【Objective】 This study was aimed to identify selection signals in the genome of the Ninglang Plateau chickens (Gallus gallus domesticus) and to identify valuable germplasm trait genes.【Method】 The study was based on whole-genome resequencing data from 57 Ninglang Plateau chickens and 10 Gallus gallus.Single nucleotide polymorphism (SNP) in the autosomes were identified using GATK software,and these SNPs were annotated using Annovar software.Principal components analysis (PCA) and phylogenetic tree analysis were performed to explore the population genetic structure.Two methods-fixation index (Fst) and pairwise nucleotide variation (θ_π),were employed to detect the selection signal regions in the genome of Ninglang Plateau chickens.The intersection of the top 5% Fst and θ_π values was used to identify the selected genomic regions.The extracted candidate genes were subjected to GO functional and KEGG pathway enrichment analyses.【Result】 A total of 10 666 468 SNPs were annotated in the whole genome of Ninglang Plateau chickens.The results of PCA and phylogenetic tree analyses indicated that the Ninglang Plateau chickens and Gallus gallus were clustered into two distinct groups,showing significant differences in their genetic backgrounds.GO enrichment analysis of the 284 candidate genes detected by both Fst and θ_π showed significant enrichment in 354 GO terms,including 236 biological processes,78 molecular functions,and 40 cellular components.KEGG pathway analysis showed that the candidate genes were mainly enriched in 24 pathways,including osteoclast differentiation,cardiac muscle contraction,mineral absorption,and the HIF-1 signaling pathway,which were primarily associated with environmental adaptation,growth,and development.Thirteen functional genes,including SEMA3C,MAPK1,EGFR,RYR2,CACNA2D3,CACNA2D1,PLCE1,FGFR2,ZFYVE9,PIK3C2G,MMP16,HESX1,and COL6A1,were identified and were mainly related to growth and development,altitude adaptation and disease resistance.【Conclusion】 There was significant population differentiation between Ninglang Plateau chickens and Gallus gallus.Compared with Gallus gallus,the selected genes in Ninglang Plateau chickens were mainly associated with growth and development,environmental adaptation,and immune traits.These findings provided valuable insights into the genetic traits of Ninglang Plateau chickens.

【Objective】 The proteomic characteristics of serum in captive giant pandas during mucus-excreting and non-mucus-excreting periods were investigated to elucidate the molecular mechanisms underlying mucus excretion and provide scientific support for the health management of captive giant pandas.【Method】 Eight captive giant pandas were selected for this study,with one blood sample collected from each panda during both the mucus-excreting period and the non-mucus-excreting period.The samples were then divided into the mucus-excreting period group (NY) and the non-mucus-excreting period group (Con).Blood was collected from the mucus-excreting group within 2 h after mucus excretion,while for the non-excreting group,blood collection occurred at least 30 days after the last mucus-excreting period.After blood proteins were extracted and digested,the resulting peptides were desalted and quantified.Data-independent acquisition (DIA) was used for liquid chromatography-mass spectrometry (LC-MS/MS) analysis,and the data were processed using Spectronaut^TM software.Data analysis was conducted on the Majorbio Cloud Platform,with criteria for screening differentially expressed proteins set at P＜0.05 and a FoldChange (FC)＞1.2 or<0.8.These proteins were further analyzed through clustering,GO functional enrichment analysis,metabolic pathway enrichment analysis,and protein interaction analysis with bioinformatics databases.Protein data were validated by parallel reaction monitoring (PRM),with peptide quantification values normalized according to reference peptides.Statistical significance was set at P＜0.05,and DIA results were compared with PRM validation outcomes.【Result】 A total of 273 proteins were identified in the blood samples of giant pandas，with 258 proteins shared between groups，12 proteins unique to the mucus-excreting period，and 3 proteins unique to the non-mucus-excreting period.Analysis of differential protein expression revealed 25 differentially expressed proteins between the mucus-excreting and non-mucus-excreting groups，including 7 up-regulated proteins and 18 down-regulated proteins.The differentially expressed proteins were found to be primarily involved in biological processes such as cell growth，immune response and inflammatory response，with significant enrichment observed in the Rap1，Estrogen,phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt),and Relaxin signaling pathways.Through protein interaction analysis，A0A7N5KNP1(FBLN5)，D2GWB9(THBS1)，D2HUL0(SERPIND1) and D2HHD2(ITGA2) were identified as key proteins，showing significant changes during the mucus-excreting period.【Conclusion】 Twenty-five differentially expressed proteins were identified in the serum of giant pandas during mucus excretion compared to the non-mucus-excreting period.These proteins were primarily enriched in the PI3K-Akt，Rap1，Estrogen and Relaxin signaling pathways，with core proteins A0A7N5KNP1(FBLN5),D2GWB9(THBS1),D2HUL0(SERPIND1) and D2HHD2(ITGA2) found to play important roles in the mucus excretion phenomenon in giant pandas.

【Objective】 The purpose of this experiment was to establish the wild-type p53-induced phosphatase 1 (WIP1) gene g.37536832 C＞A mutation swine testis (ST) cell line which was significantly associated with sperm motility by using CRISPR/Cas9 gene editing technology,and laid a solid foundation for further research on the relationship between the WIP1 gene and the semen quality traits of boar semen at the cellular level.【Method】 Three single guide RNA (sgRNA) were designed near the g.37536832 C＞A locus of porcine WIP1 gene using CRISPOR online website and connected to pX458-GFP vector.The activities of three sgRNA vectors were detected by T7E1 enzymatic cleavage assay,and the sgRNA with higher efficiency was selected.Donor vector was constructed and transfected into ST cells together with sgRNA vector.Positive cells expressing green fluorescent protein (GFP) were enriched and monoclonal cells were screened using flow cytometry,and the genotypes of the selected monoclonal cells were identified. 【Result】 Plasmid sequencing results showed that three sgRNAs were successfully ligated into the pX458-GFP vector.The results of T7E1 enzyme digestion showed that pX458-GFP-sgRNA1 and pX458-GFP-sgRNA2 transfected plasmids produced cleavage,and the efficiency was 24% and 27%,respectively,while no cleavage was detected in pX458-GFP-sgRNA3.Therefore,pX458-GFP-sgRNA2 plasmid was selected for the experiment.Donor vector was successfully constructed,and pX458-GFP-sgRNA2 and Donor vector were transfected into ST cells.Genotype identification showed that 205 of the 269 monoclones obtained had gene editing,and the gene editing efficiency was 76%.Among them,9 clones were ST cells with homozygous mutation at g.37536832 C>A of WIP1 gene,and the precise mutation efficiency was 3%.【Conclusion】 In this study,the ST cell line with the mutation of g.37536832 C＞A locus of WIP1 gene was successfully obtained using CRISPR/Cas9 gene editing technology,which provided a favourable cell model for further study of the effect of WIP1 gene on the semen quality of boars.

【Objective】 The whole genome sequence analysis of Bacillus velezensis G02 was carried out to explore the genes related to its antibacterial and bacteriogenic properties in order to analyze its genome information in detail.【Method】 The whole gene of Bacillus velezensis G02 was sequenced by Illumina NovaSeq 6000 platform using next-generation sequencing technology.Genome characteristics were analyzed by gene assembly,genome length,functional annotation and secondary metabolite prediction.【Result】 The whole genome sequencing results showed that the total length of Bacillus velezensis G02 genome was 3 891 653 bp,with 3 749 protein-coding genes and a GC content of 46%.The genome sequence consists of 12 contigs with 92 non-coding RNA,including 8 5S rRNA,2 16S rRNA,1 23S rRNA,80 trRNA and 1 tmRNA.Functional annotation results showed that 9 genes related to antioxidant activity were annotated in GO database.KEGG database annotated 31 pathways,among wihch the genes involved in bacterin synthesis and immune-related pathways were ko00253,ko00261 and ko00521,etc.A total of 12 secondary metabolite synthesis gene clusters were annotated by antiSMASH online prediction software.【Conclusion】 Bacillus velezensis G02 was a potential strain producing antibacterial active substances,and the results provided a basis for the development and exploration of the antibacterial mechanism of Bacillus velezensis G02.

【Objective】 This experiment was conducted to explore the effects of dietary superoxide dismutase (SOD) on growth performance,immune performance,antioxidant capacity and intestinal function of broilers,so as to provide reference for the application of SOD in livestock and poultry.【Method】 A total of 300 one-day-old Arbor Acres (AA) male broilers were randomly divided into 5 groups with 6 replicates per group and 10 broilers per replicate.Broilers in control group were fed the basal diet,and broilers in groups A,B,C and D were fed the basal diet supplemented with 100,200,400 and 800 mg/kg SOD,respectively.The trial period was 42 days.The feed intake of broilers was recorded every day.At the ending of the feeding trial,one broiler was randomly selected from each replicate,and weighed after 12 h of water supply and fasting.The immune organs,blood,liver and intestinal samples were collected to determine the growth performance,immune performance,antioxidant capacity and intestinal function indexes of broilers.【Result】 Compared with control group,①The feed to gain (F/G) of broilers aged 1-21 days in group B was significantly decreased (P＜0.05).②The thymus index and bursa of Fabricius index of broilers in groups A-D showed an increasing trend,but the difference was not significant (P＞0.05).The spleen index of broilers in groups B and C was significantly increased (P＜0.05).③There was no significant difference in serum immunoglobulin A (IgA) content of broilers in groups A-D (P＞0.05),but the contents of IgG and IgM in serum of broilers in group B were significantly increased (P＜0.05).④The total antioxidant capacity (T-AOC),glutathione peroxidase (GSH-Px) and total superoxide dismutase (SOD) in serum,and T-AOC and SOD activities in liver of broilers in groups B and C were significantly increased (P＜0.05),and the malondialdehyde (MDA) content in serum and liver was extremely significantly decreased (P＜0.01).The activities of GSH-Px and catalase (CAT) in liver of broilers in group B were significantly increased (P＜0.05).The MDA content in serum of broilers in group D was significantly increased (P＜0.05).⑤The length of duodenum and jejunum and the weight of duodenum of broilers in group B were significantly increased (P＜0.05).The trypsin activity in duodenum and jejunum of broilers in groups B and C were significantly increased (P＜0.05).【Conclusion】 Under the conditions of this experiment,adding 200 mg/kg SOD to diet could improve the antioxidant capacity,immunity,intestinal function and 1-21 days old growth performance of broilers.

【Objective】 This study was aimed to investigate the effects of adding hyocholic acid (HCA) on body lipid metabolism,intestinal microorganisms and bile acid metabolism in high-fat pregnant mice,and investigate the effects of HCA on improving the disorders of body lipid metabolism in mice.【Method】 Sixty-eight female and twenty-three male C57BL/6 mice with similar body weights(19.2 g±0.1 g) and good growth conditions were selected at 6 weeks of age to mate,the pregnant mice were randomly divided into four treatment groups based on their body weight:Control group (CON),high-fat group (T1),high-fat+50 mg/kg HCA group (T2) and high-fat+100 mg/kg HCA group (T3),with five replicates in each group and three mice per replicate.On the day of delivery and weaning,the growth performance,serum biochemical indices,and tissue section analysis of mice were performed.On the day of delivery,colon contents were collected for analysis of gut microbiota and bile acid metabolism.【Result】 ①Compared with CON group,the average weaning litter weight of mice was significantly increased in T1,T2 and T3 groups (P＜0.05),the subcutaneous fat weight of mice was significantly increased in T1 and T3 groups (P＜0.05),and the liver weight was significantly increased in T1 group (P＜0.05).②HCA could improve fat accumulation in liver and increase the amount of brown fat in scapular region of mice induced by high-fat diet.③Compared with CON group,the levels of total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) in serum of mice after delivery in T1,T2 and T3 groups were significantly increased (P＜0.05),the level of triglycerides (TG) in serum of mice in T1 and T3 groups was significantly increased (P＜0.05).After weaning,the levels of TC and HDL-C in serum of mice in T1,T2 and T3 groups were significantly increased (P＜0.05),the level of low-density lipoprotein cholesterol (LDL-C) in serum of mice in T1 and T2 groups was significantly increased (P＜0.05).④Alpha diversity analysis results showed that compared with CON group,Shannon and Simpson indexes of intestinal microflora of mice in T3 group were significantly decreased (P＜0.05),but Dominance index was significantly increased (P＜0.05).⑤At the phylum level,the first and second dominant bacteria in intestine of mice in each group were Bacteroidetes and Firmicutes,respectively.The third dominant bacteria in intestine of mice in T3 group was Desulfobacterota,and in other groups was Verrucomicrobiota.⑥Compared with CON group,the relative abundances of Lactobacillus,Clostridium and Bifidobacterium in intestine of mice in T1 and T2 groups were significantly increased (P＜0.05),the relative abundance of Coriobacterium in T3 group was significantly increased (P＜0.05),and the relative abundance of Bacteroides in T1,T2 and T3 groups was significantly decreased (P＜0.05).⑦Compared with CON group,the levels of 7-ketoLCA,alpha-MCA,beta-MCA and GLCA in intestine of mice in T1,T2 and T3 groups was significantly increased (P＜0.05),the levels of beta-UDCA and THCA in T2 and T3 groups were significantly increased (P＜0.05),and the level of 7,12-diketoLCA in T2 group was significantly increased (P＜0.05).【Conclusion】 HCA could improve the serum biochemical indices and promote the generation of beneficial bacteria and bile acid metabolism,thereby regulating the body fat metabolism disorder induced by high-fat diet in mice,providing a reference for the role of HCA in improving body lipid metabolism disorders under high-fat diet.

