Pluripotent stem cells (PSC) refer to cells with unlimited proliferation capacity and can differentiate to produce various tissue cells of three germ layers. They have wide application prospects in biological medicine, animal breeding and other fields. Livestock stem cells can be used to accelerate the process of breeding, generate models for biomedical research instead of mice, and produce cultured meat, etc. However, due to the interspecies differences between livestock and humans or mice, the progress of livestock pluripotent stem cell establishment is relatively lagging. At present, stable porcine PSC lines have been successfully established, while PSC lines of other livestock such as bovine, sheep, goat and horse still remain insufficient. In this review, the progress made in embryonic stem cells and induced pluripotent stem cells established in domestic animals wene summerized, as well as an outlook on the future applications of pluripotent stem cells in stem cell basis, livestock breeding and reproduction, biomedical science, and food industry was given.

Circular RNAs (circRNAs) are single-stranded, covalently closed RNA that were generated by 3' polyA and 5'tail of pre-mRNA via back-splicing. CircRNAs play a crucial role in varieties biological processes. N6-methyladenosine (m⁶A) is one of the most abundant modifications in eukaryotes, which regulate splicing, translation and degradation of RNA. There is increasing evidence that m⁶A modification also controlling circRNAs metabolism, including translation, degradation and so on. In this review, the biogenesis and function of circRNAs were summerized. Moreover, the role of m⁶A modification in the regulation of circRNAs was discussed.

The basic principle of genomic selection (GS) is to evaluate and select the genetically excellent individuals based on genome-wide high-density markers (mainly SNPs). By using genomic selection technology, it is available to accurately select young bulls and heifers early in life without relying on phenotypic information, thereby reducing the generation interval from 5-6 years to around 2 years, and drastically shortening generation intervals, thereby significantly reducing breeding costs and accelerating genetic progress in the population. In 2009, genomic selection technology has been first applied to the genetic evaluation of Holstein young bulls, marking the beginning of a new era in dairy cattle breeding. Herein, this review systematically summerizes the basic process and advantages of genomic selection, the current status of genomic selection applications in developed countries in the dairy industry, including the reference population size, selection traits and application effects, and the establishment and application effects of the genomic selection molecular breeding technology system for Chinese Holstein cattle, with the aim of providing references and directions for dairy cattle breeding program in China.

The transcription factor Yin-Yang1 (YY1) is a complex protein that regulates important life activities, such as cell proliferation, differentiation, aging, and apoptosis by inhibiting or activating multiple genes expression. YY1 mainly acts as a traditional transcription factor, regulating chromosome structure and phase separation mechanism. It was found that YY1 played an important regulatory role in the reproductive system and was closely related to animal reproductive performance. The article reviews the mechanism of YY1 on gene expression regulation and its role on animal reproductive regulation, which providing a theoretical basis for further research on animal reproductive regulation.

With the intensification of milk production, cow productivity has increased dramatically and milk production is increasing, however, the fertility of high-yielding cows is decreasing, which is associated with postpartum energy imbalance in cows. A negative energy balance occurs when a cow's postpartum energy requirements exceed her energy intake. Studies have shown that negative energy balance affects cow fertility through multiple mechanisms, including changes in endocrine and metabolic mechanisms in cows caused by negative energy balance. Therefore, this paper provides an overview of the effects of negative energy balance on cow fertility and the endocrine and metabolic mechanisms by which negative energy balance leads to reduced fertility in cows, with the aim of providing a reference for the development of methods to mitigate negative energy balance with the aim of reducing the losses caused by negative energy balance in animal husbandry.

Bone metabolism is a dynamic process of continuous remodeling and reconstruction of bones with the participation of various bone cells. The balance of bone metabolism is of great significance for maintaining bone density and bone strength. Gut microbiota is considered the second largest gene pool and plays an important role in maintaining animal health. In recent years, the relationship between bone metabolism and gut microbiota has gradually become a research hotspot. Gut microbiota is a complex microecosystem, which can maintain bone health by regulating metabolism, immune system and endocrine in animals. The abundant active ingredients in Chinese herbal medicine can regulate the structure and composition of gut microbiota, and thus maintain the relative balance of microorganism. It has been found that there is a close relationship among Chinese herbal medicine, gut microbiota and bone metabolism. Based on the worldwild research on bone metabolism, gut microbiota and traditional Chinese medicine, this paper summarizes the influence of Chinese herbal medicine on gut microbes, gut microbiota on bone metabolism, along with the effects of Chinese herbal medicine on bone metabolism through gut microbiota, which will provide a reference for the subsequent research on improving bone metabolism based on gut-bone axis.

Farm animal welfare is a significant way to ensure the sustainable development of modern animal husbandry. Scientific and operable evaluation methods are effective means to improve animal welfare. However, the classic ‘Five Freedoms’ have been shown to be disadvantageous in term of ‘freedom from’ being easily misunderstood as ‘complete liberation’ and ignores positive emotional experiences. To make up for the above shortcomings, the Five Domains Model based on the Five Freedoms focuses on animal emotions and constantly absorbs the latest research progress of animal welfare science to identify the areas of welfare compromise and welfare enhancement, which applies to the evaluation and improvement of conscious animals welfare. However, it is still impossible to evaluate the impact of some welfare on animal emotions from the animal perspective. This paper therefore, discusses the development and improvement of the Five Domains Model and its application in farm animal welfare assessment, with the view of providing a reference for the comprehensive scientific assessment of farm animal welfare in China.

Intestinal hypoxia is a pathological phenomenon in which the oxygen demand of intestinal tissues is higher than the oxygen supply. It is one of the direct triggers, early warning signals and key features of various intestinal diseases. The establishment of real and reliable animal models of intestinal hypoxia or cellular models that can simulate intestinal hypoxia is essential for the study of the pathological mechanisms of intestinal hypoxia-related diseases. The methods applicable to the construction of intestinal hypoxia models in recent years are reviewed in this paper, Focused on the construction strategies, advantages and disadvantages, and application scenarios of models including circulatory, chemical and environmental animal models of intestinal hypoxia, physically and chemically induced cellular models of intestinal hypoxia in vitro, as well as isolated intestinal organoid models of hypoxia in vitro, in the hope of providing reference for the study of the pathogenesis of intestinal hypoxia diseases in animals and the discovery and clinical pharmacodynamic evaluation of therapeutic drugs.

Dairy cows experience varying degrees of negative energy balance during the perinatal period. Severe negative energy balance leads to ketosis, abnormally elevated blood ketone body concentration, reduced performance, and often inflammatory diseases in dairy cows. β-hydroxybutyrate (BHBA) is a major ketone molecule. BHBA not only acts as an energy source, but also mediates epigenetic modifications that regulate gene transcription and expression, and can act as a signaling molecule that binds to the corresponding receptor to regulate the inflammatory response. BHBA links changes in the external environment to changes in cell function and affects disease processes. This review of BHBA signal transduction focuses on the effect of BHBA on epigenetic modification to alter gene transcription regulation, and explores the molecular mechanisms of BHBA in the regulation of inflammatory response, with the aim of providing new ideas for the study of metabolism and inflammation.

The perinatal period is an important physiological stage of dairy cows, and it is also a period of frequent and high incidence of nutritional and metabolic diseases. Cows with severe negative energy balance will have peripheral tissue insulin resistance, which makes glucose are continuously transported to the mammary gland. However, the exacerbation of insulin resistance will lead to the disorder of the body's glucose and lipid metabolism, resulting in the excessive mobilization of adipose tissue and lipid accumulation in the liver, and in severe cases, fatty liver and other diseases. A large number of studies have shown that the crosstalk between liver and adipose tissue are closely related to the development of fatty liver. This review aims to summarize the factors and their effects in mediating liver-adipose tissue crosstalk, in order to provide scientific reference for regulating glucose and lipid metabolism and improving liver health of perinatal dairy cows.

