Genomic selection (GS) is a maker-assisted selection method with the whole genome data.This approach could predict estimated breeding value with higher accuracy at early stage by analyzing the genetic markers covering the whole genome，and it also could decrease the inbreeding coefficient and improve the genetic progress substantially in swine breeding.With the achievement of swine genome sequencing and commercialization of PorineSNP60 Beadchip，the strategy of genomic selection has been becoming a new hot spot in swine breeding research area.In this review，we briefly summarized the analytical method，computing method and influence factors of GS，and we also elaborated the application situation and development tendency of GS in swine breeding.

African swine fever（ASF） is an acute，febrile，highly contagious，tick borne disease caused by African swine fever virus.The virus mainly replicate in the reticuloendothelial cells and mononuclear macrophage，resulting in cell apoptosis and causing serious impact on the immune system of the host.Even though the disease was first described in 1921，there is still no efficient vaccine available in the market because of the big virus genome，multi genotype and easily mutation.Even so，foreign scientists keep researching on the development of ASF vaccine.Although there are Chinese articles on ASF had been published，most of these articles provided brief introductions of the disease without fully discussed the development associated with ASF vaccine.Here，in order to provide reference to the research of ASF vaccine，we reviewed the current research progress of ASF vaccine.

The aim of this study was to further research the mechanism of how CuZnSOD gene effect the meat quality by expression and regulation，and explore the possibility to generate transgenic pigs by sperm carrier method mediated by magnetic nanoparticles.F₁ generation individuals were obtained by artificial insemination on the basis of the recombinant vector incubated with magnetic nanoparticles and semen，respectively.F₁ individuals were detected by PCR，qRT-PCR and Western blot.Exogenous gene copy number in the 4 slaughtered transgenic positive pigs were estimated by absolute qPCR.Individuals from positive and negative groups were selected at the weight of about 100 kg and slaughtered to determine the meat quality and the antioxidant properties.The results showed that：The positive rate was 30.23% in F₁ individuals.Compared with the negative group，the CuZnSOD expression at RNA and protein levels in 5 tissues were up-regulated in positive group.The standard curve in this study was：ΔCt=-3.121 6 lgN+17.281(R²=0.992 1，P<0.001).The exogenous gene copy number in the 4 positive pigs was 25.89，80.61，106.69 and 83.03，respectively.The results also showed that：Compared with the negative group，the positive group was significantly increased in muscle T-SOD_1d and T-SOD_2d activity(P<0.05)，but decreased in muscle drip loss，the content of MDA_1d and MDA_2d(P<0.05)，respectively.The results indicated that the overexpression of CuZnSOD gene could elevate the antioxidant properties，reduce the drip loss and further improve the meat quality.Meanwhile，our results proved that transgenic animals could be generated by sperm carrier method mediated by magnetic nanoparticles.

In the modern chicken industry，fast-growing broilers have undergone strong artificial selection for muscle growth，which has led to remarkable phenotypic variations compared with slow-growing chickens.The present study was designed to explore the molecular mechanism underlying these phenotypes differences.Agilent cDNA microarray analyses were conducted to determine gene expression profiles of soleus muscle sampled at sexual maturity age of Qingyuan Partridge chickens (QY，112 d，a slow-growing Chinese breed with high meat quality) and Cobb broilers (CB，42 d，a commercial fast-growing broiler line).A systematic identification of candidate genes and new pathways related to myofiber development and composition in soleus muscles between the 2 breeds were analyzed.1 318 genes with at least 2-fold differences were identified in soleus muscles of QY and CB chickens.When slow-growing QY chickens were compared with fast-growing CB chickens，the expression of 501 genes were up-regulated，and 817 genes were down-regulated.These genes mainly were related to muscle development，energy metabolism or lipid metabolism processes.In addition，based on KEGG pathway analysis，it was found that in addition to pathways affecting myofiber development and differentiation (pathways for Hedgehog & Calcium signaling)，energy metabolism signaling pathways (Wnt signaling pathway，mTOR signaling pathway，MAPK signaling pathway，ErbB signaling pathway and JAK-STAT signaling pathway) were also enriched.Our data indicates that energy and muscle metabolism pathways might form a network，which influence the development of myofibers，20 genes were potentially related to myofiber development and composition.However，large scale analyses are still required to validate the role of the genes identified and ultimately to find molecular markers that can be used for selection or to optimize rearing practices.

