【Objective】 Wenshang Barred chickens is the only barred chicken breed in the abundant Chinese native chicken resources.The barred-related gene is sex-linked,so the trait could be used for automatical sexing of chicks.This study was aimed to enrich the genome information of domestic chickens,and obtain the whole genome sequence information in Wenshang Barred chickens,so as to provide materials for studying the molecular mechanism of sex-linked barred feather in chickens.【Method】 Wenshang Barred chicken was used as material to construct a small fragment library based on BGI MGISEQ for genomic characterization assessment.The whole genome information database of Wenshang Barred chickens was assembled and constructed by PacBio and Hi-C sequencing technology.The obtained genome sequences were assembled and annotated based on bioinformatics methods.【Result】 A total of 59.70 Gb BGI second-generation sequencing data were obtained.31.13 Gb of PacBio data were obtained with an average reads length of 15 362 bp.The obtained Hi-C data was 95.37 Gb.Splicing and initial assembly resulted in a genome size of 1.12 Gb.After Hi-C auxiliary assembly,a total of 1.07 Gb sequence could be attached to 41 chromosomes,with a mount rate of 95.62%.The contigs N50 and scaffold N50 of the genome were 9.61 and 91.29 Mb,respectively.BUSCO was assessed at 98.50%.So the continuity and integrity of the genome were good.The assembled genome was predicted to have 22.57% repeats,with 426 tRNAs,56 rRNAs,260 miRNAs and 308 snRNAs.A total of 17 338 protein-coding genes were predicted,and 96.00% of them were annotated in the gene function databases.The length of chromosome Z in Wenhang Barred chickens was 88.23 Mb,and 742 protein-coding genes were predicted and annotated,which were significantly enriched in as amino acid and fat related metabolism pathways.The positions of feather color related genes such as TYRP1,CDKN2A and SLC45A2 were accurately located on chromosome Z in Wenhang Barred chickens.【Conclusion】 In this study,high quality chromosome level genome of Wenshang Barred chickens was obtained,which enriched the genetic information of the domestic chicken genome.Some feather color related genes on chromosome Z were accurately located.The results would provide a basis for exploring the regulation mechanism of superior traits in Wenshang Barred chickens at the genome-wide level.

【Objective】 The purpose of this study was to clone the CDS region of ring finger protein 145 (RNF145) gene in Cyprinus carpio,and conduct bioinformatics analysis and functional investigation on it.【Method】 RNF145 gene in Cyprinus carpio was cloned and sequenced,and bioinformatics analysis of RNF145 protein in Cyprinus carpio was performed using online softwares.The mRNA expression changes of RNF145 gene of Cyprinus carpio in different development stages,different tissues and stimulated by Spring Viremia of Carp virus (SVCV) and Poly(I∶C) were analyzed by Real-time quantitative PCR.【Result】 The full-length CDS sequence of RNF145 gene in Cyprinus carpio was 2 049 bp,encoding 682 amino acids.Its amino acid sequence had the highest similarity to that of Carassius auratus.The molecular weight of RNF145 protein in Cyprinus carpio was 76.56 ku,the theoretical isoelectric point was 6.16,the fat index was 115.32%,the instability index was 41.87,there was no signal peptide,and it contained 11 transmembrane helices,belonging to transmembrane protein.The results of subcellular localization prediction showed that it was located in the plasma membrane (87%) and endoplasmic reticulum (13%).This protein contained TRC8-N domain,RING_H2_RNF145 domain and RAD18 domain,and had typical RING-finger family characteristics,with alpha helix (56.45%),extended chain (9.68%),beta turn (2.35%) and random coil (31.52%).The confidence level for interactions with MFN2,NUGGC.1,ASZ1,and TRIM36 were high.In the early developmental stage,the mRNA expression of RNF145 gene in Cyprinus carpio showed a significant decrease followed by an increase,followed by a significant decrease (P＜0.05).The analysis of tissue expression profile showed that its expression was the highest in spleen and the lowest in liver.After 24 h of in vivo infection with SVCV1 (5.6×10⁷ TCID₅₀/mL),the expression of RNF145 gene was significantly increased in muscle,spleen,head kidney and heart tissues,but significantly decreased in liver (P＜0.05).When infecting carp epithelial tumor cells (EPC) with this dose,the expression of RNF145 gene began to significantly increase at 12 h and remained significantly higher than the control group at 48 h (P＜0.05).When EPC was infected with SVCV2 (5.6×10⁴ TCID₅₀/mL),the expression of RNF145 gene mRNA in Cyprinus carpio was significantly higher than that in control group at 24 h after infection,and significantly lower than that in control group after 48 h (P＜0.05).Different from the SVCV1 stimulation results,after 24 h of in vivo injection of Poly(I∶ C) (1 000 μg/mL),the expression of RNF145 gene in spleen and head kidney were significantly lower than that in control group (P＜0.05).When EPC was infected with Poly(I∶C),the mRNA expression of RNF145 gene in Cyprinus carpio was significantly higher than that in control group at 24 h after infection,and significantly lower than that in control group after 48 h (P＜0.05).【Conclusion】 The full-length CDS sequence of RNF145 gene in Cyprinus carpio was successfully cloned in this experiment,revealing its expression changes in different tissues,early stages of development,and under SVCV and Poly(I∶C) stimulation,providing a preliminary basis for further studying the function of RNF145 gene in Cyprinus carpio.

【Objective】 The purpose of this study was to clone the paired-like homeodomain transcription factor 1 (PITX1) gene in Chishui Black bone chickens and carry out bioinformatics analysis,and detect the expression of PITX1 gene in different tissues of Chishui Black bone chickens,so as to provide the materials for biological function of PITX1 gene in muscle growth and development of chickens.【Method】 The sequence of PITX1 gene CDS in Chishui Black bone chickens was cloned and sequenced using breast muscle cDNA as template.The alignment and bioinformatics analysis were carried out by online softwares.The expressions of PITX1 gene in heart,liver,spleen,kidney,lung,breast and leg muscles in Chishui Black bone chickens were detected by Real-time quantitative PCR.【Result】 The full length sequence of PITX1 gene CDS in Chishui Black bone chickens was 909 bp,which had 5 synonymous mutations,and encoding 302 amino acids.The amino acid sequence similarity of PITX1 gene in Chishui Black bone chickens were 100%,99.7%,99.0%,85.0% and 84.4% with Gallus gallus,Anas platyrhynchos,Coturnix japonica, Oryctolagus cuniculus and Mus musculus,respectively,and the sequence similarity with Homo sapiens,Bos taurus and Sus scrofa all were 85.7%.The results of phylogenetic tree analysis showed that Chishui Black bone chickens was the closest to Gallus gallus and the furthest to Homo sapiens.PITX1 protein of Chishui Black bone chickens was a hydrophilic protein,which had 47 phosphorylation sites,1 N-glycosylation modification site and 15 O-glycosylation modification sites,without transmembrane domain and signal peptide,and mainly distributed in nucleus.The secondary structure was composed of random coil,alpha helix,extended chain and beta turn,the tertiary structure prediction was consistent with it.Protein interaction prediction analysis indicated that PITX1 might be interacted with BARX1,NKX2-8,POU1F1,EGR1,NR5A1,CTNNB1,TBX5 and TBX4.Real-time quantitative PCR results revealed that PITX1 gene was expressed in different tissues of Chishui Black bone chickens,and the highest expression was found in lung,followed were liver and leg muscle,but that was the lowest in breast muscle.【Conclusion】 The sequence of PITX1 gene CDS in Chishui Black bone chickens was 909 bp,and encoding 302 amino acids,that was a hydrophilic protein,and mainly distributed in nucleus.PITX1 gene was expressed in all tissues of Chishui Black bone chickens,which was the highest in lung.The results provided a reference for further study on the function of PITX1 gene in chickens.

【Objective】 The aim of this study was to isolate and identify a strain of Klebsiella oxytoca from goat and investigate the pathogenic mechanism of Klebsiella oxytoca in animals.【Method】 The lung tissue samples were collected from Hainan Black goats for bacterial isolation and culture,and the isolates were identified by biochemical test and 16S rRNA gene detection methods,and drug sensitivity test,mouse pathogenicity test, RNA-Seq analysis,and differentially expressed genes (DEGs) analysis on the isolated bacteria were performed.【Result】 One Gram-negative short rod-shaped bacterium was isolated with a smooth round milky colony on tryptic soybean agar medium.The isolated bacteria could decompose glucose,lactose,sucrose and other carbohydrates,and the indole test was positive.16S rRNA genetic testing results showed that the similarity between the isolate and the published sequence was ＞99%, and the isolated strain was identified as Klebsiella oxytoca,which was named KOHN1.The drug susceptibility test results showed that KOHN1 strain was resistant to penicillin,oxacillin,ampicillin,carbenicillin,cephalexin,midecamycin,vancomycin and clindamycin,while it was susceptible to the other 21 antimicrobial agents tested.Acute inflammation such as pulmonary congestion,edema and exudation were observed in histopathological sections of the lungs of mice infected with the isolated strain KOHN1.DEGs enrichment analysis showed that DEGs of inflammatory cytokines and chemokines were highly expressed in lung of mice.【Conclusion】 In this experiment,a strain of Klebsiella oxytoca was successfully isolated,the isolate was highly pathogenic to mice,and the immune response pathway played an important role in the process of bacterial infection,which provided a reference for the subsequent clinical prevention,diagnosis and treatment and drug development of Klebsiella oxytoca.

【Objective】 The purpose of the experiment was to identify the expression of circular RNA (circRNA) WW domain-containing E3 ubiquitin protein ligase 1 (circWWP1) in chickens,and to further explore its tissue expression characteristics,its role in chicken muscle growth and development and its possible mechanism,so as to lay a foundation for the study of the regulatory mechanism of circWWP1 on chicken muscle development.【Method】 The authenticity and stability of circWWP1 were determined by PCR amplification,DNA sequencing,RNase R enzyme digestion and actinomycin D treatment,and the tissue expression characteristics of circWWP1 were detected by Real-time quantitative PCR.The circWWP1 miRNA binding site and its target genes were predicted by online software.The circWWP1-miRNA-mRNA network was constructed by Cytoscape 3.9.1 software,and GO function and KEGG pathway enrichment analysis were performed.【Result】 circWWP1 was present and stably expressed in chickens,which were resistant to RNase R enzyme digestion and actinomycin D treatment.circWWP1 was widely expressed in all tissues of adult chickens,and the expression level in breast muscle was significantly higher than that in other tissues (P＜0.05).It was only expressed in breast muscle and leg muscle of 22-day-old chicks.The expression level of circWWP1 in breast muscle and leg muscle of adult chickens was significantly higher than that of 22-day-old chicks (P＜0.05).The analysis of circWWP1-miRNA-mRNA network regulation obtained three target miRNAs (gga-miR-454-3p,gga-miR-130a-3p and gga-miR-301b-3p) and their downstream targets of 208 genes.GO function enrichment showed that the circWWP1 target genes were significantly enriched in 38 GO items.KEGG pathway enrichment analysis showed that circWWP1 target genes were mainly involved in Hedgehog signaling pathway related to cell proliferation and embryonic development.【Conclusion】 circWWP1 existed and was stably expressed in chickens,and was highly expressed in breast muscle and leg muscle tissues of chickens at different ages,which might play a role in chick embryo development and muscle cell proliferation and differentiation through Hedgehog signaling pathway.