【Objective】 This research was aimed to evaluate the effects of dietary organic manganese-iron-copper-zinc compound preparations on the production performance,blood biochemical indexes,follicle development and tibia quality of laying hens,so as to provide reference for the scientific application of organic manganese-iron-copper-zinc compound preparations in diets of laying hens during the laying peak period.【Method】 A total of 270 Jingfen hens aged 38 weeks were randomly assigned to 3 dietary groups,each with 6 replicates of 15 hens.Hens in control group were supplied with corn-soybean basal diet,and hens in experimental groups were fed the basal diet supplemented with 50% NCR (1994) recommended amounts of organic manganese-iron-copper-zinc compound preparation products 1 and 2 (OT1 and OT2),respectively.This study included a 1-week pre-trial period followed by a 12-week experimental period.The egg production was recorded every day,and the feed weekly.At weeks 4,8 and 12,egg quality was determined.At the end of the feeding,one layer per replicate was selected,blood sample was collected,blood routine,blood biochemical and antioxidant indices were measured,and the ileum immunity indices,oviduct and follicular development indexes and tibia quality were determined after slaughter.【Result】 Compared with control group,OT1 significantly increased the eggshell thickness of laying hens at weeks 8 (P＜0.05);OT1 and OT2 significantly decreased the platelet count and increased total protein (TP) content in serum of laying hens (P＜0.05),OT2 significantly increased the alkaline phosphatase (ALP) activity in serum of laying hens (P＜0.05),OT1 significantly increased the glutathione peroxidase (GSH-Px) activity in serum of laying hens (P＜0.05).OT1 and OT2 significantly increased immunoglobulin A (IgA) content in ileum mucosa of laying hens (P＜0.05),OT2 significantly increased IgG content in ileum mucosa of laying hens (P＜0.05).OT1 and OT2 had no significant effect on the oviduct and follicular development of laying hens (P＞0.05).OT1 and OT2 significantly increased the tibial length of laying hens (P＜0.05).【Conclusion】 Under the conditions of this experiment,the organic manganese-iron-copper-zinc compound preparation had no effect on the production performance of laying hens but improved the antioxidant capacity in serum,intestinal immune function and tibia quality.Among the two preparations,organic manganese-iron-copper-zinc compound preparation product 1 demonstrated superior efficacy.

Dogs,due to their unique digestive physiological structure,metabolic characteristics,and inherent living habits,face a heightened risk of intestinal diseases.Especially for working dogs,which need to cope with various stress factors,the susceptibility to intestinal diseases further increases.Currently,functional additives play a pivotal role in the prevention and control of intestinal diseases in dogs.These additives,derived from biological enzymatic hydrolysates,plant extracts,microecological agents,and traditional Chinese medicine compounds,exert dual therapeutic and health-promoting effects on canine intestinal health through multiple mechanisms such as regulating intestinal flora balance,enhancing intestinal immune function,optimizing intestinal digestion and absorption,and reducing intestinal inflammation.They also actively promote the growth,development,metabolism,and immune enhancement of dogs.Therefore,the scientific and rational application of functional additives can be regarded as one of the effective strategies for preventing and treating intestinal diseases in dogs.The authors have summarized the existing research findings on the effects of functional additives on animal intestinal health,delved into the classification,application,and specific effects of functional additives on intestinal health,and integrated scattered research arguments,providing a reference for subsequent theoretical and experimental research by practitioners.

【Objective】 This experiment was aimed to investigate the effects of adding different doses of epidermal growth factor (EGF) to the diet on the morphology,hormone levels,and the expression of apoptotic factors of ovaries in laying hens,so as to provide a theoretical basis for elucidating the role of EGF in promoting the growth and development of ovaries in laying hens.【Method】 Two hundred and forty healthy,high-producing White Leghorn laying hens aged 260 days with similar body weights were selected and randomly divided into four treatment groups,with five replicates per group and twelve hens per replicate.The laying hens in control group (Con) were fed a basal diet without EGF supplementation,while laying hens in three experimental groups (LG,MG and HG) were fed basal diets supplemented with 200,400 and 800 mg/kg EGF,respectively.The advanced experiment period lasted for 7 days,and the formal experimental period lasted for 42 days.From each replicate,two laying hens were selected for blood collection and sample harvesting.The weights of ovaries,oviducts and follicles were measured,as well as the number of follicle grading was counted.The concentrations of luteinizing hormone (LH),follicle-stimulating hormone (FSH),estradiol (E₂) and progesterone (P₄) in serum were assayed.The expression of apoptotic factors Bcl-2 and Caspase-3 in ovaries were evaluated using Real-time quantitative PCR and Western blotting,respectively.【Result】 Compared with Con group，①The addition of different doses of EGF to the diet had significant effects on ovarian weight,ovarian index and the number of white follicles in laying hens (P＜0.05).However,there were no significant morphological changes observed in ovaries among the different groups.②The levels of LH,FSH and E₂ in serum of laying hens in LG,MG and HG groups were significantly increased (P＜0.05),the level of P₄ in serum of laying hens in LG and MG groups were also significantly increased (P＜0.05).③The relative expression of Bcl-2 gene in ovaries of laying hens in LG and MG groups was significantly increased (P＜0.05),the relative expression of Bcl-2 protein in ovaries of laying hens in LG,MG and HG groups was also significantly increased (P＜0.05).Conversely,the relative expression of Caspase-3 gene in ovaries of laying hens in LG and MG groups was significantly decreased (P＜0.05),the relative expression of Caspase-3 protein in ovaries of laying hens in MG and HG groups was significantly decreased (P＜0.05).【Conclusion】 Under the conditions of this experiment,the addition of different doses of EGF to the diet promoted the secretion of ovarian reproductive hormones and follicular development to a certain extent,effectively inhibited cell apoptosis and thereby improved the production performance of laying hens.The recommended addition amount of EGF in diet for high-producing White Leghorn laying hens was 400 mg/kg.

【Objective】 The purpose of this study was to analyze the changes of intestinal morphology,antioxidant capacity and other related indexes of Wuzhishan piglets after weaning,and explore the mechanism of Nrf2 signaling pathway on intestinal oxidative stress in early weaned piglets.【Method】 Forty-eight 35-day-old Wuzhishan piglets of similar weight (4.43 kg±0.58 kg) and good body condition were selected and divided into 4 groups with 12 piglets in each group.They were slaughtered and collected samples on the day of weaning (0 d),and the 3rd,7th and 10th days after weaning,respectively.The intestinal morphology,blood antioxidant-related enzyme activity,the reactive oxygen species (ROS) level in intestinal mucosa,intestinal Nrf2 signaling pathway and the expression of antioxidant enzyme-related gene of piglets in each group were detected.【Result】 Compared with weaning 0 days,①On the 3rd day after weaning,the villus height of duodenum in piglets was significantly decreased (P＜0.05),and the development trend of jejunum was similar to that of duodenum.The villus height and villus height/crypt depth were significantly increased on the 7th day after weaning (P＜0.05).②The activity of glutathione peroxidase (GSH-Px) of serum in piglets was significantly decreased (P＜0.05).The total antioxidant capacity (T-AOC) showed an upward trend after weaning,and reached the highest level on the 7th day after weaning (P＜0.05).The malondialdehyde (MDA) content in serum showed a slow downward trend after weaning (P＞0.05),and significantly increased on the 10th day after weaning (P＜0.05).③The ROS level in small intestinal mucosa of piglets was significantly increased on the 3rd and 7th days after weaning (P＜0.05),and there was no significant change on the 10th day after weaning (P＞0.05).④The expression of SOD1,SOD2,GPx1 and GPx4 genes in jejunum of piglets were significantly decreased on the 7th day after weaning (P＜0.05).The expression of SOD2 gene in ileum of piglets was significantly decreased on the 7th day after weaning (P＜0.05),and the expression of GPx4 and CAT genes in ileum of piglets were significantly increased on the 10th day after weaning (P＜0.05).⑤The expression of Nrf2 gene in ileum of piglets was significantly increased on the 10th day after weaning (P＜0.05).The expression of NQO1 gene in jejunum of piglets was significantly decreased on the 7th day after weaning (P＜0.05).The expression of HO-1 gene in duodenum of piglets was significantly decreased on the 3rd and 10th days after weaning (P＜0.05),and the expression of HO-1 gene in ileum of piglets was significantly increased on the 7th and 10th days after weaning (P＜0.05).【Conclusion】 Weaning stress could significantly increase the ROS level in small intestine of weaned Wuzhishan piglets,causing oxidative stress,which could cause obvious intestinal morphological changes such as villus shedding,shortening and crypt hyperplasia in weaned Wuzhishan piglets.Oxidative stress caused by weaning could also be alleviated by up-regulating antioxidant enzyme activity and intestinal related gene expression in serum of piglets.

【Objective】 This experiment was designed to investigate the effects of chestnut bur aqueous extracts (CBE) on growth performance,organ coefficient,antioxidant function and tissue structure in mice,and provide reference for the development and application of CBE in animal production.【Method】 Forty 4-week-old SPF Kunming mice were randomly divided into 5 groups of 8 mice each.Mice in control group were given normal drinking water,and mice in experimental groups were supplemented with 0.05%,0.10%,0.25% and 0.50% CBE in drinking water,respectively.The test was maintained for 28 days.After the experiment,the average daily gain (ADG),average daily feed intake (ADFI),feed-to-gain ratio (F/G) and average daily water intake (ADWI) in each group were calculated.Blood was collected by picking eyeball,and mice were sacrificed by cervical dislocation method.Heart,spleen,thymus,kidney and liver were isolated,and organ coefficients were calculated.Tissue structure of liver and spleen was observed by HE staining,and antioxidant indicators in serum and liver were detected.【Result】 Compared with control group,①CBE had no significant effects on final body weight,ADG,ADFI,F/G and ADWI in mice (P＞0.05).②CBE had no significant effects on the indices of heart,spleen,thymus and kidney (P＞0.05).③There were no significant pathological changes of tissue structures in liver and spleen of mice in 0.05% and 0.10% CBE groups.Inflammatory cell infiltration and slight widening of hepatic sinusoids were observed in liver of 0.25% and 0.50% CBE groups.The spleen tissue structure was relatively disordered,and the white pulp area in 0.25% and 0.50% CBE groups was significantly atrophied.④The activity of glutathione peroxidase (GSH-Px) in serum of mice in 0.10%,0.25% and 0.50% CBE groups was significantly increased (P＜0.05).The activity of total superoxide dismutase (T-SOD) in serum of mice in 0.05% and 0.10% CBE groups was significantly increased (P＜0.05).The content of malondialdehyde (MDA) in serum of mice in 0.10% and 0.25% CBE groups was significantly decreased (P＜0.05),and the activity of catalase (CAT) was significantly increased (P＜0.05).The total antioxidant capacity (T-AOC) had no significant difference in serum of mice in experimental groups (P＞0.05).⑤The GSH-Px activity in liver of mice in 0.10% CBE group was significantly increased (P＜0.05),and the T-SOD activity in 0.05%,0.10% and 0.25% CBE groups was significantly increased (P＜0.05).There were no significant change of MDA content in liver of mice in experimental groups (P＞0.05).The activity of CAT and T-AOC in liver of mice in 0.10% CBE group was significantly increased (P＜0.05).【Conclusion】 Under the condition of this experiment,0.10% CBE addition to drinking water could enhance the antioxidant capacity of mice without affecting their growth performance and organ coefficients,and there were no visible damage of the tissue structure of liver and spleen.

Black soldier fly (BSF) is a resource insect with a short life cycle,strong adaptability and prolific reproductive capacity.The BSF larvae (BSFL) exhibit an extraordinary proficiency in transforming organic waste into a nutrient-dense biomass,and can thrive on a diverse range of organic waste materials.As an emerging and valuable protein resource,with a protein content reaching up to 45% (on a dry matter basis) and being replete with essential nutrients such as fats,minerals and vitamins,it has garnered significant attention within the livestock sector in recent years.The application of BSFL in pig production plays an important role in augmenting feed diversification,refining the feed structure,enhancing the production performance and pork quality of pigs,as well as safeguarding intestinal health.In order to promote the green and sustainable development of the insect industry and aquaculture industry,starting from the perspective of BSFL biotransformation,the authors elaborate in detail on the feeding value of BSFL (covering conventional nutritional components,amino acids and their digestibility,fatty acid content,etc.) as well as its application in pig production,summarize the effects of BSFL on production performance in pigs,blood biochemical indexes,intestinal health status and slaughter performance,etc.,so as to explore the appropriate addition proportion of it in pig production.Based on the literature review,the existing problems in the current industry are pointed out,and improvement measures and research directions are proposed,in order to provide reference for in-depth research in related fields in the future and the application of BSFL in pig production.

