Long noncoding RNA are a group of endogenous RNA molecules which exceed 200 nt in length，lack complete specific open reading frame，they don’t have the ability to encode proteins.But recent studies have shown that lncRNA participates in many important physiological processes，such as gene imprinting，X chromosome inactivation，and so on.They regulate gene expression mainly through the DNA methylation，Histone modification，chromatin remodeling.At the same time，lncRNA have important effect on the occurrence and development process of disease，and have very important significance to the diagnosis and treatment of disease.Therefore，this article analyzed the biological characteristics of lncRNA，lncRNA in epigenetic，transcriptional level post-transcriptional level，the role in stem cell and the research of the disease，elaborated the research progress of the current lncRNA，provided a reference for further study on the mechanism of lncRNA involved in the regulation of physiological processes.

Content of body fat in domestic livestocks and poultry determines the meat quality.Adipocyte differentiation is a complex biological process regulated by many factors.Understanding the adipose differentiation-related signaling pathways and their miRNA regulations can reveal the molecular mechanisms of adipocyte differentiation.Based on introduction to the 6 important signaling pathways regulating adipocyte differentiation，biological functions and mechanisms of 8 miRNAs for promoting and another 8 miRNAs for inhibiting adipocyte differentiation were discussed.The function of target genes of these miRNAs in adipogenesis was summarized.Studies on the related miRNAs and their target genes provide theoretical bases for genetic improvement of meat quality traits in domestic livestocks and poultry.

Influenza virus is an important respiratory pathogen，which can bring endemic infection in people every year，and can cause worldwide pandemic due to its easy variation of antigenicity.Influenza viruses can also spread in a variety of animal populations，transmit occasionally from animal species to the humans and spread in the population，resulting in potential threats to human health under certain conditions.Host innate immune response，especially early interferon response is the body’s first defense barrier against viral infections.Viruses must breakthrough that barrier in order to successfully infect the host.To fight viral infections，the host cells use a range of sophisticated anti-viral strategies：the cells firstly use pattern recognition receptor to recognize viral products，and then activate signaling cascades，leading to a range of interferon and other cytokines；downstream effector molecules are induced by interferons and inhibit viral replication；the activated cytokines contribute to adapted immune response.In the process of co-evolution with the host，influenza virus also develops perfect antagonist strategies to host interferon pathway，which help virus infect the host and spread efficiently in host cell.In recent years，the studies on how virus induces and modulates host innate immune response have made rapid development，and a large study found that the virus can utilize a variety of strategies to evade host antiviral response.Therefore，this review focuses on how influenza virus antagonizes host interferon production and evades cellular antiviral response，which will be contributed to uncover the pathogenicity mechanisms of influenza virus and reveal novel antiviral targets for the prevention and control of influenza infection.

This research aimed to investigate the potential target genes related to adipose tissue development.The bioinformatics softwares were used to predict the target gene of ssc-miR-135a-5p，and it was found that the 3′ UTR of adenomatous polyposis coli (APC) gene had 2 putative binding sites with miR-135a-5p.The wild-type (APC 3′ UTR) and 3 mutated (APC 3′ UTR m1，APC 3′ UTR m2 and APC 3′ UTR m3) dual-luciferase vectors were constructed and then co-transfected into PK-15 cells with miR-135a-5p mimics or negative control (NC)，respectively，and then the luciferase activity was detected.The results showed that miR-135a-5p mimics significantly decreased the luciferase activities of APC 3′ UTR and APC 3′ UTR m2 vectors (P<0.05)，while APC 3′ UTR m1 and APC 3′ UTR m3 completely abolished the inhibitory effects of miR-135a-5p，which demonstrated that miR-135a-5p mainly binded with the first site in 3′ UTR of APC gene.Further analysis revealed that miR-135a-5p inhibited the levels of endogenous APC mRNA and protein in porcine preadipocytes，which indicate that the target gene of ssc-miR-135a-5p is APC gene and regulates its expression.Taken together，this study will provide new insight into the biological function of ssc-miR-135a-5p and its mechanism in regulating adipogenesis.