The purpose of this study was to analyze the population structure and genetic diversity of Jianbai Xiang pigs at the molecular level and to provide technical support for the identification and conservation of germplasm resources of Jianbai Xiang pigs. Using Porcine SNP50 BeadChip (Illumina, United States) to scan the whole genome SNP of 138 Jianbai Xiang pigs, the population structure of Jianbai Xiang pigs was studied by analyzing the principal component, genetic distance, genetic relationship and boar pedigree. The genetic diversity of the Jianbai Xiang pig was determined by ROH analysis. The results showed that there was no obvious stratification in this population, but it could be roughly divided into 3 parts. The average genetic distance within the population was about 0.273, and all boars were divided into 4 lineages. A total of 2 893 ROHs were detected in Jianbai Xiang pigs, with an average of 21 ROHs per individual. The average ROH length was 7.18 Mb and the average inbreeding coefficient (F_ROH) was 0.27%, indicating that the inbreeding accumulation of Jianbai Xiang pigs was small. A variety of analyses showed that the population had a moderate number of families, a small number of male animals in individual families, moderate genetic relationships between individuals, a low degree of inbreeding, and high genetic diversity. In this study, the population genetic structure and genetic diversity of Jianbai Xiang pigs were analyzed at the genome level, which provided the molecular basis for population rejuvenation and seed industry safety measures of Jianbai Xiang pigs.

This study aimed to obtain higher purity of fibro/adipogenic progenitors (FAPs) from longissimus dorsi muscle of Suhuai pig, and evaluate the alteration of the adipogenic capacity and gene expression patterns during in vitro culture. The longissimus dorsi muscle of one-day Suhuai boar was digested to obtain suspended mixed cells. In order to determine the optimal differential adhesion time for FAPs cell, the purity of cell isolated from 4 different adhesion time were evaluated by immunofluorescence using an antibody against platelet-derived growth factor receptor α (PDGFRα). Then, the adipogenic differentiation ability of different passage of FAPs cells (P1, P3 and P5) cultured in vitro was compared, and the RNA-Seq was used to identify the differentially expressed genes (DEGs), KEGG pathways and GO functional classification in FAPs cells with different passages.The results showed that the purity of FAPs cells isolated from longissimus dorsi muscle of Suhuai pig by differential adherence for 30 min was much higher than other conditions. Evaluation of the adipogenic capacity of FAPs cells with different passages showed that the adipogenic ability of FAPs cells decreased significantly with the increase of passages in vitro. RNA-Seq results showed that the gene expression patterns of P3 and P5 generation FAPs cells were similar. Compared with P1 to P3 or P1 to P5 generation cells respectively, a total of 2 336 common DEGs was identified, including 1 102 up-regulated DEGs and 1 234 down-regulated DEGs. KEGG and GO analysis showed that the common up-regulated DEGs were mainly enriched in PI3K-AKT-FoxO, PI3K-AKT-HIF-1 and cGMP-PKG signaling pathways etc., and the common down-regulated DEGs were mainly enriched in DNA replication and repair signaling pathways etc. Among them, the genes of IRS1, FOXO3, CCNG2, EGFR and FGF1, which could inhibit cell proliferation and adipogenic differentiation were up-regulated, while the genes of CSF1R and SIPA1L2, which could promote cell proliferation were down-regulated. Compared P3 with P5 generation cells, the up-regulated DEGs were mainly enriched in NOD-like, MAPK and non-canonical Wnt signaling pathways etc.; The down-regulated DEGs were mainly enriched in VEGF, PPAR, Notch and IL-17 signaling pathways etc. Among them, TNFAIP3, AREG, FGF1 and FGF9 genes, which could inhibit adipogenic differentiation were up-regulated, and PPARγ, C/EBPα and LCN2 genes, which could promote adipogenic differentiation were down-regulated.These results showed that porcine FAPs cells with higher purity can be obtained by differential adherence for 30 min. The adipogenic capacity of porcine FAPs is continuously decreased during in vitro culture, and the gene expression patterns also undergo significant changes during in vitro culture. The major change for in vitro cultured FAPs is the reduction of gene expression related to cell proliferation and adipogenic differentiation. This study could provide a reference for developing a medium formula, which could maintain the adipogenic capacity of porcine FAPs cells during in vitro culture.

The aim of this study was to explore the effect of tyrosine-related protease 1 (tyrosinase related protein 1, TYRP1) on melanin production in skin melanocytes of Xiang pigs. Three 3-month-old healthy pigs with the hair color characteristics of "two-head-black" animals were selected. The black skin tissue on the head and white skin tissue on the back were collected for each pig.The structure of hair follicles and the distribution characteristics of melanocytes were observed by HE staining; The epidermal melanocytes were cultured in vitro and identified by Dopa (L-Dopa) staining, quantitative real-time PCR and Western Blot methods; Five siRNAs were constructed from TYRP1 gene sequence, and the siRNA with the highest interference efficiency was transfected by quantitative real-time PCR. After successful interference of TYRP1 in melanocytes, the mRNA and protein expression levels of TYRP, TYRP1 and TYRP2 were measured by quantitative real-time PCR and Western Blot, the total intracellular melanin content also been measured. The results showed that intact hair follicle structures were observed in both the black and white skin of Xiang pigs, and the melanocytes were mainly distributed in the outer root sheath of hair follicles and epidermes in the black hairy skin of Xiang pig. Under the treatment of MelM medium, the melanocytes grew vigorously, and the results of cell morphology, growth curve, Dopa staining, quantitative real-time PCR and Western Blot all indicated that the cultured melanocytes maintained normal biological characteristics. Knocking down of TYRP1 downregulated the mRNA and protein expression of melanogenesis-related genes TYR, TYRP1 and TYRP2 in Xiang pig epidermal melanocytes, and also had an inhibitory effect on melanin formation. The TYRP1 gene was able to affect the melanin production in melanocyte epidermal cells,the results provide experimental reference and basic data to explore the molecular mechanism of TYRP1 gene on melanin deposition in Xiang pigs.

The aim of this study was to identify candidate genes for hypoxia adaptation in chicken embryos by analyzing the gene expression changes in embryonic heart tissues of White Leghorn (WL) and Xueyu White (XYW) chickens incubated under hypoxic conditions. The eggs were incubated at high altitude. The heart tissues were collected from embryos at day 16 of incubation, and the RNAs were extracted for RNA sequencing (RNA-seq). Differently expressed genes (DEGs) were screened, which were validated using fluorescence quantitative PCR (qRT-PCR). The functional enrichment analysis and a transcription factor-target gene regulatory network was constructed to further screen candidate genes related to hypoxia adaptation in XYW. The 253 DEGs were screened in heart tissues between XYW and WL, and 5 DEGs were randomly selected for qRT-PCR validation. Their expression trend was consistent with the sequencing results. Enrichment analysis showed that DEGs were mainly enriched in biological processes and signaling pathways related to cardiovascular development and cardiac function. Comparing DEGs with known chicken transcription factors, FOXP2 and HOXA2 were screened, which regulated angiogenesis, myocardial contraction and other functions, and played a key role in hypoxia adaptation in XYW embryos. Through the analysis of transcriptomic data, TENM2, NOG, SMOC1, CCBE1 and other candidate genes were identified for plateau hypoxia adaptation in chicken embryos, which provide a theoretical basis for analyzing the molecular mechanism of plateau hypoxia adaptation in XYW.

