV-J and MDV in local chickens and the epidemic prevention and control of co-infection.

Chicken coccidiosis is a kind of parasitic disease which is caused by many coccidids of Eimeria mainly parasitizing intestinal epithelial cells,which seriously threatens the intestinal health of chickens.The severity of the disease is closely related to the variety and age of the host chickens,feeding management,feed nutrition,coccidia species,infection dose and other factors.Anticoccidiosis drugs are the main means to prevent and control coccidiosis,but drug resistance and drug residues are easy to appear in food safety problems. In recent years,plant extracts have attracted much attention in coccidiosis control due to their natural safety and nutritional health advantages.Plant extracts can intervene in different stages of coccidiosis life cycle to control coccidiosis,such as inhibiting the development of coccidiosis,destroying the physiological structure of coccidiosis,destroying the morphology of oocysts,so as to improve the antioxidant properties of chicken intestinal tract,improve its production performance and feed conversion efficiency.On the basis of not producing drug resistance,plant extracts can effectively control the spread of coccidia,reduce the harm of coccidia,enhance the immunity,and regulate the intestinal microflora.The author systematically reviewed the etiology of chicken coccidiosis,the factors affecting the severity of coccidiosis,and the application effect and mechanism of common plant extracts in the prevention,treatment and immune regulation of chicken coccidiosis,aiming to provide reference for the development and application of plant extracts in the prevention and control of chicken coccidiosis.

Chinese sacbrood disease (CSBD) is a viral disease caused by Chinese sacbrood virus (CSBV),which is seriously harmful to bee colonies,highly infectious,and the mortality rate is as high as 100%,which has caused huge economic losses to China’s beekeeping industry.Although a variety of methods and measures have been adopted in actual production to prevent and treat the disease,the effect is not good.The rapid development of detection technology for CSBV,especially the update of molecular biological detection methods,has greatly improved the accuracy and specificity of detection results.Egg yolk antibodies (EYA) have significant application effect in a variety of viral diseases,which has potential application and development value for the prevention and treatment of CSBD.The authors reviewd the latest research progress in the diagnosis,prevention and treatment of CSBD,and summarized the current application of EYA antibody drugs in the treatment of CSBD.In addition,on the basis of analyzing the advantages and disadvantages of EYA drugs,a variety of EYA synergistic strategies were proposed,and the research prospects against CSBV were looked forward from many aspects,such as the development of new antibody drugs,the identification of new traditional Chinese medicine monomers/formulations,and the development of nucleotide drugs,in order to provide reference for the prevention and control of viral diseases of apiculture.

