The fatty acid binding protein 5 (FABP5) is an intracellular lipid carrier. The TG GPO-POD assay kit and BODIPY staining methods were used to detect lipid secretion and triglyceride content,and the effect of FABP5 on SREBP-1c expression were detected by Real-time PCR and Western blotting methods. The results showed that high purity bovine mammary epithelial cells (BMECs) were successfully isolated and purified,and the eukaryotic expression vector pGCMV-IRES-EGFP-FABP5 was constructed in this experiment. Compared with the blank control group and empty vector group,the lipid secretion and triglyceride content, and the expression of SREBP-1c and FAS,ACC were extremely significantly increased when the FABP5 was overexpressed (P<0.01). FABP5 siRNA1 was selected as the optimal interference fragment, and when FABP5 was inhibited,the lipid secretion and triglyceride content,the expression of SREBP-1c,FAS and ACC were extremely significantly decreased (P<0.01).The results indicated that FABP5 could promote the synthesis of milk fat in BMEC by up-regulating the expression of SREBP-1c.

The study was aimed to investigate prevalence of Orf virus (ORFV) in Jiangsu province in recent years and control Orf better. A total of 121 tissue samples were collected in some farms from 2013 to 2015 and subjected to PCR detection, viral isolation and phylogenetic analysis of B2L gene. Four samples were ORFV positive by PCR. The viruses were isolated by passaging in ovine fetal turbinate (OFTu) cells and MDBK cells, and were named as ORFV/Ovis/XZ/Jiangsu/2015/China, ORFV1/Ovis/DT/Jiangsu/2015/China, ORFV2/Ovis/DT/Jiangsu/2015/China and ORFV/Ovis/SL/Jiangsu/2015/China,respectively. The B2L gene was amplified and sequenced for the phylogenetic study. The nucleotide homology of these 4 strains was 98.5% to 100.0%. ORFV/Ovis/XZ/Jiangsu/2015/China, ORFV1/Ovis/DT/Jiangsu/2015/China and ORFV2/Ovis/DT/Jiangsu/2015/China, gathered into a cluster with SC-JY, GX-YB, JS-FX isolates and the nucleic acid homology of these strains was 97.8% to 100%. ORFV/Ovis/SL/Jiangsu/2015/China gathered into a cluster with LiaoNing, HuB and Gansu isolates, the nucleic acid homology was 98.8% to 98.9%. The nucleic acid homologies of 4 strains and ORFV strain China vaccine was 96.8% to 98.1%. The result showed that the ORFVs in Jiangsu province might be from different source. For controlling the spreading of this virus, it was necessary to carry out deep epidemiological survey in Jiangsu province.

MUC4 and MUC13 genes as important candidate genes for enterotoxigenic Escherichia coil (ETEC) F4 resistance,may play an important role in the process of against ETEC F18 infection in weaned piglets. In this study,ETEC F18-resistant and -sensitive weaned Meishan piglets were used,and the expression levels of MUC4 and MUC13 genes in 11 tissues (heart,liver,spleen,lung,kidney,stomach,muscle,thymus,lymph nodes,duodenum and jejunum) were determined by quantitative Real-time PCR. The results showed that MUC4 and MUC13 genes were broadly expressed with different expression levels in all the 11 tissues. In the thymus and lymph tissues,the expression of MUC4 gene in resistant piglets was significantly higher than that in sensitive piglets (P<0.05);In the lung tissue,theMUC13 gene expression level in resistant individuals was significantly higher than that in sensitive individuals (P<0.05),and in the intestinal tissues of duodenum and jejunum, the expression level of MUC13 gene was relatively higher in resistant individuals. Thus we speculated that the high expression of MUC4 gene in immune tissues and MUC13 gene in intestinal tissues might improve the immune ability of piglets,protect and lubricate the intestinal tract, and resist ETEC F18 infection.

This study was aimed to clone the different splicing variants of myocyte enhancer factor 2A (MEF2A) gene in Mashen pig. According to the prediction results of the alternative splicing in the RNA-Seq sequencing, the coding region of MEF2A gene exons 5-8 were amplified. We analyzed the sequence characteristics of different splicing variants of MEF2A gene in Mashen pig, predicted conservative structure domain, constructed phylogenetic tree and compared the homology of MEF2A amino acid in different species by bioinformatics softwares. The results showed that 4 alternative splice variants of MEF2A gene were obtained. The exons 5-8 of MEF2A1 spliced normally. MEF2A2 lacked the exon 5, and the 5'end of exon 6 was 138 bp longer, the 3'end of exon 7 was 102 bp longer. MEF2A3 lacked exon 5, and the 5'end of exon 6 was 138 bp longer. The 3'end of MEF2A4 exon 7 of was 102 bp longer. The protein, encoded by inserted 138 bp sequence, contained a conserved domain-HJURP_C, which was the result of MEF2A participating in hepatocyte fibrosis. The MEF2A1, MEF2A4 and MEF2A1 of pig submitted in GenBank (accession No.NP_001090890.1) belonged to a subgroup, homology up to 98.9%. The MEF2A2, MEF2A3 and MEF2A2 of pig submitted in GenBank (accession No.NP_001093168.1) belonged to a subgroup, the homology was 98.2% and 98.9%, respectively. The successful cloning of 4 alternative splice variants of MEF2A gene laid the foundation for further study on the function of MEF2A protein.

Long noncording RNA (lncRNA) played an important regulating role in many biological processes.The lncRNA expression profile of liver of pre-laying hens (20 weeks old) and peak-laying hens (30 weeks old) in Lushi Green-shelled-egg chicken were obtained by lncRNA-seq. A lncRNA, which was named lncLER and expressed highly in the peak-laying hens was singled out. To investigate the expression characteristics of lncLER in liver of chicken,reverse-transcript PCR and Real-time fluorescence quantitative PCR were used to analyze the temporal expression profile of lncLER. Both individual chicken and primary hepatocytes were used to look into the effects of estradiol on expression of the lncLER in vivo and in vitro. The results showed that lncLER was expressed differently in various tissues and it's expression level was higher in the liver of peak-laying hens. The expression of lncLER, both in individual chicken and in primary hepatocytes,was up-regulated by estradiol.This research paved the way for further studying on the biological functions of lncLER in chicken egg production.