The purpose of this study was to screen candidate genes related to tibial bone metabolism and reveal the genetic mechanism of bone metabolism changes in laying hens by analyzing the transcriptional expression profile of the tibia of laying hens at the early and late stages of laying. Three Hy-line Grey laying hens aged 19 weeks old (early laying) and 79 weeks old (late laying) were selected to construct a tibia transcriptome library, and transcriptome data were used to screen differentially expressed genes and predict protein interactions; Five differentially expressed genes were randomly selected and their expression levels was verified using real-time fluorescence quantitative PCR. The effective reads of 19 034 718-22 668 315 were obtained from the 6 cDNA libraries of the tibia of Hy-line Grey laying hens with Q30 value of at least 93.68% and comparison rate of 83.78%-85.72%. A total of 1 211 differentially expressed genes were screened from the tibia of laying hens at the early and late stages of laying, of which 645 differentially expressed genes were down regulated and 566 differentially expressed genes were up regulated. GO analysis results showed that most of the differential genes were enriched in GO terms related to cell differentiation and cell development. KEGG analysis results showed that the differentially expressed genes were significantly enriched in 11 KEGG pathways (P<0.05). There were 5 pathways related to bone metabolism, namely MAPK signaling pathway, TGF-β signaling pathway, Toll-like receptor signaling pathway, glycosaminoglycan biosynthesis-chondroitin sulfate/dermatan sulfate and glycosaminoglycan degradation. Among the above 5 pathways, 59 differentially expressed genes were involved, of which 29 were up regulated and 30 were down regulated. In addition, protein interaction analysis was conducted on 59 differentially expressed genes related to bone metabolism pathways, identifying a total of 53 coding proteins and screening out 5 hub genes (IL6, IL1B, FOS, TGFB2 and BMP4). Five differentially expressed genes were randomly selected from 1 211 differentially expressed genes for real-time fluorescent quantitative PCR verification, and the results were consistent with the results of RNA-Seq sequencing. This study revealed the differential gene expression in the tibia tissue of laying hens during the early and late stages of egg laying, and screened multiple differentially expressed genes and signaling pathways that affect tibia bone metabolism in laying hens, providing a theoretical basis for studying the molecular mechanism of tibia tissue regulation of bone metabolism in laying hens.

This study aimed to explore a suitable method for assessing the genetic relationships of indigenous beef breeds in China, based on a systematic comparative analysis of different computational methods for determining kinship. This study focused on 10 local beef cattle breeds, such as Chaidamu cattle, and utilized the resampling method to generate simulated data for these local breeds. Based on this, the study utilized PCA clustering results as a reference and systematically compared different evaluation methods, including predictive error variance, generalized coefficient of determination, predictive error correlation coefficient, and the degree of linkage consistency between SNPs and QTLs, to classify the genetic relationships of these local breeds. Additionally, the study explored the influence of genetic factors on different methods of assessing kinship. The PCA analysis showed that the 10 indigenous beef cattle breeds could be classified into 3 major categories, northern cattle breeds (Chaidamu cattle, Xizang cattle, Mongolian cattle and Yanhuang cattle), southern cattle breeds (Wenshan cattle, Nandan cattle and Leiqiong cattle) and southwestern cattle breeds (Pingwu cattle, Liangshan cattle and Zhaotong cattle). The classification results were consistent with the geographical distribution of the above breeds. Compared with the PCA results, the correlation of persistence of LD phase affinity assessment method was consistent with the PCA clustering results, and the method was able to quantify the relationship using Pearson correlation coefficient relationships with better accuracy. The 3 methods, PEVD, CD and r, were susceptible to the influence of the error variance of the estimated breeding values of the traits when assessing the relationship compared to the above methods, resulting in errors in the assessment results of the relationship. The analysis of factors affecting the assessment results revealed that the PEVD, CD and r methods were susceptible to the influence of the heritability of the assessed traits compared to the PCA and LD phase consistent assessment methods, and the assessment results were less stable. On the other hand, the PCA and LD phase consistent assessment methods are more stable and quantitative in assessing relatedness among breeds because they rely only on genomic data and are not affected by heritability and have better reliability. Therefore, the results based on LD phase consistent assessment method can accurately and quantitatively assess the relationship between breeds and the assessment results are more stable.

The purpose of the study was to establish methods for isolation, culture, purification, and identification of goose skeletal muscle satellite cells in vitro. The healthy 10-week-old Xupu geese was selected as experimental materials. Satellite cells were isolated from the muscle with the action of Dispase II and collagenase II. Satellite cells were purified by differential adhesion to the culture dish. During in vitro culture, the complete DMEM/F12 growth medium containing 20% FBS and supplemented with bFGF could better maintain the differentiation potential of satellite cells, and the culture dishes involved in the culture process needed to be coated with matrigel specially. After the formation of mature myotubes, the expression of myosin heavy chain (MyHC) was detected by immunofluorescence and Western blotting. The relative expression levels of Pax7, MyoD1 and MyoG before (growth medium, GM) and after differentiation (differentiation medium, DM) were detected by qRT-PCR. There were 3 replicates in each group before and after differentiation. The results showed that the newly isolated satellite cells were small in size and strong in refraction. After adhering to the wall, they had a spindle-shaped structure with needle-like ends and puffed up in the middle. The cells were identified as Pax7 positive by immunofluorescence. Mature multinucleated myotubes could be formed after induction of differentiation. MyHC was positive by immunofluorescence detection. The statistical differentiation index was as high as 78% (P<0.01). The marker genes Pax7, MyoD1, and MyoG were detected positive by qRT-PCR. The relative expression of Pax7 gene before differentiation was 2.22 times (P<0.01) that after differentiation, while the relative expression of marker genes MyoD1 and MyoG after differentiation were 1.90 (P<0.01) and 44.22 times (P<0.01) that before differentiation, respectively. Western blotting results showed that the expression level of MyHC protein was significantly increased after differentiation. In this study, a method for the isolation and culture of goose skeletal muscle satellite cells by collagenase II and dispase II was established. The culture system can enable cells to maintain huge differentiation potential during the in vitro culture. The study results provide a good cell model for the research of the growth and development molecular regulation mechanism of goose muscle tissue.

The aim was to study the dynamic outcome of gene editing under the action of a long-acting CRISPR system by constructing an in vitro cellular model to provide research support for long-acting editing in germ line. A set of cellular model expressing CRISPR/Cas9 in a long-term manner was constructed by lentiviral random integration of FANCF and VEGFA genes, and this model was used to study the dynamic outcome of gene editing efficiency and repair under the action of the long-term CRISPR system. In the exogenous target region of FANCF and VEGFA genes, the editing efficiency of CRISPR/Cas9 gradually increased with the increase of Doxycycline treatment time, and respectively reached the highest on day 4 (FACNF) and day 3 (VEGFA); secondly, the peak time points of the endogenous target corresponding to the above target region was basically the same as that of the exogenous target, but the editing efficiency of the endogenous target was significantly higher than that of the exogenous target (P<0.000 1); thirdly, the analysis of the sequence of the target editing products revealed that the deletion, insertion and other types of the target editing products were in a stable state from day 4 to 7 of editing, and the trend of deletion, insertion and other types in the editing ending of each endogenous target and exogenous target were consistent; finally, the potential 6 off-target sites of the FANCF targets were detected, and no off-target phenomenon was found. The editing efficiency of the long-term CRISPR/Cas9 technology peaked at day 3 or 4, with a consistent proportion trend of gene editing outcome types across endogenous targets and exogenous targets, and no increased off-target risk at the FANCF locus.

The study aimed to investigate the effect of P450 aromatase (cytochrome P450, family 19, subfamily A, polypeptide 1, CYP19A1) on the proliferation and apoptosis of rabbit ovarian granulosa cells (GCs). Healthy 8-month-old New Zealand white female rabbits were selected to collect ovarian tissue, isolate and identify GCs. The full-length sequence of rabbit CYP19A1 gene was obtained by one-step cloning method and analyzed by bioinformatics. The effects of CYP19A1 gene overexpression and interference on steroid hormone synthesis-related genes, proliferation and apoptosis of ovarian GCs were analyzed using qRT-PCR, CCK8 and FITC/PI methods. Using FSHR immunofluorescence staining, isolated primary cells were identified as GCs with positive FSHR expression. The CYP19A1 gene was cloned and the full length of cDNA was 1 512 bp, encoding 503 amino acids. Bioinformatics prediction revealed that CYP19A1 protein was a stable hydrophilic protein, containing a P450 family structural domain with high homology to other species. In GCs, the change of expression of CYP19A1 gene significantly or extremely significantly affected the expression of steroid hormone synthesis-related genes IGF1R, CYP1B1, CYP1A1, BMP6, CYP17A1 (P<0.05 or P<0.01). Overexpression/knockdown of CYP19A1 extremely significantly upregulated/downregulated the proliferation level of GCs, and highly significantly inhibited/promoted the apoptosis level of GCs (P<0.01). In conclusion, CYP19A1 can promote GCs proliferation, inhibit GCs apoptosis, and regulate the expression of steroid hormone synthesis-related genes to participate in the follicular development process in female rabbits.