【Objective】 This study was aimed to investigate the effects of Angelica decoction (DGYZ) on the skin lesions of mice with atopic dermatitis (AD) induced by 2,4-dichloronitrobenzene (DNCB),provide a reference for the clinical diagnosis and treatment of AD in pets. 【Method】 A total of 90 BALB/c mice were selected and divided into six groups:Control group,DNCB group,low-dose (9.8 mg/kg DGYZ),medium-dose (19.6 mg/kg DGYZ),high-dose (39.3 mg/kg DGYZ) DGYZ groups and cetirizine group (4 mg/kg cetirizine),with 15 mice in each group.The mice in control group were treated with acetone solution as a comparison,while mice in the other groups were subjected to repeated application of DNCB on their backs to establish a mouse model of AD,followed by drug treatment according to their respective groups.After the treatment,skin samples from the back,blood and spleens were collected from the mice for subsequent analysis.Tissue thickness and the number of mast cells were observed through HE and toluidine blue staining.ELISA was used to measure serum immunoglobulin E (IgE) level.The contents of white blood cells (WBC),neutrophils and eosinophils in the blood were measured by automatic blood cell analyzer.Flow cytometry was used to detect CD4⁺/CD8⁺ cell differentiation and Th1/2 cell differentiation.Real-time quantitative PCR was used to measure the expression of cytokine-related mRNA in the back skin of mice.Ultra-high-performance liquid chromatography-time-of-flight mass spectrometer (UPLC-TOF-MS) was used to analyze the main active ingredients of DGYZ,combined with network pharmacology to explore the main targets and mechanisms of action of DGYZ in the treatment of AD.Finally,the mRNA expression of JAK1-STAT3 signaling pathway was detected by Real-time quantitative PCR. 【Result】 Compared with control group, mice in DNCB group exhibited severe skin lesions and epidermal thickening on their backs, along with a significant increase in the number of leukocytes, neutrophils, and eosinophils in the blood (P＜0.05). Compared with DNCB group,the epidermal thickening of mice in DGYZ groups at various doses and cetirizine group was effectively alleviated.And the counts of white blood cells,neutrophils and eosinophils were all decreased compared with DNCB group,DGYZ high-dose group and cetirizine groups were significantly different (P＜0.05).In addition,the serum IgE expression of mice in DGYZ high-dose group and cetirizine group were significantly reduced (P＜0.05).Flow cytometry showed that the balance of CD4⁺/CD8⁺ cells and Th1/2 cells was disrupted in DNCB group,and different doses of DGYZ significantly improved this situation (P＜0.05).Real-time quantitative PCR detection results showed that compared with blank group,the mRNA expression of interferon gamma (IFN-γ) and interleukin-12 (IL-12) genes in the skin tissue of mice in DNCB group were significantly downregulated (P＜0.05).The mRNA expression of IL-4,IL-13 and IL-6 genes were significantly increased (P＜0.05).Compared with DNCB group,the mRNA expression of IFN-γ and IL-12 genes in skin tissue were gradually increased after feeding DGYZ treatment,while the mRNA expression of IL-4,IL-13,and IL-6 genes were significantly decreased (P＜0.05).UPLC-TOF-MS identified 89 ingredients of DGYZ,including 64 active ingredients.The results of network pharmacology analysis showed that the above 64 active ingredients exerted therapeutic effects on AD-like skin lesions by acting on genes such as signal transduction and transcriptional activation protein 3 (STAT3),protein kinase B (AKT1),as well as JAK/STAT,NF-κB and Th17 cell differentiation signaling pathways.Real-time quantitative PCR detection results showed that DNCB could induce the activation of JAK1-STAT3 signaling pathway in mice,while DGYZ could inhibit the activation of this pathway. 【Conclusion】 DGYZ could alleviate AD-like skin lesions by reducing the number of mast cells in skin and the expression of IgE in serum of mice,regulating the immune balance,reducing the mRNA expression of pro-inflammatory factors and inhibiting the activation of JAK1-STAT3 signaling pathway.The results could provide a theoretical and experimental basis for the treatment of AD-like skin lesions in animals with traditional Chinese medicine.

【Objective】 An outbreak of disease occurred in a Micropterus salmoides aquaculture facility in Gao’an city,Jiangxi province.The diseased fish exhibited ulcers on the body surface and nodules in organs such as the liver,spleen and kidney,leading to subsequent mortality.The aim of this study was to isolate and characterize the pathogenic bacteria that caused ulcers on the body surface as well as nodules on the internal organs of Micropterus salmoides and evaluate the sensitivity of different antibacterials to this pathogen,so as to provide a scientific basis for the effective prevention and control of Micropterus salmoides ulcer disease. 【Method】 The diseased Micropterus salmoides from the aquaculture facility were dissected,and pathogenic bacteria were isolated from organs such as the liver,spleen,kidney and intestine,followed by Gram staining.The isolated strains underwent physiological and biochemical characterization,16S rDNA sequence identification,phylogenetic tree construction,artificial infection tests,histopathological examination,virulence gene detection,and antibiotic susceptibility testing. 【Result】 A dominant strain was isolated from the kidney nodules of the diseased Micropterus salmoides and named GALS1.The isolated strain formed round,smooth-surfaced colonies with regular edges and was identified as Gram-negative.The strain exhibited positive reactions for enzyme activity,glucose fermentation,nitrate reduction,and ammonia production,while methyl red and denitrification were negative,consistent with the biochemical characteristics of Aeromonas veronii (A.veronii).The 16S rDNA sequence of strain GALS1 clustered with A.veronii,showing 99% similarity,thus identified as A.veronii.Artificial infection test indicated that strain GALS1 was highly pathogenic to Micropterus salmoides,causing symptoms such as reduced vitality,surface bleeding,and hepatosplenomegaly.Virulence gene detection results showed that the strain carried virulence genes act,exu, fla and aerA.Drug sensitivity test results showed that strain GALS1 was sensitive to cefoperazone,tetracycline,gentamicin and ciprofloxacin,but resistant to penicillin,erythromycin and midecamycin. 【Conclusion】 The etiology of ulcerative and nodular disease in Micropterus salmoides at the aquaculture facility was identified as A.veronii.These findings provided reference for the prevention and control of Micropterus salmoides diseases caused by A.veronii.