【Objective】 To address the issues of excessive body weight,easy detachment of cannulas and the inability to separately investigate the roles of gastric and intestinal parts in digestion and absorption in the existing single-cannulas animal models,the double cannulas model of duodenum and terminal ileum in Bama Minipigs was established to investigate the feasibility and effectiveness of double-cannulas models of the animal intestine in the experiments related to the gastrointestinal digestion and absorption of nutrients and medicines.【Method】 A total of 11 nine-month-old Bama Minipigs (17.5 kg±2.0 kg) were selected for this study.After anesthesia,an incision was made in the right abdominal region to expose the intestines,followed by purse-string suturing.The cannulas were inserted and fixed,and the incisions were closed.Postoperative care was carefully managed to prevent infection.Once the animals had fully recovered,the experiment was conducted using direct ultra-high temperature (dUHT) milk as a test substance.Intestinal effluents and blood samples were analyzed using SDS-PAGE,confocal laser scanning microscopy (CLSM),and ultra-performance liquid chromatography (UPLC) to detect changes in protein and amino acid content.The dynamic changes in milk protein during digestion and absorption were assessed to confirm the reliability and applicability of the model for simulating food digestion and absorption.【Result】 All 11 experimental animals survived for two months post-surgery without any significant discomfort or complications,and showed good growth,with an average weight gain of 12.23 kg,consistent with normal growth trends.During the experimental period,no cannulas detachment was observed,and the cannulas functioned normally,enabling the smooth collection of duodenal and ileal effluents as well as blood samples.In this experiment,the protein microstructure of the effluent samples was examined,and it was observed that the protein content gradually decreased with the digestion time continuously increased.During digestion,casein and β-lactoglobulin bands showed a tendency of enhancing and then weakening.Detecting the amino acid content in the blood at different time points before and after ingestion,and the amino acid absorption curves were obtained.The incremental area under the curve (iAUC) of total amino acid in plasma was (12 105.00±2 145.57) μg·min/mL after ingestion,which was consistent with the normal kinetics of milk protein absorption.【Conclusion】 This study successfully established the double cannulas model involving the duodenum and the terminal ileum in Bama Minipigs,validating the effectiveness of the surgical technique and postoperative care regimen.The double cannulas model demonstrated good application prospects in Bama Minipigs,providing a reliable experimental animal model for studies on gastrointestinal digestion and absorption.This model offered strong support for exploring the digestion and absorption of nutrients,new drug development,and evaluating the absorption of existing drugs.

【Object】 This experiment aimed to explore innovative feeding resources and enrich the basic data of feed mulberry research.【Method】 One hundred and ninety-two Yellow-feathered chickens at 43 days old were randomly divided into 4 groups with 6 replicates in each group and 8 birds per replicate.The chickens in control group were fed with the basal diet,and those in three fermented groups were fed with 3%,6% and 9% fermented feed mulberry,respectively,replacing the same amount of the basal diet.The experiment lasted for 42 days.At the end of the experiment,cervical venous blood,intestinal tissues and cecal contents of Yellow-feathered broilers were collected to determine serum biochemical indexes,intestinal tissue morphology,and cecal microflora,respectively.【Result】 Compared with the control group,①The serum glucose (GLU) levels of chickens of 6% and 9% fermented groups were increased significantly (P＜0.05).②The villus height and crypt depth of the duodenum of 9% fermented group,the villus height of the jejunum of 3 test groups,the villus height to crypt depth ratio (V/C) of jejunum of 3% and 6% fermented groups and the V/C of the ileum of 6% fermented group were decreased significantly (P＜0.05).③The ACE index and Chao1 index of 9% fermented group were decreased significantly (P＜0.05),and the Shannon index of 6% fermented group was increased significantly (P＜0.05).The Beta diversity analysis showed that the cecal microbials composition of 6% and 9% fermented groups were significantly different.At phylum level,the relative abundances of Firmicutes,Epsilonbacteraeota,and Tenericutes in the cecum of 6% and 9% fermented groups were increased significantly (P＜0.05),while the relative abundances of Kiritimatiellaeota,uncultured_bacterium_k_Bacteria,Verrucomicrobia of 6% and 9% fermented groups,and Bacteroidetes of 9% fermented group were decreased significantly (P＜0.05).At genus level,the relative abundances of Campylobacter,[Ruminococcus]_torques_group,Faecalibacterium in cecum of 6% and 9% fermented groups were increased significantly (P＜0.05)，while the relative abundances of uncultured_bacterium_o_WCHB1-41,uncultured_bacterium_f_Clostridiales_vadinBB60_group,and uncultured_bacterium_k_Bacteria in cecum were decreased significantly (P＜0.05).In addition,the relative abundances of Megamonas,Ruminococcaceae_UCG-014,Prevotellaceae_UCG-001,Megasphaera,and uncultured_bacterium_f_Firmicutes_bacterium_CAG_822 in cecum of 9% fermented group were increased significantly(P＜0.05),while the relative abundances of Rikenellaceae_RC9_gut_group and uncultured_bacterium_o_Bacteroidales in cecum were decreased significantly(P＜0.05).The differential prediction of KEGG function of cecal microbials showed that the metabolic pathways of ABC transporters and pyrimidine metabolism of 6% and 9% fermented groups were up-regulated significantly(P＜0.05),while the metabolic pathways of biosynthesis of secondary metabolites were down-regulated significantly (P＜0.05).【Conclusion】 The basal diet containing 6% and 9% fermented feed mulberry significantly increased the serum GLU level of Yellow-feathered chicken,had a negative effect on intestinal tissue morphology，and significantly increased the relative abundance of Firmicutes in cecum,etc.Under the conditions of this experiment,the appropriate amount of fermented feed mulberry should be controlled at 6% or below.

As the scale of livestock and poultry farming expands and intensive farming methods become more widespread,the frequent occurrence of bacterial diseases and the problem of antimicrobial resistance due to antibiotic overuse have become increasingly prominent.Reducing the use of antibiotics has become an urgent issue in the livestock industry,making the exploration of green and efficient “antibiotic reduction and replacement” farming models particularly pressing.Probiotics,as a type of living microorganisms that can colonize and have beneficial effects in the host’s body,have garnered widespread attention for their role in animal health management.These actions effectively reduce the reliance of the livestock industry on antibiotics and help improve animal health,offering an ideal alternative to address the issue of antimicrobial resistance.However,the application of probiotics in livestock and poultry farming still faces numerous challenges,including concerns about the safety and stability of probiotics,lack of market regulation,and inefficiencies in strain selection and renewal.This article provides a systematic review of the currently common probiotic species and explores their mechanisms of action in depth.Probiotics exert their beneficial effects through various mechanisms,including promoting nutrient absorption,generating short-chain fatty acids,competitively inhibiting pathogenic bacteria,and regulating immune functions.Future research should focus on addressing these issues to promote the widespread application of probiotics in livestock and poultry farming.Therefore,probiotics hold great potential and application prospects in the livestock industry,with the potential to provide new solutions for addressing antibiotic overuse and microbial resistance problems.

【Objective】 This study aimed to evaluate the effects of dietary supplementation with Andrographis paniculata extract (APE) on the growth performance,serum biochemistry and gut health of Ningdu Yellow chickens.【Method】 A total of 270 healthy 1-day-old Ningdu Yellow chickens with similar body weights were randomly assigned to three groups,each with six replicates of 15 chickens.The chickens in APE group were received a basal diet supplemented with 0.1% APE,the chickens in antibiotic control group were given a basal diet with 0.2% chlortetracycline,and the chickens in blank control group were fed a basal diet without additives.The experimental period lasted 42 days.At the ending of the experiment,the body weight and feed intake of Ningdu Yellow chickens were counted to determine the growth performance.Blood samples were collected to determine the serum biochemical indexes.The jejunum tissues and cecal contents were collected to determine intestinal morphological indexes and cecal microbiota structure indexes.【Result】 ①Compared with blank control group,the chickens in APE group exhibited significantly higher final body weight and average daily gain (ADG) (P＜0.05) and a significantly lower feed-to-gain ratio (F/G) (P＜0.05).②Compared with blank control group, the chickens in APE group had significantly higher levels of serum total protein(TP) and albumin(ALB) (P＜0.05). Compared with blank control and antibiotic control groups, the chickens in APE group had significantly higher levels of interleukin-10 (IL-10) (P＜0.05), while the levels of low-density lipoprotein (LDL), triglycerides (TG), IL-1β, IL-6, and tumor necrosisfactor-α (TNF-α), and the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were significantly lower (P＜0.05).③The chickens in APE group had a significantly reduced crypt depth (CD) in jejunum compared with blank control group (P＜0.05).The villus height-to-crypt depth (VH/CD) ratio of chickens in APE group was significantly higher than that in antibiotic control and blank control groups (P＜0.05).④Beta diversity analysis revealed significant differences in cecalmicrobial communities among three groups (P＜0.05).Compared with blank control group,the chickens in APE group showed a significant reduction in the relative abundance of Spirochaetes and Deferribacteres (P＜0.05),while the relative abundance of the Rikenellaceae-RC9 gut group increased,which was significantly higher than that in antibiotic control group (P＜0.05).Additionally,the chickens in APE group exhibited a significantly lower relative abundance of Firmicutes and Coprobacillus and a higher abundance of Bacteroidetes compared with blank control group (P＜0.05).【Conclusion】 Dietary APE supplementation improved the growth performance of Ningdu Yellow chickens,reduced blood lipid levels and serum inflammatory markers,enhanced intestinal morphology,and regulated gutmicrobiota structure,thereby promoting better gut health.

【Objective】 The purpose of this study was to determine the protein requirements of ewe lambs of Hu sheep during growth period.【Method】 Thirty-six ewe lambs of Hu sheep in the growth stage were selected for the current trial,with 12 lambs at each of the ages of 3,4,and 5 months.The lambs of different ages were randomly divided into three groups,with feeding levels of ad libitum (AL),ad libitum 70% (AL70),and ad libitum 40% (AL40) for each group.Each group had four replicates and was raised in a single pen for 45 days.During the experimental period of 31-35 days,a digestion and metabolism trial was conducted using the full collection of feces and urine method to investigate the protein requirements of Hu sheep ewe lambs in growth period.【Result】 The dry matter intake (DMI) and average daily weight gain (ADG) of 3,4,and 5 month old ewe lambs significantly decreased with the decrease of feeding levels (P＜0.05).Due to the decrease of feeding levels,the final body weight of ewe lambs at each month showed a decreasing trend,but there was no significant difference (P＞0.05);The decrease in feeding level resulted in a significant decrease in nitrogen intake of ewe lambs at different ages (P＜0.05),and subsequently,the fecal nitrogen and digestible nitrogen content of ewe lambs in each group also decreased significantly (P＜0.05).On the basis of digestion and metabolism experiments,multiple regression equations were fitted to obtain prediction equations for feed intake and protein requirements of 3,4,and 5 month old Hu sheep ewe lambs.Among them,the maintenance requirements of crude protein,digestible protein,and net protein for 3-5 month old Hu sheep ewe lambs were respectively 9.10,5.60 and 2.80 g/(kg BW^0.75·d);The requirement of 1 g weight gain for crude protein,digestible protein,and net protein for ewe lambs were respectively 0.194,0.113 and 0.088 g.When the daily weight gain was 100-300 g/d,the crude protein requirement for growth of 3-5 month old Hu sheep ewe lambs was 88.76-174.85 g/d,the digestible protein requirement was 53.98-105.68 g/d,and the net protein requirement was 30.14-62.29 g/d.【Conclusion】 The protein requirements of Hu sheep ewe lambs during the growth period differ from the current recommended amount for sheep,which was related to their breed,age,environment,and nutrition level.The prediction equation obtained in this experiment could be used to estimate the protein requirements of Hu sheep ewe lambs during the growth period of 3-5 month old.

【Objective】 This study was conducted to evaluate the effects of Lactobacillus acidophilus (LA) E,Pediococcus pentosaceus (PP) JQ-M3 and Lactobacillus plantarum (LP) FRT4 on AA broilers.【Method】 Two hundred and forty 1-day-old AA broilers were selected and randomly divided into four groups with six replicates in each group and 10 chickens in each replicate.The broilers in control group were fed a basal diet,and in three experimental groups were fed diets supplemented with Lactobacillus acidophilus E (LA group),Pediococcus pentosaceus JQ-M3 (PP group),and Lactobacillus plantarum FRT4 (LP group),respectively,at a level of 5×10⁶ CFU/g in the basal diet.The experimental period was 42 d.The effects of three probiotics on growth performance,slaughter performance,immune organ index and nutrient apparent metabolic rate of broilers were studied.【Result】 ①There was no significant difference in BW,ADG,ADFI and F/G among all the groups in 1-21,22-42 and 1-42 d (P＞0.05).②Compared with control group,the rate of total clean rump was significantly higher in LA group (P＜0.05),the rate of belly fat was significantly lower in LP group (P＜0.05),and other slaughtering performance indicators had no significant difference among all the groups (P＞0.05).③Bursa of Fabricius index was significantly higher in PP group than that in control group (P＜0.05),and spleen index had no significantl difference among all the groups (P＞0.05).④The apparent metabolic rate of crude protein in broilers of LA group and the corresponding indicator of ether extract in LP group were significantly higher compared with control group (P＜0.05),and there was no significant difference in the apparent metabolic rate of total energy and dry matter between the groups (P＞0.05).【Conclusion】 Adding Pediococcus pentosaceus JQ-M3 to the feed could improve the bursa of Fabricius index in AA broilers.Adding Lactobacillus acidophilus E and Lactobacillus plantarum FRT4 were beneficial for improving the digestive capacity and slaughter performance of AA broilers.