The purpose of this experiment was to study the effects of serine on growth performance, intestinal morphology and immune related indexes of lactating piglets with intrauterine growth retardation (IUGR). Sixteen healthy newborn piglets with similar body weight of (1.27±0.01) kg were selected as the control group, and 16 newborn IUGR piglets with similar body weight of (0.98±0.01) kg were selected as the treatment group. Eight IUGR piglets were fed 0.8% 3 mL serine at the 1st, 4th, 7th, 11th, 15th, 19th, 22nd and 26th day, and eight healthy piglets were fed 3 mL normal saline at the same time. All piglets were suckling normally. The test period was 28 days. Other piglets were slaughtered on the first day of newborn. The results showed that:1) Newborn IUGR piglets have significantly lower body weight than normal piglets (P<0.05), but after serine administration, there is no significant difference in body weight between piglets in two groups at 28 days (P>0.05); 2) On the first day of newborn, the villi in the jejunum and ileum of IUGR piglets were short and irregularly flocculent on the surface, with significant inflammation. After feeding with serine to the 28th day, the villi in the jejunum and ileum of IUGR piglets were tightly arranged and smooth on the surface, without significant inflammatory response, the villus height of the ileum in IUGR piglets significantly increased compared to the control group (P<0.05), but there was no significant improvement in the villus height and crypt depth of the jejunum in IUGR piglets compared to the control group (P>0.05); 3) On the first day, the serum albumin (ALB), immunoglobulin A (IgA), immunoglobulin G (IgG) and immunoglobulin M (IgM) content of IUGR piglets had no significant difference compared with those of the control group (P>0.05), the total protein (TP) content and aspartate aminotransferase (AST) activity were significantly lower than those of the control group (P<0.05), the alanine aminotransferase (ALT) activity was significantly higher (P<0.05), after feeding with serine to the 28th days, the serum ALB content of IUGR piglets was significantly higher than that of the control group (P<0.05), while the TP content, AST and ALT activities had no significant difference compared with the control group (P>0.05), however, serine could not make the content of IgA, IgG and IgM in serum of IUGR piglets reach the level of normal piglets at the 28th days; 4) On the first day, compared with the control group, the number of CD4⁺T cells in the peripheral blood of IUGR piglets showed a decreasing trend(P=0.077), the number of CD8⁺T cells significantly increased (P<0.05), and the ratio of CD4⁺to CD8⁺significantly decreased (P<0.05), after feeding with serine to the 28th days, there was no significant difference in the number of CD4⁺T cells and CD8⁺T cells in the peripheral blood of IUGR piglets compared to the control group(P>0.05). 5) After 28 days of serine administration, the protein expression of interleukin 10(IL-10) in jejunum significantly increased. In summary, exogenous addition of serine can promote the growth and development of IUGR newborn piglets, improve the morphology and structure of intestine, and improve the immune function of piglets, so that the body weight of IUGR piglets can reach the level of normal piglets, and the results may provide certain reference for the research and feeding of IUGR piglets, and provide new ideas for the nutritional regulation of IUGR piglets as well.

The purpose of this experiment was to investigate the effects of carvacrol on the growth performance, apparent nutrient digestibility, intestinal morphology, short-chain fatty acids content, gut microbiota structure, and metabolic pathways of gut microbiota in meat rabbits. A hundred and sixty 35-day-old healthy rabbits were randomly divided into 4 groups, each with 40 replicates and one rabbit per replicate. The control group (CON group) was fed with basal diet, and the treatment groups (T1, T2 and T3 groups) were fed with basal diets containing 100, 200 and 300 g·t^-1 carvacrol, respectively. The pre-test period was 5 days, and the test period was 28 days. The results showed that:1) Compared with the CON group, the average daily gain and average daily feed intake of rabbits in T1 and T2 groups were significantly increased (P<0.05), diarrhea frequency and mortality were significantly reduced in the T1 group (P<0.05), the final weight of T1 group was significantly increased (P<0.05). 2) The apparent digestibility of crude protein in T1, T2 and T3 groups were significantly higher than that in CON group (P<0.05). 3) Compared with CON group, T1, T2 and T3 groups had significantly higher ileal villus height and mucosal thickness (P<0.05), and the villus height to crypt depth raito of ileum in T1 and T2 groups were significantly higher than that in CON group (P<0.05). 4) The cecal butyric acid content in T1 group was significantly higher than that in CON group (P<0.05). 5) The relative abundance of Firmicutes and Oscillospira in cecum of T1, T2 and T3 groups were significantly higher than those of CON group (P<0.05). The relative abundance of Bacteroidetes in T1, T2 and T3 groups were significantly lower than that in CON group (P<0.05). 6) Compared with the CON group, the steroid hormone synthesis, degradation of glycosaminoglycans, synthesis of secondary bile acids, primary bile acid synthesis, biosynthesis of terpenoid quinones such as ubiquitin ketone, N-glycan synthesis, ketone body synthesis and degradation of cecal microbiota metabolic pathways in the T1 group were significantly up-regulated (P<0.05), sphingolipid metabolism and lipopolysaccharide synthesis were significantly down-regulated (P<0.05). In conclusion, dietary carvacrol can improve the growth performance and apparent nutrient digestibility, promote the morphology and structure of ileum, increase the content of butyric acid in cecum, improve the structure of cecum flora, and positively regulate the metabolic pathways of cecum flora in rabbits. Under the conditions of this experiment, considering the effects of carvacrol on rabbits, the recommended amount of carvacrol added is 100 g·t^-1.