 To investigate the single nucleotide polymorphisms (SNPs) of GPR147 gene and the correlations between SNPs and laying traits，the SNPs in the 5′ regulatory region of GPR147 of Shouguang chicken were detected by direct sequencing method and their associations with laying traits of Shouguang chickens were analyzed.The results showed that there were 11 SNPs loci in the 5′ regulatory region of GPR147 gene detected in the population.The －593 and －579 loci had significant effects on egg production from 45- to 56-week-old and total egg number until 56-week-old (P<0.05).Genotype TT at the －593 locus and AA at －579 locus were associated with higher egg production.Haplotype analysis of the 2 loci showed that hens with haplotype TA laid 1.5，2.5，1.6 and 4.4 eggs more than that with haplotype CG during 26-44 weeks of age (P=0.041 8)，45-56 weeks of age (P=0.032 6)，the period until 300 days of age (P=0.1) and the total period until 56 weeks of age (P=0.014 4)，respectively.In summary，the 5′ regulatory region of the GPR147 has highly polymorphic，SNPs and haplotypes at －593 and －579 loci have significant impacts on the egg number of Shouguang chickens，and they can be used as potential and valuable candidate molecular markers.

This study was conducted to detect single nucleotide polymorphisms（SNPs）in NLRC5 gene promoter region of Langshan chicken，and further determine genetic effects of different genotypes which were verified by progeny segregating group，aiming to develop genetic markers associated with innate immune traits.MALDI-TOF-MS method was applied to scan SNPs in NLRC5 gene promoter region；afterwards，some immune traits and their differences between individuals with different genotypes were analyzed.The SNP scanning results found A/G mutation at g.628981 site，along with 3 genotypes，namely，AA，AG and GG.The immune indexes presented significant difference among individuals with different genotypes.The H/L value of individuals with AA genotype was significantly lower than that of individuals with GG genotype，but spleen index，thymus index，lymphocyte transformation rate and content of IgG were significantly higher than that of individuals with GG genotype (P<0.05)；it was also found that the traits of individuals with AA genotype were better than that of individuals with GG genotype in F₂ generation of AA and GG segregating groups.Collectively，combining with the transcription differences of NLRC5 gene in thymus and spleen tissues，our study indicate that birds with AA genotype show better performances of innate immunity and g.628981(A/G) site of NLRC5 gene can be used as an effective genetic marker of innate immune traits.

This study aimed to identify single nucleotide polymorphism (SNP) of the buffalo STAT1 gene，investigate population genetics characters of SNPs and find molecular markers for milk production traits in Chinese buffaloes.The polymorphisms of STAT1 gene were detected by PCR and sequencing methods.Population genetic polymorphisms for 357 buffaloes were genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technology，and the associations analysis between genotypes and milk production traits was performed by the SAS (9.3) software with generalized linear model.The results showed that the total of 3 SNPs were detected on the 5′UTR，exon10 and 3′UTR in STAT1 gene，namely g.68G>A，g.986 G>T and g.2881 C>A，respectively.Association analysis indicated that 305-day milk yield and fat percentage were significantly associated with the g.986 G>T of STAT1 gene (P<0.05).The results of Bonferroni t-test revealed that 305-day milk yield of individuals with TT and GG genotypes were significantly higher than those with GT genotypes (P<0.05)，and fat percentage of individuals with TT genotype were significantly higher than those with GG and GT genotypes (P<0.05).And the 305-day milk yield tended to increase from first to later parities，reaching the maximum at the 3rd or 4th calving，indicating that parity was one of factors affecting the milk production of buffalo.Our findings in this study implied that the g.986 G>T of STAT1 gene might be a candidate molecular marker for milk production traits in buffalo，which provide a foundation for studying the marker-assisted selection programs in Chinese buffaloes.

The small RNA transcriptome profile of yak ovary was described by Solexa deep sequencing，and provided the basic data for future study on yak breeding performance.In this study，yak ovaries were used for building small RNAs library，and then Solexa sequencing and bioinformatics were applied to analysis.Meanwhile，the expression of selected miRNAs was validated by RT-qPCR.After Solexa sequencing，a total of 12 126 208 clean reads were obtained from the ovary library，which contained 212 757 distinct sequences.Alignment analysis showed that 7 383 536 (60.89%) of total sequences and 80 981 (38.06%) distinct sequences were mapped to the yak reference genome.The results of differential expression analysis showed that 56 small RNAs were up-regulated and 33 small RNAs were down-regulated in yak ovary compared to the cattle counterparts.Among these RNA，miR-135a and miR-2316 had the largest fold-change.The expression of 6 selected miRNAs in yak ovary tissues obtained by RT-qPCR was consistent with the Solexa sequencing results.Furthermore，5 novel small RNAs were predicted after compared to the yak EST sequence information.All above suggested the small RNAs transcriptome profile of yak ovary was successfully described，and our results confirmed that Solexa sequencing technology has a great advantage in facilitating small RNA information and mining new miRNAs，and provide valuable small RNA data for further facilitate the yak genetic breeding and study the adaptation and resistance to high altitude and other related fields of highland animal.