In order to study the association of AA-NAT gene and year-round estrus in sheep，year-round estrous Small Tail Han ewes and seasonal estrous Tan ewes were selected as tested subjects.Real-time PCR method was used to detect AA-NAT mRNA expression in hypothalamus，pituitary gland，pineal gland，ovary，uterus body and adrenal gland at different estrus stages.The results showed that the expression of AA-NAT gene in all 6 tissues at different estrous stages of the 2 breeds was significantly different.The expression of AA-NAT gene was at high level in ovary，uterus body and pineal gland in sheep at estrus.In ovary and uterus body， AA-NAT gene expression was significantly lower (P<0.01) in Small Tail Han sheep at spring and fall estrus stage than that in Tan sheep at fall estrus stage，but in pineal gland it was significantly higher (P<0.01).The results preminarily indicated that the up-regulated expression of AA-NAT gene in ovary，uterus body and pineal gland was associated with year-round estrus in Small Tail Han sheep.

The aim of this study was to find and map novel genes related to lambing number in goat by genome-wide association study(GWAS).A total of 302 Yunnan Black goats from 6 families were genotyped by Illumina Goat60K iSelect array.The GWAS on goat lambing number was performed.The Results showed that 2 SNPs located at the downstream of SLC4A10 and upstream of TBR1 on chromosome 2 were significantly associated with lambing number (P<1.48E-6) at 5% genome-wide level.Five SNPs were suggestive associated with lambing number (P<2.97E-5).These 5 SNPs were located on chromosome 1，21，28，respectively，including SENP7，Hypothetical Protein，WDFY4，TMEM26 and BICC1 genes.These genes and SNPs offer essential information for understanding the molecular mechanisms of lambing number and provide foundation for the application of marker-assisted selection in breeding program of goat.

The aim of this study was to construct IGF2 expression vector with efficient and specific promoter and study its effects on bovine skeletal muscle satellite cell proliferation.The 3 eukaryotic expression vectors containing IGF2 and muscle-specific promoter were transfected into bovine skeletal muscle satellite cells and fetal fibroblasts，the relative expression of IGF2 was detected by RT-PCR to screen efficient and specific vector.EdU experiments were carried out and RT-PCR was used to detect the cell cycle-related genes.The different promoter （desminpro，CMV-MyoGpro and MyoGpro-double） IGF2 expression vectors were constructed successfully.The test results of RT-PCR showed that pGL3-desminpro-IGF2 was an efficient and specific vector.The vector transfected into cultured cell in vitro increased the speed of cell proliferation and up-regulated the expression of cell cycle-related genes，CDK6 and IGF2.The result has laid an important foundation for the production of transgenic bovine.

The epidermal type fatty acid binding protein (FABP5) and testicular fatty acid binding protein (FABP9) genes of yak were sequenced，and their expressions as well as activities of some enzymes related to energy metabolism in the testes were compared between yak and sterile F1 males (male cattle × female yak)，aiming to explore the association between the two genes and energy metabolism with the sterility of F1 males.Total RNA was extracted from yak testes and the cDNA sequences of FABP5 and FABP9 genes were obtained using conventional PCR methods.The coding region of yak FABP5 and FABP9 genes were 408 and 399 bp，respectively，and showed 1 and 6 nucleotide differences compared with those of cattle，respectively，the latter caused 5 amino acid substitutions in the deduced amino acid sequences.Real-time quantitative PCR analysis showed that the expression of FABP5 gene in the sterile F1 testes was significantly greater than yak，but not for FABP9 gene.Isocitrate dehydrogenase activity in sterile F1 testes was significantly higher than yak (P<0.01)，while β-hydroxyacyl CoA dehydrogenase and lactate dehydrogenase activities were similar in the testes of yak and sterile F1 males.The up-regulated expression of FABP5 gene and the increased activity of isocitrate dehydrogenase involved in citric acid cycle in the sterile F1 testes may indicate that the level of fatty acid oxidation for energy is higher in the testes of sterile F1 males than adult yak.