The study was aimed to investigate the effects of high fiber diet on growth performance, meat quality and intestinal health of growing-finishing pigs. A total of 72 healthy cross-bred (Duroc×Landrace×Large White) pigs with an average body weight of (48.83±0.49) kg were randomly divided into control group and high-fiber group with four replicates in each group and nine pigs per replicate. The trial lasted for 84 days. Pigs in the control group were fed with basal diet, pigs in the high fiber group were fed with the high fiber diet with 15% wheat bran, and the late stage (six weeks later) the two groups were both fed with the high fiber diet. The initial body weight, body weight every three weeks, final weight and feed consumption of each pig were determined. At the end of the experiment, the longissimus dorsi was taken to detect meat quality and muscle fiber characteristics, ileum sample was taken to detect intestinal morphology and intestinal barrier related indexes, cecum and colon contents were taken to detect intestinal microbiome and their metabolites. The results showed that compared with the control group, at 1-3 weeks of the experiment,the body weight(BW) at the third week and average daily gain (ADG) in high fiber group were significantly decreased (P<0.05) and the ratio of feed intake to gain (F/G) was significantly increased (P<0.05). At 7-9 weeks of the experiment, the weight of the high fiber group at the 9th week was significantly higher than that of the control group (P<0.05), and ADG had an increasing trend (P=0.055). During the whole experiment, ADG in the high fiber group increased significantly compared with the control group (P<0.05). In the high fiber group, the 24 hours after slaughter pH (pH24_h) of meat samples increased significantly (P<0.05), the cross-sectional area of muscle fibers was significantly decreased (P<0.05) and the mRNA expression level of MyHC I, which determines the type of muscle fiber was significantly increased(P<0.05) compared with the control group. Compared with the control group, villus height and villus height to crypt depth ratio (V/C) of ileum were extremely significantly increased in the high fiber group (P<0.01),the crypt depth was significantly decreased (P<0.05), while the mRNA expression levels of tight junction protein Claudin-1 and Occludin were significantly increased (P<0.05). Compared with the control group, the number of goblet cells in the high fiber group was extremely significantly increased (P<0.01), and the mRNA expression level of Muc-2 was significantly increased (P<0.05). Compared with the control group, the relative abundance of Firmicutes and Proteobacteria in cecum of the high fiber group were extremely significantly increased (P<0.05), whereas the relative abundance of Bacteroidetes was extremely significantly decreased (P<0.01), the relative abundance of Clostridium was significantly increased (P<0.05), while that of Streptococcus was significantly decreased (P<0.05). In the colon, the relative abundance of Bacillus was extremely significantly increased (P<0.01), while that of Spirochaetes and Streptococcus was extremely significantly decreased (P<0.01) in the high-fiber group. In the cecum, compared with the control group, the concentrations of acetic acid (P<0.05), propionic acid (P<0.05) and butyric acid (P<0.05) were significantly increased in high fiber group. In the colon, the concentrations of acetic acid (P<0.05), propionic acid (P<0.05), butyric acid (P<0.05), valerate acid (P<0.05) and isovalerate acid (P<0.05) were significantly increased. In conclusion, adding 15% wheat bran to the diet of growing-finishing pigs can improve the growth performance, significantly increase the longissimus dorsi pH_{24 h} of finishing pigs, reduce the cross-sectional area of muscle fiber, promote the expression of slow muscle fiber related genes, improve intestinal morphology, intestinal barrier and intestinal microbial composition, increase the production of short chain fatty acids, which is beneficial to the body health and reduction of feeding cost.

This study aimed to analyze the effects of different levels of wheat bran replacing basal diet on blood routine, blood biochemistry, serum immunoglobulin, and large intestinal mucosal secretory immunoglobulin A (SIgA) of Meishan pigs, using Large White pigs as the control. Then further studied the mechanism of dietary fiber affecting the immune indicators of Meishan pigs from the perspective of host intestinal genes and microorganisms. In this study, 28 Meishan pigs (initial body weight was (67.08±1.53) kg) and 28 Large White pigs (initial body weight was (81.04±1.64) kg, at the same physiological stage as Meishan pigs) were randomly and respectively divided into 4 treatment groups with 7 replications in each group for 1 per duplicate. During the pre-feeding period of 7 days, all pigs were fed the basal diet, and during the main trial period of 28 days, they were fed with the basal diet (Basal), 7%, 10.5%, and 14% wheat bran substituted in the basal diet (7% WBR, 10.5%WBR and 14% WBR), respectively. During the trial period, all pigs had free access to food and water. At the end of the experiment, all pigs were slaughtered, and blood samples were collected for the determination of blood routine, blood biochemical and serum immunoglobulin indicators. Cecal and colonic mucosal samples were collected for SIgA determination, and colonic mucosal were collected to perform RNA-seq. Colonic contents were collected for metagenomic sequencing. The results showed that:1) With the increasing of wheat bran replacing basal diet level, the number of eosinophils and basophils, and percentage of eosinophils decreased in Meishan pigs linearly, (P<0.05), and the serum globulin level of Meishan pigs in the 14% WBR group were significantly higher than that of Large White pigs (P<0.05). 2) With the increasing of wheat bran replacing basal diet level, the serum immunoglobulin M (IgM) and immunoglobulin G (IgG) of Meishan pigs increased linearly, (P<0.01), and the serum IgM of Large White pigs increased (linear, P<0.01). The serum IgG concentration of Meishan pigs in the 14% WBR group was significantly higher than that of Large White pigs (P<0.01). In addition, compared with the Basal group, the concentration of colonic mucosal SIgA of Meishan pigs in the 14% WBR group was significantly increased (P<0.01), but there was no significant change between the 14% WBR group and the Basal group in Large White pigs. 3). To elucidate the mechanism of increased colonic mucosal SIgA concentration of Meishan pigs in the 14% WBR group, on the one hand, the colonic mucosa of Meishan pigs in the Basal group and the 14% WBR group were selected to perform RNA-seq. A total of 38 differentially expressed genes were identified, and the functional items enriched by GO and the signaling pathways enriched by KEGG were mainly related to the immune system. The expression of CD4 molecule (CD4) and C-C chemokine receptor 9 (CCR9) regulating intestinal SIgA production was significantly increased in the 14% WBR group (P<0.05). On the other hand, the colonic contents of Meishan pigs in the Basal group and the 14% WBR group were selected to perform metagenomic sequencing. The results of LEFSe analysis showed that 14% WBR group was significantly enriched to 2 family-level microorganisms, 1 genus-level microorganism, and 5 species-level microorganisms. Correlation analysis revealed that there was no direct interaction between the differentical microorganisms at speices level and the host mucosal genes which regulating the production of intestinal SIgA (P>0.05), but Sutterella sp., Clostridium sp. CAG:138, Clostridium sp. CAG:762 and Nitrospira sp. were significantly positively correlated with serum IgG. Moreover, Clostridium sp. CAG:138 and Nitrospira sp. were significantly positively correlated with colonic mucosal SIgA. Finally, KEGG functional analysis found that the relative abundance of the intestinal immune network for IgA production in the 14% WBR group was significantly higher than that of the Basal group (P<0.05). In summary, replacing part of the basal diet with wheat bran could reduce the inflammatory level, enhance humoral immunity and promote the health of the colon of Meishan pigs, and the beneficial effect of 14% wheat bran replaced basal diet on Meishan pigs is better than that on Large White pigs. In addition, this study also found that the effects of dietary fiber on colonic mucosal SIgA of Meishan pigs may be through up-regulating the expression of CD4 and CCR9 genes in the colonic mucosa, and affecting the composition of intestinal microorganisms, thus enhancing the functional pathway of intestinal immune network for IgA production, improving intestinal barrier function and promoting body health.

This experiment was conducted to investigate the effects of dietary methionine (Met) and metabolizable energy (ME) levels on growth performance, carcass characteristics, and plasma biochemical parameters of Pekin ducks from 15 to 42 days of age, and to determine the ME requirements of Pekin ducks at different dietary Met levels. A 2×6 two-way completely randomized experimental design was used, and 576 male Pekin ducks, with similar weight[(545.9±3.3) g] at 15 days of age, were randomly divided into 12 groups with 8 replicates per group and 6 ducks per replicate. The present experiment was set with 2 Met levels (0.30%, 0.50%) and 6 dietary ME levels (10.47, 11.10,11.72, 12.35, 12.98, and 13.61 MJ·kg^-1). The experiment was lasted for 28 days. The results were showed as follows:1) As dietary ME levels increased, the average body weight at 42 days of age and the average daily weight gain of Pekin ducks from 15 to 42 days of age were significantly increased (P<0.05), average daily feed intake and feed to gain ratio decreased significantly (P<0.05). 2) As dietary ME levels increased, the percentage of breast meat and leg meat were decreased significantly (P<0.05), the percentage of eviscerated carcass, abdominal fat, and subcutaneous fat were significantly increased (P<0.05). 3) With the increasing dietary ME levels, the plasma total cholesterol and high density lipoprotein cholesterol contents of Pekin ducks at 42 days of age were significantly decreased (P<0.05), while the free fatty acid content was significantly increased (P<0.05), and the albumin content had a tendency to decrease (P=0.053). Dietary Met supplementation significantly increased plasma albumin and reduced free fatty acid contents (P<0.05), and there exists a significant interaction effect between dietary ME and Met levels on plasma total cholesterol and high density lipoprotein cholesterol contents (P<0.05). 4) Based on the linear broken line model, the ME requirements to meet the optimal average daily weight gain of Pekin ducks were 12.46 and 12.85 MJ·kg^-1 at dietary 0.30% and 0.50% Met levels, respectively. The t test showed that the ME requirements of Pekin ducks at dietary 0.50% Met level tended to be greater than those at 0.30% Met level (0.10<P<0.05). Taken together, increasing dietary energy level can improve the growth performance of Pekin ducks, and dietary Met level could affect dietary ME requirement of Pekin ducks.