This study aims to investigate the effect of Wnt signaling pathway on proliferation and estrogen secretion of sheep granulosa cells and to explore whether the effect was related to FSH(Follicular stimulating hormone，FSH).With or without FSH，sheep granulosa cells were cultured in medium with different concentrations of Wnt signaling pathway inhibitor IWR-1 for 168 h.Then，Guava ViaCount^® Reagent was used to detect the changes of cell number and sheep ELISA kit was used to detect the changes of estrogen concentrations.The relative expression of CYP19 and CCND2，which are the target genes of FSH，was analyzed by qRT-PCR.The results showed that IWR-1 could cause a significant(P<0.05) reduction in the number of granule cells whether FSH existed or not.With the presence of FSH，the addition of IWR-1 could significantly(P<0.05) decrease estrogen concentration.When the concentration of IWR-1 was 1.0 μmol•L^-1，its inhibitory effect on granulosa cells was of most obvious.Besides，IWR-1 decreased the abundance of CYP19 mRNA and CCND2 mRNA.In conclusion，Wnt signaling pathway can improve the biological function of sheep granulosa cells，and this function may be related to FSH.

This experiment was conducted to investigate the distribution of gene product 9.5 (PGP 9.5) and neuropeptide Y (NPY) in Tibetan Plateau sheep testis and in an attempt to explore their relationships with testicular spermatogenesis at different ages.Testis from 0.5-，2-，5-，8-，12-and 18-month-old Tibetan Plateau sheep were sectioned and immunostained with antisera to the NPY and PGP 9.5.Furthermore，IPP (Image-Pro Plus) statistics methods were used to compare the average absorbance of PGP9.5 and NPY expression in all of these testis.The testicular parenchyma did not show any NPY- and PGP9.5-containing immunoreactivity in 0.5-month-old sheep，and very scattered immunoreactivities were present within the gonocytes，but the expression of PGP9.5 in testis of 2-month-old sheep was significantly stronger than NPY at the same age (P<0.01)，both of the PGP9.5 and NPY were strongly present in 18-month-old sheep(P<0.01).By contrast，no expression of NPY and PGP9.5 immunoreactivities were observed within the primary spermatocytes in 18-month-old sheep.The expression of PGP9.5 in Sertoli cells underlie age-related declines，which was poorly investigated at 12-month-old and no expression at 18-month-old，but they were obviously detected in Leydig cells and vscellum at different ages.The NPY expression in Leydig cells were also poorly investigated，and were mainly expressed in Sertoli cells in 2-month-old sheep testis，and after that，the expression of NPY in vscellum with a manner of age-related enhances.The results suggest that the PGP9.5 and NPY expression was significantly difference in Tibetan Plateau sheep testis at different ages might serve as regulators for the testicular functions，also the expression of PGP9.5 in Leydig cells in the testis reflect the functional regulates of testosterone.Namely，the distribution of NPY in the wall of testis vascular significantly stronger in a manner of age-related increase may provide new indexes for the research of plateau adaptability mechanism in testicular blood regulation，and play a role in the local microcirculation and the interactions with the Sertoli cells.

 The aim of this study was to explore the effect of lipopolyscharride (LPS) on induction of sheep beta defensin-1 (SBD-1) in ovine oviduct epithelial cells (OOECs).In this study，OOECs were cultured and then exposed to LPS for up to 24 hours，with a range of concentrations (10 ng•mL^-1-1 mg•mL^-1).qRT-PCR was performed to detect SBD-1 mRNA.The results showed that LPS stimulated the expression of SBD-1 in a time-(maximal at 12 hours) and concentration-(maximal at 100 ng•mL^-1) dependent manner.Moreover，IHC staining showed that SBD-1 was mainly expressed in epithelial cells.Importantly，TLR4 was detected in OOECs and stimulated by LPS.LPS induced SBD-1 mRNA expression was markedly inhibited by blockage of TLR4 activity using anti-TLR4 antibody.In conclusion，these results suggest that LPS might induce the expression of SBD-1 in the ovine oviduct epithelial cells,and the expression are mediated by TLR4.