In order to explore the molecular genetic mechanism of fur color formation between chinchilla rex rabbits and white rex rabbits.The experiments were divided into 3 groups，every group contained one chinchilla rex rabbit and one white rex rabbit，which came from full-sib family.The Agilent’s rabbit gene expression microarray was used to determine the differentially expression genes between different fur color groups of rex rabbits，and the expression patterns of selected differentially expressed genes were further identified by quantitative real-time PCR.The results showed that 545，1 680 and 2 092 differentially expressed genes associated with fur color of rex rabbits were screened out from 3 groups of chinchilla rex rabbits and white rex rabbits，respectively.A total of 172 mutual genes were found among these 3 rex rabbits groups.GO (Gene Ontology) analysis results revealed that the differentially expressed genes were related to cell differentiation，proliferation，apoptosis，growth，ionic transport altered and immune response，etc.The quantitative real-time PCR showed gene expression trend of Creb1，Wnt2，Gnaq and Gna14 genes was consistent with that of gene expression microarray data，indicating that the result of gene chip was reliable.Combined with bioinformatic analysis and related literatures，some genes were potentially related to fur color formation，such as Creb1，TH，Wnt2，Gnaq，Dvl1，Mapk12，and so on.

 The objectives of present study were to investigate whether two key genes of enzymes for melatonin biosynthesis，arylalkylamine N-acetyltransferase (AANAT) and hydroxyindole-O-methyltransferase (HIOMT)，and melatonin receptor MT1 were expressed in thyroid gland in sheep，and whether melatonin could be independently synthesized and secreted in the gland.The expression of AANAT，HIOMT and MT1 was firstly detected by using RT-PCR，and was then confirmed by immunofluorescenct histochemical assay in tissues of thyroid gland of sheep.The specificity of cultured primary thyroid gland cells was characterised by immunofluorescenct cytochemical assay.The synthesis and secretion of melatonin in sheep thyroid gland cells were analysed using ELISA.The results showed that AANAT， HIOMT and MT1 mRNAs were expressed in sheep thyroid tissue.Immunofluorescence assays confirmed that HIOMT and MT1 protein were localized on follicular cells in thyroid gland.Meanwhile，ELISA assay demonstrated that the thyroid gland of sheep could synthesize and secret melatonin autonomously.The present study evidenced，for the first time，that the melatonin synthesizing enzymes and melatonin receptor were presented in the thyroid tissue，and thyroid gland was able to synthesize and secret melatonin autonomously in sheep.The data provided new evidence for a putative novel intrathyroidal regulatory pathway that melatonin might be involved in thyroid-hormone synthesis.

The aim of present study was to investigate the effects of mitochondrial transplant (MIT) on the developmental potential of buffalo oocytes.The mitochondrial DNA (mtDNA) copy number in the oocyte，and the developmental competence，exogenous mitochondria distribution，as well as mitochondrial membrane potential (ΔΨm) in the preimplantation embryos after the MIT were examined.The result showed that the average mtDNA copy number of buffalo oocytes in the first level of oocytes was evidently higher than the second and the third level of oocytes (（202 101±74 432） vs （118 483±17 028），（39 177±7 938），P＜0.01），and the average mtDNA copy number in the second level of oocytes was significantly higher than that of the third level of oocytes (（118 483±17 028） vs （39 177±7 938），P<0.01).Furthermore，the cleavage rates and blastocyst rates of the first level of oocytes were significantly higher than those of the second and the third level of oocytes after parthenogenetic activation (P<0.01)，and the cleavage rates and blastocyst rates of the second level of oocytes were remarkably higher than those of the third level of oocytes (P<0.01).The exogenetic mitochondria labeled with Mito-Tracker fluorescent probe distributed into each of blastomeres with the embryonic development after MIT.Moreover，more the second level of oocytes that received MIT developed to the blastocyst stage after parthenogenetic activation in comparison with oocytes that did not received MIT or were injected with solution (27.3% vs 17.4%，7.84%，P<0.05)，however，there were no significant difference in the blastocyst rates of the third level of oocytes than the control group and the nothing injection group after MIT.The ΔΨm of buffalo preimplantation embryo presented an increased trend during embryonic development，and the ΔΨm of embryo derived from MIT group was significantly higher than that of the control group (P<0.05).These results showed that the mtDNA copy numbers in different quality buffalo oocytes have significant differences，and the mtDNA copy numbers of buffalo oocytes are positively related with the quality of oocytes and their developmental potential，and the developmental ability of the second level of oocytes can be improve by MIT.