【Objective】 To explore the utilization of energy,protein,and amino acid of corn germ meal from different regions for Cherry Valley ducks.【Method】 Seventy healthy Cherry Valley ducks weighted 3.25 kg±0.25 kg at 18 weeks of age were randomly divided into 5 groups.14 ducks were in each group,and 1 duck per replicate.They were raised individually in cages.The ducks in 3 experimental groups were fed the diets with corn germ meal and corn starch at a ratio of 7∶3,and the corn germ meal were collected from Liaoning,Shandong,and Henan provinces,respectively.The ducks in corn starch group were fed on the 100% corn starch diet,while in endogenous group was fed nothing.Force-feeding test were carried out,with all the excrement collected.Additionally,gross energy(GE),crude protein(CP),and the amino acid concent of the diet and excreta were measured.【Result】 The GE of corn germ meal from Liaoning and Shandong provinces was higher than Henan province,while the CP content of corn germ meal from Liaoning and Shandong provinces was lower than that from Henan province.The apparently metabolizable energy and true metabolizable energy of corn germ meal from Liaoning province were significantly higher than those from Henan province (P＜0.05).The true digestibility of aspartic acid,threonine,leucine,phenylalanine,lysine,histidine,and arginine of corn germ meal from Liaoning and Shandong provinces were significantly lower than those from Henan province (P＜0.05).The true digestibility of seven essential amino acids (threonine,methionine,leucine,phenylalanine,lysine,histidine,and arginine) and five non-essential amino acids(aspartic acid,serine,glutamic acid,glycine,and proline) of corn germ meal from Henan province was higher than those from the other two regions.【Conclusion】 There were significant differences in the energy and amino acid utilization of Cherry Valley ducks of corn germ meal among different regions,while the difference in protein utilization was small.The utilization of energy of Cherry Valley ducks was in the following order:Shandong＞Liaoning＞Henan.The utilization of crude protein by Cherry Valley ducks was in the following order:Liaoning＞Shandong＞Henan.And the utilization of amino acid by Cherry Valley ducks was in the following order:Henan＞Liaoning＞Shandong.

Soy isoflavones are a type of secondary metabolite produced by leguminous plants，which have various biological functions,including anti-cancer properties,prevention of cardiovascular diseases,and improvement of bone health.Initially,they were primarily utilized in the pharmaceutical and food industries.Subsequent research revealed that soy isoflavones play a positive role in enhancing animal growth performance,improving reproductive performance,and enhancing the quality of livestock products.Consequently,soy isoflavones have been widely used in the livestock industry as a green,safe,and efficient feed additive.Soy isoflavones are a polyphenolic mixture consisting of 12 components,with the aglycone structure of the free form being chemically similar to estrogen,enabling it to exert estrogen-like effects.Particularly,the aglycone and daidzein in soy isoflavones can improve reproductive performance in breeding animals.Additionally,soy isoflavones possess strong antioxidant properties,showing significant potential for application in livestock and poultry production.However,the optimal supplementation levels of soy isoflavones at different growth stages of livestock and poultry,as well as the reasons for their varying effects on growth performance,remain unclear.The author introduces the structure and physicochemical properties,absorption and metabolism,biological functions,and applications of soy isoflavones in animal production.It also addresses the current issues in the use of soy isoflavones and highlights future research priorities,with the aim of providing a reference for the further development and utilization of soy isoflavones in livestock production.

【Objective】 This study was aimed to investigate the molecular genetic information of litter traits in Hainan Black goats and the correlation between polymorphism of growth differentiation factor 9 (GDF9) gene and litter size,in order to provide useful molecular markers for prolific breeding in goats.【Method】 Using Hainan Black goats as the research object,blood samples were collected from 222 goats for non-synonymous single nucleotide polymorphism (nsSNP) screening of GDF9 gene.Genotyping was performed using SnaPshot method,and the association analysis between GDF9 gene polymorphism and litter size in Hainan Black goats using the General Linear Model of SPSS 19.0 software,and the bioinformatics analysis was carried out on nsSNP.【Result】 A total of 15 variant sites were detected in GDF9 gene,including 7 missense mutations (T755C,G1264T,G2296A,G2335A,C2730T,G277A and C3330T),6 synonymous mutations (G888A,T951G,A972C,T631C,A2871C and G3101A),and 2 insertion sites (3101G312 and 3140T3141).The T→C mutation at 755 bp caused a mutation from methionine (Met) to threonine (Thr),the G→T mutation at 1 264 bp caused a mutation from alanine (Ala) to serine (Ser),the G→A mutation at 2 296 and 2 335 bp caused a mutation from valine (Val) to isoleucine (IIe),the C→T mutation at 2 730 bp caused a mutation from leucine (Leu) to phenylalanine (Phe),the G→A mutation at 2 773 bp caused a mutation from alanine (Ala) to threonine (Thr),and the C→T mutation at 3 330 bp caused a mutation from proline (Pro) to leucine (Leu).The insertion of G and T at 3 101-3 102 and 3 140-3 141 bp completely altered the amino acids.The average litter size of TT and CC genotypes in T755C of Hainan Black goats was significantly higher than that of TC genotype (P＜0.05).The average litter size of AA genotype in G2335A and G2773A was significantly higher than that of GG and GA genotypes (P＜0.05).The average litter size of TT genotype in C2730T was significantly higher than that of CC and CT genotypes (P＜0.05).The results of nsSNP functional prediction and advanced structure analysis showed that 5 nsSNPs of T755C→M252T,C2730T→L912F,G2335A→V780I,G2296A→V767I,and G2773A→A926T were deleterious,with significant changes in the mRNA secondary structure and protein tertiary structure at T755C→M252T and C2730T→L912F,which were predicted to have a greater effect on protein function.【Conclusion】 This study screened out 5 deleterious mutation sites of GDF9 gene in Hainan Black goats.Based on the correlation analysis with litter size and protein function prediction,it was speculated that T755C→M252T and C2730T→L912F could be used as molecular markers for the breeding of prolific trait in Hainan Black goats,providing a reference for molecular-assisted breeding in goats.

【Objective】 Systematic classification of ovine horn types were carried out to address the deficiencies in current statistical data and literature,thereby offering a scientific reference for the enhancement of livestock breeds and the efficient use of resources.【Method】 Three distinct populations of sheep,including 286 Small-tailed Han sheep, 299 Dorper×Small-tailed Han sheep crossbreed from Linyi,Shandong,and 195 Tibetan sheep from Dangxiong,Tibet were selected for observation and measurement of their horn types.【Result】 The ovine horn phenotype was not confined to horned and polled,but instead exhibit complex and varied characteristics.In this study,a systematic observation and analysis of sheep horn types were conducted,confirming the known types of sickle horn,scurred horn,and small horn,identified and designated the following horn types:Polled,ginger horn,a large and small horn, spiral and horizontal outward extension horn (SHOE horn), spiral and horizontal inward extension horn (SHIE horn),sickle and spiral horn,and inside buckle horn.Among the populations examined,the Small-tailed Han Sheep had the most horn type classifications,with rams having more types than ewes.The horn types of rams were divided into eight distinct types,predominantly featuring SHOE horn and sickle horn,which accounted for 35% and 31%,respectively;The horn types of ewes were categorized into five horn types,with sickle horn and polled being the most common,representing 50% and 35% of the types,respectively.The Dorper×Small-tailed Han sheep crossbreed had a higher proportion of polled sheep compared to the Small-tailed Han sheep.The horn types of rams in this crossbreed were categorized into seven horn types,with sickle horn and SHIE horn as the primary types,each constituting 40% and 35% of the total,respectively;The horn types of ewes were divided into five horn types,with the polled being the most prevalent,comprising 76% of the observed types.The horn types of Tibetan sheep rams were divided into five types,the horn types of ewes were divided into four types,SHOE horn emerged as the most common type among both male and female Tibetan sheep,accounting for 78% and 74% of the respective horn types.【Conclusion】 Sheep horn types were classified based on criteria of horn length,morphology,and the direction of the horn tip,identifying a total of 10 different horn types.The Small-tailed Han sheep population primarily displayed the SHOE horn and sickle horn.Among the Dorper×Small-tailed Han sheep crossbreeds,the rams mainly exhibited the sickle horn and SHIE horn,with the ewes predominantly being polled.This study provided an important theoretical basis for studying the genetic mechanism of horns and served as a reference resource for subsequent molecular breeding.

Skeletal muscle is the main product of livestock and poultry,an important source of meat and protein for human beings,and also an important economic character of aquaculture.Skeletal muscle satellite cells (SCs)，located between the sarcolemma and basement membrane,are the stem cells of skeletal muscle,the regulation on proliferation and differentiation plays an important role in the development,maintenance,regeneration and restoration of skeletal muscle after birth,and are closely related to muscle production and quality.Long non-coding RNA (lncRNA) is non-coding RNA molecule with a length of more than 200 nucleotides and low or no protein-coding potential,which exists widely in the nucleus,organelles,cytoplasm and membrane of eukaryotic cells.By acting as competitive endogenous RNA (ceRNA),lncRNA serves as a sponge for target microRNA (miRNA),is participating in various biological processes such as gene expression regulation,epigenetic regulation,cell cycle and differentiation regulation,and organ development.With the development of transcriptomics,proteomics and metabolomics,new lncRNA involves in the regulation of skeletal muscle development in cattle,sheep,pigs,monkeys,chickens and mice have been discovered and reported.lncRNA regulates the activation,proliferation,differentiation and lipid metabolism of SCs.The authors review the key lncRNA,upstream and downstream targets,signaling pathway and mechanism in the proliferation and differentiation of skeletal muscle SCs,and forward prospect for the molecular mechanism and technical research of lncRNA regulating skeletal muscle SCs,in order to provide theoretical references for the muscle development,meat production performance and improvement of meat quality in livestock and poultry.

【Objective】 The aim of this experiment was to establish an efficient in vitro isolation and culture method for spermatogenic cells from the testes of Congjiang Xiang pigs,providing materials for the study of reproductive characteristics of Xiang pigs and technical references for the isolation and culture of spermatogenic cells from other mammals.【Method】 In this experiment,60-day-old Congjiang Xiang pigs’ testes were collected from Yueqian Group Breeding Farm of Guizhou Congjiang.The tissue was digested using 0.25% trypsin-EDTA solution and 0.1% type Ⅳ collagenase.The spermatogenic cells were purified by differential adhesion.Indirect immunofluorescence staining was used to identify DEAD-box helicase 4 (DDX4).After that,PCR was performed to validate the spermatogenic cells by detecting the expression of three spermatogenic cell-specific marker genes DDX4,ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL-1),and Thy-1 cell surface antigen (THY1).The proliferation of spermatogenic cells was assessed using the CCK-8 cell proliferation assay.Additionally,histological validation of the testicular tissues from Congjiang Xiang pig was conducted through HE staining to analyze morphological characteristics.【Result】 Using a combination of 0.25% trypsin-EDTA solution,0.1% type Ⅳ collagenase digestion method,and differential adhesion method,a large number of pig spermatogenic cells and Sertoli cell suspensions were obtained.Immunofluorescence staining revealed that DDX4 was specifically expressed in spermatogenic cells,while GATA-4 was expressed in Sertoli cells,with positivity rates exceeding 90%.The expression of DDX4,UCHL-1,and THY-1 genes was confirmed in isolated spermatogenic cells through RT-PCR.A 2D co-culture system of spermatogenic and Sertoli cells was established,in which spermatogenic cells either adhering to the Sertoli cell monolayer or suspended in culture medium (DMEM/F12 with 10% fetal bovine serum,33 ℃,5% CO₂).In this culture system,the Sertoli cell-spermatogenic cells had been successfully subculture to the fifth generation.Within 24 h of culture,high proliferation efficiency was observed in spermatogenic cells,and these cells entered the logarithmic growth period.However,after 72-96 h,the efficiency of spermatogenic cells slowed down,and until 120 h,a decline in cellular activity was noted in this culture system with low viability,and an S-shaped growth curve observed in primary spermatogenic cells.In addition,HE staining of the testicular tissue from Congjiang Xiang pigs confirmed that the cellular composition of the seminiferous tubules was consistent with the types of spermatogenic cells isolated in this study.【Conclusion】 In this study,spermatogenic cells from Congjiang Xiang pigs were isolated in vitro using a combination enzyme digestion method with 0.25% trypsin-EDTA solution and 0.1% type Ⅳ collagenase.Purification was performed via differential adhesion,achieving a DDX4 immunopositively rate of over 90%.The spermatogenic cell-specific marker genes DDX4,UCHL-1,and THY1 were all amplified the expected bands.The isolated spermatogenic cells were cultured in a 2D system,reaching logarithmic growth phase from 0 to 24 h and entering plateau phase from 72 to 120 h,which conformed to the conventional growth pattern and proliferation rules of spermatogenic cells.