This study aimed to investigate the change of rectal and surface temperature of sows during estrus, the temperature was separately measured by infrared temperature measurement device and conventional electronic thermometer. In addition, the effects of ambient temperature, wind speed and relative humidity were studied as well. A total of 150 sows selected from Duroc, Landrace and Large White, were splited into 5 batches, for each sow, its rectal temperature and surface temperature at 10 time points of mating were measured. Our results showed that：1）Within a distance range of 5-30 cm, surface temperatures were not affected by the distance of infrared device with sow; 2）Surface temperature measured at different body parts were significantly different (P<0.05), and the back of pig was an ideal position for measurement of body temperature; 3）The rectal temperature increased with estrus starting, then reached a peak at mating, thereafter decreased significantly (P<0.05), the surface temperature also reached highest during mating; 4) Estrus significantly influenced rectal temperature and surface temperature (P<0.05), and the measurement time did not take effect on them. Within the appropriate range, the ambient temperature, wind speed and relative humidity had rare influence on rectal and surface temperature, but not vice versa.

The objective of this study was to screen，identify and analyze the differentially expressed proteins in the potentiated and dormant antler stem cells in sika deer (Cervus nippon)，and then to shed lights on the molecular mechanisms underlying antler regeneration.The two-dimensional fluorescence of gel electrophoresis (2D-DIGE) was used to separate the protein spots；Differentially expressed protein spots were selected by DeCyder 2D (version 7.2)；Matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS) was carried out to obtain peptide mass fingerprinting，Mascot software was used to search the matched proteins in the NCBInr database；PANTHER (Protein Analysis Through Evolutionary Relationships) and REACTOME analysis were performed to further explore the involved signal pathways about these identified proteins.The proteomic profile of the potentiated antler stem cells compared with the dormant antler stem cells was explored by 2D-DIGE.One hundred fifty-nine protein spots with more than 1.1-fold changes and less than -1.1-fold changes and P values less than 0.05 differentially expressed by the potentiated over the dormant antler stem cells，including 110 up-regulated and 49 down-regulated protein spots.Multiple markers were obtained by extended data analysis(EDA) module.MALDI-TOF-MS identified 84 differentially expressed protein spots and 48 of them which came from 27 kinds of proteins were positive.There is a significant difference at proteomic level between the potentiated and the dormant antler stem cells，and some identified proteins which are involved in multiple functional categories might be related to antler regeneration.Therefore，antler regeneration is a process from the dormant to the potentiated states in antler stem cells，which is regulated by multiple proteins and a complicated signal network.

The study was conducted to evaluate the nutritional value of spray-dried chicken plasma (SDCP) in piglets.A single factor design was adopted in this experiment.A total of 24 healthy crossbred “Duroc × Landrace × Yorkshire” barrows with an initial body weight of (24.96±1.05) kg were randomly allotted into 3 dietary treatments with 8 replicates per treatment.The 3 diets were N-free diet，corn-soybean basal diet and SDCP-diet (40% protein of basal diet were substituted by SDCP).After 6 days adaptation，all feces and urine from 24 piglets were collected for 4 days to determine the nutrient digestibility and availability.When the experiment ended，all piglets were euthanized and slaughtered to collect ileal digesta for determining apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids.The results showed that crude protein content of SDCP reached up to 69.36%，lysine content was 4.53%，methionine content was 1.65%，and lysine∶methionine∶tryptophan∶threonine=100∶36∶30∶91，which closed to the ideal protein animo acids model in pig.The apparent digestibility energy of SDCP was 16.02 MJ•kg^-1，and the apparent metabolizable energy was 15.39 MJ•kg^-1；apparent and true digestibility of crude protein were 87.58% and 91.11%，respectively；standardized ileal digestibility of all amino acids other than glycine were higher than 80%.Overall，spray-dried chicken plasma is a superior animal protein resource.