【Objective】 The purpose of this experiment was to clarify the infection of Haemophilus parasuis (Hps) in a pig farm in Zhejiang province,and clarify the serotype,biological characteristics and pathogenicity of the isolate,so as to provide theoretical reference for clinical control of Hps. 【Method】 The strain was isolated and purified from lung,heart blood,joint fluid and other disease materials of infected pigs.Gram staining microscopy,16S rRNA gene PCR amplification and sequencing were performed to determine the serotype of the isolate.The virulence genes,susceptibility to common antibiotics and pathogenicity of the isolate were detected.The secreted protein was extracted by saturated ammonium sulfate method,and the main enrichment regions of the protein were analyzed by electrophoresis. 【Result】 The isolate grew round,smooth and moist,pale in color,and pinpoint-sized colonies with neat edges on TSA medium.After inoculation into TSB medium,the isolate grew slowly at 1-3 h,entered the logarithmic phase at 3-4 h,and entered the stable phase at 4-12 h.Gram staining microscopy showed red short rod shape,long rod shape,varying in length,suspected Hps.PCR amplification of 16S rRNA gene showed a specific band of 680 bp,which was consistent with expectations.The results of serotype identification showed that specific bands of Hps serotype 2 were detected.BLAST comparison showed that the isolate was Hps serotype 2.Virulence gene test results showed that the isolate carried cdtA,cdtB,cdtC,vtaA1, rfaD,rfaE, gnd,cpaD,espP2,vacJ,rfaF,vtaA2,htrA and ompP2 genes.When the isolate infected BALB/c mice at a dose of 1.0×10⁹ CFU/mL,the mice died within 5-10 h，and caused nucleus concentration and necrosis in the liver,a large amount of serous exudate in the alveolar cavity,mixed with red blood cells and bacteria,and inflammatory cell infiltration in the spleen.The results of drug sensitivity test showed that the isolate was resistant to cefoperazone,cefuroxime sodium,piperacillin and penicillin,intermediate to chloramphenicol,and sensitive to ciprofloxacin,levofloxacin and azithromycin.The size of secreted protein mainly concentrated in 25-180 ku. 【Conclusion】 In this study,a strain of Hps serotype 2 was isolated and identified.The isolate encoded a variety of virulence genes,was pathogenic,had obvious resistance to a variety of commonly used antibacterial drugs,and secreted a variety of proteins.The results indicated that quinolones,macrolides and aminoglycosides could be used for prevention and control in this farm.