【Objective】 The aim of this study was to study the growth and development patterns as well as the meat performance of Guizhou Recessive White-feather chickens.【Method】 The experiment was conducted at the scientific research chicken farm of Guizhou University.A total of 140 Guizhou Recessive White-feather chickens (equally divided by sex) were selected,and their body weight was measured at fasting intervals at fixed times at 0,2,4,6,8,10,12,14,16,and 18 weeks of age,respectively.The growth curve of the chickens’ body weight from 0 to 18 weeks was fitted using the Logistic,Gompertz,and Von Bertalanffy models. At 18 weeks of age,40 Guizhou Recessive White-feather chickens (equally divided by sex) were randomly selected,and their body size traits,slaughter performance and meat quality traits were measured. Difference analysis and Pilson correlation analysis were performed for these indexes in roosters and hens.【Result】 The growth and development of Guizhou Recessive White-feather roosters and hens from 0 to 18 weeks of age were best modeled by the Von Bertalanffy equation,with a high goodness-of-fit (0.998).The growth inflection point for roosters was observed at 7.75 weeks,with a body weight of 760.58 g,while for hens,it was reached at 6.64 weeks with a body weight of 520.20 g.All body size indexes of the roosters were found to be significantly larger than those of the hens (P＜0.01).There was a extremely significant or significant positive correlation between body weight and body slant length,breast width, hip width in roosters (P＜0.01 or P＜0.05),and a significant or extremely significant positive correlation between body weight and body slant length,tibia length, breast circumference in hens (P＜0.05 or P＜0.01).In terms of slaughter performance,the slaughter rate of Guizhou Recessive White-feather chickens was found to range from 84.17% to 85.81%.The evisceration rate ranged from 60.76% to 62.79%,the breast muscle rate from 11.09% to 12.47%,and the leg muscle rate from 18.45% to 19.30%.In roosters,there was a extremely significant positive correlation between hamstring rate and hamstring weight (P＜0.01).In hens,there was a extremely significant or significant positive correlation between pectoral rate and pectoral weight,full clearbore rate (P<0.01 or P<0.05),and their hamstring rate was significantly positively correlated with hamstring weight (P＜0.05).Regarding meat quality,the pH values of the breast and leg muscles ranged from 6.2 to 6.4.The shear force of the breast muscle was recorded between 18 and 19 N,while the leg muscle shear force ranged from 27 to 33 N.Additionally,the water loss rate of the breast and leg muscles ranged from 17% to 20%.There was a extremely significant positive correlation between pectoral muscle pH and hamstring muscle pH (P＜0.01),and a significant or extremely significant positive correlation between hamstring muscle cook rate and pectoral muscle shear,hamstring muscle water loss (P＜0.05 or P＜0.01).【Conclusion】 This study revealed the growth and development pattern of Guizhou Recessive White-feather chickens from 0 to 18 weeks of age and the trend of body weight growth at each stage through the Von Bertalanffy model,and found that Guizhou Recessive White-feather chickens had good meat production performance,which provided a scientific basis for the subsequent rearing management,breeding selection and the development and utilization of Guizhou Recessive White-feather chickens.

【Objective】 This study was aimed to amplify and explore the coding sequence (CDS) sequence characteristics of heme oxygenase 2 (HMOX2) gene in Lijiang pigs, and analyze its expression in different growth stages and tissues of Lijiang pigs,establishing a foundation for molecular marker-assisted breeding utilizing HMOX2 gene.【Method】 The HMOX2 gene sequence of Lijiang pigs was amplified by PCR.The physicochemical properties,codon preferences,and predicted protein structure were analyzed using bioinformatics software.The expression of HMOX2 gene were detected using Real-time quantitative PCR in heart,liver,spleen,lung,kidneys,and longissimus dorsi muscle of 2-month-old Lijiang pigs,as well as in the subcutaneous fat of 2-,4-,and 6-month old Lijiang pigs,and compare the expression of HMOX2 gene in subcutaneous fat of 2-month-old Lijiang pigs and Duroc pigs.【Result】 The CDS of HMOX2 gene in Lijiang pigs was found to be 951 bp long,encoding 316 amino acids,and the codon prefers to end with C or G.The HMOX2 gene in Lijiang pigs showed high similarity to Bos taurus, Bos indcus, Capra hircus and Ovis aries (90.1%-91.2%),and the lowest similarity to Gallus gallus (71.3%).Among six local pig breeds,except Bamei pigs and Rongchang pigs, HMOX2 gene in Lijiang pigs showed 100% similarity to local pigs,and the similarity with five exotic pigs was 99.8%.Two base synonymous mutations were present in the CDS region of HMOX2 gene in Lijiang pigs compared with Duroc pigs. HMOX2 protein were determined to be stable transmembrane hydrophilic proteins without a signal peptide,featuring one transmembrane structure,primarily functioning in cytoplasm,and containing 21 phosphorylation and 33 glycosylation sites.The secondary structure of HMOX2 protein was predominantly composed of alpha helix (54.43%) and random coil (42.00%).Protein interaction network analysis demonstrated that HMOX2 protein might interact with 10 proteins,including FECH and HMOX1,primarily playing a role in lipid metabolism.Real-time quantification PCR results indicated that HMOX2 gene was expressed in heart,liver,spleen,lung,kidney,longissimus dorsi muscle,and subcutaneous fat of Lijiang pigs,and the expression increased with the increase of age in subcutaneous fat.Compared with Duroc pigs,the expression of HMOX2 gene in subcutaneous fat of Lijiang pigs was significantly higher than that of Duroc pigs (P＜0.05).【Conclusion】 HMOX2 gene in Lijiang pigs was successfully amplified,and its molecular characteristics were elucidated.It was expressed in seven tissues such as lung,liver,and subcutaneous fat,and its expression in subcutaneous fat increased significantly with the increase in monthly age.These results provided a foundation for further investigation into the role of HMOX2 gene in fat deposition in Lijiang pigs.

Oocytes develop and mature depending on the mitochondria to produce large amounts of adenosine triphosphate (ATP) to maintain transcription and translation necessary for maturation.In addition,mitochondria also carry the rate-limiting effect of steroid production.Therefore,mitochondrial dysfunction often leads to adverse pregnancy outcomes.The irrational environment,oxidative stress and other adverse factors in vitro culture medium are easy to damage oocyte mitochondria,resulting in the decrease of ATP and mitochondrial DNA (mtDNA) copy number,the increase of reactive oxygen species (ROS),the obstruction of spindle assembly,and the decrease of oocyte maturation rate and development potential.Studies have shown that exogenous substances such as melatonin and resveratrol can improve the mitochondrial function of oocytes and increase the maturation rate of oocytes.Although improving the quality of mitochondria can improve the production efficiency of domestic animal oocytes in vitro,the specific regulatory mechanism is still unclear.Therefore,it is necessary to investigate the mechanism of mitochondria in oocytes.The author briefly introduced the structure and function of mitochondria.Several mechanisms of mitochondrial regulation of oocyte maturation were reviewed,including signaling regulation of oocyte maturation,mtDNA and oocyte development,oocyte mitochondrial energetics and dynamics.The methods to improve oocyte mitochondria was proposed and its research prospect was prospected,aiming to provide reference for exploring the development ability of domestic animal oocytes through targeted improvement of mitochondrial function.

【Objective】 This study was aimed to construct a IPEC-J2 cell line stably overexpressing non-muscle myosin ⅡA tail (NM-ⅡA Tail) using a lentiviral vector system and investigate its role in the process of Porcine epidemic diarrhea virus (PEDV) infection,so as to provide a theoretical evidence for elucidating the infection mechanism of PEDV.【Method】 The recombinant plasmid pLV-CMV-NM-ⅡA Tail-3×Flag-CopGFP-Puro was constructed using homologous recombination technology.This recombinant plasmid was co-transfected with auxiliary plasmids pMD2.G and psPAX2 into HEK-293FT cells to produce the lentiviral particles.IPEC-J2 cells were infected with Lentivirus and subjected to drug selection,the expression of EGFP fluorescent tag protein was observed,and the construction of NM-ⅡA Tail-overexpressing cell line was confirmed using Western blotting and Real-time quantitative PCR.Western blotting and immunofluorescence assay (IFA) were used to examine the change during the PEDV internalization stage.The effects of NM-ⅡA Tail overexpression on PEDV replication and release were analyzed by measuring viral particle copy numbers and viral titers.【Result】 In the successfully constructed overexpression cell line,the mRNA transcription level of NM-ⅡA Tail was 15 times higher than that in control group (P＜0.01),and Western blotting results confirmed the efficient expression of NM-ⅡA Tail protein.During the PEDV internalization stage,the expression of PEDV N protein in NM-ⅡA Tail-overexpressing cells was extremely significantly higher than that in control group (P＜0.01).IFA results showed stronger fluorescence signals for NM-ⅡA and PEDV in NM-ⅡA Tail-overexpression group compared with control group.During the PEDV replication stage,the copy number of PEDV M gene and viral tissue culture infectious dose 50% (TCID₅₀) in NM-ⅡA Tail-overexpressing cells were significantly or extremely significantly higher than that in control group (P＜0.05 or P＜0.01).During the PEDV release stage,compared with control group,the copy number of PEDV M gene in supernatant of NM-ⅡA Tail-overexpressing cells was 2.7 times higher,and the viral TCID₅₀ was extremely significantly increased (P＜0.01).【Conclusion】 This study successfully constructed a stable IPEC-J2 cell line overexpressing NM-ⅡA Tail,so as to provide a valuable experimental model for further investigation of the role of NM-ⅡA in PEDV infection mechanism.The results demonstrated that NM-ⅡA Tail overexpression significantly promoted PEDV internalization,replication and release,offering new insights into the infection mechanism of PEDV and potential strategies for disease prevention and control.

【Objective】 This experiment was conducted to determine the cause of morbidity and mortality of breeding geese in a goose farm in Guizhou,and provide reference for the prevention and treatment of mixed infection of multiple pathogens in breeding geese.【Method】 Clinical symptoms,necropsy observation,tissue section observation,bacterial isolation,culture and identification,and PCR detection of 6 common waterfowl viruses (Duck plague virus (DPV),Duck circovirus (DuCV),Avian influenza virus(AIV),Goose parvovirus (GPV),Duck viral hepatitis virus (DHV) and Avian Tambusu virus (TMUV)) were performed on the affected gray geese.Furthermore,the similarity analysis,capsular serotype identification,drug sensitivity test and pathogenicity test of the pathogenic bacteria were carried out,and the pathogenicity of the isolated virus was detected.【Result】 The head and neck of the affected gray goose were enlarged,and there were gray-yellow necrotic foci on the surface of the liver,and hemorrhagic spots on the surface of the heart and lung.The results of tissue sections showed that the affected gray goose had obvious lesions in liver,lung and kidney.The isolated bacterial colonies were gray-white,like dew drops with smooth surface.Gram staining showed short red rod-shaped negative bacteria.Wright’s staining showed highly stained coccobacillus at both poles.The results of biochemical tests showed that the isolated strain was positive for glucose,fructose,mannitol and maltose.PCR detection and 16S rRNA gene identification results showed that the isolated strain amplified a 460 bp Pasteurella multocida specific gene Kmt1.The similarity of 16S rRNA gene sequence between the isolate and NCBI reference Pm strains was 98.6%-99.3%,which indicated that Pm isolate was identified as Pasteurella multocidal (Pm).The Pm isolate was identified as A capsular strain by serotype analysis.The Pm isolate was susceptible to norfloxacin,gentamicin and gentamycin,and moderately susceptible to vancomycin.The minimum lethal dose (MLD) of Pm strain to mouse was less than 5 CFU.The PCR and sequencing analysis of the virus showed that the affected gray geese were infected by Duck plague virus (DPV),the UL6 gene sequence of the DPV isolate shared 98.9%-100% similarity with the reference DPV strains of NCBI.After three passages of blind transmission from duck embryos,DPV was detected by PCR in allantois fluid.Duck embryo fibroblasts (DEF) were inoculated with DPV.After 9 h,DEF shranked,and attached DEF fell off or formed syncytia after 24 h.The median tissue culture infective dose (TCID₅₀) of DPV isolate was 2.88×10^-9/0.1 mL.【Conclusion】 In this study,the infected grey goose was finally diagnosed as mixed infection of DPV and Pm,and one virulent Pm strain of capsular serotype A and one virulent DPV were isolated.The results of this study could provide scientific basis and technical support for the prevention and control of diseases caused by Pm and DPV infection of waterfowl,etiological investigation and multi-combination vaccine.