In order to investigate goose hemorrhagic polyomavirus (GHPV) infection status in Fujian, China, 19 samples which were collected from different duck species were used to detecte GHPV, only one sample from Cheery Valley duck was tested positive (designated GHPV-FJ201601 strain). VP3 gene specific primers were designed by comparing the characterization of GHPV genomic sequences based on the genomic sequences download from GenBank. The length of the cloned VP3 gene was 654 bp, coding 217 amino acids. The theoretical pI of VP3 protein was 9.37, with 23 total number of negatively charged residues (Asp + Glu) and 28 total number of positively charged residues (Arg + Lys), respectively. The instability index of VP3 protein was 38.43, and it was a stable protein; The fat coefficient was 64.33; The total average hydrophobic index was -0.744. Also, the VP3 protein did not have signal peptides which was located in nucleus and having 14 phosphorylation sites. Nucleotides homology analysis of VP3 gene of GHPV isolates were higher with each other, which were no less than 99.7%. Phylogenetic analysis based on the VP3 gene showed that GHPV-FJ201601 strain shared the same genetic evolution cluster with goose-origin GHPV (14234 strain from Hungary and Toulouse Goose 2000 strain from France) rather than the duck-origin GHPV (Toulouse Muscovy Duck 2008 strain and Toulouse Mule Duck 2008 from France and 106 strain from China), all VP3 gene shared closer genetic distance with each other. In conclusion, this study was first evidence of Cheery Valley duck could infect GHPV in Fujian, which laid a good foundation for the enrichment the GHPV epidemiology data from different area and host.

In order to study different expressed proteins of one-year-old Tan sheep skin, two-dimensional gel electrophoresis (2-DE) was used to separate the Tan sheep skin proteins of different growth stages by Coomassie blue staining, with PDQuest 8.0 software to detect and analyze differences in protein spots,and were identified by MALDITOF/TOF-MS/MS.Protein maps of four growth stages were performed between pairwise, after testing found a total of 19 differentially expressed proteins, mass spectrometry successfully identified 15 protein spots and a total of 13 proteins, of which 14-3-3 σ protein isoforms, annexin A2, keratin 25 and tubulin α chain might be related to growth regulation sheep skin. Those different expressed proteins might be associated with different stages of growth of Tan sheep skin follicles cyclical changes. The different proteins of one-year-old Tan sheep skin provided theoretical basis for annual variation of Tan sheep skin.

In order to extend the anagen of cashmere goat hair follicles and increase the production of cashmere,this study was performed with artificially shorten the daylight time among Arbas White cashmere goats. Skin tissue sections from cashmere goats were collected to compare the morphologic changes between artificial daylight and natural daylight,and immunohistochemical method was used to study the hair follicle cell proliferation and important protein expression in related signaling pathways. The results showed that strong cell proliferation occurred in cashmere goat hair follicle cells during artificial daylight,plenty of cytokeratin 15 (K15) positive signals were distributed in the outer root sheath,β-catenin protein was actively expressed in hair matrix and root sheath, indicating that the hair follicles were in the anagen growth phase;Meanwhile,cashmere goat hair follicles under natural daylight were in telogen with weak signals. Above all prove that short photoperiod played an important role in promoting hair follicle growth,the artificial short photoperiod could change hair follicle growth cycle and make hair follicles earlier enter to the anagen growth phase,causing a variety of typical gene expressions during hair follicle growth.

The experiment was performed to evaluate the nutritive value of apple pomaces by Cornell net carbohydrate and protein system (CNCPS) and in vitro gas production technique.In these series of researchs,apples pomace collected from Jinzhou (Liaoning province),Tangshan (Hebei province), Dangshan (Anhui province) and Beijing were used as test materials.The nutritive value of apple pomaces was evaluated by CNCPS,the fermentation situation were studied and their energy value was calculated.The results showed that there were significant differences in nutritive components between apple pomaces from different regions.As for the nitrogenous compounds,PA contents of 4 kinds of apple pomaces were all more than 60%,but PB₁ contents were all less than 3%.For the carbohydrate compounds,CC contents were high (51% to 62%). The gas production (B) of Beijing apple pomace was the highest which was extremely significantly higher than others (P<0.01). And the gas generation rate (C) of Tangshan apple pomace was extremely significantly higher than Dangshan and Beijing apple pomaces (P<0.01).Dangshan apple pomace had the highest NH₃-N content,extremely significantly higher than the others (P<0.01), there were significant difference in VFA among 4 kinds of apple pomaces (P<0.01). TDN and other energy values had obviously difference between apple pomaces from different places which Dangshan apple pomace had the highest energy value,extremely significantly higher than others (P<0.01).In conclusion,the apple pomaces from different regions had significant differences in chemical components and in vitro fermentation parameters. These series of experiments not only supplied the database of beef cattle common feeds but also establishsd the data foundation for the development and utilization of no-grain feeds,carried the point of scientific and reasonable utilization.

The breeding experiment was carried out based on Tongcheng pig which were female paternal lines while Landrace pig and Yorkshire pig were male paternal lines,and two hybridization combinations Landrace×(Yorkshire×Tongcheng) and Yorkshire×(Landrce×Tongcheng) (LYT and YLT) were got. The growth performance,carcass traits and meat quality of both parent and offspring were determined. The results suggested that two hybridization combinations LYT and YLT showed significant heterosis in growth performance,carcass traits and meat quality. The relative heterosis of average daily gain during the trial,feed to gain ratio, average of live backfat thickness,muscle shear force,marbling score and intramuscular fat content were 12.54%,-13.89%,10.39%,-8.71%,-8.33% and 8.57% in LYT,and that were 10.81%,-11.05%,10.55%,-6.50%,6.67% and 2.44% in YLT,respectively. The average daily gain during the trial,loin eye area and lean and bone of the ham proportion were 843.4 g/d,34.51 cm² and 73.54% in LYT, and those were 808.6 g/d, 31.45 cm² and 70.67% in YLT,and there were significant difference among the indexes between the two hybrids (P<0.05). Finally,the study demonstrated that the three-way crossbred was better than Tongcheng pig in growth performance and carcass traits,and better than both of Yorkshire and Landrace in meat traits,furthermore,LYT were given a more general evaluation than YLT.

This study was aimed to investigate the effect of feed supplemented with fermented tomato pomace on the antioxidant properties of perinatal dairy cows.Sixteen dairy cows with similar physical,prenatal period,body weight,parity and lactation yield were divided into two groups with 8 dairy cows per group.The dairy cows in control group were fed TMR regular diet and that of experimental group was fed diet supplemented with fermented tomato pomace (13% in pre-partum period and 11% in post-partum period).The preliminary trial period was 14 d and trial period lasted for 60 d (30 d before delivery to 30 d after delivery). The results showed that compared with control group,the milk yield of dairy cows of experimental group in post-partum period was significantly increased (P<0.05);In the whole trail period,the activity of GSH-Px,T-SOD and T-AOC in experimental group were increased,and that in pre-partum period were significantly increased (P<0.05),while compared with pre-partum period,that in post-partum period showed a downward trend.The MDA content of experimental group in post-partum period was significantly decreased (P<0.05),there was no significant difference between pre-partum period and post-partum period (P>0.05);Compared with control group,the contents of white blood cells,hemoglobin,urea nitrogen, low density lipoprotein and Fe of experimetal group in post-partum period were significantly increased (P<0.05),and other indexes had no significant differences (P>0.05).In conclusion,diet supplemented with fermented tomato pomace had a certain improvement effect on the antioxidant properties and milk yield of dairy cows in the perinatal period.