This study was conducted to investigate the effects of dietary rumen-protected glucose (RPG) supplementation on performances and blood biochemical parameters of postpartum cows.Twenty-eight healthy postpartum Holstein cows with similar weight and body conditions score were randomly assigned into 4 groups (Ⅰ，Ⅱ，Ⅲ and Ⅳ).The cows in group Ⅳ (the control group) were fed with the basal diet.Except for the same basal diet，the cows in the experimental group Ⅰ，Ⅱand Ⅲ were supplemented with additional 200，300 and 400 g•d^-1RPG per cow from the first day of calving.The experiment lasted for 28 days.(1) The postpartum weight loss of the groups Ⅰ，Ⅱ，Ⅲ and Ⅳ were 61.99，43.2，42.83 and 62.66 kg，respectively.Comparing to that of group Ⅳ，postnatal weight loss in groups Ⅱ and Ⅲ were significant less (P<0.01).(2) The milk yield of group Ⅱ and Ⅲ were 26.68 and 26.84 kg•d^-1•cow^-1，which were significantly higher than that of group Ⅳ (24.49 kg•d^-1•cow^-1) (P<0.01).The milk yield of group I was at 25.66 kg•d^-1•cow^-1，which is not significant different from that of group Ⅳ (P>0.05).(3) In comparison with the control，all the experimental groups improved milk protein and lactose content.But the differences among them were not significant (P>0.05).(4) All the experimental groups increased the serum glucose concentration and decreased serum NEFA (nonesterified fatty acids，NEFA) and BHBA (β-hydroxybutyric acid，BHBA) concentration.Especially for group Ⅲ (P<0.01). Our results suggest that in early lactation，diets with RPG can effectively reduce weight loss，increase milk production，increase serum glucose concentration，and decrease serum NEFA and BHBA concentrations.It indicates that RPG supplication can relieve negative energy balance and improve the body conditions of postpartum cows.

The experiment was conducted to study the effect of the different dietary Manganese (Mn) levels on production performance，blood serum biochemical parameters and organ index in male mink.Seventy-five healthy male minks with samilar weight were randomly divided into 5 groups with 15 replicates per group and 1 mink per replicate.0 mg•kg^-1（I），50 mg•kg^-1（Ⅱ），100 mg•kg^-1（Ⅲ），300 mg•kg^-1（IV）and 600 mg•kg^-1（V）of Mn levels were added in basic diet.The trial lasted for 75 d.Production performance was examined，organ index was calculated and proteins indices，nitrogen metabolism indices，enzymes activity of serum were determined.The results showed that，body weigh,body length and pelt length were highest in group Ⅲ，and they were similar between group Ⅲ and IV (P>0.05)，but significantly higher in group Ⅲ than that in group I，Ⅱ and V(P<0.05).Liver index，heart index and kidney index were not significantly affected by dietary Mn levels (P>0.05)，spleen index of group IV and V were significant higher than that of group I，Ⅱ and Ⅲ (P<0.05).The content of albumin (ALB) and serum total protein (TP) in group Ⅲ were significantly higher than that in group I and Ⅱ (P<0.05)，the content of serum globulin in IV and V groups were significantly higher than that in group I，Ⅱ and Ⅲ (P<0.05)，and the highest one was in V group.The activity of serum AST in group Ⅱ and Ⅲ were significantly higher than that in group I (P<0.05)，the activity of LDH in group I，IV and V were significantly higher than that in group Ⅱ (P<0.05)，the activity of ALP in group Ⅲ was significantly higher than that in other groups (P<0.05 )，CK was similar among all groups (P>0.05).In conclusion，under this experimental conditions，when the diet supplementation with 100 mg•kg^-1 Mn，the minks had the best production performance and relatively higher protein synthesis rate，enzyme activity and it also could improve the growth performance and no damagement on the spleen of male mink.

This study was performed to investigate the co-infection and natural recombination of Marek’s disease virus (MDV) and reticuloendotheliosis virus (REV) in chicken flocks in China，and evaluate the potential influences of viral recombination on MDV biology.Based on polymerase chain reaction (PCR)，DNA sequencing and indirect immunofluorescent assay (IFA)，we presently studied a total of 17 MDV field isolates obtained from the vaccinated chicken flocks in Henan province.The PCR results showed that，among the 17 Henan isolates，two isolates，HNGS206 and HNXZ103，are recombinant MDVs containing the REV－LTR inserts.Subsequent experiments showed that neither of the two isolates are natural recombinant viruses and the integrations of LTR into the viral genomes may result from the clinical co-infection and/or virus isolation procedure.Our data indicates that although a wide-spread co-infection of both MDV and REV exists in chicken flocks in China，the epidemiology of the naturally occurring recombinant MDVs needs to be further monitored.

This experiment was conducted to study pathogenicity changes in susceptible goslings of cell attenuated goose parvovirus YG strain.To obtain attenuated vaccine strain，goose parvovirus(GPV) YG strain was propagated alternately in goose embryo fibroblasts(GEF) and duck embryo fibroblasts(DEF).Cells infected with YG strain began to induce cytopathogenic effect after 12 passages.Results of indirect immunofluorescence assay(IFA) showed that the numbers of infected cells with green fluorescence increased with the time of infection，and the highest number of positive cells were obtained at 96 h post-infection.Virus titers increased with serial passages going and virus titer reached 10^6.5 TCID₅₀•mL^-1 after passage 50.Compared to parental virus，the mortality and morbidity of goslings decreased obviously after challenged with virus passage 50.There were no observed characterized pathogenic changes or clinical symptoms of Derzsy’s disease in goslings after challenged with passage 50 YG virus.