The purpose of this research was to investigate the effect of glucagon-like peptide-2(GLP-2) and lipopolysaccharide (LPS) on the gene expression of tight junction in piglets jejunum epithelial IPEC-J2 cells and to deeply discuss the possible mechanism of GLP-2 regulating the expression of intestinal TJ gene of the piglet.Trial 1，single factor design was adopted and 4 treatments(control，GLP-2，LPS，LPS+GLP-2) were used to test the effect of GLP-2 and LPS on the mRNA expression of Occludin，Claudin-1 and ZO-1 in IPEC-J2 cells.The results showed that：100 nmol•L^-1 GLP-2 could improve cellular morphology and significantly increase the expression level of Occludin，Claudin-1 and ZO-1 mRNA in IPEC-J2 cell (P<0.01)；100 μg•mL^-1  LPS could significantly destroy cellular morphology and significantly reduce the mRNA expression of TJ in IPEC-J2 cells (P<0.01).LPS with 100 nmol•L^-1 GLP-2 could improve cellular morphology and significantly increase the expression of Occludin，Claudin-1 and ZO-1 mRNA in IPEC-J2 cell (P<0.01) for 46.3%，65.1% and 30.3%，respectively.Trial 2，PI3K specific inhibitor，Wortmannin (Wort) and LY294002 (LY)，were added to investigate whether GLP-2 modulates TJ’s mRNA expression in IPEC-J2 cells through PI3K-Akt-mTOR signal transduction pathway.Four treatments(control，GLP-2，GLP-2+Wort，GLP-2+LY) were designed.The results showed that：100 nmol•L^-1 GLP-2 with 10 nmol•L^-1 Wort could significantly decrease the expression of Akt，mTOR，Occludin，Claudin-1 and ZO-1 mRNA in IPEC-J2 cells (P<0.01) for 46.9%，50.5%，38.1%，49.6% and 18.9%，respectively；GLP-2 with LY could significantly decrease the expression of Akt，mTOR，Occludin，Claudin-1 and ZO-1 mRNA in IPEC-J2 cells (P<0.01) for 67.2%，70.8%，49.6%，60.9% and 25.8%，respectively.In summary，the results showed that GLP-2 can effectively inhibit the damnification of TJ mRNA expression by LPS.GLP-2 may modulate TJ’s mRNA expression through PI3K-Akt-mTOR signal transduction pathway in IPEC-J2 cells.

To investigate whether pattern recognition receptor RIG-I has antiviral role against foot-and-mouth disease virus (FMDV)，we extracted porcine cellular RNA from PK15 cells，and the complete CDS region of RIG-I was obtained by using two-segmental amplification and fusion PCR methods.Subsequently，the eukaryotic expressing plasmid was constructed.The expression of the plasmid was confirmed by Western blotting and indirect fluorescence assay (IFA)，which showed RIG-I was successfully expressed.The IFA result indicated porcine RIG-I protein was located in the cellular cytoplasm.The results of infection assay suggested that FMDV infection induced the upregulation of RIG-I expression，which implied the potential connection between RIG-I and FMDV.Over-expression assay confirmed that RIG-I inhibited FMDV replication，and downregulation of RIG-I significantly promoted FMDV replication.These results indicated that RIG-I had antiviral effect against FMDV.In conclusion，this study provided references for further research on antiviral mechanism of RIG-I against FMDV.It also paves ways for the research of antiviral mechanism of innate immune system after FMDV infection.