【Objective】 The purpose of the trial was to explore the variation and epidemic trend of Pseudorabies virus (PRV) wild strains,and provide data reference for researching new vaccines against PRV.【Method】 In this study,samples from pigs suspected to be infected with PRV which immunized with Bartha-K61 vaccine were collected from large-scale farms in Baoding city,Hebei province.Pathogen detection was performed by PCR.The filtrate of tissues with only PRV positive was inoculated with PK-15 cells for virus isolation and purification.The isolated virus was identified by indirect immunofluorescence assay and electron microscope observation.The virus titer of the isolated strain was determined and the growth curve was drawn.Serum neutralization test,animal pathogenicity study and gE and gC gene sequence analysis were performed.【Result】 The results showed that the isolate produced typical lesions such as wiredrawing,rounding,aggregation and shedding in PK-15 cells.The purified virus was subcultured to F10 generation,and the target band of about 742 bp could be amplified by PCR alternate generation detection.The isolate was named BD-HB-2024.The green fluorescent labeled cells were identified by indirect immunofluorescence assay.Transmission electron microscopy showed that the virus particles were about 150 nm in diameter and were spherical,which was consistent with the typical particle characteristics of PRV.According to Reed-Muench method,the TCID₅₀ of the strain was 10^5.55/0.1 mL.Serum neutralization test showed that the neutralizing antibody titer of the serum against Bartha-K61 strain was 1∶11.22,while the neutralizing antibody titer of the serum against the variant strain was 1∶89.13.The strain had certained pathogenicity to mice,and the median lethal dose (LD₅₀) of F10 generation virus to mice was 10^-2.5 TCID₅₀/0.1 mL.The nucleotide sequence similarity was 99.8%-99.9% and 99.8%-100% compared with the gE and gC gene sequences of domestic PRV reference strains,respectively.Genetic evolutionary tree analysis showed that the isolated strain had low similarity with classical strains such as SC,Italiy2014 and Kaplan,and was far related.It had high similarity with the variant strains HNB,HLJ8,JM and SX1911 isolated in China in recent years.It was closely related and located in the same evolutionary branch.After comparing the amino acid sequence,it was found that it conformd to the typical changes of domestic variant strains.【Conclusion】 This test confirmed the existence of PRV infection in the farm,and a PRV variant strain was successfully isolated.This study provided reference for the subsequent research and development of new vaccines and the preparation of immune prevention and control programs.

【Objective】 The purpose of this study was to obtain recombinant Porcine pseudorabies virus (PRV) expressing Porcine circovirus type 2d (PCV2d) Cap protein using homologous recombination technology and CRISPR/Cas9 gene editing technology,providing data support for the development of vaccines to prevent and control PCV2d and PRV infection.【Method】 According to the ORF2 gene sequence of the PCV2d KF1 strain,a pair of primers was designed and synthesized.The ORF2 gene was amplified by PCR from DNA extracted from the PCV2d KF1 strain,and was introduced into the PRV eukaryotic expression vector pG carrying the green fluorescent protein (EGFP) gene through BamH Ⅰ to construct a recombinant plasmid pG-PCV2d-EGFP.The recombinant virus was constructed by transfecting the plasmid pG-PCV2d-EGFP and DNA of the parental strain rPRV-gE^-/gI^-/TK^-PRV into ST cells using the transfection reagent ZLip2000,and the CRISPR/Cas9 EGFP knockout plasmid pX459-gRNA1-EZ-gRNA2 was used to knockout the EGFP gene of the recombinant virus.And the recombinant virus was identified by EGFP gene sequencing,PCR and Western blotting.【Result】 The recombinant virus strain rPRV-PCV2d-EGFP was obtained by eight rounds of the green fluorescent plaque screening.After EGFP gene was knocked out using the CRISPR/Cas9 EGFP knockout plasmid pX459-gRNA1-EZ-gRNA2,the recombinant virus rPRV-PCV2d was harvested after three rounds of the plaque screening without green fluorescent.The EGFP gene of recombinant virus rPRV-PCV2d was sequenced,and the results showed that EGFP gene was truncated by 1 251 bp.The results of PCR and Western blotting showed that the ORF2 gene of rPRV-PCV2d could be transcribed and expressed in ST cells.【Conclusion】 The recombinant virus rPRV-PCV2d expressing Cap protein of PCV2d was successfully constructed,which laid a foundation for further development of recombinant live vector vaccine.

【Objective】 This study aimed to express protein N of Canine parainfluenza virus (CPIV) through the eukaryotic expression system,and prepare polyclonal antibodies against N protein,so as to provide the basis for the subsequent identification of CPIV N protein and the study of the function of the virus during its life cycle.【Method】 pCAGGS-N was constructed,after the function of the plasmid was verified by PCR and Western blotting,mice were immunized to prepare polyclonal antibody against CPIV N protein.The immunity was terminated when the antibody titer reached the ideal titer detected by ELISA.The antibodies were identified and analyzed by Western blotting and indirect immunofluorescence assay,and the neutralizing activity of the polyclonal antibodies was measured.【Result】 pCAGGS-N was successfully constructed and validated through restriction enzyme digestion and sequencing,and the recombinant plasmid could be transcribed and translated normally in eukaryotic cells.Mouse polyclonal antibody against CPIV N protein was successfully prepared by DNA immunization with a titer of 1∶128 000.Moreover,Western blotting analysis showed that the antibody could bind to purified virions and exogenous expression of CPIV N protein,with a molecular mass of about 59 ku.Indirect immunofluorescence assay result showed that the polyclonal antibody could specifically recognize and bind N protein with spatial conformation,but the polyclonal antibody did not have virus-neutralizing activity.【Conclusion】 In this experiment,the eukaryotic expression plasmid pCAGGS-N was successfully constructed,and the mouse polyclonal antibody against CPIV N protein was successfully prepared by DNA immunization.The antibody showed good reactivity and specificity,but did not show the activity of neutralizing the virus.This results provided a basis for further study of the function of CPIV N gene and other cellular immunological experiments.

【Objective】 The purpose of the experiment to develop a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of eprinomectin (EPR) in rabbit plasma,and to compare the pharmacokinetics of two EPR injections in commercial rabbits,so as to provide support for subsequent formulation development.【Method】 12 healthy New Zealand rabbits,half male and half female,were divided into a reference preparation (marketed EPR injection) group and a test preparation (self-developed EPR extended-release injection) group.After subcutaneously injecting the same dose of the two preparations,the plasma samples were collected at different time points.The concentration of EPR was determined by HPLC-MS/MS using moxidectin as an internal standard.The specificity,detection limit,quantification limit,standard curve,accuracy and precision,matrix effect and stability of the established method were investigated.The actual sampling concentration-time data were analyzed with the software Phoenix WinNonlin for non-compartmental model with a weight of 1/Y,and the pharmacokinetic parameters of the two formulations in rabbits were obtained.【Result】 The limit of detection and the limit of quantitative were 0.5 and 1 ng/mL,respectively.The standard curve had a good linear relationship in the range of 1-200 ng/mL with a correlation coefficient (R²) ＞0.99.The intra-assay and inter-assay accuracies of the four concentrations were in the range of 93.70% to 107.73%,and the intra-assay and inter-assay RSDs were all less than 15%.The results showed that the peak time (T_max) of EPR in the reference preparation and the test preparation was (0.39±0.09) and (0.22±0.04)d respectively,the peak concentrations (C_max) were (112.82±29.40) and (30.86±5.11)ng/mL,the half-lives (t_1/2) was (7.14±0.58) and (22.15±1.22)d respectively,the area under the drug time curves (AUC_0→∞) were (420.55±21.74) and (300.65±13.62) ng·d/mL,the mean retention time (MRT) was (3.74±0.80) and (41.62±9.04)d,respectively.【Conclusion】 The results showed that the established HPLC-MS/MS method was sensitive,accurate,stable and reliable,and could be used for the determination of EPR in rabbit plasma samples.The two preparations differed significantly in the rate and extent of absorption as well as in the rate of elimination.The test formulation significantly prolonged the presence of EPR in rabbit plasma compared to the reference formulation.

【Objective】 This experiment was to develop a composite nanoemulsion of Eucalyptus oil and peppermint oil to lay a foundation for clinical application.【Method】 The nanoemulsion was prepared by phase transition method.The formulation and process were optimized by single factor test and pseudo-ternary phase diagram method.The type was determined by staining method.The morphology and particle size distribution were determined by transmission electron microscopy and particle size analyzer.The content of the main components was determined by high performance liquid chromatography.Stability test was carried out under different temperature and humidity conditions.In vitro antibacterial test was carried out by double dilution method and micro chessboard dilution method.【Result】 The optimal formula of nanoemulsion was:Polyoxyethylene castor oil EL 28.54%,1,2-propylene glycol 9.51%,Eucalyptus oil and peppermint oil mixed solution with 1,8-cineole and menthol in a ratio of 10∶1 9.51%,and distilled water 52.43%.The prepared nanoemulsion was oil-in-water type with dilution stability.The morphology was uniformly distributed spherical,with Zeta potential of －3.16 mV,average particle size of 14.6 nm,and polydispersity index (PDI) of 0.211.The content of Eucalyptus oil and peppermint oil in the composite nanoemulsion were 55.98 and 5.61 mg/mL，respectively.In the accelerated test,the solution remained clear and transparent,and the contents of 1,8-cineole and menthol changed to 53.85 and 5.32 mg/mL,respectively.In the long-term test,the solution was stable,and the contents of 1,8-cineole and menthol changed to 53.50 and 5.33 mg/mL,respectively,and the changes of solution content were in accordance with the requirements.In vitro antibacterial tests showed that,for Salmonella,the MIC and MBC values of the composite nanoemulsions were 1/2 and 1/4 of those of the Eucalyptus oil nanoemulsions and 1/32 of those of the peppermint oil nanoemulsions,respectively.For Escherichia coli,the MIC and MBC values of the composite nanoemulsions were 1/4 and 1/2 of those of the Eucalyptus oil nanoemulsions and 1/128 and 1/32 of those of the peppermint oil nanoemulsions,respectively.For Staphylococcus aureus,the MIC and MBC values were 1/2 and 1/8 of those of Eucalyptus oil nanoemulsion and 1/32 of those of peppermint oil nanoemulsion,respectively.Therefore,the composite nanoemulsion had good antibacterial properties,and the combination of the two drugs showed an additive effect on Salmonella and Escherichia coli,and a synergistic effect on Staphylococcus aureus,without antagonistic effect.【Conclusion】 The composite nanoemulsion preparation was prepared by phase transition method and pseudo-ternary phase diagram method.The process was simple,met the quality requirements of nanoemulsion,and provided ideas and methods for the preparation of aqueous solvents for poorly soluble drugs.

【Objective】 This study aimed to explore the relationship between β-lactase blaZ gene and microorganisms in milk of cows with latent mastitis in Shandong region,and provide theoretical basis for preventing and controlling latent mastitis in cows and reduce antibiotic resistance genes in raw milk.【Method】 From February to June 2023,478 milk samples from 478 cows randomly selected from 33 dairy farms in 15 cities were tested for the β-lactase blaZ gene and 15 microbial genes using PCR method.Heatmap of the relative abundance of blaZ genes and microorganisms based on the pheatmap function in R language was drew,Logistic regression fitting was performed using the glm function in R language.The above scheme was repeated with 506 milk samples from 506 cows with latent mastitis in 5 cities of Shandong province.【Result】 The positive rate of blaZ gene in randomly obtained milk samples from 15 cities in Shandong province was 19.25%,with a high positive rate in small ranches.The relative abundance of coagulase-negative Staphylococcus,yeast and Enterococcus spp.in milk was relatively high,and they were positively correlated with the blaZ gene (P＜0.01 or P＜0.05).blaZ gene was only negatively correlated with the relatively low abundance of Klebsiella spp.(P＜0.05).The positive rate of blaZ gene in milk of cows with latent mastitis was 52.17%.The relative abundance of yeast,Enterococcus spp.and coagulase-negative Staphylococcus in milk was relatively high.The blaZ gene was only positively correlated with coagulase-negative Staphylococcus (P＜0.01) and negatively correlated with Streptococcus uberis (P＜0.01).【Conclusion】 The expression level of blaZ gene in milk with latent mastitis in Shandong region was higher than that in randomly sampled milk. In milk from Shandong region, blaZ gene mainly originated from coagulase negative Staphylococcus aureus, which was also the main pathogenic bacterium causing latent mastitis in the region.