The main objectives of this study were to investigate the main pathogens causing postweaning multisystemic wasting syndrome (PMWS) on a large-scale pig farm in Hubei Province. In this study, tissue samples were collected from piglets with typical clinical symptoms of PMWS in this pig farm, and PCR detection revealed the presence of porcine circovirus type 2 (PCV2) infection. The complete genome of PCV2 was cloned and sequenced. Then, the sequence of the complete genome and key genes of the positive samples were compared with other PCV2 strains around the world, and their nucleotide homology was analyzed. The virus strain was isolated, cultured, and identified by using porcine kidney epithelial cell line PK-15, and the epitope and immunogenicity in mice of nucleocapsid protein Cap were analyzed and evaluated. The isolation and identification results showed that we successfully isolated a PCV2 strain (name:XY2022; GenBank accession No.:OM249965.1). The complete genome length of XY2022 was 1 767 bp, and the titer of XY2022 on isolated cells was 10^5.70TCID₅₀·mL^-1. Sequence analysis showed that XY2022 belonged to PCV2d, the nucleotide homology of the reference strains was 94.3%-99.8%, and that of ORF2 was 89.2%-99.6%. The results of immunogenicity analysis and evaluation of Cap showed that XY2022 and other genotypes of PCV2 had different sites in the linear immunodominant region, linear neutralization epitope, and conformational neutralization epitope. Both PCV2d (XY2022) Cap and PCV2b (WH) Cap can induce the production of neutralizing antibodies to inhibit PCV2-infection in mice, but the level of neutralizing antibody induced by 2d Cap is more stable. This study provides a reference for the epidemiological study of PCV2 and the prevention and control of the mutated strains in Hubei Province and provides materials for the study of the pathogenesis of PCV2 and the development of novel vaccines.

This study was conducted to develop a rapid and accurate method for detection of African swine fever virus (ASFV) antibody based on x-MAP technology. In our study, pET-28a-p30 expression plasmid was constructed, and ASFV recombinant P30 protein was expressed in Escherichia coli. Then the recombinant P30 protein was coupled with carboxylated fluorescent microspheres and an x-MAP multiple bead-based technology was developed for detection of ASFV P30 antibody. The recombinant plasmid was successfully expressed in inclusion body form in Escherichia coli BL21. Western blot analysis showed that recombinant P30 protein could react specifically with ASFV positive serum, indicating that it had good reactivity. The detection threshold of the x-MAP based ASFV antibody detection method is MFI 1 575.7, and the optimal binding protein concentration is 6 μg per 1.25×10⁶ microspheres, the optimal serum dilution is 1:600, and the optimal concentration of secondary antibody is 1 μg·mL^-1, the method has good specificity, sensitivity and repeatability. Ninety-two clinical pig serum samples were tested by x-MAP analysis and compared with the result tested by a commercial ELISA kit. The results showed that the consistency was 92.39%. The recombinant P30 protein was successfully expressed, and the ASFV antibody detection method based on x-MAP technology was established, which provides a new method for the early serological detection of ASFV infection.

African swine fever (ASF), caused by the African swine fever virus (ASFV), is a devastating infectious disease in wild boars and domestic pigs. The extremely high infectivity and morbidity of ASFV have caused enormous socioeconomic losses. Given that there is no effective vaccine available for ASFV infection, early diagnosis is crucial for the prevention and control of ASF. Therefore, it is of great significance to develop a sensitive and rapid method for the on-site detection of ASFV. Firstly, the detection probe of quantum dot microspheres (QDM) coupled ASFV recombinant antigen p30 and the quality control probe of QDM coupled anti-chicken IgY were prepared based on the condensation reaction between amino and carboxyl groups. Then, the immunostrip was prepared by immobilized anti-porcine IgA-Sc antibody and chicken IgY protein on the detection line and control line, respectively. The ASFV-specific sIgA antibody in the oral fluid can be captured by the QDM-p30 fixed on the T-line. Finally, the detection sensitivity was tested by detecting the ASFV-positive oral fluid with double gradient dilution; the specificity was verified by detecting several other common swine disease viruses; and the clinical diagnostic efficacy was evaluated by testing clinical oral fluid samples from ASFV-negative and ASFV-positive animals. The proposed method shows good specificity and no cross-reaction with PRV, CSFV and PRRV; shows high sensitivity with the lowest detected dilution of 1:64 for ASFV-positive oral fluid; shows short time consuming within 20 minutes; and is easy to operate without intrusive sampling. In addition, sIgA-positive conversion could be detected as early as the 6th day after ASFV infection, suggesting the potential for early diagnosis. Here, we developed a QDM-based immunostrip for on-site early detection of ASFV sIgA antibody in oral fluid, which provides new technical support and supplement for ASFV monitoring, prevention and control.

This study focused on developing an antibody-detecting ELISA capable of distinguishing BEFV infected and vaccinated animals. Based on the identified specific reactivity between the truncated BEFV G_NS protein and sera from BEFV infected cattle, the full-length G_NS recombinant protein was expressed in prokaryotic system, purified and used for developing an antibody-detecting ELISA to distinguish BEFV infected and vaccinated animals under the optimized reaction conditions. The G_NS was expressed in Escherichia coli and deposited mainly in inclusion bodies. The purified recombinant protein had a molecular weight of 73 ku. Western blot demonstrated that sera from BEFV infected cattle but not sera from BEF vaccine immunized cattle reacted strongly with the purified G_NS protein. The optimal concentrations of plate-coating antigens and the dilution of sera were 0.50 μg·mL^-1 and 1:20, the HRP conjugated secondary antibody was determined to be 1:4 000, and the S/P ratio=0.206 9 was selected as the negative/positive cut-off value. Acceptable specificity and repeatability were confirmed by no cross reactivity with positive sera of BVDV, FMDV and IBRV as well as coefficient of variation less than 10% in intra-batch and inter-bath. The DIVA (differentiation of infected from vaccinated animals) ELISA was developed and can be used for distinguish BEFV infected and vaccinated cattle.

This study aimed to establish rapid and simple direct PCR methods for the detection of Eimeria stiedae, E. intestinalis, and E. magna in rabbits. The mitochondrial DNA (mtDNA) of E. stiedae and the rpoB of E. stiedae, E. intestinalis, and E. magna were cloned and sequenced, then homologous sequences of other rabbit coccidia available in GenBank were downloaded for the comparison analysis. The specific primers were designed based on the hypervariable regions of sequences with significant inter-species differences, and the PCR conditions were optimized, then their sensitivity and specificity were evaluated. In this study, we determined the complete mtDNA sequence of E. stiedae and the ropB sequences of E. stiedae, E. intestinalis, and E. magna apicoplast for the first time. The length of the mtDNA sequence of E. stiedae was 6 277 bp, including 3 protein-coding genes, the multiple mtDNA sequence comparison of E. stiedae and other 6 rabbit coccidia showed that the similarity ranged from 93.90% to 97.45%; the ropB sequences of E. stiedae, E. intestinalis, and E. magna apicoplast were about 500 bp, and the similarity ranged from 93.93% to 95.30%. Target genes screened showed that compared with other genes (ropB and mtDNA), ITS of the three Eimeria species had the characteristics of intra-species conservation and inter-species variation, which was more suitable for molecular diagnosis. Among the primers based on ITS sequences, Ps1, Pi2, and Pm2 showed good sensitivity and specificity. The ITS sequences were screened for molecular diagnosis by comparing the sequences' similarity of PCR-detection candidate targets (ITS, mtDNA, and rpoB) of Eimeria spp. The single and multiplex direct PCR methods based on ITS sequences have the advantages of easy operation, high specificity and sensitivity, and can be used for clinical or epidemiological studies of E. stiedae, E. intestinalis, and E. magna.