In order to study the influence of the 3′-U3 region with regular mutations of epidemic J subgroup avian leukosis virus (ALV-J) strains isolated from egg-type flocks on its replication capacity in vitro，a full-length cDNA clone was constructed based on ALV-J prototype HPRS-103 strain infectious clone via replacing its 3′-U3 region by the corresponding part of egg-type isolate SD09DP04.Both the constructed chimeric infectious clone and the HPRS-103 infectious clone were transfected into DF1 cells by lipofectamine 2000，respectively.The two infectious clones were passaged to another generation.And the harvested viruses were respectively confirmed by indirect immunofluorescence (IFA)，ALV-antigen test kit and reverse transcriptase activity test kit.Analyzing the 3′-U3 region’s promoter activity or enhancer activity and TCID₅₀ growth curves showed that such U3 region with regular mutations had no evident effect on the virus’s replication capacity in vitro.The successful rescue of the chimeric virus plays the basic role in further exploration of the functions and the significance of the regular mutations in the 3′-U3 region in the epidemic ALV-J strains in recent years.

 To clarify the epidemiology of infectious bronchitis virus (IBV) in Shandong province，the antigenic difference among field isolates and vaccine strains was studied.The monovalent antisera against 3 commercial IBV vaccine strains (H120，Ma5 and 4/91) and 18 field isolates were prepared in SPF chickens.The cross viral neutralization (VN) test was performed in SPF chicken embryos to determine the endpoint titers for homologous and heterologous neutralization.The serotype of IBV strains was determined based on antigenic relatedness values (ARV) calculated by the formula R=r1×r2.As a result，vaccine strain 4/91 was belong to serotype I.Vaccine strain H120，Ma5 and two isolates （SDWF0608 and SDLY0701）were grouped in the same serotype.SDZB0808 and the other 15 isolates were grouped in the same serotype.CK/CH/SD09/006 and CK/CH/SD10/001 were in 2 other different serotypes，together with other 3 or 6 IBV isolates，respectively.Moreover，some IBV strains showed one-way neutralizing reaction with others and some IBV strains in the same serotype had different ARVs.The resultes indicate that the antigenicity of IBV strains is very complicated and there are evident antigenic difference between IBV isolates and 3 vaccine strains.

A variety of proteins are released during protozoan parasites invasion and growth in the host cell.Dense Granule protein is one of the key proteins which form and modify the parasitophorous vacuolar (PV).GRA6 gene was cloned from Neospora caninum genomic DNA.We constructed prokaryotic expression vector pGEX-GRA6 and eukaryotic expression vector pcDNA-GRA6.The protein was purified and immunized BALB/c mice to obtained high titer of serum.Results of indirect immunofluorescence (IFA) showed that GRA6 located at parasitophorous vacuolar network structure (PVN).BALB/c mice were immunized with recombinant protein or eukaryotic expression vector and challenged with Neospora caninum (2×10⁶).We monitored clinical symptoms and detected antibody levels of mice before each immunization.Thirty days after infection，brain burden of Neospora caninum was detected by RT-PCR.There were significant difference between immunization groups and control group (P<0.05)，which indicated that NcGRA6 had good immunoprotection for mice in both recombinant protein and eukaryotic expression vector.

The aim of this study was to clone 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) gene in Eimeria tenella，and analyze its enzymatic activity.The predicted sequences of Etdxr were obtained from EuPathDB by bioinformatics analysis.The full-length cDNA was amplified by PCR and then cloned into pCold I vector.The recombinant plasmid was transformed into E.coli Rosetta (DE3) and induced by IPTG.The expression products were analyzed by SDS-PAGE and Western blot，and then were purified.We further evaluated the enzymatic activity of EtDXR by monitoring the consumption of NADPH.The results showed that the open reading frame of E.tenella DXR was 1 746 bp.Further analysis of the amino acid sequence revealed that EtDXR contains the conserved domains with other DXRs.The results showed that the recombinant vector pCold I-EtDXR was constructed successfully.The SDS-PAGE and Western blot results showed that the purified protein was 50 kDa.The characterizations of reaction conditions used in the experiments，such as pH and ion concentration have significant effects on the enzymatic activity of rEtDXR.According to the response surface plots，the maximum enzymatic activity was pH 7.0 and 4.5 mmol•L^-1 Mg²⁺.This study provides a foundation for the further study to select inhibitors of E.tenella DXR.