The experiment was aimed to investigate the effects of ethanol extracts from bee pollen (EEBP) on learning, memory and brain antioxidant abilities in aged mice induced by D-galactose. Fifty ICR mice were randomly divided into five groups, designated as normal control, model control, low-dose, moderate-dose and high-dose EEBP groups. The mice in normal control group were given saline by gavage, in the other groups were given D-galactose solution by neck back subcutaneous injection at the daily dose of 500 mg/kg·BW for 8 consecutive weeks. At the same time,EEBP treated mice were administered EEBP by gavage at the daily doses of 400,800 and 1 600 mg/kg·BW, respectively. The learning and memory abilities of mice were determined by Y-maze and step-down tests. The content of malondialdehyde (MDA) and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in brain tissue of the mice were measured. The results showed that EEBP could enhance the memory, increase the activities of SOD,GSH-Px and decrease the content of CAT in mice.In conclusion, EEBP could ameliorate the degeneration of learning and memory abilities in D-galactose-induced aging mice,improve brain antioxidant abilities and thus delay brain aging.

The effects of Ampelopsis grossedentata extract on growth performance, diarrhea rate and anti-oxidation function in mice were studied in this experiment. 90 mice were randomly divided into five groups: Blank group, experimental groups Ⅰ,Ⅱ,Ⅲ and control group. The mice in blank group were fed with basal diet, the experimental groups were added with 0.02, 0.04, 0.06 mg/(g·BW) of Ampelopsis grossedentata extract and the control group was added with colistin sulfate in basal diets, respectively. On the 26th day of the trial, the mice were administered folium senna and then record their diarrhea condition. The results showed that, the finial weights of mice in experimental and control groups were higher than that in blank group, and the difference between the blank and control groups were significant (P<0.05). Adding Ampelopsis grossedentata extract had a tendency to increase growth performance and liver weight, but the difference was not significant (P>0.05). The diarrhea rates in the control and experimental groups Ⅱ,Ⅲ were significantly lower than the blank and experimental group Ⅰ(P<0.05). Compared with the blank group, the activity of the serum glutathione peroxidase (GSH-Px) was significantly increased in control group (P<0.05), while the increasing trends were not significant in experimental groups (P>0.05). The activity of catalase (CAT) in control group was significantly higher than that in experimental group Ⅱ (P<0.05), and the serum superoxide dismutase (SOD) activities among the experimental groups were not significant (P>0.05). In conclusions, the growth performance and anti-oxidation function in mice could be increased, while the diarrhea rate could be decreased by adding the Ampelopsis grossedentata extract. It suggested that Ampelopsis grossedentata extract was expected to become a substitute for antibiotics in animal feeds.

The experiment was carried out to study the composition and contents of fatty acids of Nanyang Black pig, and to provide a theoretical basis for the protection and exploitation of local pig genetic resources in China. 12 Nanyang Black pigs and 12 Large White pigs were chosen, and the composition and contents of fatty acids in longissimus dorsi muscle were measured, and the quality of fatty acids was comprehensive evaluated from nutrition, health, flavor and storage aspects. Monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), 12-16 carbon saturated fatty acids (SFA1), other saturated fatty acids (SFA2), unsaturated fatty acids (UFA), saturated fatty acids (SFA), SFA2/SFA1, MUFA/PUFA, essential fatty acid (EFA), conjugated linoleic acids (CLA), PUFA/SFA and ω-6 PUFA/ω-3 PUFA were used as the indexes of multiple comparison. The results showed that there were 30 kinds of fatty acids were detected and 23 of them had significant or extremely significant differences between the two pig breeds (P<0.05;P<0.01). Nanyang Black pig had higher values of above measured indexes than that of Large White pig in addition to SFA2/SFA1 and ω-6 PUFA/ω-3 PUFA. 11 indexes such as SFA1,MUFA,PUFA,SFA,UFA, UFA/SFA,SFA2/SFA1,PUFA/MUFA, EFA,CLA, PUFA/SFA and ω-6 PUFA/ω-3 PUFA differed significantly or extremely significantly between the two pig breeds (P<0.05;P<0.01), while SFA2 and PUFA/MUFA had no significant differences between the two pig breeds (P>0.05). In conclusion, the fatty acids of Nanyang Black pig were significantly better than that of Large White pig.

This study was aimed to explore the effects of genetic variations of Lpin2 gene on tail type and slaughter traits in sheep. Two breeds of fat-tailed sheep such as Guangling Large Tailed sheep and Small Tailed Han sheep were chosen to identify the single nucleotide polymorphisms (SNPs) in 5' non-coding region of Lpin2 gene by using direct DNA sequencing, and the associations between SNPs and tail type and slaughter traits were analyzed. The results showed that three novel SNPs were found in 5' non-coding region about 1 200 bp upstream sequence from start codon ATG in Lpin2 gene, namely NC_019480.2: g.－663 dup ATT (SNP1), g.－388 T > C (SNP2) and g.－330 T > G (SNP3), sequencing data revealed that the trinucleotide ATT repeat expansion at SNP1 was cope number variation (CNV) of short tandem repeats (STR), the mutation frequency was significant higher in Guangling Large Tailed sheep than that in Small Tailed Han sheep (P<0.05), and caused the significant decreasing in carcass weight and dressing percentage in Guangling Large Tailed sheep (P<0.05), however this variation exhibited non-significant effects on the slaughter traits in Small Tailed Han sheep (P>0.05). SNP2 and SNP3 could be constructed into a haplotype block while the haplotypes didn't significantly affect the examined traits in two sheep breeds. This finding would provide references for marker assisted selection of the sheep meat quality traits.