This study aimed at researching neutralizing activity of VP3 antiserums and determining B-cell epitopes of VP3 protein from duck hepatitis A virus type 1(DHAV-1).The pGEX-4T-1 expression plasmid was used to express VP3 gene of DHAV-1 in E.coli BL21(DE3).The expressed recombinant VP3 protein was purified by gel extraction and was used as immunogen to rabbit to prepare polyclonal antibodies.Chicken embryo neutralization test was conducted to detect the neutralizing titer of polyclonal antibodies.Moreover，Karplus&Schulz，Emini，Jameson-Wolf and Parker method were used to analyze the flexibility，surface accessibility，antigenicity and hydrophilicity of the VP3 protein，respectively.This contributed to obtain four probable B-cell epitopes for VP3 protein.The rabbit anti-VP3 polyclonal antibody was used as the first antibody of indirect ELISA to identity the synthetic peptides.Furthermore，a panel of clinical duck serum samples was used to evaluate capacity of the identified B-cell epitopes for antibodies detection.The results showed that the recombinant VP3 protein was expressed as inclusion body in E.coli BL21(DE3) with a molecular weight about 54 kD，and proved to be with good reactogenicity by Western blot analysis.The prepared polyclonal antibodies reached an titer of 1∶16 by AGP test，it could neutralize DHAV-1 and reached a titer of 1∶39.Furthermore，the B-cell epitopes identified by indirect ELISA were GKRKPCRRPIHKPKNPPQEP(1-20 aa)，FNTGRYQMSWYPIADGEQSL(131-150 aa) and VNSSAPSNID(200-209 aa).The test for antibody detection ability revealed the epitopes were capable of detecting clinical duck antiserums of DHAV-1.This study proved antiserums to VP3 protein of DHAV-1 with neutralizing activity and identified VP3’s three promising B-cell epitopes，1-20 aa，131-150 aa and 200-209 aa，for clinical use.

 One NDM-1-Producing Escherichia coli strain，designated as E120413，was isolated from a clinical pig case in China.Here we determined its transmissibility，pathogenicity and in vivo distribution in pigs.We performed kinetic bacterial distribution assays of porcine fecal samples，blood samples and organ tissues.The results demonstrated that E120413 strain can quickly infect the Close contacts of piglets from the inoculated piglets after being given 2 mL of the bacterial suspension containing 1.1×10¹⁰ CFU of E120413 strain.In these two groups，similar numbers of organisms were isolated from the fecal samples of these two groups of piglets，giving the longest persistence terms of over 11 weeks and 9 weeks，respectively.The E120413 organisms also could be isolated from the blood samples from day 2 to day 10 in the inoculated piglets and from day 4 to day 10 in the control piglets with the peaks of 3.7×10⁵ and 4.3×10⁵ CFU•mL^-1 respectively，suggesting that the E120413 organisms might reach the porcine blood circulation and tissues effectively after infection.The presence of live E120413 organisms was then observed in brain，heart，liver，spleen，lung，kidney，stomach，duodenum，and mesenteric lymph nodes in both oral delivery group and control group.The stronger persistence of E120413 organisms in the mesenteric lymph nodes (≥11 weeks) may result from the environment，which was less hostile than that in any other organs of pig based on tissue specificity.But，no obvious signs of disease and serious pathological changes were observed in these two groups of pigs during the entire experimental period.In conclusion，we have shown that the NDM-1-Producing Escherichia coli E120413 strain has the stronger transmissibility and ability to cause persistent infection in pigs.

As a kind of external environment receptor，phoP/phoQ is involved in regulating bacterial adaptability to external environment.The aim of this study was to investigate the effect of phoP/Q two-component system to biological characteristics of avian pathogenic Escherichia coli (APEC) such as growth，engraftment，and virulence.The phoP-phoQ deletion mutant strain was constructed by homologous recombination assay，and the complement strain was constructed through transformation deletion strain with the plasmid complement.The growth curve determination and motility assay，the adhesion and invasion to chicken embryo fibroblast (CEF)，detection of virulence gene transcription and median lethal dose (LD₅₀) experimental were used to compare biological characteristics of wild strain，deletion strain and complement strain.Compared with the wild strain，the growth characteristics of the mutant strain did not change；the motility of the mutant strain felled by 63% comparing with wild strain；its ability of adhesion and invasion to DEF cells respectively decreased to 69.83% and 62.17%；and LD₅₀ was significantly reduced by 13.3 times.The transcription of polA，tsh respectively increased by 41% and 54%，while the sodA and iss decreased by 64% and 98%.The phoP/Q two-component system is involved in the regulation of the APEC pathogenic，and its deletion can reduce the pathogenicity of APEC.