【Objective】 Based on UPLC-Q-TOF-MS technology,global natural products social molecular networking system (GNPS) and network pharmacology,the mechanism of action of extract of Physalis Calyx seu Fructus on infectious bronchitis (IB) was explored to provide theoretical basis for the treatment of IB.【Method】 The chemical ingredients in extract of Physalis Calyx seu Fructus were analyzed by UPLC-Q-TOF-MS and GNPS,and the active ingredients and the targets were screened by oral bioavailability ≥30% and drug-like properties ≥0.18 matching with TCMSPS and SwissTargetPrediction databases,and then intersection targets with IB were performed.The interaction network diagram between extract of Physalis Calyx seu Fructus and the disease targets was drawn, the degree value of each node was analyzed by using the CytoNCA plug-in in Cytoscape 3.10.1,the core protein-protein interaction (PPI) network and the active ingredient target network were constructed by using the intersecting targets,and the key targets were analyzed in terms of GO function and KEGG pathway enrichment. AutoDock Vina was used for molecular docking validation.【Result】 Ten substances were analyzed in UPLC-Q-TOF-MS in negative ion mode,and 32 substances were analyzed in positive ion mode.Luteolin and kaempferol-7-O-glucoside could be detected in both positive and negative ion modes.Among them,18 compounds met the conditions required for network pharmacology,and there were 145 intersecting targets between the action targets of these compounds and the disease targets related to IB.Based on the intersecting targets,network pharmacological analyses were carried out,and the main components in the network interactions diagram between the extract of Physalis Calyx seu Fructus and the disease targets were screened,and among the active ingredients of extract of Physalis Calyx seu Fructus those ranked in the top 10 were selected as the core components.PPI analysis revealed that tumour necrosis factor (TNF),protein kinase,cysteine-aspartate protease (CASP3) and other proteins were the core targets of extract of Physalis Calyx seu Fructus against IB.GO function enrichment analysis revealed that it mainly involved hormone response,cell activation,membrane rafts,membrane microregions,protein kinase activity,phosphotransferase activity,etc.KEGG pathway enrichment analysis revealed that the pathway of extract of Physalis Calyx seu Fructus against IB was mainly related to PI3K-Akt signaling pathway.Molecular docking revealed that the 10 core components in the active ingredients of extract of Physalis Calyx seu Fructus had strong binding energies with 9 core targets.It was found that the docking energies of TNF to cyclohexanol,prostaglandin endoperoxide synthase 2 (PTGS2) to luteolin,and matrix metalloproteinase 9 (MMP9) to luteolin were smaller,with values of －10.5,－9.4 and －10.6 kJ/mol,respectively，determined by Auto Dock Vina.【Conclusion】 Based on UPLC-Q-TOF-MS technology,GNPS,network pharmacology and molecular docking technology,this study revealed that the extract of Physalis Calyx seu Fructus might regulate the occurrence and development of IB through the action of its active components luteolin and cycloartenol on the core targets of TNF and MMP9.The result of this study provided the theoretical basis for researching the potential molecular pharmacological mechanism of the extract of Physalis Calyx seu Fructus against IB.

【Objective】 This experiment was conducted to reveal the effects of Qilan compound on immunity function,reproduction performance and defecation function of perinatal sows,and provide a reference for improving the health of perinatal sows.【Method】 Twenty-five binary sows (30-40 gestational age) were selected and divided into blank group (N),0.1%,0.2% and 0.4% Qilan compound groups (L,M and H) and positive control group (A),5 replicates per group and 1 sow per replicate.The pigs in Qilan compound groups were supplemented with 0.1%,0.2% and 0.4% Qilan compound in the basal diet,respectively,and pigs in positive control group were supplemented with 50 mg/kg Elaxin in the basal diet.The test started on day 91 of gestation and ended at weaning (21 days postpartum).Blood was collected at 91 days of gestation,4 and 21 days postpartum to measure the serum antioxidant function (T-AOC,GSH-Px,SOD and MDA),immunoglobulins (IgG,IgM and IgA),inflammation factors (IL-6 and IL-1β) and gastrointestinal hormones (SP,MTL and VIP) contents and PRRSV antibody levels.Reproductive function indicators and constipation rate were counted,and the feces of the test pigs were collected at 21 days after parturition to detect the effect of Qilan compound on fecal short-chain fatty acids.【Result】 On postnatal days 4 and 21,compared with group N,T-AOC,GSH-Px and SOD activities in serum of sows in Qilan compound groups were significantly increased (P＜0.05),and MDA content were significantly decreased (P＜0.05);The contents of immunoglobulin IgG,IgM and IgA were significantly increased (P＜0.05),and the contents of IL-6 and IL-1β were significantly decreased (P＜0.05),and H group had the most significant effect;S/P value of PRRSV antibody was significantly decreased (P＜0.05);The content of VIP was decreased significantly (P＜0.05),and the contents of SP and MTL were increased significantly (P＜0.05).Compared with group N,the rate of stillbirth and weak piglets were significantly decreased in the Qilan compound groups (P＜0.05),litter weight at birth and weight of weaning litter were significantly increased (P＜0.05);The constipation rate in Qilan compound group were significantly decreased (P＜0.05);The content of SCFAs in feces of sows in Qilan compound group were significantly increased (P＜0.05).【Conclusion】 Qilan compound had a significant effect on the immunity function,reproduction performance and defecation function of perinatal sows,the effect of 0.4% Qilan compound in diet was the best,and could be used for perinatal sow health care.

【Objective】 This study was conducted to explore the distribution of drug resistance and virulence genes of pathogenic Salmonella Enteritidis isolated from a commercial meat duck farm,and provide reference for the prevention,control and medication of the disease.【Method】 The livers of dead meat ducks were collected for bacterial isolation,and the serotype of the isolated strains was identified by separation and purification,Gram staining microscopy,biochemical test and PCR amplification.The drug sensitivity test was carried out by K-B disk method,and the drug resistance of the strain was analyzed by combining the drug resistance genes.The pathogenicity test of duckling was used to monitor the virulence,mortality and body weight changes of duckling anal swabs,and to evaluate the pathogenicity of strains combined with virulence genes.【Result】 The isolated strain showed purple colonies on the Salmonella chromogenic medium,and the results of Gram staining microscopy were Gram-negative brevis.The results of biochemical identification were negative for indigo matrix,amino acid decarboxylase control,urease,potassium cyanide test biochemical tube and potassium cyanide test control,and positive for lysine decarboxylase,which was consistent with the biochemical characteristics of Salmonella.The target fragment 304 bp was further amplified by PCR primer of Salmonella Enteritidis,which was consistent with the expected fragment size,and then the strain was identified as Salmonella Enteritidis.The results of drug sensitivity showed that the isolate was sensitive to fluoroquinolones and chloramphenicols,but resistant to tetracyclines and β-lactams.Meanwhile，tetA and bla_TEM were detected as drug resistance genes.Eleven virulence genes were detected:bcfC,avrA,sopE,spvR, spvB,spvC,spvD,sopB,siiD,mgtC and ssaQ.The pathogenicity test of ducklings showed that the mortality rate of 7-day-old ducklings was 90%.Salmonella pathogen was detected by anal swab 2 days after the challenge,and the weight of ducklings increased slowly.Anatomical symptoms showed varying degrees of cellulose exudates in the heart and liver.【Conclusion】 In this study,Salmonella Enteritidis were isolated and identified from commercial meat ducks.The strain had strong pathogenic ability to meat ducks,and there were two drug resistance genes and multiple virulence genes.The experimental results could lay a theoretical foundation for further research on the pathogenesis,prevention and treatment of Salmonella Enteritidis.

【Objective】 The study was conducted to isolate and identify Klebsiella pneumoniae from fecal samples of quail with diarrhea,in order to provide a basis for the prevention and control of Klebsiella pneumoniae disease in quail.【Method】 The purified colonies were screened from 8 fecal samples of quail with diarrhea,and the bacteria were isolated and purified by plate scribing method. 16S rDNA sequence was amplified by PCR and sequenced,and the phylogenetic tree was constructed using Mega 11.0 software.K-B method was used to detect the sensitivity of strains to common antibiotics, the distribution of drug resistance genes and virulence genes in strains was detected,and the biological characteristics was explore.The pathogenicity of the strains was evaluated by animal tests.【Result】 In this study,two strains of Klebsiella pneumoniae were isolated and identified from fecal samples of diarrhea quail,named Ksp-A1 and Ksp-A2,respectively,both belonging to K57 serotype.Phylogenetic tree showed that the two isolates were similar to other known Klebsiella pneumoniae strains,and belonged to the same evolutionary clade as Klebsiella pneumoniae strains DB-4 and WGT-31.The results of drug sensitivity test showed that the isolates were resistant to ampicillin,oxacillin,erythromycin,and so on.Isolates Ksp-A1 and Ksp-A2 carried multiple resistance genes,including bla_SHV,aacC2,oqxAB,tetA,tetM and cat1 genes.The two isolates carried virulence genes such as K88,hlyE, iucD,irp2,ompA and ompC.Biological characteristics analysis showed that in LB broth medium with pH 7.0,isolates Ksp-A1 and Ksp-A2 entered the logarithmic growth phase within 2 h,and reached the peak at 12 and 9 h,respectively.The results of pathogenicity test in mice showed that after the injection of the bacterial solution,the mice showed infection symptoms such as coarse hair,depression,shortness of breath and diarrhea,and the mortality rate of the mice gradually increased with the increase of the bacterial solution concentration,and the mortality rate of the mice reached 100% when the bacterial solution concentration was 1×10⁹ CFU/mL. The median lethal dose (LD₅₀) of isolates Ksp-A1 and Ksp-A2 to mice were 3.3×10⁷ and 2.6×10⁶ CFU,respectively. 【Conclusion】 Two strains of Klebsiella pneumoniae K57 from quail were successfully isolated in the experiment，which showed resistance to β-lactam drugs,had rapid growth rates,and showed high tolerance to acidic and alkaline conditions.The results provided basic data for the prevention and treatment of Klebsiella pneumoniae disease in quail.

【Objective】 This study aimed to investigate the effects of β-defensin yak tracheal antimicrobial peptide (yTAP) on intestinal morphology and microbiota diversity in mice,in order to reveal the effect of yTAP on intestinal health and provide a reference for developing yTAP as novel antimicrobial agent.【Method】 Twenty-four 4-week-old ICR mice without specific pathogen (SPF) were randomly divided into 3 groups:Control group (CON),5 mg/kg yTAP group (LOW) and 10 mg/kg yTAP group (HIGH) (n=8).Mice in the experimental groups were injected with corresponding concentration of yTAP via tail vein,and mice in the control group were injected with equal volume sterile saline (0.5 mL/mouse).After administration,the mice were fed normally for 7 days,and then killed after weighing,organ tissues were collected and weighed quickly,and organ coefficients were calculated.The intestinal morphology was observed by hematoxylin-eosin (HE) staining.Colon contents of mice were collected,genomic DNA was extracted and 16S rRNA was amplified and sequenced based on NovaSeq 6000 sequencing platform.【Result】 There was no significant effect of 5 and 10 mg/kg yTAP on body weight and organ coefficients of mice (P＞0.05).Compared with control group,the crypt depth of ileum in 10 mg/kg yTAP group was significantly decreased (P＜0.05),and the ratio of villus height to crypt depth was significantly increased (P＜0.05).The Shannon index of colon microflora in 5 mg/kg yTAP group was significantly decreased (P＜0.05),and the Shannon and Simpson indices of colon microbiota in 10 mg/kg yTAP group were significantly decreased (P＜0.05).At the phylum level,compared with control group,the relative abundance of Firmicutes and the ratio of Firmicutes to Bacteroideta (F/B) in the colon of 10 mg/kg yTAP group were significantly decreased (P＜0.05).At the genus level,compared with control group，the relative abundance of Lactobacillus in the colon of 5 mg/kg yTAP group increased (P＞0.05).The relative abundance of Odoribacter in the colon of 10 mg/kg yTAP group was significantly decreased (P＜0.05).Compared with 5 mg/kg yTAP group,the relative abundance of Lactobacillus and Bacteroides in the colon of mice in 10 mg/kg yTAP group was significantly decreased (P＜0.05).LEfSe analysis results showed that the dominant bacteria in the colon of mice in 5 mg/kg yTAP group were Lactobacillus and Bacteroides,and the dominant bacteria in the colon of mice in 10 mg/kg yTAP group were Staphylococcales.【Conclusion】 Under this experimental conditions,yTAP had no acute toxicity to mice,among which 10 mg/kg yTAP could improve the morphology of ileum mucosa and significantly reduce the Alpha diversity of microbiota.5 mg/kg yTAP could increase the relative abundance of dominant strains such as Lactobacillus and Bacteroides in mice.

【Objective】 The objective of this experiment was to investigate the therapeutic effect and mechanism of Dihuang Guiqin capsules on atopic dermatitis induced by dinitrochlorobenzene solution in rats,and provide theoretical basis for the research and development of new veterinary drugs for pets.【Method】 The atopic dermatitis model was replicated by applying 2% dinitrochlorobenzene solution on the back of rats.After successful modeling,40 rats with atopic dermatitis were randomly divided into 4 groups:Model control group,Dihuang Guiqin capsules low (0.1 g/kg),medium (0.2 g/kg) and high (0.4 g/kg) dose groups,with 10 rats in each group.10 healthy rats were selected as blank control group.Rats in each dose group were given Dihuang Guiqin capsules by intragastric administration according to the corresponding dose.Rats in model control and blank control groups were given intragastric drinking water,0.2 mL/rat each time,once a day,for 14 consecutive days.The skin lesions of rats were evaluated according to SCORAD.Scratching times of rats were recorded to evaluate the pruritus of rats.The pathological changes of the skin were observed by HE staining,and the histopathological score was performed by Baker score.The number of mast cells was detected by toluidine blue staining.Western blotting was used to detect the expression of interleukin-31 (IL-31) protein in skin tissues.【Result】 Compared with blank control group,the skin lesion score of rats in model control group was significantly increased (P<0.05),a large number of inflammatory cells infiltrated,and the Baker score was significantly increased (P<0.05).Compared with model control group,the skin lesion score and scratching times of rats in each dose group of Dihuang Guiqin capsules were significantly decreased (P<0.05).The Baker score and the number of mast cells in medium and high dose groups of Dihuang Guiqin capsules were significantly decreased (P<0.05),and the expression of IL-31 protein in skin tissue was significantly decreased (P<0.05).【Conclusion】 Dihuang Guiqin capsules could effectively relieve pruritus in rats with atopic dermatitis,and its mechanism related to repairing skin barrier,relieving inflammatory cell infiltration,reducing the number of mast cells and down-regulating IL-31 protein expression.