In order to explore the polymorphisms of myxovirus resistance (Mx1) gene in pig populations from different genetic background,we cloned Mx1 gene and tested the polymorphisms on exon 2 of Mx1 gene in Min pig, crossbred from wild boars in Changbai Mountain with Min pig (crossbred wild boars) and Large White pig population using high resolution melting (HRM). The results showed that four Mx1 mRNAs were cloned from Min pig and crossbred wild boars, and they had whole ORF which was 1 992 bp in length and coded 663 amino acids. In the four Mx1 mRNA, there were 30 SNPs in nucleotide and 17 mutations in amino acid. The location of SNPs displayed that almost mutations located on two sides of the function domains in Mx1 protein. The polymorphism data in HRM test showed that the DD genotype was the dominant genotype which had the highest frequency in three populations. The DD genotype frequency was 100% in Large White pig population, 62.5% in crossbred wild boars, and 56.2% in Min pig.Some novel mutations in both nucleotide and amino acid on exon 2 region were explored in polymorphism test. In conclusion, there was more polymorphism of Mx1 gene in Min pig and crossbred wild boars.

In this study, the single nucleotide polymorphism(SNP) of MSTN gene and its correlation with the production performance was tested, and explored the molecular genetic marker of breeding in Baicheng fatty chicken. 96 Baicheng fatty chicken roosters were selected randomly and divided into 3 groups, there were 32 chicken in each group. The indexes of production performance were measured in 12, 18 and 24 weeks old and the SNP of MSTN gene was detected by PCR-RFLP method, and analyzed the relationship between gene polymorphism and production performance indexes.The results showed that 3 genotypes of AA,GA and GG were found in Baicheng fatty chicken, GA was the dominant genotype, and allele A was the dominant allele, the allele frequency was not in the Hardy-Weinberg equilibrium (P<0.05). At 12 weeks old,AA genotype was significantly higher than GA genotype in body weight, carcass weight,semi-eviscerated weight, eviscerated weight, breast muscle weight and leg muscle weight (P<0.05). At 18 weeks old,GA genotype was significantly higher than GG genotype in body weight, breast muscle weight and leg muscle weight (P<0.05). At 24 weeks old,AA genotype was extremely significantly higher in body weight, carcass weight and semi-eviscerated weight than GG genotype (P<0.01),and AA genotype was significantly higher in eviscerated weight and leg muscle weight than GG genotype (P<0.05). GA genotype was significantly higher in body weight, carcass weight,semi-eviscerated weight and leg muscle weight than GG genotype (P<0.05), there were no significant difference in the other indexes among different genotypes at different ages (P>0.05). MSTN gene polymorphism was closely related to the production performance indexes of Baicheng fatty chicken, it was speculated this gene could be used as one of the molecular genetic markers for the breeding of Baicheng fatty chicken.

This study was aimed to investigate popular genotype and phylogenesis of VP2 gene of canine parvovirus (CPV) in Guiyang area. Ten strains of viruses were isolated from Guiyang and the VP2 gene was amplified by PCR, cloned and sequenced. Results showed that the isolate virus grew could produce typical CPE in F81 cells, seven strains of CPV were CPV type 2a and others were CPV type 2c, named as GY-1 to GY-10. The nucleotide homologies of the isolated strains compared with 3 vaccine strains were 98.4% to 99.4%, with others reference strains nucleotide homologies within 97.7% to 99.9%.This research firstly reported the prevalence of CPV genotype was CPV type 2a in Guiyang area with such CPV type 2c, this was very important for monitoring the trend of CPV genetic variation and the development of vaccine.

The experiment was aimed to study the synonymous codon usage features of leptin receptor (LEPR) gene in buffalos, the codon usage differences and evolutionary relationships between buffalo and other reference species. The coding region of LEPR gene from 27 river buffalo and 41 swamp buffalo were sequencing,and Bos taurus,Bos mutus,Bos bison,Ovis aries,Capra hircus,Mus musculus and Homo sapiens were chosen as reference species from NCBI database. The results showed that all synonymous codons were used in the LEPR gene of river buffalo and swamp buffalo. Two kinds of buffalo had 28 biased usage codons. Among them,strongly biased codon was AGA (RSCU≥2),which indicated that codon usage features were similar in LEPR gene of two types of buffalo. Furthermore,buffalo and the species compared in this study were bias toward the synonymous codons with A/U at the third codon position in LEPR gene.However,the types and numbers of bias usage codons were different between buffalo and the species compared. Clustering analysis showed that the relationship between river buffalo and swamp buffalo was the closest,and they gathered into one group firstly,then they gathered with Bos taurus,Bos mutus and Bos bison,and further gathered in turn with Ovis aries,Capra hircus,Mus musculus and Homo sapiens.The frequency differences of synonymous codon usage between buffalo LEPR gene and yeast genome were less than that between buffalo and E.coli,Mus musculus genome,suggesting that yeast might be more suitable as an external expression system for buffalo LEPR gene.

A candidate structure variation (SV) 184 was screened out from the resequencing data of Xiang pig. To explore the polymorphism of SV184 among pig breeds, the genotype distributions of SV184 in leukocyte antigen protein (CD53) gene was detected by PCR method taking six Chinese and European pig breeds as samples including Xiang pig,Large White pig,Nuogu pig,Kele pig,Jiangkouluobo pig and Rongchang pig breeds. Furthermore, the primary transcripts of three genotypes of SV184 were determined using RT-PCR technology. Results showed that the type VN was dominant in Xiang pig,while type NN was mainly in others. Both of two primary transcripts of CD53 gene were determined from the heterozygous genotype of SV184,which indicated that the presence of SV184 might not disturb the template selection in the process of CD53 gene transcription. It suggested that SV184 could be taken as one of molecular marker to distinguish Xiang pig from other pig breeds.

The purpose of this study was to identify candidate genes associated with reproduction traits and explore the available molecular marker in British Landrace pig breed. The PCR-RFLP technique was applied to analyze the distribution of estrogen receptor (ESR), retinol binding protein 4 (RBP4), leptin (LEP) and follicle-stimulating hormone β (FSHβ) genes in British Landrace pigs. The genetic effects of ESR, RBP4, LEP and FSHβ on the reproductive traits included total number born, number born alive, weaning weight of litter, weaning piglet, which were analyzed by using least square method of SPSS 19.0 software. This results demonstrated that A was dominant allele in ESR, RBP4, LEP genes, and B was dominant allele in FSHβ gene. The result of χ² test showed that the polymorphic sites of LEP, FSHβ genes were fit with Hardy-Weinberg equilibrium (P>0.05), while this site of ESR and RBP4 were not fit with Hardy-Weinberg equilibrium (P<0.01). In addition, the statistical analysis indicated that the total number born, number born alive and number of alive weaning litter with BB genotype of LEP were higher than AA genotype, which were significantly increased by 1.3219, 1.6855 and 1.1710 (P<0.05), respectively;The FSHβ loci had a remarkable effect on reproductive performance, the average weaning weight with BB genotype was significantly higher than AA genotype, which was significantly increased by 5.1129 kg (P<0.05). The ESR and RBP4 loci had no significant effect on reproductive traits (P>0.05), while the LEP and FSHβ genes were valuable candidates for possible marker-assisted selection in British Landrace pigs population.