This experiment was conducted to prepare the virus-like particles containing the partial gene fragment of African horse sickness virus (AHSV).Genome segment 7 (S7) encoding protein VP7，the group-specific protein of AHSV，is a primary target for reverse transcription-PCR and real time reverse transcription-PCR detection of AHSV.The conservative sequence of S7 gene was synthesized and cloned into plasmid pNH-MS2his，which contained the coat protein gene of E.coli bacteriophage MS2 and His tag，to construct the prokaryotic express vector pNH-MS2his-VP7.The recombinant plasmid pNH-MS2his-VP7 was transformed into BL21 (DE3).Expression of the target protein was induced by IPTG for 5 h.The virus-like particles containing the S7 RNA sequence of AHSV were simply obtained by induction and sequent Ni+ chromatography purification.The virus-like particles were confirmed have good uniformity and stability.They have great prospect as the standard and quality control in the detection of AHSV.

The aim of the present study was to investigate if the changes of inflammatory cytokines (interleukin 1，interleukin 6，interleukin 8，tumor necrosis factor alpha) and tracheal washing liquid and trachea mucosal secretory immunglobulin A (SIgA) can be used as judgments or warning indicators of respiratory diseases.We established a respiratory diseases model by infecting SPF chickens with Newcastle disease LaSota live vaccine and low pathogenic influenza virus (H9N2) single or mixed.Inflammatory factors of serum and SIgA were measured by double antibody sandwich ELISA method to analyze the inner relationship between the quantity changes and respiratory diseases.The results showed that SPF chickens appeared respiratory symptoms after inoculating LaSota vaccine and H9N2 AIV，content of inflammatory factors and mucosal antibody became significantly higher than those in control group，the changes of five cytokines content induced by two viral infection had obvious differences with time going，inflammation mediums became roughly same while the content in serum were less than in washing liquid.Pathological changes of chicken respiratory tract infection were closely related to the changing process of five inflammatory factors.With the help of detection of inflammatory factors，especially the IL-8，the severity of respiratory tract inflammation could be identified，so the detection of its content would have important reference value for the judgment of respiratory illness and early warning.

In order to obtain active pig liver carboxylesterase 1 (PLE1) and study its function，PLE1 were obtained by RT-PCR and normal PCR from large white pig liver. PLE1 ORF was linked into the prokaryotic expression vector pET15b，and was functional expressed in E.coli Origami^TM 2(DE3) cells which were transformed ahead with pGro7.The target protein was purified and its enzyme activity was tested.The sequencing results showed that total length of PLE1 ORF is 1 686 bp，which coding 562 aa.The SDS-PAGE and Western Blotting results demonstrated that recombinant protein PLE1 was expressed successfully，and the highest amount was acquired after culture in 30 ℃ for 6 h，and most of the protein is soluble，and the recombinant PLE1 hydrolysis activity for p-NPA is 1.24 U.The research results not only provide high purity active PLE1 for the study of PLE1 hydrolysis of veterinary medicine，but also provide the theory basis，technical methods for the function study of other important PLE isoenzymes.