The aim of this study was to evaluate the immunoprotective effect of rEm-GAPDH, a recombinant protein of Eimeria magna, on rabbits and to lay the foundation for the development of a recombinant subunit immunization vaccine for rabbits. Screening of Em-GAPDH gene based on transcriptome data for prokaryotic expression and protein purification.Then 50 45-day-old coccidia-free rabbits were randomly divided into 5 groups (Unimmunized and unchallenged group, unimmunized and challenged group, Trx-His-S tag-challenged group, Quil-A saponin-challenged group and rEm-GAPDH immunized group). 1 mL PBS, 1 mL PBS, 1 mL PBS containing 100 μg pET-32a and 1 mg Quil-A, 1 mL PBS containing 1 mg Quil-A, 1 mL 100 μg rEm-GAPDH and 1 mg Quil-A were respectively injected subcutaneously via the neck to the rabbits, and were booster immunized with the same dose 14 d after the first immunization. The clinical manifestations of each group were observed after orally infected 1×10⁵ sporulated oocysts of Eimeria magna to every rabbit, while blood sample and body weight data were collected at regular intervals every week. After 14 d of the challenge, rabbits were dissected, and oocyst output, relative weight gain, cytokines, and specific IgG antibodies were measured and counted for each group. The results showed that the recombinant protein rEm-GAPDH was successfully expressed, with a size of about 59 ku and mostly expressed in the inclusion bodies. The immunoprotection test showed that typical symptoms of rabbit intestinal coccidiosis appeared in the unimmunized and challenged group after infection, while rEm-GAPDH immunized group showed no significant symptoms. rEm-GAPDH immunized group showed 57.16% oocyst reduction, the relative weight gain rate was significantly greater than the unimmunized and challenged group (P<0.05), specific IgG antibody levels, cytokine (IFN-γ, IL-2, IL-4, IL-10, TGF-β) levels were significantly different from those of the control group (P<0.05). The ACI of rEm-GAPDH immunized group was 144.96. The recombinant protein rEm-GAPDH of E.magna can reduce weight loss and oocyst excretion, trigger cellular and humoral immune responses in the host, and have certain immunoprotective effects, thus can be used as a candidate antigen for E.magna recombinant subunit vaccine.

To investigate the effect of G protein-coupled receptor kinase 2 (GRK2) on the replication of foot-and-mouth disease virus (FMDV), the porcine cellular RNA from PK-15 cells were extracted and the complete CDS region of GRK2 was obtained by Polymerase Chain Reaction (PCR) methods. Subsequently, the eukaryotic expressing plasmid was constructed. The Western blot and indirect immunofluorescence experiments showed that GRK2 was expressed in the transfected cells and located in the cytoplasm. The infection assay suggested that the transcription level and protein level of GRK2 firstly increased and then decreased in FMDV-infected PK-15 cells. Overexpression assay indicated that GRK2 significantly inhibited FMDV replication, and siRNA assay showed that downregulation of GRK2 promoted FMDV replication, revealing the antiviral function of GRK2 against FMDV. Further studies showed that FMDV 3C^pro protein interacted with GRK2 and degraded GRK2 to promote FMDV replication. In conclusion, this study laid a foundation for analysis of the antiviral mechanism of host protein GRK2 against FMDV.

The aim of this study was to explore the antibacterial mechanism of tirapazamine (TPZ) on Salmonella. We screened three multi-drug resistant Salmonella strains through drug sensitivity test, and measured the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antibacterial effect, time bactericidal curve and biofilm formation ability of TPZ against multi-drug resistant Salmonella. The growth and proliferation of TPZ on Salmonella, the effects of drug resistance phenotype and biofilm formation were analyzed. The results showed that TPZ had obvious antibacterial effect on multi-drug resistant Salmonella, and the MIC values respectively of Salmonella strains ST, ST-6 and ST-7 were 12.5, 25 and 25 μmol·L^-1. MBC value was 50 μmol·L^-1. With the increases of the action concentration and prolongation of the action time of TPZ, the growth of Salmonella was significantly inhibited after co-culture for 4 hours, the cultivation of 50 μmol·L^-1 of TPZ was co-cultured with Salmonella ST, ST-6 and ST-7 for 8, 20 and 20 h respectively, and all Salmonella was killed; TPZ significantly reversed the drug resistance phenotype of multi-drug resistant Salmonella; TPZ had a significant inhibitory effect on the formation ability and amount of Salmonella biofilm (P<0.0001). TPZ had obvious antibacterial effect on multi-drug resistant Salmonella, and it could reverse the multi-drug resistance phenotype and reduce the formation of biofilm. The results of the study elucidated the antibacterial activity of TPZ against multi-drug resistant Salmonella, and new therapeutic drugs had been provided for the treatment and control of infections caused by Salmonella infection.

The incidence of odontogenic tumors in dogs and cats is gradually increasing. The occurrence of odontogenic tumors is closely related to the development of teeth, and its diagnosis is difficult. To analyze the incidence and pathological manifestations of odontogenic tumors in dogs and cats from 2007 to 2022 by retrospective pathological methods, and to provide reliable basis for the pathological diagnosis of odontogenic tumors, and to provide meaningful guidance for clinical treatment and prognosis. A total of 371 samples or sections of dog and cat oral tumors were collected from several pet hospitals in China. The information of the cases was analyzed, HE staining was performed on typical cases to observe their characteristic pathological manifestations, and immunohistochemical staining for CK14 and vimentin were used to differentiate between odontogenic epithelial components and odontogenic extracellular matrix components, respectively. Among 371 samples or sections, 117 were odontogenic tumors, including 93 in dogs and 24 in cats. In dogs, the incidence of peripheral odontogenic fibroma is the highest, with males having a higher incidence than females. In cats, gingival hyperplasia is more common and there is no sex bias. Odontogenic tumors have a high incidence in dogs and cats, so the accurate diagnosis of these tumors deserves more attention. CK14 can be used as a good marker of odontogenic epithelium, which can help with accurate histopathological diagnosis and meaningful guidance for clinical treatment and prognosis judgment.

This study aimed to investigate the effect and mechanism of microRNA-502(miR-502) targeting RBMS1 on proliferation, migration and epithelial-mesenchymal transition (EMT) of canine mammary tumor cells. The transcription level of miR-502 and RBMS1 mRNA in canine mammary tumor cell lines (CHMp and CHMm) and normal mammary gland tissues were detected by realtime quantitative PCR (qRT-PCR). The miR-502 mimic/inhibitor and negative control mimic/inhibitor NC were transfected into CHMp/CHMm cells using liposome transfection method,respectively,and the expression levels of miR-502 in cells were detected by qRT-PCR method. MTT assay and Transwell assay were used to detect the proliferation and migration ability of CHMm cells; the expression levels of epithelial cell marker E-cadherin, mesenchymal cell marker vimentin, cell migration markers matrix metalloproteinase (MMP2) and cell proliferation marker PCNA after transfection with miR-502 were detected by qRT-PCR and Western blot methods. qRT-PCR and double-luciferase reporter gene assay were adopted to verify the targeting relationship between miR-502 and RBMS1 gene. The results showed that compared with normal mammary tissues, the expression level of miR-502 in canine mammary tumor cells was significantly up-regulated, while RBMS1 was down-regulated. Transfection of miR-502 mimic up-regulated the expression level of miR-502, whereas miR-502 inhibitor down-regulated the expression level of miR-502. Compared with the miR-NC group, transfection of miR-502 mimic significantly promoted the proliferation and migration of CHMm cells, moreover, down-regulated the expression of E-cadherin mRNA and protein, and up-regulated the expression of vimentin, MMP2, PCNA mRNA and protein. On the contrary, transfection of miR-502 inhibitor significantly suppressed the proliferation and migration of CHMm cells, up-regulated the expression of E-cadherin and down-regulated the expression of vimentin, MMP2, PCNA mRNA and protein; qRT-PCR and luciferase report experiments showed that miR-502 inhibited the expression of RBMS1 by targeting RBMS1 3'-UTR. Therefore, miR-502 is highly expressed in canine mammary tumor cells, and interfering with its expression might affected the proliferation, migration and EMT of the canine mammary tumor CHMm cells, and miR-502 targeted regulation the expression of RBMS1 mRNA.