This study was aimed to investigate the genetic diversity and the reason for the degradation of the reproductive performance of Pudong White pig. The genetic diversity of Pudong White pig, six Taihu pig breeds and three Western pig breeds were analyzed based on the genome-wide SNPs.The genetic diversity and population structure of these pig breeds were also explored based on the SNPs related to reproductive traits. The results showed that Pudong White pig displayed a lower level of the genetic diversity than the Taihu area pig breeds. For the reproductive-related loci, except for Fengjing pig, Pudong White pig displayed the lowest propotion of polymorphic markers, expected heterozygosities and allelic richness (excluded Duroc pig). The result of PCA showed that Pudong White pig displayed its uniqueness in the reproductive-related SNPs. With the comparsion of Taihu pigs and Western populations, Pudong White pig displayed a lower level of the genetic diversity and more homozygous reproductive-related loci. Nevertheless, a certain number of favorable alleles were still harbored in Pudong White pig, which might result high heterosis in the offsprings. In conclusion, the results of this study might provide some valuable information for the breeding, conservation and utilization of this breed.

To explore the influence of Gaopo pig myostatin (MSTN) gene polymorphism on meat quanlity traits (moisture,crude fat,crude protein,crude ash, loin muscle area, marbling score, pH value, color of meat,tenderness,drip loss, water loss rate), MSTN gene was chosen as a candidate gene for research meat quality traits in this study. 50 Gaopo pigs at 10 months old were selected,the single nucleotide polymorphism (SNP) of three exons of MSTN gene in Gaopo pig were detected by direct sequencing of PCR amplification products, and the correlation between MSTN gene SNP and meat quality traits was analyzed using SPSS 20.0 software. The results showed that a C/T mutation had been found at 63 bp of MSTN gene exon 3,the site was silent mutation, and did not caused changes of encoding amino acid. Genotype analysis showed only three samples had mutations in the site, CC genotype was the dominant type and allele C was the dominant gene, but there was no TT homozygous genotype. The test of Hardy-Weinberg equilibrium showed the research group obeyed the genetic equilibrium (P>0.05). Population genetic parameter analysis showed the heterozygosity (He) of C63T was lower, and had a low variation in Gaopo pig population. Polymorphism information content (PIC) analysis showed that it was a low polymorphic loci (PIC<0.25), and the site could provide a little genetic imformation. There was no significant difference between the different genotypes and meat quality traits (P>0.05).Given the above, the polymorphism of MSTNgene exon was found in Gaopo pig, with less variation and relatively conservative.It's needed to expand the number of sample for further explore whether the site could be considered as genetic markers for meat quality traits of Gaopo pig or not.

This study was aimed to research the gentic variations of ACTA1 gene in Yanbian Yellow cattle, and analyze the influence of genetic polymorphisms on meat quality traits. PCR-RFLP and PCR-SSCP technique were used to analyze the association between the polymorphisms of ACTA1 gene and meat quality traits. The results showed that there were two SNPs, A193G which with replacement of Arg by Gly amino acid, A298G which with replacement of Lys by Arg amino acid. χ² test showed A193G and A298G were in Hardy-Weinberg equilibrium (P>0.05). The association analysis indicated that the genotypes of different mutations in ACTA1 gene were found to be significantly related to myristic acid, oleic acid, loin muscle area, marbling score (P<0.05). ACTA1 gene had potential effects on meat quality traits of Yanbian Yellow cattle, and could be used for candidate gene in early selection of new varieties of Yanbian Yellow cattle.

This study was aimed to analyze the association of myostatin (MSTN) gene polymorphisms with meat quality traits in Chishui Black-bone chicken. The DNA pooling was constructed and the direct sequencing technology of PCR product was used to detect the single nucleotide polymorphism (SNP) of MSTN gene. The results showed that C324T were detected in exon 1 of MSTN gene in Chishui Black-bone chicken. However, there was not found SNP site in exon 2 and exon 3 of MSTN gene. The C324T site was devised into three genotypes of CC, CT and TT. The association relationships between the genotype of MSTN gene and meat quality traits revealed that chest muscle pH and leg muscle pH value of Chishui Black-bone chicken with CT genotype were significantly higher than that of CC and TT genotypes (P<0.05), the shear force of CT genotype was significantly higher than that of TT genotype (P<0.05), there was no significant difference in other meat quality traits (P>0.05). This results suggested that the pH value and shear force of MSTN gene had a larger genetic effect in Black-bone chicken,MSTN gene was one of genes which could control the preliminary inference, might affect the pH value and shear force or with the main gene chain in Black-bone chicken, and could be used as pH value and shear force of molecular markers of Black-bone chicken.

The research was aimed to analyze the association of Leptingene and breed traits on pigs. Three pairs of primers were designed which based on DNA sequence of pig Leptin gene (GenBank accession No.U66254, AF026976),the single nucleotide polymorphisms (SNPs) of Leptin gene were detected by PCR-SSCP in Sujiang and Jiangquhai pigs. The results showed that three genotypes of AA,AB and BB were identified, and the mutation (T3469C) in CDS of Leptin gene was found,but amino acid change weren't happened. The Chi-square test results showed that the Leptin genotype distribution of Sujiang and Jiangquhai pigs was in Hardy-Weinberg equilibrium (P>0.05). The polymorphism information content (PIC) were moderate polymorphism in Sujiang pigs,and low polymorphism in Jiangquhai pigs. The statistic analysis results showed that there were no significant association between the SNP of Leptin genotype and litter size trait(P>0.05). But the average litter size of T3469C site AB genotype was higher than AA and BB genotypes, it was concluded that the T3469C polymorphism of Leptingene might be the genetic marker which potentially affected pig breed traits.