We investigated the infection of Giardia duodenalis in dairy cattle from an imported farm，and then we analyzed the distribution of the genotypes and assemblage of G.duodenalis.The detection of G.duodenalis in dairy cattle base on the locus of SSU rRNA，tpi，gdh and bg by PCR. Results indicated that the prevalence of G.duodenalis in dairy cattle is 9.8% (48/507) based on SSU rRNA by PCR，and 48 positive samples were identified assemblage E.The prevalence of G.duodenalis in post-weaning calves was the highest (20.70%)，the difference of the prevalence of G.duodenalis in cattle in different ages was significant.The 48 positive samples were amplified 19，28 and 34 base on tpi，gdh and bg locus respectively，one sample was mixed infection (assemblage A and assemblage E).Multilocus sequence and phylogenetic analysis indicated that G.duodenalis infecting dairy cattle from an imported farm may be from the local area. The results indicate that imported adult dairy cattle is not ease to carry Zoonotic G.duodenalis，dairy cattle from an imported farm have a lower risk to transmite Zoonotic G.duodenalis.

The objective of this study was to examine the fitness cost of a multidrug plasmid pHN7A8 carrying bla_CTX-M-65，rmtB，and fosA3.Plasmid pHN7A8 carrying bla_CTX-M-65，rmtB，and fosA3 from E.coli 7A8 was transferred into E.coli JM109 by electroporation.Transformant 7A8JT containing pHN7A8 was obtained.Growth curve and growth competition experiments were performed to assess the fitness cost of pHN7A8 upon its host.Growth curve showed no significant difference between the transformant carrying pHN7A8 and sensitive recipient E.coli JM109.Competition experiments between E.coli JM109 strain and transformant 7A8JT revealed a competitive advantage for the transformant versus the recipient.The results showed that no fitness cost was observed for plasmid pHN7A8.More attention should be taken into account the effect of the clinical use of antibiotics on the selection of multidrug resistance encoding plasmids.

The objectives of this study were to investigate resistance，virulence genes and resistance genes of Escherichia coli isolated from dairy cow mastitis in Ningxia.The antimicrobial resistance of 197 Escherichia coli from dairy cow mastitis cases to 16 drugs was determined by the methods of K-B and the virulence genes and resistance genes were detected by PCR.The results showed that the resistance rate of ampicillin was the highest and it achieved 54.69%.Furthermore，the resistance rates of doxycycline，tetracycline and streptomycin were about 39%.It was more sensitive to cephazolin，cefotaxime，polymyxin，florfenicol，quinolones，and the sensitive rates were above 60%.The results of genes detection showed that the detection rates of virulence genes astA，escV，eaeA，sepA，hlyA were 20.30%，14.72%，8.12%，2.03% and 1.02% respectively.The virulence genes sta and stx2e were not detected.Tetracycline resistant genes were detected and the detection rate of tetC was 24.87%.The detection rate of fluoroquinolone resistance genes GyrA，GyrB and ParC were 97.46%，98.98% and 98.48%，respectively.Our study demonstrates Escherichia coli isolates from dairy cow mastitis in Ningxia carrying virulence genes astA，eaeA，sepA，escV，hlyA and the genes mediate resistance to tetracyclines，fluoroquinolones，and those isolates have varying degrees of resistance 16 kinds of antibacterial drugs，and some isolates are multi-resistant strains.