This study was conducted to retrospectively analyze and summarize the surgical methods and long-term clinical effects of the new biotissue-engineered cornea (BEC) in the treatment of corneal diseases in canine and feline. This study reviewed the medical records of canine and feline useing BEC for ocular surface transplantation from 2018 to 2022 and followed up for at least 3 months. The eyes of animals including sequestrum, deep corneal ulcer, descemetocele and corneal perforation were included in the study. The patients were examined regularly every week after surgery, and selected eyes were examined with optical coherence tomography at 0, 3, 6 and 12 months after surgery. The corneas of the patients were graded according to the results of the last examination. A total of 139 eyes (112 of feline and 27 of canine) were included in this study, including 103 eyes with lamellar keratoplasty and 36 eyes with full-thickness keratoplasty. Four different thicknesses of BEC implants (200, 300, 400 and 450 μm) were used. The average diameter of the graft was 7.74 mm (range:3-13 mm). Postoperative complications with relatively impact included partial graft loosening or dehiscence (5 cases, 3.60%), graft dissolution or perforation (8 cases, 5.76%), corneal graft bed sequestrum (1 case, 0.72%) and atrophia bulbi (1 case, 0.72%). The follow-up time spanned 3-50 months (median 18 months). Finally, 139 eyes maintained the integrity of cornea and eyeball, and 133 eyes (95.68%) retained relatively sharp vision. Statistical analysis showed that corneal graft transparency was significantly and positively correlated with animal age (P=0.021), species (P=0.000), Graft diameter (P=0.032), full thickness transplantation or not (P=0.000), and corneal re-epithelialization time (P=0.000). BEC is a safe and effective corneal graft, which can be used for lamellar or full-thickness keratoplasty in canine and feline, and has extensive clinical application value.

The trial aimed to study the effect of Pulsatilla Powder prescription on the intestinal barrier function of piglets infected with porcine epidemic diarrhea virus (PEDV). Twenty-four 7-day-old piglets (du×long×large) were randomly divided into 4 groups:control, PEDV, decoction and fermentation groups. The test period was 12 days. On day 4, piglets in the control group were inoculated with saline and the other three groups were inoculated with PEDV (HN2021) at a dose of 10^4.5 TCID₅₀ (50% tissue culture infection dose) per pig, and on days 5-9, the decoction and fermentation groups were orally given decoction and fermentation solution (0.2 mL·kg^-1) daily. To evaluate the growth performance, diarrhea index, viral copies, intestinal bacterial composition, intestinal morphology, intestinal barrier function of piglets, and antioxidant indicators in the serum and intestine. The results showed that the decoction and fermentation solution significantly increased the average daily gain (ADG), reduced diarrhea rate and inhibited viral replication in the intestine of the PEDV-infected piglets (P<0.05); and also regulated the intestinal bacteria composition of piglets, significantly increased the number of Lactobacillus and Bifidobacterium(P<0.05); the administration alleviated the significant decrease in intestinal villus height (VH) and increase in crypt depth (CD) in piglets caused by PEDV infection, improved intestinal morphology, significantly increased D-xylose content and decreased fatty acid binding protein (I-FABP) concentration in serum, thereby enhancing intestinal barrier function (P<0.05). In addition, the decoction and fermentation solution reduced oxidative stress, manifested by significantly increased total superoxide dismutase (T-SOD) activity and decreased malondialdehyde (MDA) content (P<0.05). These dates indicate Pulsatilla Powder can enhance intestinal barrier function in PEDV-infected piglets.

The aim of this study was to compare the anti-inflammatory effects of matrine combined with different antibiotics. Five antibiotics including amoxicillin, chlortetracycline, doxycycline hydrochloride, florfenicol and tilmicosin were selected in this experiment. Using porcine reproductive and respiratory syndrome virus (PRRSV) 5'UTR RNA and lipopolysaccharide (LPS) co-stimulated porcine alveolar macrophage (PAMs) as inflammatory model, IL-1β as the detection index, to screen antibiotics with similar anti-inflammatory effect to matrine. Then using qPCR and Western blot to detect the effect of matrine combined with antibiotics on IL-1β expression. The results showed that, the inhibitory effect of amoxicillin and aureomycin treatment group were consistent with that of matrine on IL-1β mRNA expression. When matrine was used in combination with amoxicillin or aureomycin, an interaction was noted between matrine and amoxicillin, while matrine and aureomycin lack such type of interation, which indicated that matrine could minimize part dosage of amoxicillin. These results indicated that, in the process of inhibiting IL-1β expression induced by PRRSV 5'UTR RNA and LPS co-stimulation, when combined with amoxicillin, matrine can partially replace the efficacy of amoxicillin and reduce the dosage of amoxicillin. This study provides data support for the clinical application of matrine as an antibiotic substitute.

The aim of this study was to establish a rapid, efficient and sensitive assay for the dual detection of classical swine fever virus (CSFV) and bovine viral diarrhea virus (BVDV) by real-time PCR. Specific primers and probes were designed according to the highly conserved regions of CSFV E2 gene and BVDV 5'UTR gene sequences, respectively, and optimized the reaction conditions and program to establish a dual RT-qPCR method. The results showed that the limit detection of this method was 5 copies·μL^-1, which was about 200 times more sensitive than the traditional PCR. This method with high specificity could distinguish CSFV and BVDV, and had no cross-reactivity with common pig pathogens such as foot-and-mouth disease virus (FMDV) and pseudorabies virus (PRV). The coefficients of variations of intra- and inter-group data were less than 2%, demonstrating the good repeatability of this assay. Finally, 109 clinical samples and 7 commercial bovine sera were detected to compare the dual RT-qPCR assay with the CSFV RT-qPCR assay (GB/T 27540-2011) and BVDV RT-qPCR assay (GB/T 18637-2018). The coincident rate was 100%, and the results also illustrated that the BVDV contamination was existed in some commercial fetal bovine serums. Together, this assay could provide technical support for the differential diagnosis and epidemiological field investigation of CSFV and BVDV.

With the beginning of Genotype I African swine fever (Genotype I ASFV) epidemic in China, it makes the diagnosis, prevention and control of ASF in China more challenging. In this study, primers and probes of B646L recommended by China Animal Disease Control Center (CADC) was used, combined with primers and probes designed for the conserved specific region of GenotypeⅠ ASFV EP402R gene, to establish a rapid detection method that can identify GenotypeⅠ ASFV while diagnosing ASF, and its sensitivity and specificity were tested. The results show that the method has good sensitivity and specificity and can be effectively used for the clinical diagnosis of ASFV and the monitoring of GenotypeⅠ ASFV.

This research was conducted to describe computed tomographic angiography (CTA) diagnosis and surgical treatment in two vascular ring anomaly (VRA) dogs. Using CTA to confirm VRA before surgery,which was left 4th intercostal thoracotomy for ligaturing the ligamentum arteriosum. Case 1 was followed by esophageal balloon dilatation. CTA confirmed persistent right aortic arch (PRAA) in both dogs and also revealed other vascular anomalies, ectopic origin of the right carotid artery and persistent left cranial vena cava, respectively. After surgery, the esophageal stenosis was fully corrected, and regurgitation was disappeared. CTA can be used in diagnosis of VRA more accurately, which is of benefit to surgical plan. The surgical treatment for PRAA is effective in dogs.