【Objective】 The objective of this experiment was to establish a visual detection method for Pasteurella multocida and Escherichia coli of avian origin. 【Method】 Recombinant enzyme polymerase amplification (RPA) was combined with clusters of regularly spaced short palindromic repeats and their associated proteins (CRISPR-Cas) system to design specific CRISPR-associated RNA (crRNA) sequences，and screen RPA primers.The CRISPR detection system was optimized to explore the single-tube double-target amplification system,evaluate the specificity and sensitivity of the detection method,and verify the feasibility of clinical sample detection. 【Result】 The optimal combination of detection methods established in this study was:20 mmol/L Mg²⁺ in buffer,80 nmol/L Cas12a protein,400 nmol/L crRNA and 14 μmol/L ROX fluorescent probe.The specificity and sensitivity test results showed that the detection method established in this study had good specificity,and the sensitivity was consistent with Real-time quantitative PCR when observed under blue light,and 100 times higher than ordinary PCR.The results of the clinical samples showed that Pasteurella multocida and Escherichia coli were effectively detected in the samples,and the clinical compliance rate of the method established in this study was 100%. 【Conclusion】 This study successfully established a visual detection method for Pasteurella multocida and Escherichia coli of avian origin，which had high specificity and sensitivity,and could accurately detect target pathogens in clinical samples.The results provided a new method for monitoring and controlling avian bacterial diseases.

Foodborne pathogens are the most important pathogenic factors causing foodborne diseases in animals and humans.Common foodborne pathogens include Salmonella, diarrheagenic Escherichia coli,Campylobacter,Vibrio parahaemolyticus,Shigella and Staphylococcus aureus.Due to their strong invasion and colonization ability,these bacteria can contaminate a variety of fruits and vegetables and animal-derived foods,and spread through the “farm-to-table chain”.Due to the abuse of antibiotics,these bacteria have developed resistance to antibiotics,which makes it difficult for traditional antibiotics to deal with the increasingly serious bacterial resistance problem,thus making the treatment of foodborne bacterial infections faced with many challenges such as limited drug selection,poor bioavailability and difficult toxicity control.With the development of nanotechnology,various micro/nanomaterials have been gradually applied in the field of biomedicine,and have shown excellent therapeutic effects.Micro/nanomaterials mainly refer to a series of composite materials with an average particle size at the micron or nano level.In the treatment of foodborne pathogens,micro/nanomaterials are mainly drug delivery systems formed by combining micron and nano materials,which have the advantages of micron and nano scale materials,and have good biocompatibility,targeted drug delivery,controllable long-term release,and multiple antibacterial effects.The authors summarize the basic concepts,common types,special advantages and progress in the treatment of different foodborne pathogens of micro/nanomaterials.It also discusses the application potential and current challenges of micro/nanomaterials in solving various foodborne bacterial infections and alleviating antibiotic resistance,which will help promote the further exploration and application of micro/nanomaterials in the treatment of foodborne cell infections.

Antimicrobial peptides (AMPs) are a class of small peptides encoded by host genes with broad-spectrum bactericidal effects,and are important components of non-specific immunity in almost all organisms.There are many kinds of AMPs,which can be divided into antibacterial,antifungal,antiviral,antiparasitic,antitumor and other types according to their biological activities.AMPs are generally positively charged and amphiphilic,interacting with hydrophobic surfaces and membrane structures,breaking the integrity of the membrane and inhibiting the activity of intracellular nucleic acids and proteins,and exerting bacteriostatic effects on cell walls,cell membranes,intracellular and virus-related targets.Among the AMPs targeting cell membranes,relevant studies have proposed different cell membrane damage models such as barrel plate,ring hole,carpet,cohesion,etc.AMPs exhibit broad-spectrum bioactivities such as anti-bacterial,anti-fungal and anti-viral through different bactericidal mechanisms.AMPs have a broad application prospect due to their unique bactericidal mechanism.In the process of livestock and poultry breeding,AMPs as a kind of green feed additives, AMPs can increase the body weight of livestock and poultry,improve the number of intestinal beneficial bacteria,increase the content of immunoglobulin,and reduce the concentration of inflammatory factors,which play an important role in the production performance,intestinal flora,immunity and disease prevention of livestock and poultry,and is a good choice for the replacement of anti-products for the future development of the livestock and poultry industry.However,AMPs still have constraints such as the usage dosage has not been clarified,the cost of use is high,and the effect of combined use is not clear,etc.The authors summarized the mechanism of the bacteriostatic effect of AMPs and their application in livestock and poultry,and looked forward to the future development of them,with a view to providing a reference for the research and application of AMPs.