Small RNA (miRNA) is a class of endogenous，single strand，small non-coding RNAs，which is recently discovered.Its regulation in the process of immune defense in mammary tissue gradually attracted people’s attention.Expression changes of inflammation-related miRNAs have been detected in mouse mammary epithelial cells when inflammation reaction induced with LPS occurred with qRT-PCR；we have also constructed 3 kinds of miR-223 eukaryotic expression vectors and tested recombinant vectors transfection efficiency.Mouse mammary epithelial cells (EpH4-Ev cells) have been incubated with different dose of LPS for 48 h，then，expressions of miR-223，miR-146a，miR-181a and miR-155 have been detected with qRT-PCR.Genomic DNA of EpH4-Ev cells were used as a template and pre-miR-223 cDNA sequence was amplificated with PCR.PCR product was combined with Minicircle，pcDNA3.1(+) and piggyBac transposon，separately，to construct three kinds of miR-223 eukaryotic expression vectors.Three kinds of recombined vectors were transfected into EpH4-Ev cells，respectively.Expression of miR-223 was measured and green fluorescence was observed in order to evaluate transfection efficiency of recombinant plasmid.qRT-PCR results showed that expression of 4 kinds of inflammation-related in EpH4-Ev cells significantly increased when inflammation induced by LPS (P<0.05 or P<0.01)，and the expression change was in a dose-dependent manner.qRT-PCR results showed that the expression level of miR-223 had no significant change (P>0.05) when Mini-miR-223 plasmid transfected into the EpH4-Ev cells，while the expression of miR-223 significantly increased when PB-miR-223 and pcDNA-miR-223 transfected EpH4-Ev cells (P<0.001).Inflammation-related miRNAs have been showed involved in the process of inflammation induced by LPS in mouse EpH4-Ev cells.Three kinds of miR-223 eukaryotic expression vectors have been constructed successfully，and may contribute to further research of the modulation significance of miRNAs in the mammary gland immune reaction.

To understand the differences in metabolic changes between cows with ovarian inactivity and estrus cows，we selected cows at 60-90 d postpartum，which had similar age，parity，body condition score and milk yield.According to clinical manifestations，B-ultrasound scan，rectal examination and hormone tests，10 cows were assigned to the estrus group (A) and 10 to the ovarian inactivity group (B).All plasma samples were analyzed by ¹H NMR spectroscopy to compare plasma metabolomic profiles between the groups.We used multivariate pattern recognition，to screen for different metabolites in plasma of anestrus cows.Compared with normal estrous cows，there were abnormalities in 12 kinds of metabolites in postpartum cows with ovarian inactivity，including an increase in acetic acid，citric acid and tyrosine，and a decrease in low-density lipoprotein，very low density lipoprotein，lipids，alanine，pyruvate，creatine，choline，phosphorylcholine and glycerophosphorylcholine.These metabolites were closely related to abnormality of glucose，amino acid，lipoprotein and choline metabolism，which may disturb the normal estrus.The decrease in plasma creatine and the increase in tyrosine were new changes for ovarian inactivity of postpartum cows.In conclusion，a variety of metabolic disorders indicate that ovarian inactivity is related to negative energy balance in early lactation，and has the risk of ketosis and fatty liver.The decrease of creatine and choline concentration and increase of p-hydroxyphenylalanine concentration in cows with ovarian inactivity provide a new direction for research on the mechanism of ovarian inactivity in cows.

In postpartum，cows often suffer from negative energy balance，resulting in physical dysfunction.The aim of this study was to define the physiological mechanism of cows exercising metabolic energy shortage after calving.¹H-NMR technology was used for measurement of metabolites.Results were analyzed in multivariate statistical methods to find out the trend of plasma metabolites changing after calving and the influence on energy metabolism pathway.Results showed that：the biomarkers profile of plasma was not significantly different in Day 7 from Day 1 after calving；but a significant difference were found between Day 14 and Day 1 after calving.The biomarkers are unsaturated fatty acid，choline and trimethylamine oxide；There were significant differences in biomarkers profile between Day 28 and Day 1 after calving with different markers of unsaturated fatty acid，choline，trimethylamine oxide，citric acid and glucose.After calving，unsaturated fatty acid，choline and tricarboxylic acid expression gradually increased，whereas trimethylamine oxide and glucose expression gradually decreased.With the increasing lactating yield after calving，cows showed a negative energy balance.In response，the lipolysis and fatty acid oxidation，the oxidation of choline，re-methylation methionine and methyl metabolic pathways were increased，relieving the negative energy balance.This study could provide a scientific basis for the physiological mechanism of the negative energy balance after calving for dairy cows.

In order to more effectively apply CRISPR-Cas9 in researches on gene functions and transgenetic animals，we transfected the PK15 cell line with the CRISPR-Cas9 system containing GFP and Myostatin.Positive cells were separated and collected by flow cytometry.Point mutations were detected and analyzed by PCR and DNA sequencing.The results showed that，among 100 randomly-selected positive clones，the mutation rate was 38%，including 32 insertions and 6 deletions.Mutant 1(one of the insertions) had the highest frequency(47.4%).In this experiment，the mutation rate of CRISPR-Cas9 system is 38% and certain mutation type bias is observed.