【Objective】 Avian mesenchymal stem cells (MSCs) were taken as the research target to investigate the differences in biological characteristics and clinical application potential of MSCs from different sources.【Method】 MSCs derived from bone marrow(BM),adipose tissue(AT),umbilical cord (UC) and spleen (S) of four different tissues and organs in White Leghorn chickens were cultured.The expression of cell surface markers was detected by Real-time quantitative PCR,and the population doubling time was observed by cell growth curve.The cytotoxicity of SDF-1 to MSCs from different sources were determined by thiazole blue cytotoxicity assay (MTT),and the in vitro migration of MSCs was detected by Transwell test.The influencing factors of MSCs migration in vitro were determined by Western blotting.Finally,in vitro differentiation of MSCs from different sources were observed by osteogenic differentiation and lipogenic differentiation.【Result】 The morphology of MSCs from different sources were basically consistent.The marker CD29,CD44,CD71,CD90 and CD105 genes were positively expressed.The relative expression of surface markers in MSCs from different sources were different,and the relative expression of CD29 gene was basically the same,the relative expression of CD44 gene in AT-MSCs was significantly higher than that in BM-MSCs (P＜0.05),and the relative expression of CD71 gene in UC-MSCs was significantly lower than that in BM-MSCs (P＜0.05).The relative expression of CD90 gene in UC-MSCs and S-MSCs was significantly lower than that in BM-MSCs (P＜0.01).The relative expression of CD105 gene in S-MSCs was significantly lower than that in BM-MSCs (P＜0.05).The four sources of MSCs all had good growth potential in vitro,with the longest incubation period of 40 h for S-MSCs.All the MSCs from the four sources had strong in vitro migration ability,and the low expression of CXC-chemokine receptor 4(CXCR4) in S-MSCs might be the cause of their low in vitro migration efficiency.MSCs from the four sources all showed in vitro osteogenic and adipogenic differentiation abilities,among which BM-MSCs had strong osteogenic differentiation ability,while S-MSCs had strong adipogenic differentiation ability.【Conclusion】 MSCs could be derived from four sources of tissues and organs in White Lehang chickens,and all had good in vitro proliferation,migration and differentiation ability.The biological characteristics of the four MSCs were different,inducing different clinical application potential.BM-MSCs had superior comprehensive performance,while S-MSCs had significant advantages in adipose induction differentiation.This study strengthened the understanding of avian MSCs,which was of great significance for the study of MSCs treatment of avian related diseases and the protection of rare birds.

【Objective】 This experiment was conducted to investigate the protective effect of glutamine (Gln) on intestinal damage in mice infected with enterotoxigenic Escherichia coli (ETEC),and provide a theoretical basis and rationale for Gln to alleviate E.coli intestinal injury.【Method】 Twenty-four health SPF KM mice were randomly allocated to 3 groups:Control group (Con),model group (ETEC) and Gln intervention group (ETEC+Gln).Mice in Con and ETEC groups were given 0.2 mL saline daily by gavage,and mice in ETEC+Gln group were given 0.2 mL 1% Gln.On days 7,the mice in ETEC and ETEC+Gln groups were challenged with 0.2 mL 8.6×10⁹ CFU/mL ETEC K88 by gavage.The trial lasted for 10 days.Mice were weighed daily.The pathological changes of jejunum were observed by hematoxylin-eosin (HE) and periodic acid-schiff (PAS) staining.The concentrations of serum inflammatory factors were determined by ELISA.The mRNA and protein expressions of inflammatory factors (IL-1β,IL-6,TNF-α and IFN-γ),tight junction proteins (Occludin,Claudin-1 and ZO-1),intestinal epithelial cell proliferation (TGF-β1,PCNA and EGF) and apoptosis (Bax and Bcl-2) in jejunum were detected by Real-time quantitative PCR and Western blotting,respectively.The protein expression of TLR4 and NF-κB p65 in jejunum were detected by immunohistochemistry.【Result】 Compared with Con group,the body weight of mice in ETEC group was significantly decreased (P＜0.05),while Gln treatment prominently reversed that.The spleen index of mice in ETEC group was significantly higher than that in Con and ETEC+Gln groups (P＜0.05).Compared with ETEC group,treatment with Gln significantly improved the villus height,the ratio of villus height/crypt depth,the number of goblet cells and the mucus thickness in jejunum (P＜0.05).Compared with Con and ETEC+Gln groups,the IL-1β and TNF-α contents,D-lac concentration and DAO activity in serum of mice in ETEC group were significantly increased (P＜0.05).Compared with ETEC group,treatment with Gln significantly decreased the mRNA expressions of IL-1β,IL-6,TNF-α,IFN-γ,TLR4,NF-κB p65 and Bax,and significantly increased the mRNA and protein expressions of Occludin,Claudin-1,ZO-1,Bcl-2,PCNA and TGF-β1 in jejunum (P＜0.05).【Conclusion】 Gln alleviated ETEC K88-induced intestinal damage of mice by restoring intestinal barrier integrity,suppressing inflammatory responses and promoting epithelial cells proliferation.

As a new mode of intercellular information exchange,exosomes regulate a variety of biological processes under physiology and pathology recipient cell functions through the factors they carry,such as miRNA,mRNA and proteins.miRNAs are one of the main factors in the functioning of exosomes,without protein coding,miRNAs are 19-25 nt in length and single-stranded RNAs.miRNAs cause inhibition of mRNA translation or degradation of transcripts by binding to target genes,which has regulatory effects on lipid metabolism.Exosomes have a lipid bilayer membrane structure that serves as a good carrier for miRNA transport to recipient cells,where they play a role in physiological and pathological processes.The regulatory role of exosomal miRNAs may be a new type of inter-tissue communication.Adipose tissue is the main endocrine organ of livestock and poultry,and the adipokines it secretes play an important role in regulating the metabolic homeostasis of the body.As a novel adipokine,adipose-derived exosomal miRNAs regulate gene expression in other tissues and play an important role in maintaining metabolic homeostasis in vivo.The author reviews the molecular regulatory role and related mechanisms of lipid derived exosomes miRNAs in lipid metabolism,aiming to provide theoretical support for studying the mechanism of lipid derived exosomes miRNAs,preventing and treating metabolic related diseases.

【Objective】 The aim of this study was to explore the appropriate metabolic energy levels of 20-22 weeks old male pheasants,providing data reference for scientific breeding of pheasants and improving production efficiency.【Method】 A total of 160 healthy male pheasants at 20 weeks of age with similar weight were randomly divided into 4 groups,each group was set up with 5 replicates,each replicate was 8 chickens,and the dietary metabolic energy levels of each group were 11.30,11.72,12.14 and 12.56 MJ/kg,respectively,with a pre-trial period of 5 days and a positive trial period of 16 days.The growth performance,slaughter performance,and meat quality of pheasants were measured.【Result】 The level of dietary metabolic energy affected the average daily gain (P＜0.01),the slaughter rate,total purification rate and leg muscle rate,and the crude protein content of pectoral muscle (P＜0.05),while had no significant effect on the organ index of pheasants (P＞0.05).The average daily gain of 11.72 and 12.14 MJ/kg group were higher than that of 11.30 (P＜0.01) and 12.56 MJ/kg group (P＜0.05).The slaughter rate and total purification rate of pheasants in the 12.56 MJ/kg group were significantly higher than those in the other groups (P＜0.05),and the leg muscle rate in the 11.72 MJ/kg group was higher than that in 11.30 and 12.14 MJ/kg group (P＜0.05).The crude protein content of pectoral muscle in 12.14 and 12.56 MJ/kg group were higher than that in 11.30 MJ/kg group (P＜0.05).Using the average daily gain as the estimation indicator,the optimal metabolic energy level for male pheasants during this period was to be 11.98 MJ/kg through a univariate quadratic regression model analysis.【Conclusion】 In summary,under the conditions of this experiment,the suitable metabolic energy level of male pheasants during 20-22 weeks old was 11.98-12.56 MJ/kg.

【Objective】 The purpose of the experiment was to explore the changes of bacterial composition,abundance and diversity in the feces of pure blood ponies in the middle and later stages of lactation,so as to provide reference basis for optimizing nursing and efficient and healthy breeding of foals during lactation.【Method】 Five male foals with similar birth date and weight of (144.33 ±16.10) kg in the middle and later stage of lactation were selected for 60 days feeding experiment.Fecal samples were collected without DNA enzyme tube before weaning (3,4 and 5 months old),and the microbial diversity in fecal samples was detected by IlluminaMiSeq high-throughput sequencing platform.【Result】 ①There were 627 OTU in fecal flora of 3-,4-and 5-month-old foals,and the number of endemic OTU was 202,177 and 194,respectively,but there was no significant difference in Chao1,ACE,Shannon and Simpson index among the three stages (P>0.05).The results of principal component analysis showed that the difference of microflora in the feces was small and stable.②The dominant phylums in the faeces of 3-,4-and 5-month-old foals were Firmicutes,Bacteroidota,Actinobacteriota,Verrucomicrobiota and Patescibacteria,while the dominant families were Lachnospiraceae,Planococcaceae,Micrococcaceae,Oscillospiraceae and Anaerovoracaceae.The dominant genus were Arthrobacter,Psychrobacillus,unclassified_Lachnospiraceae,uncultured_rumen_bacterium and Christensenellaceae_R_7_group.③At the phylum level,the relative abundance of verruca in the feces of 5-month-old foal was significantly lower than that of 3-month-old,the relative abundance of Spirochete was significantly higher than that of 3- and 4-month-old,and the relative abundance of Fibrillaria was significantly higher than that of 4-month-old (P＜0.05).At the family level,the relative abundance of Ackermanniaceae in the feces of 3-month-old foal was significantly higher than that of 4- and 5-month-old (P＜0.05).At the genus level,there was no significant difference among the ten dominant bacteria of each month (P＞0.05).【Conclusion】 To sum up,in the same feeding environment,the diversity index of fecal microflora of foal fluctuated with the increase of age,and the dominant species of the top 10 microorganisms in feces were the same,but the relative abundance was different.and the differential bacteria in foal feces decreased with the increase of age.