【Objective】 The experiment was to explore the effect of single amino acid substitution on the hemolytic activity of heterozygant peptide KL-21,compare the changes in the structure and activity of polypeptide before and after amino acid substitution,and initially explore the key sites and factors affecting the bioactivity of KL-21.【Method】 Based on the heterozygous peptide KL-21,a new derivative peptide KL-21a was obtained using bioinformatics method using replacing the 14th glycine with alanine.Bioinformatics analysis of two polypeptides was performed using a variety of online tools.The secondary structure of polypeptide was determined by circular dichroism spectroscopy.The antibacterial activity of peptides was investigated by detecting minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).The hemolytic activity of polypeptides was determined by spectrophotometry.【Result】 Most of the physical and chemical properties of peptides KL-21a and KL-21 were less different,but the differences related to hydrophobicity were more obvious.The secondary structure of the two peptides was dominated by alpha-helix,and the side chain of KL-21a was more contracted and the helix content was lower than that of KL-21.They showed inhibitory activity against Escherichia coli,Pseudomonas aeruginosa,Staphylococcus aureus and Candida albicans,and had the most similar inhibitory effect against Staphylococcus aureus.When the concentration of polypeptide was 256 μg/mL,the hemolysis rate of KL-21 was greater than 50%,and KL-21a had no hemolysis activity.【Conclusion】 The derivative peptide KL-21a had good antibacterial activity,and the hemolysis effect was significantly reduced.The results indicated that the 14th amino acid was the key site affecting the bioactivity of KL-21,which could provide basis and reference for the subsequent design and modification of antimicrobial peptides.

【Objective】 The aim of this study was to investigate the inhibitory effect of total flavone from Melastoma dodecandrum Lour.(TFMD) on iron death in diabetic nephropathy (DN) mice and its related mechanism.【Method】 In this study,MPC5 cells were used to establish an in vitro DN model with high glucose-induced.Cells were divided into six treatment groups: Control group (5.5 mmol/L glucose),DN model group (60 mmol/L glucose),TFMD low (60 mmol/L glucose＋25 μg/mL TFMD),medium (60 mmol/L glucose＋50 μg/mL TFMD) and high (60 mmol/L glucose＋100 μg/mL TFMD) dose groups,and Fer-1 group (60 mmol/L glucose ＋2 μmol/L Fer-1).Cell viability was detected by cytotoxicity assay.The activity of superoxide dismutase (SOD) and the levels of glutathione (GSH) and malondialdehyde (MDA) were detected by the kits.The level of reactive oxygen species (ROS) was detected by DCFH-DA fluorescent probe.The mouse in DN model was constructed by high-fat diet combined with streptozotocin (STZ),and then the experiment was carried out in vivo.Sixty mice were divided into six treatment groups: Control group,DN model group,metformin positive group (0.5 g/kg) and TFMD high (1.2 g/kg),medium (0.8 g/kg) and low (0.6 g/kg) dose groups,10 mice in each group.The contents of urinary microalbumin (MAU),urinary total protein (TUP),serum urea nitrogen (BUN),creatinine (SCr),SOD activity,GSH and MDA contents in each group were detected.The content of iron ion in serum and kidney was also detected.The pathological changes of podocyte mitochondria in kidney were observed by transmission electron microscopy.Western blotting was used to detect Nrf2,NQO1 and GPX4 proteins expression in kidney of mice in each group.【Result】 In vitro test results showed that,compared with control group,the survival rate of MPC5 cells in DN model group was extremely significantly decreased (P＜0.01),MDA and ROS levels were extremely significantly increased (P＜0.01),GSH content and SOD activity were extremely significantly decreased (P＜0.01).Compared with DN model group,survival rate of MPC5 cell in TFMD dose groups and Fer-1 group was extremely significantly increased (P＜0.01),MDA and ROS levels were extremely significantly decreased (P<0.01),GSH content and SOD activity were extremely significantly increased (P＜0.01). In vivo tests showed that,compared with control group,the contents of MAU,TUP,SCr,BUN,MDA and iron ion in serum and kidney of mice in DN model group were extremely significantly increased (P<0.01),while the SOD activity and GSH content in serum were extremely significantly decreased (P<0.01).Compared with DN model group,the levels of MAU,TUP,SCr,BUN and MDA, and the content of iron ion in serum and kidney of mice in each dose group of TFMD were extremely significantly decreased (P＜0.01),and the SOD activity and GSH content were extremely significantly increased (P<0.01).The pathological observation results showed that TFMD could ameliorate mitochondrial related pathological injury of podocytes and improve mitochondrial morphology in different degrees.Western blotting results showed that compared with control group,the expressions of Nrf2,NQO1 and GPX4 proteins in kidney of mice in DN model group were extremely significantly decreased (P<0.01).Compared with DN model group,the expressions of Nrf2,NQO1 and GPX4 proteins in kidney of mice in TFMD dose groups were extremely significantly or significantly increased (P<0.01 or P<0.05). 【Conclusion】 The intervention effect of TFMD on mouse DN was related to the regulation of iron metabolism and the improvement of lipid peroxidation imbalance，through the activation of Nrf2/NQO1/GPX4 signaling pathway in kidney,thereby inhibiting the occurrence of iron death in podocyte.

【Objective】 The purpose of this experiment was to understand the main pathogens causing respiratory tract diseases in sheep in Inner Mongolia,and explore the pathogenicity and drug resistance,so as to provide reference for the control drugs selection of related disease.【Method】 The pathogenic bacteria were isolated,cultured,biochemical and molecular identified from the lung tissue of dead sheep,and the pathogenicity test was carried out in mice.The virulence genes of the isolates were detected by PCR.The drug susceptibility of isolates was detected by K-B method,and the drug resistance genes of the isolates was detected by PCR method.The in vitro inhibitory effects of berberine,citraldehyde and thymol on the isolated strains were determined by Oxford cup method.【Result】 The isolated strains formed β-hemolysis grey white colonies on the blood agar plate medium,and two suspected strains were isolated，and named Mh1-1 and Mh1-2,respectively.Biochemical identification showed that maltose,mannose,sucrose,xylose and sorbitol of the isolates were positive.PCR amplified the specific gene of Mannheimia haemolytica with the size of 453 bp and the capsular serotype A1 band with the size of 306 bp.The similarity comparison results showed that the similarity between the isolate Mh1-1 and Mannheimia haemolytica GDZJcattle2014 (accession No.:KM576848.1) was 98.49%,and the similarity between the isolate Mh1-2 and Mannheimia haemolytica 38599 (accession No.:CP017491.1) was 98.14%.The two isolates were identified as serotype A1 Mannheimia haemolytica.The results of pathogenicity test in mice showed that the LD₅₀ of Mh1-1 was 2.2×10⁷ CFU/mL,and the LD₅₀ of Mh1-2 was 1.0×10⁷ CFU/mL.Virulence genes gs60,lktC,lktA,tbpB,adh and nmaA were detected in both isolates.The results of drug sensitivity test showed that Mh1-1 was resistant to tetracycline and lincomycin,and intermediated to streptomycin.Mh1-2 showed resistance to streptomycin and lincomycin,and intermediated to tetracycline.The two isolates were sensitive to ofloxacin,ciprofloxacin,enrofloxacin,cotrimoxazole,cefotaxime and flufenicol.The results of drug resistance gene detection showed that the two isolates carried strA,strB and tetA genes.The results of in vitro bacteriostatic test showed that berberine and citraldehyde had good inhibitory effects on the isolates.【Conclusion】 In this study,two strains of serotype A1 Mannheimia haemolytica were isolated from the lung tissues of dead sheep with respiratory diseases.Two isolates were pathogenic and carried a variety of virulence genes，and resistant to lincomycin,and carried resistance genes such as strA.The results provided reference for rational selection of antibiotics in clinical,and provided ideas for the development and research of subsequent therapeutic drugs.

Cancer has become a big threat to the health of canines,especially for those over the age of 10.Given the same living environment shared between dogs and humans,and high degree of genetic homology,research on the mechanisms of canine tumor occurrence,progression,and effective treatments is not only crucial for pet dogs,but also provides valuable models and insights for human cancer research.In veterinary clinic,the conventional treatment for canine tumors includes surgical resection,chemotherapy and radiotherapy.Although they have certain curative effects,some side effects and limitations accompanied cannot be ignored.While immunotherapy has brought new hope and perspectives to the treatment of cancer due to its high safety and efficacy.With its rapid development,antibody therapy is making new breakthroughs.And therapeutic antibodies are used to treat various human tumors for their high affinity and selectivity.However,compared to the field of human medicine,the application of antibody therapy in veterinary oncology clinical practice is relatively limited.Here after combined the application of antibody therapy in human tumor treatment,the latest progress and potential research directions of therapeutic antibodies in canine tumor research were reviewed,aiming to provide new ideas for research and clinical trials in canine tumor treatment.

Inflammatory bowel disease (IBD) is a gastrointestinal inflammatory condition that poses significant health risks to companion animals.The primary clinical manifestations include vomiting,diarrhea,abdominal pain,bloody mucous stools,and weight loss.Currently,there is no definitive cure for IBD,and its precise pathogenesis remains unclear.Lactic acid bacteria (LAB),recognized as essential probiotics,have the potential to modulate gut inflammatory disorders by influencing relevant signaling pathways and inhibiting the release of inflammatory mediators.LAB can directly or indirectly regulate metabolites,thereby increasing the concentration of short-chain fatty acids (SCFAs) such as acetic acid,propionic acid and butyric acid,which play a pivotal role in protecting the intestinal mucosa and intestinal epithelial cells by providing direct energy,and consequently mitigating intestinal inflammation.LAB can suppress Toll-like receptor 4 (TLR4) signaling pathway,thereby reducing the production of pro-inflammatory cytokines,and diminishing the expression of tight junction proteins such as ZO-1 and Occludin,as well as Claudin 1.Furthermore,LAB have been shown up-regulating interleukin-22 (IL-22) through the aryl hydrocarbon receptor (AhR),which subsequently impacts the activity of immune cells,including T cells and B cells,thereby influencing the overall immune response.Following in the gut,LAB generally induce beneficial alterations in the intestinal microbiota by reshaping and enhancing the diversity of beneficial microbial populations.They can also modulate certain microRNAs (miRNAs),after transcription,exert positive effects on innate immune responses,help maintain intestinal barrier,and reduce the production of proinflammatory cytokines.Additionally,LAB regulate the expression of Th1,Th17 and Treg-related cytokines,and play a therapeutic and intervention role in inflammatory bowel disease.By exploring the mechanism of action of LAB,we hope to provide more theoretical support for the future use of LAB in the treatment of IBD.

【Objective】 The purpose of this experiment was to evaluate the disinfection effect of the new full spectrum TiO₂ disinfectant and provide theoretical basis and reference for the clinical application of this disinfectant.【Method】 Through the laboratory disinfection test,the disinfection effect of full spectrum TiO₂ disinfectant was first investigated,and different bacterial liquids (Staphylococcus aureus,Bacillus subtilis,Pseudomonas aeruginosa and Escherichia coli) were coated and cultured for 24 h after spraying the disinfectant,and the growth status of the strains was observed to evaluate the preventive effect of the disinfectant on common bacteria.The disinfectant was sprayed immediately after the bacterial solution was coated on the medium,and the bactericidal rate was calculated at different time periods to investigate the bactericidal effect of the disinfectant on bacteria.Metal corrosion test tablets were immersed in disinfectants to assess the degree of erosion to clinical production equipment.The effect of light on bacteriostatic effect of disinfectant was also investigated.At the same time,clinical disinfection trials were carried out in a large-scale farm.The air and surface of the building were sampled and cultured before and after the use of the disinfectant,and the bactericidal effect of the disinfectant in clinical application was investigated by counting the total number of colonies,so as to comprehensively evaluate the disinfection effect and safety of the disinfectant.【Result】 In the laboratory disinfection evaluation, the results of prevention test showed that no bacteria colonized in the tested disinfectant group except Pseudomonas aeruginosa. The bactericidal test results showed that the test disinfectant could play a good sterilization effect within 10 min, the bactericidal rate of Staphylococcus aureus,Bacillus subtilis and Escherichia coli was over 99.80%.The bactericidal rate of Pseudomonas aeruginosa decreased after 6 h.The metal corrosion test results showed that the corrosion rate of 304 stainless steel under test for 72 h was 0.0047 mm/a,and there was basically no corrosion.The results of light test showed that there was no bacterial colonization in both the light avoiding and the non-light avoiding groups.In the clinical production investigation,compared with disinfectant control group,the total number of bacterial colonies in the air of hoggery in test disinfectant group was extremely significantly decreased (P<0.01),but the total number of bacterial colonies on the surface of objects had no significant difference (P＞0.05).【Conclusion】 The full spectrum TiO₂ disinfectant had a strong killing effect on common pathogens,and had a good performance in clinical efficacy evaluation.The bactericidal rate in the air was as high as 100%,and the use cost was low,which had a good application and development prospect,and provided a new scheme for the environmental disinfection of large-scale farms.