Bama miniature pigs, which are local high-quality species of China, have the advantages of genetic stability, ideal hair distribution, microsomatia, prolificacy, low fodder demand, strong disease resistance, and they are similar to human beings in aspects of physiology, anatomical structure, drug metabolism, biochemical indicators, disease mechanism, etc. Bama miniature pigs have been used in the wide fields of medical research, such as cardiovascular system, skin plastic, endocrine and metabolism, digestive system, oral medicine, heterograft, Chinese medicine, anesthesiology, nervous system, etc., and been applied to establish the animal models which are similar to human diseases, such as myocardial ischemia, coronary micro-embolization, atrial septal defect, atherosclerosis, skin injury, transdermal drug, metabolic syndrome, diabetes mellitus and complications, obstructive jaundice, chronic pancreatitis, liver cirrhosis, liver radiofrequency ablation, periodontal tissue inflammation, mandibular defect, heterogeneous organ/cell transplantation, syndrome of Chinese medicine, anesthesia, cerebral ischemia, stent implantation, shock, etc. Bama miniature pigs, as an ideal experimental animal, have broad application prospects in biomedical research.In this article,we mainly summarized the progress of Bama miniature pigs in the field of medicine, to understand the types, construction methods and pathological characteristics of Bama miniature pigs disease models, which contribute to further explore the specific etiology, pathogenesis, complications, prevention and control measures, etc., and laid the scientific foundation for expanding the research scope and improving the medical level.

The purpose of this study was to examine the effects of fluoride on epididymal morphological structure and mRNA expression of tight junction genes.60 healthy male mice were divided into four groups randomly, including control group (distilled water) and 25,50,100 mg NaF/L groups, respectively. After 60 days, the thighbones were collected and fluoride contents were determined by fluorine ion selective electrode method. Paraffin slides of right epididymis with HE stain were produced to evaluate epididymal morphological structure under light microscope. The left epididymis were collected to isolate total RNA and detect the mRNA expression of tight junction genes by qRT-PCR. The results showed that the fluoride contents of thighbones increased in a dose-dependent manner, and were extremely significantly higher in 50 and 100 mg/L groups than those in control group (P<0.01).NaF extremely significantly increased the thickness of cauda epididymal pipe wall in fluoride groups (P<0.01) and the Claudin-2 mRNA expressions in fluoride groups were extremely significantly decreased (P<0.01) and the ZO-1 mRNA expression in 100 mg/L group was significantly decreased (P<0.05) as compared with control group. In conclusion, excessive NaF ingestion adversely affected epididymal morphological structure and mRNA expressions of Claudin-2 and>ZO-1,which might contribute to the damage of blood-epididymal barrier.

MC1R gene, as one of the important candidate genes for controlling coat color, not only plays an important role in the process of melanin synthesis, but also participates in the formation of coat color and also has different effects on human and animal diseases, growth traits and behaviors. The study of MC1R gene has attracted the attention of scholars.In order to deepen the understanding of MC1R gene, the structure, function, mechanism, gene locus, polymorphism analysis and research progress of human and animal of MC1R gene were reviewed and new ideas were put forward in this review.

This study was to establish a method for the identification of Ornithodoros lahorensis with molecular biology. The samples of Ornithodoros lahorensis were collected from sheep in Xinjiang region and the morphological characters were screened by stereo microscopy and electronic microscopy. Then the 16S rDNA,18S rDNA and cytochrome oxidase Ⅰ(COⅠ) of samples were amplified by PCR and subsequently sequenced. Then the analysis of genetic divergences and Neighbor-Joining (NJ) phylogenetic tree were carried out based on the sequences acquired from Ornithodoros lahorensis,combined with the reference sequences of GenBank database. In this study,the comprehensive and clear micromorphological traits of ovoid scutum,round fovea of Ornithodoros lahorensis were provided. Besides,the DNA sequences of Ornithodoros lahorensis were assembled together with sequences of Argasidae and form monophyletic clades in the 16S rDNA and COⅠ based Neighbor-Joining trees. According to the intraspecific K2P genetic distances of Ornithodoros lahorensis (0~0.3%),we determined that the molecular biology method based on 16S rDNA and COⅠ could rapidly and accurately identify the species of Ornithodoros lahorensis.

The aim of the study was to prepare a monoclonal antibody (McAb) against cephalexin(CEX),and preliminarily establish an ELISA method to detect residues of CEX in milk. The CEX was conjugated to carrier bovine serum albumin (BSA) and ovalbumin (OVA) by two-step glutaraldehyde method. BALB/c mice were immunized with the prepared CEX-BSA conjugate. After five times immunization, we built and screened two strains of hybridoma cells (2G4 and 5B3) which secreted McAb against CEX by hybridoma technology.The 2G4 cell lines were injected into BALB/c mouse's abdominal cavity to produce ascites. Finally the ascites were purified and identified. The results showed that antibody titer of the McAb 2G4 was above 1∶1.28×10⁵,its antibody subtype was IgG2b(κ) and affinity constant K was 1.51×10⁹ L/mol. The cross experiment result evidenced that the cross reaction rate of cefradine was 52.55%, ceftiofur, ceftriaxone, cefotaxime, cephalothin, penicillin, streptomycin and tetracycline had no cross reaction. We established an ELISA method to detect CEX residues in milk and its linear range was 20 to 1 000 ng/mL, linear equation y=0.4674x-0.5359(R²=0.9909), its limit of detection (LOD) was 19.68 ng/mL and the average recovery rate was 91.31%, the average coefficient of variation was below 15%. The detection limit was lower than the maximum residue limit of cefalexin in China and European Union. So this detection method might have good application foreground.

In this study,the biological and genetic characterization of a paramyxovirus type Ⅰ strain (GSFY strain) which was obtained from Muscovy duck were determined. Afterward,GSFY strain was developed as an inactivated oil emulsion vaccine. The protective evaluation of this new vaccine candidate was conducted on the Muscovy duck. The results showed that the mean death time (MDT) of chicken embryo,the intracerebral pathogenicity index (ICPI) of 1-day-old chicken and the intravenous pathogenicity index (IVPI) in 6-week-old chicken were 71 h,1.75 and 2.49, respectively. Homologous comparison of F gene nucleotide sequence showed that the GSFY strain shared 97.1% with Chicken/China/Guangxi 9/2003,which was the highest homology,and they all belonged to type Ⅶ. The results suggested that this newly isolated strain was the type Ⅶ high virulent paramyxovirus. The immunize protective evaluation results suggested that the mean antibody titer of 7 and 21 days after the third immunization were 6log2 and 8log2,respectively. When the immunized duck were attacked with GSFY strain,100% protective rate could be expected when the mean antibody titer was above 5log2. This study provided the basic data for vaccine development of avian type Ⅰ paramyxovirus.