【Objective】 This experiment was conducted to investigate the effects of lysine levels on laying performance,egg quality,plasma biochemical index and follicle development in peak-laying Shanma ducks,so as to evaluate the lysine requirement of peak-laying ducks.【Method】 Five hundred and forty Shanma ducks with similar body weight were randomly assigned into 6 groups with 6 replicates of 15 ducks each.The ducks were fed diets with six lysine levels (0.75%,0.80%,0.85%,0.90%, 0.95% and 1.00%) for 12 weeks.The number and weight of eggs in each repeated per day were recorded.The egg laying rate,daily egg weight and feed-egg ratio were calculated at the end of the experiment.Three eggs were collected from each repeat to determine quality index,and two experimental ducks whose weight close to the average weight of each repeat were selected,slaughtered after collecting blood from wing vein.The ovaries,follicles and fallopian tubes were separated and collected to determine the weight,number and length.【Result】 Dietary lysine levels significantly affected the egg production,daily egg mass and feed/egg mass of 22-24 week old Shanma ducks (P＜0.05),egg production and daily egg mass were highest and feed/egg mass was lowest in the 0.85% lysine group.Except for the egg shape index, the other egg quality indicators had no siginificant difference (P>0.05). Dietary lysine levels had no significant effect on plasma estradiol (E₂) and luteinizing hormone (LH) concentrations in Shanma ducks (P＞0.05),but significantly affected plasma follicle stimulating hormone (FSH) concentrations (P＜0.05),plasma FSH concentration was lowest in the 0.85% lysine group.Dietary lysine levels had no significant effect on the weight of oviducts and ovaries,as well as the length of oviducts in Shanma ducks (P＞0.05).The number of small yellow follicles and total follicles in the 0.85% lysine group were significantly higher than those in other groups (P＜0.05).With the increase of dietary lysine level,the number of large yellow follicles and plasma uric acid content showed a quadratic curve (P＜0.05).When the dietary lysine level was 0.87%,the number of large yellow follicles was the highest and plasma uric acid content was lowest.【Conclusion】 In summary,based on production performance,follicular development and plasma uric acid content,the appropriate level of dietary lysine for 22-33 week old Shanma ducks was 0.85%-0.87%.

【Objective】 This experiment was conducted to investigate the effects of different levels of spent mushroom substrate of Pleurotus ostreatus (P.SMS) on the growth performance, nutrient apparent digestibility, slaughter performance and organ indexes of Hu sheep in mixed diet, so as to provide practical reference for feed utilization of P.SMS. 【Method】 Forty-five 3-month-old male Hu lambs with similar weight were randomly divided into 5 groups with 9 lambs(3 replicates) in each group and 3 lambs in each replicate. The lambs in group Ⅰ (control group) was fed a total mixed diet without P.SMS, and the lambs in groups Ⅱ, Ⅲ, Ⅳ and Ⅴ were fed 5%, 10%, 15% and 20% P.SMS replaced with whole plant corn silage in the diet, respectively. The growth performance, nutrient apparent digestibility, slaughter performance and organ indexes of Hu lambs were measured through feeding and slaughter experiments. 【Result】 On the 30th day, the body weight of lambs in groups Ⅲ, Ⅳ and Ⅴ were significantly higher than that in group Ⅱ (P＜0.05). At 1-30 days of old, the average daily gain of lambs in group Ⅴ was significantly higher than that in groups Ⅰ and Ⅱ, and groups Ⅲ and Ⅳ were significantly higher than group Ⅱ (P＜0.05). At 60-90 days of old, the average daily gain of lambs in groups Ⅰ, Ⅱ and Ⅲ were significantly higher than that in group Ⅴ (P＜0.05), and group Ⅲ was significantly higher than groups Ⅳ and Ⅴ (P＜0.05). The feed-to-gain ratio (F/G) of lambs in group Ⅱ at 1-30 days of old was significantly higher than that in group Ⅴ (P＜0.05), lambs in groups Ⅳ and Ⅴ at 60-90 days of old were significantly higher than that in other groups (P＜0.05), and lambs in group Ⅴ at 1-90 days of old was significantly higher than that in group Ⅰ (P＜0.05). The apparent digestibility of dry matter of lambs in group Ⅲ was significantly higher than that in group Ⅱ (P＜0.05). The apparent digestibility of organic matter and crude protein of lambs in groups Ⅰ and Ⅲ were significantly higher than that in group Ⅱ (P＜0.05). The slaughter rate of lambs in groups Ⅲ and Ⅳ were significantly higher than that in group Ⅰ (P＜0.05). The spleen weight of lambs in group Ⅲ was significantly higher than that in groups Ⅱ and Ⅴ (P＜0.05). The liver index of lambs in group Ⅴ was significantly lower than that in other groups (P＜0.05), the lung index of lambs in group Ⅳ was significantly higher than that in other groups (P＜0.05). 【Conclusion】 Comprehensive analysis showed that it was feasible to feed fattening Hu sheep with 10% P.SMS instead of whole plant corn silage. The addition of high proportion (20%) P.SMS had better feeding effect in the first two months of fattening period, but with the extension of feeding time, the feeding effect would become worse. It was recommended that the feeding time should not exceed two months.

【Objective】 To study the effects of adding different levels of recombinant human lysozyme to the diet on growth performance,blood physiology,plasma biochemistry,tissue structure changes,and intestinal microbiota structure of Yellow feather broilers,in order to evaluate the biological safety of recombinant human lysozyme application in broilers.【Method】 The experiment was conducted using a single factor completely randomized design,with 192 1-day-old healthy fast Yellow feathered broilers randomly divided into 4 groups,with 48 chickens in each group (male and female in half).The recommended dose group (20 000 U/kg),3 times the recommended dose group (60 000 U/kg),and 5 times the recommended dose group (100 000 U/kg) were set up,and a basic diet group was also set as the control group.The experimental period was 54 days.The fasting weight of Yellow feathered broilers was measured at 21,42,and 54 days,and the feed consumption was counted.The average daily gain (ADG),average daily feed intake (ADFI),and feed to gain ratio (F/G) of the broilers during the experimental period were calculated.At the end of the experiment,8 Yellow feathered broilers were selected from each group to collect blood for testing of routine physiological and plasma biochemical indicators.Collect chicken heart,liver,spleen,lungs,kidneys,jejunum,and ileum tissues for histopathological examination after slaughter.Collect chicken cecal contents and detect the structure of cecal microbiota.【Result】 During the experimental period,all broilers in each dose group displayed normal clinical signs.There was no significant difference in growth performance between the test groups and the control group(P＞0.05).There was also no significant difference in blood physiological parameters(P＞0.05) except than the variation coefficient of red blood cell distribution width,which was considerably greater in 60 000 U/kg group (P＜0.05).The plasma albumin of 60 000 U/kg group was significantly lower than that of the control group (P＜0.05),while other plasma biochemical markers did not significantly differ between the groups (P＞0.05).When broilers fed with various quantities of recombinant human lysozyme were autopsied and histopathologically examined in comparison to the control,no discernible change was discovered.Feeding different levels of recombinant human lysozyme had no significant effect on the diversity and structure of intestinal microflora in broilers (P＞0.05).【Conclusion】 Adding 20 000 U/kg recombinant human lysozyme to the diet of Yellow feather broilers had a safety factor of more than 5 times,indicating that adding less than 100 000 U/kg recombinant human lysozyme to the diet was safe for Yellow feather broilers.

【Objective】 The experiment was aimed to investigate the effects of different grains on the enzyme activity,starch content and VFA concentration in the intestinal contents of weaned foals,and to provide a reference for the development and health of the intestinal tract,nutrient digestion and ration mix of weaned foals.【Method】 Eighteen Kazakh male foals with similar birth date and weight (112.39 kg±7.50 kg) and weaned at 5 months of age were selected and randomly divided into three groups of six foals each and supplemented with maize,oats and barley.Under the same roughage condition,the supplemental feeding amount of each group was determined by the principle of equal starch,and a 60 d supplemental feeding trial was conducted.After the foals were slaughtered,the contents of each intestinal segment were collected and the amylase activity,amylose content and volatile fatty acid(VFA)concentration were determined.【Result】 ①The small intestinal amylase activity of foals in the oat group was higher than that in the maize group (P＜0.01) and barley group (P＜0.05).The small intestinal β-amylase activity of foals in the maize group was higher than that in the oat and barley groups (P＜0.01).② The ileal branched-chain amylose content of foals in the oat group was lower than that in the maize and barley groups (P＜0.01),the straight-chain amylose content was lower than that in the maize group (P＜0.05),and the fecal branched-chain amylose content was higher than that in the barley group (P＜0.05).The cecum straight-chain amylose content of foals in the maize group was lower than that in the oat group (P＜0.05) and barley group (P＜0.01),and the colonic rectal starch content was also lower than that of the oat and barley groups (P＜0.05).③ Total ileal VFA concentration in the oat and barley groups were higher than that in the maize group (P＜0.01).Cecum valeric acid content (P＜0.05) and isovaleric acid content (P＜0.01) in the maize group were higher than that in oat and barley groups,and colonic valeric acid content was higher than that in the barley group (P＜0.01).【Conclusion】 Corn and oat starch showed better improvement of enzyme activity in the small intestine of foals.Oat starch had better digestion and utilization in the ileum of foals,while in the cecum and colon of foals,corn starch had better digestion and utilization.

Polyunsaturated fatty acids (PUFA) are bioactive molecules that regulate lipid metabolism in poultry,among them,n-3 PUFA and n-6 PUFA are important lipid components in sperm and ovum,and their content and n-6/n-3 PUFA ratio are closely related to fatty acid deposition,reproductive energy supply and other aspects of poultry.n-3 PUFA and n-6 PUFA coordinate and restrict each other in affecting lipid metabolism and reproductive performance.n-3 PUFA and n-6 PUFA metabolize in poultry using a set of enzymes,α-linolenic acid (ALA) and linoleic acid (LA) can produce longer chain n-3 PUFA and n-6PUFA,respectively.n-3 PUFA inhibited the derivations of n-6 PUFA,and the deposition of n-3 PUFA and n-6 PUFA in cells had competitive effect.PUFA can activate peroxisome proliferator-activated receptors in poultry,promote fat synthesis and decomposition,and reduce fat deposition.ALA and docosahexaenoic acid (DHA) of n-3 PUFA could improve the antioxidant capacity of sperm,improve the fluidity of sperm plasma membrane and enhance sperm motility.n-6 PUFA is the main fatty acid in poultry sperm.It promotes spermatogenesis and improves the antioxidant capacity of sperm by promoting the synthesis and secretion of testosterone and prostaglandins (PG).n-3 PUFA affects the fatty acid composition of oocytes and embryos,regulates the synthesis and secretion of sex hormones,improves the antioxidant capacity and quality of oocytes and embryos,and reduces cell apoptosis and embryonic mortality.Eicosanotetraenoic acid (EPA) and arachidonic acid (ARA) synthesize corresponding PG,which regulate follicular development and ovulation in female birds.However,excessive PUFA deposition may cause fat deposition and induce cellular oxidative stress.At present,great progress has been made in the research of dietary PUFA on improving the performance of livestock and poultry,but the mechanism of PUFA regulating lipid metabolism and reproductive performance of poultry still needs further investigation.Based on the nutritional metabolism of PUFA in poultry,the authors reviewed the effects of n-3 PUFA,n-6 PUFA and n-6/n-3 PUFA ratio on lipid metabolism and reproductive performance of poultry,in order to provide a theoretical basis for the efficient utilization of PUFA in the field of poultry nutrition and breeding.