In recent years,immune stress caused by lipopolysaccharide (LPS) has become a potential threat in animal husbandry production.As a common bacterial endotoxin,LPS exhibits multiple immune activities and plays a important role in immune regulation and cell signal transduction.LPS can quickly activate the immune system of animals and triggering the secretion of various inflammatory factors such as tumor necrosis factor (TNF) and interleukin-1β (IL-1β).Moderate LPS stimulation can improve the animal’s disease resistance and help it effectively fight infection and external stress.However,excessive or long-term exposure to LPS may lead to excesstive activation of the animal’s immune system,cause inflammatory diseases,and even affect its production performance and health status.At present,LPS has been widely used to establish animal models related to immune stress.A deep understanding of the impact of LPS on immune stress in different animals is crucial to animal husbandry production, and is also the key to the development of veterinary drugs in the veterinary field.The author reviews the structure and function of LPS,the commonality and difference in immune stress induced by LPS in different animals,and the measures to alleviate immune stress induced by LPS.It also summarizes the establishment methods of LPS immune stress models and their applications in diseases,and provides suggestions and prospects for future research on animal immune stress induced by LPS,aiming to provide a reference for the research of LPS and the practice of animal husbandry production.

Feline asthma is an eosinophilic inflammatory disease of the lower respiratory tract caused by allergens.The clinical manifestations are recurrent cough,shortness of breath,and even dyspnea.The pathological mechanism of feline asthma is similar to that of human high-Th2 asthma,with airway hyperreactive changes,high expression of mucin genes,and eosinophil infiltration.At present,there are no accepted diagnostic guidelines for feline asthma.Chronic bronchitis in the differential diagnosis is very similar to its clinical symptoms and imaging manifestations,and should be the focus of clinical diagnosis.Asthma risk of cat in chest X-ray films showed bronchial or bronchial stroma,bronchial lavage visible eosinophil inflammation.Among the new diagnostic methods,exhaled breath condensate analysis and barometric whole body plethysmography are non-invasive diagnostic methods and can be used in cats in the awake state.After the standardization of exhaled breath condensate biomarkers and barometric whole body plethysmography,the two new diagnostic methods are expected to be applied in the clinical practice of pet cats.Clinical commonly used drugs to corticosteroids,use bronchodilator in cat bronchospasm.Among the new treatment options,rush immunotherapy is a new treatment technology that is expected to completely cure asthma by establishing immune tolerance mechanism for allergens and treating from the initial stage of the allergic inflammation cascade.At present,there are few studies on new diagnostic and therapeutic techniques in pet cats,and most of them are used in feline asthma models established in laboratory.More clinical data are still needed before they can be applied to clinical practice in pet cats.

With the rapid development of the global livestock industry,the amount of livestock and poultry manure generated has increased annually,making the efficient utilization of this manure particularly important.Among the various manure treatment methods,such as feed conversion,energy production,and biogas fermentation,the composting process is considered the most effective method for decomposing organic matter in livestock and poultry manure into high-quality,harmless organic fertilizer,which is essential in promoting sustainable agricultural development and environmental protection.However,traditional composting methods often encounter issues such as prolonged fermentation cycles and incomplete decomposition,which limit both fermentation efficiency and effectiveness.Therefore,this paper analyzes the innovative approach of modern composting technology that employs exogenous microorganisms as an auxiliary method.This approach not only significantly enhances the fermentation efficiency of livestock and poultry manure but also improves the quality of the final product,thus opening new pathways for the resourceful utilization of this manure.The article reviews the impact of microbial agents in sheep manure composting,specifically examining the effects of exogenous microbial agents on the abundance and diversity of compost flora,as well as their influence on the enhancement of compost’s physicochemical properties,drawing on studies conducted by scholars both domestically and internationally.The effects of applying microbially fermented sheep manure on soil physicochemical properties and crop quality are further examined,highlighting the significant role of microbial agents in sustainable agricultural development.Additionally,this paper foresees the future development of microbial agents in the resourceful utilization of manure,aiming to provide a scientific basis for the sustainable development of agriculture.