Myeloid differentiation factor 88 (MyD88)，an important adaptor protein in TLRs/IL-1R signaling pathways，plays an important role in immune response and disease prevention.This study intends to obtain pig small intestinal epithelial cells in which MyD88 gene is silent mediated by lentiviru，as an effective model for analyzing molecular mechanism of intestinal disease caused by pathogenic bacteria.In this study，four plasmid expression vectors were constructed，which coded shRNAs against pig MyD88 gene，and the over-expression vector coding MyD88 gene was also constructed.By the method of real-time fluorescent quantitative PCR，the level of MyD88 gene in the cotransfected 293 cells was detected.The highest efficiency vector was adopted and packaged into lentiviral vector to obtain pig small intestinal epithelial cells with silent MyD88 gene.The IPEC-J2 cell was obtained in which the MyD88 mRNA expression was reduced by 69.3%，meeting the requirement for gene function analysis.The obtained pig intestinal epithelial cell with stable MyD88 gene silencing provides important material for mechanism research of TLRs/IL-1R signal pathway caused by pathogenic microorganisms in pig intestines.

The experiment was carried out to investigate the effect of acidifiers with different levels in the same basal diet on intestinal villus morphology，nutrient digestibility and N，P excretion in growing mink.One hundred black male minks were randomly allotted into 10 treatment groups.Every group consisted of 10 minks.The control was fed conventional fresh diet，the testing groups were added acidifier，phosphoric acid 0.4%(Ⅱ)，0.6% (Ⅲ) and 0.8%(Ⅳ)，citric acid 0.5%(Ⅴ)，1.0%(Ⅵ) and 1.5%(Ⅶ)，lactic acid 0.5%(Ⅷ)，1.0%(Ⅸ) and 1.5%(Ⅹ)，respectively.The results indicated that there were no significantly difference (P＞0.05) in the DMI and digestibility of DM，CP and Ca among groups，but there were clearly increasing tendencies for these with acidifiers adding.The EE digestibility in groupⅠ and Ⅳ were significantly higher than that in group Ⅴ，Ⅸ，Ⅹ（P＜0.05）.The P digestibility in group Ⅷ and Ⅸ were higher than that in other groups(P＜0.01)，and Ⅸ group was the best.The height of intestinal villus was similar(P >0.05) among groups，and Ⅷ group was the highest，it was 145.8% and 120.3% compared to group Ⅲ and Ⅰ.The average surface area of intestinal villus had not significantly different(P＞0.05) among groups，however，it in Ⅷ group were 160.24% and 131.77% respectively to group Ⅲ and Ⅰ.There were no significantly different (P＞0.05) in the density of intestinal villus；The N excrention was similar(P>0.05) among groups and the decrease tendencies with acidifiers addition was clearly，the group Ⅰ was higher 34.02% than group Ⅷ.The quantity of P excrention was significantly different (P＜0.001)，group Ⅷ was the lowest and fewer 57.33% than group Ⅰ.The results showed that it can significantly improve the activity of nutrient digestion and intestinal villus morphology and decrease N，P excretion，by adding 0.5% of lactic acid during hair growth period in mink diets.

The aim of this study was to prepare antiserum against the goose CD8α protein.Specific primers for goose CD8α gene were designed according to public Mallard duck reference sequence (AF378373) in GenBank.Then Northeast White Goose CD8α gene was cloned by RT-PCR successfully.According to goose CD8α ORF sequence，specific primers were further designed and goose CD8α extracellular region was cloned.The recombinant goose CD8α extracellular region protein was expressed in prokaryotic expression system，pET-30a(+) and pET-28a(+) /Rosetta(DE3)pLysS.The recombinant protein was induced by IPTG and was purified by Ni-NTA column affinity chromatography.As immunogen，the purified recombinant protein stimulated the rabbit to produced anti-goose CD8α extracellular region serum.I-ELISA，Western blot analysis showed that antiserum could identify recombinant goose CD8α extracellular region protein and peripheral blood T lymphocytes respectively.Indirect immunofluorescence test confirmed that the purified antiserum could identify goose CD8α extracellular protein expressed by eukaryotic expression system specifically.The laser confocal scanning microscope had observed the fluorescence signal on the cell membrane.The above results show that antiserum can be used as detection reagent to detect the goose CD8⁺ T lymphocytes.