【Objective】 The aim of the study was to investigate the effects of dietary vitamin D (VD) supplementation on reproductive performance of sows,growth performance of piglets and fecal flora of sows and piglets.【Method】 Forty pregnant sows (7±1 fetal periods,Yorkshire×Landrace) were selected and randomly divided into 2 groups with 20 replicates per group and 1 sow per replicate.The sows in control group were fed the basal diet,and each sow in VD group was supplemented with 1.0 g/d VD on the basis of the basal diet.The trial lasted from day 90 to day 113 of gestation and from the begainning to day 14 of lactation.The reproductive performance of sows (labor course,litter size,born alive rate,mummy rate,etc.) and the growth performance of piglets (birth litter weight,weaning litter weight,diarrhea rate,etc.) were measured during the experiment.Fecal samples of sows at day 113 of gestation, 14 of lactation, and piglets on 14 days old were collected for high-throughput sequencing of 16S rRNA gene,and microbial community structure and diversity were analyzed.【Result】 Compared with the control group,the mummy rate and IUGR rate of pregnant sows in VD group were significantly decreased (P＜0.05),and the average litter weight of newborn piglets was significantly increased (P＜0.05).Shannon index of lactating sows in VD group was significantly increased (P＜0.05).At phylum level,compared with control group,the abundance of Proteobacteria and Firmicutes in feces of pregnant sows in VD group was significantly decreased (P＜0.05).The abundance of Spirochaeta in fecal microorganisms of lactating sows was significantly increased (P＜0.05).The abundance of Bacteroidetes was significantly increased in lactating piglets,while the abundance of Spirochaeta and Firmicutes and the ratio of Firmicutes to Bacteroidetes were significantly decreased (P＜0.05).At genus level,compared with control group,the abundance of Family_ⅩⅢ_AD3011_group in fecal microorganisms of pregnant sows in VD group was significantly decreased,and the abundance of Candidatus-saccharimonas was significantly increased (P＜0.05).The abundances of Treponema and Parabacteroides in fecal microorganisms of lactating sows were significantly increased (P＜0.05).【Conclusion】 Supplementation of VD during late gestation and lactation period could improve the reproductive performance of sows,increase the relative abundance of beneficial bacteria such as Firmicutes,Bacteroides,Spirochaeta,Treponema and Paracellosis in fecal flora of sows and piglets,and reduce the relative abundance of harmful bacteria such as Proteobacteria,thereby improving the intestinal microbial structure of sows and piglets and achieving a new balance of intestinal microbes.

Cinnamaldehyde is the main active ingredient of essential oil extracted from cinnamon and other plants.Due to different areas,varieties and parts,the main components of cinnamaldehyde will also be different,but the main components are trans-cinnamaldehyde.Cinnamaldehyde has a variety of biological functions:It can bacteriostasis by destroying the permeability of bacterial cell membrane,inhibiting cell membrane synthesis and bacterial cell division,reducing the energy source of bacteria and so on.It can exert antioxidant effect by activating antioxidant enzyme system and apoptosis pathway in the body and removing excess oxygen-containing free radicals.It plays an anti-inflammatory role by inhibiting a variety of inflammatory signaling pathways and reducing the expression of inflammatory factors in the body.It can play a role in regulating glucose and lipid metabolism by regulating peroxisome proliferator activated receptor-γ (PPAR-γ) or Amp-activated protein kinase (AMPK) signaling pathways,promoting insulin secretion and reducing lipid accumulation.Cinnamaldehyde,as a kind of aromatic aldehyde plant essential oil,has been gradually applied in livestock and poultry production.In pig production,the addition of cinnamaldehyde can relieve diarrhea and oxidative stress of piglets,improve performance,immune and antioxidant capacity of growing-finishing pigs.In the production of cattle and sheep,the addition of cinnamaldehyde can regulate rumen microbial protein synthesis and fermentation system and improve feed digestibility.In poultry production,the addition of cinnamaldehyde can improve intestinal health,growth performance and meat quality,and enhance immunity and antioxidant function.In this paper,the physicochemical properties and biological functions of cinnamaldehyde were firstly reviewed,then the application of cinnamaldehyde in the production of pigs,cattle,sheep,poultry and other livestock was described,and finally the prospects of cinnamaldehyde were summarized,in order to provide reference for the scientific application of cinnamaldehyde in livestock breeding and rational development in livestock feed.

【Objective】 The purpose of this study was to investigate the effects of subacute rumen acidosis(SARA)on the microbial flora structure and B vitamins expression abundance in rumen fluid of Hu sheep,and to analyze the correlation between them.【Method】 Twelve healthy Hu sheep were randomly divided into 2 groups,with 6 sheep in each group.The ratio of feed concentrate to forage in control group was 3∶7,and that in SARA group was 7∶3 to establish SARA model.The structural changes of bacteria were analyzed by 16S rRNA sequencing technology,the abundance of B vitamins expression in rumen fluid was analyzed by LC-MS method,and the correlation between them was analyzed by Pearson method.【Result】 The rumen microbial diversity index (Shannon and Chao1) of Hu sheep in control group was significantly higher than that in SARA group,and the microbial diversity was significantly higher than that in SARA group (P＜0.05).At the level of the phylum bacterialis,the abundance of Actinobacteria,Candidatus_Saccharibacteria and Tenericutes in control group were significantly higher than that in SARA group (P＜0.05).At the genus level,Bifidobacterium,Sharpea,Saccharibacteria,unclassified_Ruminococcaceae in control group were significantly higher than that in SARA group (P＜0.05),but unclassified_Desulfovibrionaceae,unclassified_Clostridiales,Alloprevotella were significantly lower than that in SARA group (P＜0.05).Six different metabolites,VB₆ (pyridoxal,pyridoxine,pyridoxine),VB₃,VB₉ and VB₁₂,were screened out from control group and SARA group,and their expression abundance in SARA group was significantly higher than that in control group (P＜0.05).Pearson correlation results showed that six different B vitamins species were significantly associated with the vast majority of rumen microorganisms (R＞0 or R＜0).【Conclusion】 SARA changed the phylum and genus level structure of bacteria in rumen fluid,resulting in decreased bacterial diversity and increased the abundance of VB₆,VB₃,VB₉ and VB₁₂ expression,which was significantly correlated with most of the bacteria in rumen fluid.

Plant polysaccharides,as a group of structurally complex macromolecular compounds widely found in nature,have a variety of physiological regulatory functions.The intestinal microbiota is able to metabolize polysaccharides that the host itself cannot digest and has a reciprocal symbiotic relationship with the host.Polysaccharides entering the gut are important factors influencing the physiological state and composition of the intestinal microbiota,and the degradation of non-starch polysaccharides in plants by intestinal microbiota can significantly modulate the composition and structure of the intestinal microbiota and intestinal health.Different intestinal symbiotic bacteria have different preferences for polysaccharides entering the intestinal tract,and the degradation pathways are complex and diverse.The authors briefly introduce the types of non-starch polysaccharides in plants,summarize the effects of plant polysaccharides on the intestinal environment,review the intestinal microbiota that can degrade non-starch polysaccharides in plants and their specific degradation mechanisms,and introduce the various plant polysaccharide degradation systems of representative intestinal microbiota,with a view to providing a theoretical basis for subsequent functional studies of intestinal microbiota in polysaccharide degradation and the development and utilization of novel microecological agents.

【Objective】 The objective of this study was to evaluate the effects of dietary supplementation of tea polyphenols on performance,serum biochemical and antioxidant indexes of dairy cows in late perinatal period.【Method】 Thirty-six Chinese Holstein cows with similar parity and expected perinatal period (28 days before delivery) were randomly divided into 3 groups,control group,tea polyphenol group 1 (TP1) and tea polyphenol group 2 (TP2),with 12 cows in each group.Cows in control group were fed a basal diet,and cows in TP1 and TP2 groups were fed the basal diet supplemented with 15 and 30 g/cow of tea polyphenols per day,respectively.The pre-trial period lasted for 7 days and the experimental period lasted for 42 days.After the experiment,milk and blood samples were collected to determine milk composition and serum biochemical and antioxidant indexes.【Result】 Compared with control group,milk fat yield in TP1 and TP2 groups was significantly increased (P＜0.05),milk fat percentage and total solid content in TP2 group were significantly increased (P＜0.05).The total antioxidant capacity (T-AOC) in TP2 group was significantly increased,and the activities of glutathione peroxidase (GSH-Px),superoxide dismutase (SOD) and catalase (CAT) were significantly increased (P＜0.05).In addition,milk fat percentage,total solids content,T-AOC,GSH-Px,SOD and CAT activities in TP2 group were significantly higher than those in TP1 group (P＜0.05).【Conclusion】 Dietary supplementation of tea polyphenols could increase postpartum milk fat yield,milk fat percentage and total solid content,and increase serum T-AOC,SOD,CAT and GSH-Px activities in late perinatal period.In this experiment,adding 30 g/cow of tea polyphenols had the best effect.