In order to study the expression and immunogenicity of porcine pseudorabies virus (PRV) gB protein,the specific primers were designed with the template of PRV preserved in the laboratory, and the 612 bp conserved gene fragments were amplified and sequenced, then it was cloned into the expression vector pET-28a and transformed into E.coli BL21 (DE3), the target protein was obtained after induced expression and purification.Western blotting was performed to analyse its immunogenicity. The results showed that gB protein was 30 ku, which mainly expressed in the form of inclusion body, and the concentration of the protein was 106 μg/mL, with well reactogenicity. 13 PRV positive serum and 16 negative serum in the samples were detected using ELISA Kit on sale, using positive serum, the PRV antibody detection method was initially established with the PRV gB protein as antigen package.

The study was aimed to research the antibiotics resistance of Escherichia coli (E.coli) isolated from different sources of Chifeng and Tongliao areas in Inner Mongolia.Using K-B method, we analysed the resistance situation of 46 strains E.coli isolated from goose, bovine and porcine to thirteen kinds of antibiotic drugs. The resistance rates of E.coli isolated from goose and porcine had the highest resistance to doxycycline hydrochloride drug, which were 95.2% and 93.3%,respectively. The resistant rate of E.coli isolated from bovine had the highest resistance to sarafloxacinhydrochloride,enrofloxacin and hydrochloric acid doxycycline, which was 80.0%. Multi-resistance results showed that the prevalence of E.coli in diseased animals with 6 resistance mainly(23.9%);Bovine source with 7 resistance (40%). The resistance type in general was enrofloxacin/florfenicol/doxycycline/amoxicillin/neomycin sulfate. E.coli from different sources of diseased animals to antibiotics had a serious resistance. So,it is not only necessary for farmers to learn to use antibiotics rationally, but also to develop new drugs that are resistant to drug resistance or new drug allergic to antibiotics.

In order to prove the effect of immunomagnetic beads adsorption technology on separation efficiency of bovine E.coli O157∶H7 in practice,a total of 18 fecal samples, 162 anal samples,10 fodder samples,17 water samples and 36 samples of carcass surface cotton were collected from three cattle farms in Wujiaqu,Yining and Changji. The samples were taken by EC bead enrichment and direct SMAC and MUG test,respectively. Then,the bacterial rfbE gene and flagellarfliC gene were detected by PCR. Finally,the suspected E.coli O157∶H7 bacteria were detected by biochemical test. 8 and 4 strains of E.coliO157∶H7 were isolated from 243 samples,respectively. There was no statistical difference between the two methods. This experiment showed that the immunomagnetic beads adsorption technique in practice was not statistically significant compared with the conventional method, but it did increase the number of isolated E.coli O157∶H7,which was consistent with previous research results.

This experiment was conducted to isolate and identify a strain of Bacillus coagulans from the soil at the bottom of the pond, and study its probiotic properties. A strong acid producing bacillus was isolated from the soil at the bottom of the pond and identified as Bacillus coagulans through the physiological and biochemical characteristics and 16S rDNA sequence analysis. The strain had high tolerance to the simulated gastric juice (pH 2.5, 12 h of incubation, survival rate was 71.9%) and simulated intestinal fluid (bile salt concentration 0.3%, 12 h of incubation, survival rate was 84.4%) and had high antibacterial activity to E.coliK88, E.coliK99, S.agalactiaeand A. hydrophila. It could degrade nitrite effectively and the degradation rate was 96.80% in 48 h. Two hundred and seventy AA broilers aged 1 day were randomly allocated into 3 groups. Diets were added 0 (group Ⅰ), 1.0×10⁶ (group Ⅱ) and 1.0×10⁷ CFU/g (group Ⅲ) Bacillus coagulans NJ102, respectively. The experiment lasted for 42 d. The average daily gain and final body weight of group Ⅱ and Ⅲ were significantly higher than that of group Ⅰ(P<0.05), and the feed weight ratio of the two groups were significantly lower than that of groupⅠ(P<0.05). There was no significant difference in average feed intake among three groups (P>0.05). It was found that the soil-derived Bacillus coagulans NJ102 from the bottom of the pond had a certain degree of resistance and potential probiotic ability, which could improve the growth performance of broilers and had the potential to be a microbial feed additive.

17 feces samples of yak which were collected in Hongyuan county were measured with Gram staining method and 16S rRNA molecular identification in this study.8 suspected Enterococcus were separate from feces samples by bacteria purification and PCR amplification with 1 500 bp specific band. 6Enterococcus faecalis and 2Enterococcus faecium were identified through 16S rRNA sequencing.The homology analysis of the strains revealed that the homology between Enterococcus faecalis and reference strains sequence were 99.7% to 100%,that of Enterococcus faecium and reference sequence were 98.2% to 99.2%,indicating that the yak Enterococcus was highly conserved in the process of genetic evolution.The drug sensitive test results showed that the isolated strains were highly resistance to aminoglycoside antibiotics.Enterococcus faecium 11-1-2 strain was not only 5 multi-resistant,but also showed resistence to vancomycin.Enterococcus faecalis strains was most 3 multi-resistant.The antibiotics resistance results revealed that the resistance of yak Enterococcus was serious and should be taken seriously.

The study was aimed to establish a method for detection of rifaximin related substances by reversed-phase high-performance liquid chromatography with UV detector. The instrument methods was WondaSil C18-WR 250 mm×4.6 mm 5 μm column, mobile phase was methanol∶acetonitrile∶3.16 g/L ammonium formate (concentrated aqueous ammonia adjusted to pH 7.2)=31.5∶31.5∶37, with detection wavelength 276 nm. Area normalization method was used to calculate the limit of detection, limit of quantification and concentration of rifaximin uterine injectant; The precision of the method, linear correlation and related substances specificity were explored. And the degradation degree of the peak area of the principal components was compared by the destruction of the extreme conditions, the content of the related substances and the separation degree. 40 to 150 μg/mL concentration of rifaximin, peak area and concentration showed a good linear relationship (R²=0.9998), the related substances concentration on peak area linear regression equation was y=23 510x+7 182, within a certain period of time after preparation of acids, alkalis, oxidation, high temperature degradation damage in varying degrees, in the main ingredient content in the sample before the damage was 100.00%, after oxidative damage and heat damage the main component was 13%, acids, alkalis destruction of the main component degradation was about 18%, the main component peak retention time was consistency before and after the destruction. The retention time and resolution of rifaximin and related-substance were good. (The separation between the main component peak and the impurity peaks were greater than 1.5, the degree of separation between the impurity peak and impurity peaks greater than 1.2). The substance detection methods of rifaximin uterine injectants was simple and had specificity and good repeatability, selective and sensitive, which could be used to analyze the related substance of rifaximin uterine injectants.