【Objective】 This study was aimed to evaluate the effect of adding insulin-transferrin-sodium selenite (ITS) to production,4 ℃ hypothermic storage and programmed freezing system of bovine in vitro embryos,so as to improve the production and preservation effect of in vitro bovine embryos via ITS.【Method】 After in vitro fertilization of bovine oocytes derived from slaughterhouse ovaries,the following experiments were carried out:① An experiment to study the effect of adding ITS to anaphase culture medium M2 on blastocyst rate,with M2+ITS and M2-control (without ITS,control) groups. ② An experiment to further investigate the effect of adding ITS to prophase culture medium M1 on early embryonic development,with M1+M2+ITS(both M1 and M2 with ITS addition) and M1-control (without ITS addition but M2,control) groups. ③ An experiment to further evaluate the effect of ITS in improving embryonic development under three gases culture conditions,with ITS (with ITS) and control (without ITS) groups.The cleavage rate,day-7 blastocyst rate,and total blastocyst rate were calculated for each of the above groups.④ The day-7 bovine embryos were stored at 4 ℃ for 24 h by M2 storage solution with ITS (Hypo-ITS group),or day-7 in vitro embryos in frozen solution with ITS were frozen by programmed procedure (Cryo-ITS group),with Hypo-control (without ITS) and Cryo-control (without ITS) group,and the survival and hatching rates of the recovered and thawed embryos were counted,respectively.【Result】 Compared with control group,the day-7 blastocyst rates of M2+ITS and M1+M2+ITS groups were significantly increased (P＜0.05);Under the three gas culture conditions,the day-7 blastocyst rate in ITS group was also significantly increased (P＜0.05).There was no significant difference of the survival rate between Hypo-ITS and Hypo-control groups (P＞0.05),but the hatching rate of Hypo-ITS group was significantly higher than that of Hypo-control group (P＜0.05).There was no significant difference of the survival and hatching rates of programmed freezing between Cryo-ITS and Cryo-control groups (P＞0.05).【Conclusion】 ITS could be used as additive and hypo-protectant to improve the effect of bovine in vitro embryo production and hypo-preservation.However,the addition of ITS in the freezing solution did not significantly improve the programmed freezing effect of bovine in vitro embryos.

The first and second generation sequencing technology has been widely used in species genome assembly,but with the deepening of genomics research,which has been unable to meet the needs of comprehensive detection of genome variation and complete analysis of unknown regions of the genome.The third generation sequencing technology has brought genome sequencing into the era of long reading, and genome assembly based on the third generation sequencing data has become the mainstream choice for genome research of various species.High-quality genome assembly plays a crucial role in animal and plant genetics and genomics research,providing essential support for comprehensive understanding of genome structure,function,and evolution.The author reviewed the development and application of the first,second and third generation sequencing technology and auxiliary assembly technology,introduced the splicing principle,application scope and corresponding bioinformatics tools of genome assembly algorithm,and elaborated the application of high-quality reference genome in the detection of genetic variation and functional gene mining of livestock and poultry combined with the published research.In order to provide reference for the protection of animal germplasm resources and molecular breeding practice in the future.

【Objective】 This experiment was conducted to study the effects of long-distance transportation on body weight,slaughter rate and liver mRNA expression profile of fattening cattle and to screen for key genes affecting liver function in long-distance transportation.【Method】 Twenty-two Angus fattening bulls of similar weight were randomly divided into 2 groups,9 of which were slaughtered on the spot in the control group,and 13 of which were slaughtered after long-distance transportation in the experimental group,and the effect of long-distance transportation on body weight and slaughter rate was observed.In addition,three bovine liver tissues of similar weight were collected in the two groups.Transcriptome sequencing (RNA-Seq) was performed to screen differentially expressed genes,and GO functional annotation and KEGG pathway enrichment analysis were performed on them.【Result】 The live body weight of cattle decreased by 4.5% after long-distance transportation,and there was no significant difference in slaughter rate compared with the control group (P＞0.05).The RNA-Seq results showed that 182 genes were significantly upregulated and 91 genes were significantly downregulated in liver tissues of the long-distance transportation group.GO enrichment and KEGG pathway analysis showed that 182 up-regulated genes were significantly enriched in the terms of regulation of response to stimulus,peroxisome,oxidoreductase activity,cAMP signaling pathway,MAPK signaling pathway,and longevity regulating pathway.According to the results of GO enrichment and KEGG pathway analysis,four genes (ACOX3,FOS, HSPA1A,HSPA6) were screened out that were closely related to the changes of liver energy metabolism,liver cell damage and post-injury adaptive protection mechanism of fattening cattle after long-distance transportation.【Conclusion】 The live weight of Angus fattening cattle was reduced by 4.5% after long-distance transportation.Four key genes ACOX3,FOS,HSPA1A and HSPA6 affecting liver function of Angus fattening cattle after long-distance transportation were screened.The results provided a reference for future research on the mechanism,prevention and treatment of transport stress in beef cattle.

Duck feet,as an important byproduct of poultry with significant economic value,have witnessed a rapid increase in consumer demand.Consumers prefer larger-sized and heavier duck feet,making quality breeding one of the means to obtain these desirable traits.While scholars both domestically and internationally have conducted research on the morphology,weight,size,and meat quality of duck feet,there is a lack of reported studies on quality breeding of duck feet.A comprehensive understanding of the regulatory mechanisms underlying the growth and development of duck feet,as well as the screening of associated genetic markers,serves as an important theoretical foundation for quality breeding.It can provide crucial genetic resources for the improvement of meat duck varieties.Therefore,this paper provides an overview of the research progress on various traits of duck feet,including their basic structure,external morphology,weight,size,and meat quality measurement indicators and methods.It briefly describes the developmental process of duck feet during the embryonic stage,and focuses on discussing factors influencing the size,weight,external morphology,and meat quality of duck feet.Feasibility of quality breeding of duck feet is analyzed from a genetic perspective,and genes and genetic markers related to duck feet discovered in previous studies are summarized.Moreover,modern technologies and prospects for the study of duck feet meat quality are analyzed.Finally,this paper presents prospects for the future breeding direction of duck feet,advocating for the accurate assessment of duck feet using modern techniques,and the cultivation of meat duck strains with larger size and greater weight through the selection of molecular genetic markers associated with metatarsal and toe bones.This approach not only enhances their economic value but also benefits the health of ducks,further improving production performance and laying the foundation for genetic improvement of meat ducks and the development of related industries.

【Objective】 The objective of this study was to clone the xynA gene of Bacillus cereus W-3 and analyze its bioinformatically.The allogeneic expression and enzymatic characteristics were studied.【Method】 xynA gene was cloned by homologous amplification,prokaryotic expression vector pCola-xynA was constructed,and heterologous expression was performed using Escherichia coli BL21 (DE3).The recombinant protein was isolated and purified by nickel column affinity chromatography and identified by SDS-PAGE. The bioinformatic analysis of xynA protein was carried out by online software.The enzymatic properties of xynA at different temperature and pH were studied using beech xylanan as substrate.【Result】 xynA gene was 642 bp in length and contained a complete open reading frame,encoding 213 amino acids.Amino acid sequence comparison showed that the similarity between xynA and Bacillus methylotrophicus subspecies FZB42 xylanase (AJD80562.1) was 96%,the similarity of NBRC15307 xylanase with Paenibacillus macerans (AAZ17386.1) and Bacillus altitudinis with the family xylanase (WP-007407578.1) was 94%.The N-terminal of xynA protein contained a signal peptide with a theoretical isoelectric point of 9.42 and a molecular weight of 23.3 ku.The protein was a hydrophilic protein with stable structure,5 potential glycosylation sites and 38 phosphorylation sites,and belongs to the glycoside hydrolase 11 family.The enzyme activity of xynA was 733.826 U/mg,the optimum temperature was 70 ℃,and the optimum pH was 9.0.It had good stability at 60-80 ℃ and pH 8.0-11.0,50.3% enzyme activity could be retained at 80 ℃ for 1 h,and 94.63% enzyme activity could be retained at 70 ℃ and pH 9.0 for 1 h.【Conclusion】 Xylanase xynA gene was successfully cloned from the natural microorganism Bacillus cereus W-3 strain.xynA protein was a stable hydrophilic protein,belonging to the glycoside hydrolase 11 family.xynA showed the characteristics of heat resistance,alkali resistance,high enzyme activity,and wide adaptability to temperature and pH.The results laid a theoretical foundation for the development and utilization of xynA.

Whole genome resequencing (WGRS) is the whole genome level sequencing between different individuals of species with known reference genome sequences,which has the advantages of abundant detection variant types,high cost performance and wide application.With the reduction of sequencing cost and the completion of animal genome sequencing,WGRS technology has become an important tool for the research of genetic variation in animals.The large amount of genetic variation information obtained through WGRS,including single nucleotide polymorphism (SNP),insertion/deletion (InDel),structural variation (SV) and copy number variation (CNV),etc.,enriches the existing genome sequence.The resulting large-scale dataset of WGRS provides a genomic information base for exploring phenotypic traits and genetic improvement in animals,and promotes the in-depth study and utilization of the genetic resources.In this article,the condition of WGRS technology and its key influencing factors (sequencing depth,sequence comparison and variant detection) were summarized,the application progress on this technology in the research field of important farm animals (cattle,sheep,pigs and chickens) was reviewed,and the future research trend focusing on integrated analysis of resequencing data,accurate phenotypic records and multi-omics information was prospected.

The content of intermuscular fat is closely related to meat quality,which determines sensory indicators such as flavor,juiciness,and tenderness of pork.Therefore,increasing intermuscular fat deposition plays an important role in improving meat quality.Intermuscular fat deposition is a complex biological process influenced by multiple regulatory factors and lipogenesis-related signaling pathways,among which the role of non-coding RNA (ncRNA) has attracted much attention from researchers. ncRNA is a class of RNA molecules that do not encode proteins,and plays a regulatory role in cell proliferation,differentiation,apoptosis and other biological processes.Recent studies have shown that microRNA (miRNA),long non-coding RNA (lncRNA) and circular RNA (circRNA) are potential regulators of intermuscular fat deposition and are involved in the regulation of fat deposition in animals.The authors summarized the biological characteristics of ncRNA,introduced the origin of intermuscular fat cells,and summarized the current research progress of ncRNA in pig intermuscular fat deposition,in order to provide basic data for pork quality improvement.

【Objective】 The widespread prevalence of porcine epidemic diarrhea (PED) has caused serious losses for pig farms.Existing vaccines provided very limited protection against mutated strains and the effective immune-related molecular markers screened from a host perspective were lacking.This study was aimed to identify differentially expressed genes (DEGs) in jejunum of Yorkshire piglets infected with Porcine epidemic diarrhea virus (PEDV),which would lay the foundation for research on the pathogenic mechanism of PEDV.【Method】 Eight 0-day-old Yorkshire piglets without colostrum were selected and rasied by milk powder until 3 days of age,four of them were attacked by PEDV as the infected group,and the other four piglets belong to control group.The jejunum were collected from the eight piglets died after infection and alive in control group for transcriptome sequencing.The genes associated with viral replication and organismal immune response were identified by differential analysis,and the GO and KEGG functional annotation were carried out for DEGs.In addition,five DEGs was randomly selected to perform Real-time quantitative PCR validation.【Result】 In total,16 256 protein coding genes (PCGs) were identified by quality control and comparative analysis of sequencing data,and 1 328 DEGs were detected through the differential analysis,of which 629 were up-regulated and 699 were down-regulated.GO function and KEGG pathway enrichment analysis revealed that up-regulated DEGs were significantly involved in 106 GO terms and 36 KEGG pathways,that were mainly associated with organismal systems and environmental signalling processes.The down-regulated DEGs were significantly involved in 54 GO terms and 23 KEGG pathways,that were mainly associated with metabolic responses.Real-time quantitative PCR results showed that the expression trends of CCND2,CREBBP,EGFR,MCL1 and PIK3CB genes were consistent with the transcriptome sequencing results.【Conclusion】 In this study,1 328 DEGs were identified,of which 629 were up-regulated and 699 were down-regulated.The up-regulated DEGs genes were mainly involved in environmental information processing and organismal system pathways,while the down-regulated genes were mainly involved in metabolic pathways,providing a theoretical basis for investigating the molecular mechanism of PEDV pathogenesis.

【Objective】 This study was aimed to explore the effect of tannic acid on the replication of Porcine epidemic diarrhea virus (PEDV),and provide a new reference for clinical treatment of PEDV infection.【Method】 The toxicity of tannic acid on Vero and LLC-PK1 cells were assessed by detecting the effects of different concentrations of tannic acid on cell activity.The effect of tannic acid on the replication of PEDV YN13 strain was detected through Real-time quantitative PCR and indirect immunofluorescence assay.The effect of tannic acid on PEDV replication was tested by replacing the PEDV YN13 strain with the PEDV DR13-GFP strain and the Vero cell line to the LLC-PK1 cell line. The tannic acid was added at different time points of virus infection,and the influence of tannic acid on PEDV replication were detected by Real-time quantitative PCR,Western blotting and 50% tissue culture infectious dose (TCID₅₀),respectively.The extracellular effect of tannic acid on PEDV 3C-like proteases activity was examined by fluorescence resonance energy transfer test.【Result】 Low concentrations of tannic acid was almost nontoxic to the cells.Tannic acid could inhibit the replication of PEDV YN13 strain in a concentration dependent manner,all concentrations of tannic acid could inhibit PEDV replication after changing PEDV strain and cell lines.Tannic acid could inhibit PEDV infection by inhibiting PEDV adsorption or invasion process and viral early replication,and also inhibit PEDV 3C-like protease activity in a concentration dependent manner.【Conclusion】 Tannic acid could inhibit PEDV infection in vitro by affecting the viral adsorption or invasion process,and it might also inhibit the viral replication process by inhibiting the viral 3C-like protease.

【Objective】 The objective of this study was to develop a Pseudorabies virus (PRV) gB antibody detection strip based on quantum dots (quantum dots,QDs) technique and provide a rapid and simple detection technique for evaluating the immune efficacy of PRV vaccines. 【Method】 In this study,PRV gB protein expressed by insect cell expression system and carboxyl-modified water-soluble QDs were used,gB-QDs fluorescent coupling compounds were prepared under the action of the coupling agent EDC.Staphylococcus aureus protein A (SPA) and the monoclonal antibodies of anti-gB protein were fixed on the nitrocellulose membrane as detection line and control line,respectively.Sample pads,quantum dots labeled pads,absorbent pads,and support plates were assembled into quantum dots-based fluorescent immunochromatographic strip (QDs-FICS) according to the production process.Then,the sensitivity,specificity of the QDs-FICS and the coincidence rate of it with commercial ELISA kit were detected.【Result】 The sensitivity test results showed that the sensitivity of QDs-FICS was 1∶6 400.The specificity of QDs-FICS showed that the QDs-FICS was highly specific to anti-PRV serum and had no cross-reaction with Classical swine fever virus (CSFV),Foot-and-mouth disease virus (FMDV),Porcine circovirus type 2 (PCV2) and Porcine reproductive and respiratory syndrome virus (PRRSV) positive serum,the specificity of it was 100%.Through the detection of field pig serum samples and comparing with commercial ELISA kit,the results showed that among the 113 field pig serum samples,11 were inconsistent between the two methods,and 102 were consistent with the results,the coincidence rate of the QDs-FICS with the commercial ELISA kit was 90.3%.【Conclusion】 The color of the test line of the developed strip was clearly visible with high recognition under ultraviolet lamp.The QDs-FICS had a high specificity and sensitivity,it could be used to detect the antibody of PRV gB protein.

【Objective】 It was aimed to isolate a phage with effective cracking for Salmonella,and provide experimental data and reference for exploring the countermeasure method of Salmonella.【Method】 Salmonella Pullorum X-1014 was used as the host bacteria,and the phage was isolated and purified from sewage by double-layer plate method.The phage was evaluated by plaque and electron microscopy,host spectrum,biological characteristics test,antibacterial test in vitro and whole genome sequencing analysis.【Result】 A lytic phage was isolated and purified,named ZH5 (GenBank accession No.:OM864357.1),which could lyse Escherichia coli and Salmonella.The results of double-layer plate method showed that the plaque was transparent and the edge was clear.Electron microscopy showed that phage ZH5 had an icosahedral head with a straight diameter of about 50 nm,a tail with a length of about 20 nm.The phage ZH5 could lyse three strains of Salmonella and one strain of Escherichia coli.The results of biological characteristics showed that the optimal multiplicity of infection was 10,the incubation period was 20 min and the outbreak period was 60 min,and the lysis volume was about 139 PFU/cell.The acid-base tolerance range was pH 4.0-10.0,and it could survive for 30 min in the environment of 4-50 ℃.Phage ZH5 showed the best inhibitory effect on Salmonella X-1014 and CVCC 1806 when the multiplicity of infection was 10.The whole genome analysis showed that the length of the phage was 42 949 bp,and the GC content was 51.41%,of which the proportion of known functional coding sequences (CDS) was 52%.Phage linear alignment showed that the genome of phage ZH5 was the most similar to the Escherichia phage Minorna(identity 94.19%;cover 84%).Phylogenetic tree analysis showed that phage ZH5 belonged to the Drulisvirus genus.【Conclusion】 A phage capable of cross-host lysis of Salmonella and Escherichia coli was isolated,which provided a good theoretical material for further research on Salmonella antibacterial agents.

【Objective】 This study was aimed to understand the virus-carrying status of infected cattle with Lumpy skin disease virus (LSDV) under natural infection and the potential vectors of the virus,so as to provide reference for the prevention and control of lumpy skin disease.【Method】 The different tissue types of specimens were collected from cattle suspected infected with LSDV in Wenshan city,Yunnan province during July 2021.The midges and mosquitoes were collected from cattle feedlots which suspected infected with LSDV in Kunming,Wenshan city and Shuangjiang county,Yunnan province in August 2020 and July 2021 to August 2021,respectively,and the morphological identification was performed.The nucleic acid of LSDV in different tissue types of specimens of infected cattle and midges and mosquitoes were detected by Real-time quantitative PCR.PCR amplification and sequencing of the skin lesions specimens were carried out with specific primer pair of LSDV127 gene.The nucleotide homology and phylogenetic analysis were performed by DNAStar and Mega 6.0 softwares.【Result】 The test of LSDV in whole blood,serum,nasal swab and skin lesion specimens of three infected cattle were positive,and the signals of LSDV amplification curve were the strongest in skin lesion specimens.In addition,the result of LSDV127 gene sequence analysis showed that three positive of nucleic acid of LSDV in skin lesion specimens were 100% homogeneity,and had the closer genetic relationship and clustered together with other LSDV which isolated from Russia,Thailand,Vietnam and South Africa,and showed 99.7%-100% homogeneity.A total of 4 822 midges specimens were trapped and identified constituting 3 different species including C.tainanus,C.jacobsoni and C.oxystoma,as well as 150 specimens of mosquitoes. No specimens of midges and mosquitoes tested were positive for nucleic acid of LSDV.【Conclusion】 These results suggested that the different parts such as blood,nasal secretions and skin lesions of cattle which naturally infected with LSDV might provide a plentiful source of pathogens for arthropod vectors to acquire and spread LSDV,and it was necessary to further investigate whether arthropod vectors such as midges and mosquitoes were involved in the transmission of local LSDV.

【Objective】 The objective of the experiment was to express the replicase protein (Rep) of Porcine circovirus type 4 (PCV4) by prokaryotic expression system,and immunize mice with purified Rep protein to prepare polyclonal antibody.【Method】 The PCV4 Fujian strain (FJ2020001) was used as the template,the Rep gene fragment was amplified by PCR, and the prokaryotic expression plasmid pET-30a-Rep was constructed.pET-30a-Rep was transformed into Escherichia coli BL21 (DE3) competent cells,and 0.5 mmol/L IPTG induced the expression of recombinant Rep protein.SDS-PAGE and Western blotting were used to identify recombinant proteins.The expression products were purified by nickel column and immunized BALB/c mice to prepare polyclonal antibodies.Western blotting and indirect ELISA were used to identify the immunogenicity and antibody titer of the murine polyclonal antibodies.【Result】 PCV4 Rep gene was cloned successfully,and the prokaryotic expression plasmid was constructed which could express recombinant Rep protein.SDS-PAGE results showed that the molecular weight of the recombinant protein was about 35 ku,mainly in the form of inclusion.Western blotting results showed that the protein could be specifically recognized by PCV4 positive serum and murine polyclonal antibody,and the prepared murine polyclonal antibody titer could reach 1∶16 000.【Conclusion】 The recombinant Rep protein of PCV4 with antigenicity was successfully expressed and purified,which could lay a foundation for the development of PCV4 serological diagnosis kit and PCV4 epidemiological investigation in pig farms.

【Objective】 Based on bioinformatics analysis,the biomarker genes of Porcine reproductive and respiratory syndrome virus (PRRSV) infection were analyzed,and the composition identification and network pharmacology of the Yinhua Gancao decoction were conducted to explore the mechanism of the treatment of PRRSV by the Yinhua Gancao decoction.【Method】 Transcriptome data of PRRSV infection in different tissues or bodies were collected using high-throughput gene expression (GEO) database,differentially expressed genes were screened using GEO2R online software,protein interaction network was constructed using STRING software,and core proteins were screened using CytoNAC software.GO function and KEGG pathway enrichment analysis were used to determine the changes of core protein signaling pathways and biological functions after infection.Ultra high performance liquid chromatography time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was used to identify the components of the Yinhua Gancao decoction,and the active ingredient screening and target prediction were carried out by the SwissTargetPredication database,and the prevention and control mechanism of the Yinhua Gancao decoction for PRRSV infection was further predicted by network pharmacology.【Result】 A total of 4 476 differentially expressed genes after PRRSV infection were identified by 5 groups of gene chips in GEO database,and 164 core proteins were screened by protein interaction analysis.After PRRSV infection,the main genetic characteristics of the non-conventional ribosomal protein S27a (RPS27A),ubiquitin A-52 residue ribosomal protein fusion product 1 (UBA52) and RPS family were changed,and the biological function changes were biosynthesis process and ribosome structure,etc.The signal transduction pathways included autophagy,iron death and apoptosis.The Yinhua Gancao decoction contained a total of 70 effective components (isoliquiritigenin,formononetin,etc.),which act on 189 genes of PRRSV infection,involving apoptosis,cell senescence and other signaling pathways.Its core targets against PRRSV infection included tumor suppressor protein 53 (TP53),extracellular signal-regulated kinase 1 (MAPK1),tumor necrosis factor (TNF),MAPK14,etc.【Conclusion】 PRRSV infection might cause autophagy,iron death and apoptosis,and the active components of the Yinhua Gancao decoction might resist PRRSV infection by regulating genes such as TP53,TNF,CASP3 and STAT3,and cell cycle and apoptosis signaling pathways.