The experiment was aimed to study the effects of herbal compound Outikang on antibody titer of foot and mouth disease vaccine type O,type A and type Asia Ⅰ,serum levels of ten cytokines and biochemical indices. 200 healthy adult cows were averagely divided into drug group and blank control group. Vaccinating the cows with FMD triplex vaccine when Outikang was given to the cows of drug group for 7 d running and then got the blood of all the cows on 0, 14, 28 and 56 d, respectively. Then blood biochemical examination, vaccine effectiveness and serum levels of cytokines were performed. The results showed that there were no significant differences in antibody titer of FMDV between blank control group and drug group on 0, 28 and 56 d after vaccination (P>0.05), while on 14 d the effect of Outikang on antibody titer of FMDV reached extremely significant level (P<0.01). Compared with blank control group, the contents of T-Bil in drug group was significantly decreased on 0 and 28 d (P<0.05), while it was extremely significantly decreased on 56 d (P<0.01).Compared with blank control group, the contents of Glu had significant difference on 28 and 56 d (P<0.05).The contents of P had extremely significant difference on 0 d (P<0.01), which was within the normal range. On 14 d after vaccination, the content of CD4 significantly increased in the drug group comparing to those in blank control group (P<0.05). On 28 d after vaccination, the content of CD4, IL-2, IL-6, IL-10, IL-12, IL-18 and IFN-γ extremely significantly increased in the drug group comparing to those in blank control group (P<0.01). On 56 d after vaccination, the contents of IL-6 and IL-12 extremely significantly increased in the drug group comparing to those in blank control group (P<0.01), while the content of CD4, IL-2, IL-4 and IL-18 significantly increased (P<0.05). Therefore, Outikang could significantly rise the antibody titer of foot and mouth disease vaccine type O, type A and type Asia Ⅰ.While it had no damage to the liver and kidney functions and had cholagogue effect, and it could enhance cellular immunity and humoral immunity function obviously.

In order to clarify the pathogenic characteristics and drug-resistant spectrum of a newborn piglet diarrhea outbroke recently in a large-scale pig farm of Henan province, the study was carried out by the isolation of intestinal pathogenic Escherichia coli and system identification. Escherichia coli strains were isolated from the faeces of diarrhea piglets. 13 virulent genes were tested by PCR. The antibiotic susceptibility of the strains was determined. The results showed that the positive rate came up with 34.8% for EAST1 gene. All of the strains were multiple-drug resistance and resistant to at least 5 types of antibiotics. 75.3% strains were resistant to more than 9 types of antibiotics. All of the strains were resistant to ampicillin, piperacillin, ciprofloxacin, levofloxacin and moxifloxacin. The result of the phylogenetic background showed that 21.7% E.coli isolates belonged to group B2 and D which were pathogenic. According to the synthesis analysis of virulence factors, resistance and phylogenetic background of the strains isolated from the diarrhea piglets, proper clinical treatment and prevention and control measure could be provided.

In order to establish and perfect the quality standard of Sihuangzhili granules, this experiment was conducted to identify coptidis rhizome, cortex phellodendri, rhubarb, scutellaria baicalensis, and radix isatidis in Sihuangzhili granules. We used TLC identification method to investigate the factors such as the developing agent, the expansion temperature, the expansion of the humidity, the source of the thin layer, the batch number and the color developing conditions.In the experiment, the mixture of cyclohexane, ethyl acetate, isopropyl alcohol, methanol, water, and triethylamine (3∶3.5∶1∶1.5∶0.5∶1) as the developing agent, was put into the expansion cylinder with the pre-saturated ammonia vapor, and was used to identify coptidis rhizome and cortex phellodendri under the UV lamp(365 nm);The mixture of ethyl acetate, butanone, formic acid and water (5∶3∶1∶1) as developing agent, sprayed with 2% ethanol solution of ferric chloride, was used to identify scutellaria baicalensis;At last, n-butanol, acetic acid, and water (19∶5∶5) as developing agent, dried and sprayed with indene ketone solution, heated at 105 ℃, was used to identify radix isatidis. The test results showed that under the test condition, the target spot was clear, with no tail, and the experiments were specifically suited in this test with strong specificity and good reproducibility.

In order to evalutate the safety of 10% phosphoric acid tilmicosin soluble powder on chickens. Forty healthy White-feathered hybrid chickens (20♂+20♀) at the age of 25 days were divided into 4 groups randomly. Each group was given tilmicosin with water at dosage of 0 mg/L,recommended dosage (75 mg/L),3 times of recommended dosage (225 mg/L) and 5 times of recommended dosage (375 mg/L) for 9d continuously. During the experiment, clinical feature,weight change and food consumption were observed,and when this experiment was ended, general pathology examination,clinical hematologic studies,blood biochemical indexes examination and physiological parameters examination were undertaken. The results showed that there were no significant influence on growth performance of chicken at the maximum dosage of 5 times of recommended dosage for 9d continuously (P>0.05), and there were no dose-dependent significant changes in physiological parameters and blood biochemical indexes. The conclusion revealed that it was very safe for chickens to use 10% phosphoric acid tilmicosin soluble powder at recommended dosage (75 mg/L).

The paper is a brief introduction of porcine endogenous retrovirus (PERV) innovative research results in the world and also expounds the passing PERV existence situation on different varieties of miniature pig, analyzes the PERV-virus gene cloning and sequence, appraises method on cell level, create the platform of infection HEK293 cells research, study on pigs A3F inhibition of PERV, and reveal the innovative research results on the specific molecular genetics in the different strain of PERV, analyzes the advantages of Wuzhishan miniature pig inbred line such as low gene copy of PERV,and there is no passing PERV-C specificity and as well as looking forward to cultivate the methods for new strain of PERV negative pigs. It will provide a scientific counter measure and new perspective to solve the spread of disease risk of miniature pig PERV and product safety for human xenotransplantation and biomedical materials of research and development.

In this study, the air environment quality indicators of a large tower type cowshed for dairy cattle in North China were monitored and evaluated at all seasons of one year, including the indicators of thermal environment, the content of ammonia (NH₃), carbon dioxide (CO₂), microbe and the dust in the air. The objective was to study the change rules of the mentioned indicators, to evaluate whether this type of cowshed could meet the production requirements, and to provide theoretical basis for the design and daily management of the cowshed in the Northern region of China. The results showed that all the indicators mentioned above varied with seasons and time to some extent. The wind speed inside was below the standard of dairy cattle cowshed in summer, and the temperature in 14∶00 of summer was above 27 ℃, and THI was beyond 69, so the dairy cattle suffered slight heat stress in summer. The other air environment quality indicators monitored in any time and any space all met the standard. In conclusion, the tower type cowshed monitored was suitable for dairy cattle in North China, but some facilities should be added to decrease the temperature and the heat stress in summer.