【Objective】 Yaks,as one of the important hosts of zoonotic and multi-drug resistant pathogens in Tibet Autonomous Region,the abuse of antibiotics during the breeding process is the main reason for the development and spread of multi-drug resistance in yaks.The aim of this study was to conduct correlation analysis on the virulence characteristics,drug resistance,integrase and biofilm-forming phenotype of Escherichia coli (E.coli) strains from Tibetan yaks.【Method】 200 samples of yaks diarrhea were collected from farmers in Lhasa,Linzhi,and Nagqu in Tibet.Use bacteriological methods to isolate and purify E.coli by MacConkey Agar medium and Eosin-Methylene Blue Agar medium.PCR amplification and sequencing of the suspected E.coli were performed with 16S rDNA universal primers.The obtained sequence were BLAST aligned in NCBI database.7 classes of 16 antimicrobial drug susceptibility tests were performed on E.coli.Using PCR amplification to detect 4 categories of 10 virulence genes,20 common drug resistance genes,and 2 class Ⅰ integrator that were closely related to pathogenicity.The modified semi-quantitative crystalline violet staining method was performed on the isolated E.coli to determine their biofilm-forming phenotype,and conducted correlation analysis.【Result】 91 strains of E.coli from yaks were isolated and identified.The antibiotic drug sensitivity test of 16 antibiotics in 7 categories showed that E.coli had the strongest drug resistance to clindamycin (87.91%).Meanwhile,there was a phenomenon of multiple drug resistance,with some strains being resistant to up to 13 antibiotics.4 types of virulence genes,STEC,ETEC,EPEC and NTEC,were found to be positive in virulence test,among these detected virulence genes,F17 gene accounted for 59.34% (54/91) and stx1 gene accounted for 49.45% (45/91).Drug resistance gene testing showed that the most common among the 22 drug resistance genes was bla_TEM gene,followed by tetracycline tetA and sul1 genes.Class Ⅰ integrator analysis detected intⅠ1 and intⅠ2 integrase genes,with separately rates of 29.67% (27/91) and 1.10% (1/91).The formation of biofilm was one of the main mechanisms for bacteria to survive in harsh environments.The detection of biofilm showed that 48.35% (44/91) of 91 E.coli strains showed weak adhesion ability,and the data analysis showed that the detection rate of STEC and ETEC of E.coli was positively correlated with the detection rate of drug resistant genes,class Ⅰ integrator and biofilm.【Conclusion】 A variety of virulence genes and drug resistance genes were detected from 91 strains of E.coli isolated from yaks,and the data showed that there was a certain correlation between the diversity of its drug resistance genes and class Ⅰ integrator and the ability of biofilm formation.The results provided a theoretical basis for the study of drug resistance mechanism of E.coli from yaks and the reasonable use of antibiotics.

【Objective】 The macrophage immunosuppression model was established in vitro to investigate the effect and regulatory mechanism of cichoric acid (CA) on macrophage immunosuppression induced by phosphoramide mustard (PM),which would provide a theoretical basis for the development of CA as a new drug for clinical prevention and treatment of immunosuppressive diseases.【Method】 The macrophage-derived exosomes were extracted by ExoQuick immunoprecipitation kit.The morphology,particle size and concentration of exosomes as well as the expressions of surface marker proteins CD63 and HSP90 were identified by transmission electron microscopy (TEM),nanoparticle tracking analysis (NTA) and Western blotting.Meanwhile,macrophages were induced by PM with a concentration of 3 μmol/L for 24 h,the immunosuppression model was established,then low,medium and high doses of CA (25,50,100 μmol/L) were given for intervention.CCK-8 was used to measure cell viability,neutral red was used to measure phagocytosis ability,and NTA was used to measure exosome particle size and concentration,so as to study the mechanism of CA mediated exosomes to enhance immunity.【Result】 The extracted macrophage derived exosomes had intact cup shape,particle size between 30-200 nm,clear expression of marker proteins,and good biological activity.According to the results of CCK-8,neutral red,and NTA measurements,CA had no toxic effect on macrophages in the concentration range of 3.12-400 μmol/L.Compared with PM model group,low,medium and high doses of CA could extremely significantly improve the activity and phagocytosis of immunosuppressive macrophages (P＜0.01),promote the secretion of exosomes observably (P＜0.01).【Conclusion】 CA might activate macrophages by regulating the secretion of macrophage-derived exosomes,enhancing the cell viability and phagocytosis ability,revealing the potential mechanism of CA in enhancing immunity.

【Objective】 The experiment was aimed to master the drug resistance,resistance genes,and molecular characteristics of Escherichia coli (E.coli) in domesticated Nipponia nippon in Deqing county,Zhejiang province,and provide basic data for the treatment of E.coli infection in Nipponia nippon.【Method】 Fresh feces of Nipponia nippon were collected and E.coli isolates were identified by using bacteria isolation and culture,biochemical characteristics and 16S rDNA sequencing. Then the broth dilution method was used to detect the minimum inhibitory concentration (MIC) of seven kinds of antimicrobial agents,including ciprofloxacin,gentamicin,amikacin and so on,against E.coli isolates from different Nipponia nippon. Nine quinolone resistance genes such as qnrS1,gyrA, gyrB and so on of the respective strains were identified by PCR and sequencing,and the relationship between the mutation of the amino acid and drug resistance was analyzed.The horizontal transfer of plasmids carrying resistance genes were detected by conjugation experiments,and drug resistance were determined.The association between host’s age,drug resistance-genes and drug resistance were analyzed by using Chi-square test and Fisher exact test.【Result】 A total of 98 Nipponia nippon feces were collected and all were isolated and identified with E.coli strains.Of which,98 isolates from different captive Nipponia nippon were highly resistant to quinolone ciprofloxacin (65.3%,64/98),and highly sensitive to the remaining 6 drugs (sensitivity rates were above 90%).The age of Nipponia nippon was highly significantly correlated with ciprofloxacin resistance (P＜0.01).Thirty-one E.coli strains isolated in this study were selected for resistance genes detection.The prevalence of mutations in the quinolone resistant genes marR,gyrA,parC,and gyrB in 31 selected isolates ranged from 3.2% to 80.6%,and the proportion of strains carrying the plasmid resistant gene qnrS1 was 22.6% (7/31).The isolates carrying one or more resistance genes accounted for 93.5% (29/31),and were distributed in six drug resistance genotypes,including 10 strains of marR/gyrA/parC genes,6 strains of marR/qnrS1 genes,6 strains of marR gene,3 strains of gyrA/parC genes, 3 strains of marR/gyrA genes,and 1 strain of marR/gyrB/qnrS1 genes.The ciprofloxacin resistance phenotype was significantly correlated with drug resistance genotype (P＝0.026). Both monogenic and combined mutations of the gyrA and parC genes were related to quinolone resistance (P＝0.038).The conjugation experiment results showed that the transfer success rate of the qnrS1 resistance gene carried by the E.coli isolates in this study was 28.6% (2/7) in one conjugation event,which could lead to an increase in quinolone resistance in the recipient bacteria.【Conclusion】 This study identified the antibiotic resistance of E.coli from Nipponia nippon,and identified that the main cause of quinolone resistance in Nipponia nippon was single or combined mutation of gyrA and parC genes,carrying the horizontally transferable resistance gene qnrS1.This study provided a reference for rescuing Nipponia nippon and a baseline data for quinolone resistance surveillance of Nipponia nippon.

【Objective】 The experiment aimed to explore the metabolic differences of traditional Chinese medicine in the fermentation of Banqi Qingfei prescription by Bacillus subtilis at the metabolomics level.【Method】 Using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) technology,multiple statistical analysis and metabolic pathway analysis such as principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA),the differential metabolites and metabolic pathways between the traditional Chinese medicine powder of Banqi Qingfei prescription and the traditional Chinese medicine powder of Banqi Qingfei prescription fermented by Bacillus subtilis were explored.【Result】 A total of 34 624 differential metabolites were screened out in the fermentation group of Banqi Qingfei granules (Enzyme group) and the control group of unfermented Banqi Qingfei granules (Water group) in the positive ion mode,and 15 762 differential metabolites were screened out in the negative ion mode.Cluster analysis was conducted on the differential metabolites,and the identified differential metabolites could be divided into 203 categories.The PCA diagram of the relationship between the positive and negative ion mode groups showed good differentiation effect.After fermentation,the main up-regulated differential metabolites include equol,ethynodiol diacetate,vanylglycol,D-ornithine,quinestrol,cholesterol and acetylcholine,and the down-regulated differential metabolites include Aspergillus flavus,erucic acid,myristic acid and xanthine.After enrichment analysis of KEGG metabolic pathways,27 significantly different metabolic pathways were screened,including proximal tubule bicarbonate recovery,arginine biosynthesis,biosynthesis of histidine and purine derived alkaloids,biosynthesis of plant secondary metabolites,phenylpropane biosynthesis,protein digestion and absorption,etc.【Conclusion】 After the fermentation of Banqi Qingfei prescription,amino acids such as lipids and ketones of differential metabolites increased significantly,and acid amino acids decreased significantly,involving multiple amino acid biosynthesis and purine metabolism,providing a theoretical basis for the fermentation products of Banqi Qingfei prescription.

With the deepening understanding of the pathophysiology of heart failure (HF),an increasing number of therapeutic drugs for HF have been developed.The new drug empagliflozin has been approved and widely used in the treatment of HF in human medicine.However,the development of HF treatment drugs for dogs and cats has been relatively slow.The available drug options are limited,with a single mechanism of action,and lack sufficient safety and efficacy data.Accelerating the research and development of novel HF treatment drugs for dogs and cats is crucial for the management and treatment of HF in these animals.In this study,key words such as "heart failure","therapy","medicine","dogs","canine","cats","feline" were used to search databases including PubMed,Google Scholar,Web of Science,Baidu Scholar,CNKI,and so on.The review of results indicates that the current focus of HF drug development is on inhibiting or directly reversing ventricular remodeling,including drugs that act directly on the heart or on the peripheral circulation.Recent studies have shown that sodium-glucose cotransporter 2 inhibitors (SGLT2i),angiotensin receptor-neprilysin inhibitors (ARNi),mineralocorticoid receptor antagonists (MRA),soluble guanylate cyclase (sGC) stimulators,and cardiac myosin activators are five categories of drugs with potential for HF treatment.These drugs have unique mechanisms of action,and animal experiments or human clinical trial results have demonstrated their significant improvement in cardiac contractile function,prevention or reduction of harmful neurohormonal activation and ventricular remodeling.They hold promise as novel frontline drugs for the treatment of heart failure in dogs and cats.This article summarized the research progress on the mechanisms of action,efficacy,and safety of these five categories of drugs,aiming to provide insights for future research on HF drugs in dogs and cats.

【Objective】 This study was aimed to investigate the role of antimicrobial peptide bovine neutrophil β-defensins 5 (BNBD5) in regulating the innate immune response of lung against Actinobacillus pleuropneumoniae (APP) infection,and provide experimental basis and theoretical support for the prevention and control of porcine pleuropneumonia.【Method】 30 BALB/c mice were randomly divided into three groups,which were normal control group (Con),APP infection group (APP), antibacterial peptide BNBD5 pretreatment and APP infection group (B5),10 mice in each group. Mice in Con group were treated with PBS (20 μL per mouse) two times at two-day intervals. Mice in APP group were treated with PBS (20 μL per mouse) two times at two-day intervals and intranasally challenged with 10⁷ CFU of APP 3 d after treatment. Mice in B5 group were treated with antibacterial peptide BNBD5 (20 μg per mouse) two times at two-day intervals and intranasally challenged with 10⁷ CFU of APP 3 d after treatment.Mice were euthanized 6 h after APP challenge.The general pathological changes of lung and spleen were observed,and the organ coefficient and bacterial load in lung were measured.The pathological changes of lung were observed by HE staining.Levels of cytokines tumor necrosis factor α (TNF-α),interleukin 1β (IL-1β),IL-23,IL-17 and IL-22 in lung were tested using ELISA.The number of neutrophils in lung was measured using flow cytometry.【Result】 Compared with Con group,mice in APP group had rough and disordered hair,decreased mental state,enlarged lungs,and obvious patchy or punctate bleeding.Microscopically,there was significant bleeding and a large amount of inflammatory cell infiltration in lung.The cytokine levels of TNF-α,IL-1β,IL-17,IL-22 and IL-23 in lung were not significantly changed (P＞0.05),but they all decreased to different degrees,and the number of neutrophils decreased.Compared with APP group,the mental state of mice in B5 group was better,the degree of lung swelling was reduced,the lung index was significantly decreased (P＜0.05),no obvious plaque bleeding was observed,the bacterial load in lung was extremely significantly decreased (P＜0.01),and the inflammatory cells in lung were significantly decreased.The levels of TNF-α,IL-1β,IL-17 and IL-22 in lung were significantly increased (P＜0.05),and the number of neutrophils in lung was extremely significantly increased (P＜0.01).【Conclusion】 Antimicrobial peptide BNBD5 could ameliorate APP-caused immune suppression of lung and enhance the innate immunity of lung against APP in the early stages of infection.

【Objective】 The prevalence and antibiotic resistances of Mycoplasma synoviae (MS) isolates were investigated in the Southern region of Hebei province of China,so as to provide scientific basis for the control of MS infection in this region.【Method】 Samples (the exudate from the airbag,cleft palate,or paw pad of diseased chickens) were collected from 7 large-scale chicken farms suspected of MS infection in the Southern region of Hebei province from 2019 to 2022.Strains were isolated from the samples and identified by PCR.DNA sequence analysis of the vlhA gene was conducted for genotyping of the isolated strains.Minimal inhibitory concentration (MIC) values of the strains were determined by the microbroth dilution method.【Result】 Nine suspected MS strains were isolated from the collected samples.All the strains could turn the liquid culture medium orange and showed typical "fried eggs" colonies on solid culture medium.PCR identification and sequencing results showed that the 9 isolated strains had 100% similarity with the typical HN01 strain,indicating that all of which were MS strains.The vlhA gene typing sequence analysis showed that 9 strains all had 35 amino acis in the proline-rich repeats (PRR),which hence belonged to the L-type,with a nucleotide sequence similarity of 99.7% to 100%.The phylogenetic relationships of isolated strains were close with those L-type strains isolated from other regions of China,whereas far from the L-type strains reported in Thailand.MIC_50/90 values of the 9 MS strains for tylosin,tilmicosin,spiramycin,lincomycin,valnemulin,tiamulin,doxycycline,oxytetracycline,florfenicol,and enrofloxacin were 0.25/0.25,0.5/0.5,0.5/0.5,1/1,≤0.016/≤0.016,0.062/0.125,1/1,2/2,4/4 and 32/32 μg/mL,respectively.【Conclusion】 Nine L-type MS strains were isolated in the Southern region of Hebei province,which showed tiny differences from strains isolated in other regions of China and were relatively stable in genetic evolution.The tiamulin,valnemulin,tylosin,tilmicosin,spiramycin could be recommended for the therapy of MS infections in the region followed by lincomycin,doxycycline,oxytetracycline.The presented data might serve as a guide for the prevention and control of MS infection in the region.

【Objective】 Based on network pharmacology combined with molecular docking technology,the effects of Codonopsis pilosula-Glycyrrhiza extract on immune function of weaned piglets and its mechanism were investigated.【Method】 Weaned piglets at 28 days of age were randomly divided into control group and Codonopsis pilosula-Glycyrrhiza low,medium and high dose groups, and 12 piglets each group.Piglets in the control group were fed a basal diet,while piglets in the low,medium and high dose groups were fed the basal diet supplemented with 0.5%,1% and 1.5% Codonopsis pilosula-Glycyrrhiza extract for 28 consecutive days,respectively.The average daily gain and feed to gain ratio of weaned piglets in each group were analyzed.The contents of IgA,IgM and IgG in serum were detected.The potential active components and target were screened through TCMSP and SwissTargetPrediction database,and immunosuppressive related targets were searched through OMIM and GeneCards database to obtain the potential target for enhancing the immune effect of Codonopsis pilosula-Glycyrrhiza.The protein-protein interaction (PPI) network was constructed with STRING database,and the GO function and KEGG pathway enrichment analysis were performed with Metascape database.AutoDock 1.5.6 and PyMOL software were used for molecular docking verification and visualization of some key targets,and the results were verified.【Result】 Compared with the control group,the average daily gain, IgA,IgM and IgG contents of serum of weaned piglets in Codonopsis pilosula-Glycyrrhiza extract medium dose group were significantly increased,and the feed to gain ratio was significantly decreased (P ＜ 0.05).Network pharmacological analysis showed that the main active components of Codonopsis pilosula-Glycyrrhiza might be quercetin,kaempferol,luteolin and taraxerol,and there were 95 key targets for their intersection with immunosuppressive diseases.The highest correlation in the immune PPI network was serine/threonine protein kinase 1(AKT1),vascular endothelial growth factor A (VEGFA),interleukin 6 (IL6) and tumor necrosis factor α (TNF-α).GO functional enrichment analysis showed that the key targets were enriched to 1 778 items,mainly related to the positive regulation of calcitriol 1-monooxygenase activity,the transcription of RNA polymerase Ⅱ promoter is positively regulated during hypoxia,serine protease inhibitor complex,Bcl-2 family protein complex,peptidase inhibitor complex,etc.KEGG pathway enrichment analysis showed that the immune regulation of Codonopsis pilosula-Glycyrrhiza was mainly enriched in PI3K-Akt,TNF,MAPK signaling pathways.Molecular docking results showed that quercetin,kaempferol,luteolin and taraxerol had good binding activity with key targets IL6,VEGFA and TNF-α.【Conclusion】 Codonopsis pilosula-Glycyrrhiza extract could improve the growth performance and immunity of weaned piglets,which was closely related to the intervention of PI3K-Akt,MAPK and NF-κB signaling pathways.

Ivermectin is widely used in the treatment of livestock and poultry parasitic diseases and human river blindness because of its broad-spectrum antiparasitic effect.Some studies have found that it also has antiviral,antitumor and immunomodulatory effects,and has great potential for exploitation.However,the clinical application of ivermectin has been greatly restricted due to its poor water solubility.In recent years making nano-delivery systems,cyclodextrin inclusion compounds,solid dispersions and self-emulsifying delivery systems are common methods to improve the water solubility of ivermectin and can be used as potential drug carriers.Nanodelivery systems include nanosuspensions,microemulsions,nanoparticles and hybrid micelles,which usually require the addition of surfactants or nanocarriers to prepare them,mainly by reducing the particle size of the drug to improve its aqueous solubility.Cyclodextrin inclusion compounds are formed by embedding the drug (guest molecule) with cyclodextrin (main molecule),which can improve the water solubility and stability of the drug,reduce the toxic side effects of the drug,and also have the ability to control the drug release.Solid dispersions are used to increase drug solubility by maintaining the amorphous state of the drug,but the amorphous state of the drug is in a high-energy state and has the tendency to aggregate.Self-emulsifying drug delivery systems are isotropic systems,consisting of oil,emulsifier,co-emulsifier and drug,which can spontaneously emulsify to form emulsions in a state of in vitro agitation with water or in vivo peristalsis in an aqueous environment.The authors describe the research on improving the aqueous solubility of ivermectin in recent years,with the aim of providing a theoretical basis for the preparation process and clinical development and application of ivermectin formulations.

Hyperlipidemia,as one of the most common diseases in large-scale donkey breeding farms,has the characteristics of high morbidity,high mortality and difficult early diagnosis,which seriously harms the healthy development of China’s donkey industry.The underdeveloped pathway of ketone body production in donkeys,coupled with multiple factors such as innate insulin resistance,makes them more susceptible to hyperlipidemia.This disease is caused by excessive mobilization of adipose tissue due to a negative energy balance which can be divided into primary hyperlipidemia caused by stress,obesity,pregnancy,lactation and genetics,as well as secondary hyperlipidemia caused by various systemic diseases that contribute to the negative energy balance of the body.Its etiology and mechanism mainly include blood lipid accumulation,tissue resistance to insulin,primary disease,intestinal flora disorder and genetic effects.The disease can be diagnosed by measuring the concentration of serum lipids combined with its clinical manifestations.With the development of metabonomics,we can also make a more accurate early diagnosis of hyperlipidemia by looking for relevant small molecular biomarkers combined with the concentration of serum triglycerides.The author reviewed the etiology,mechanism and clinical diagnosis methods of donkey hyperlipidemia,and prospected the future direction of donkey hyperlipidemia research,in order to promote the clinical diagnosis and treatment of donkey hyperlipidemia and the development of disease resistance breeding technology.