To explore the possible reasons for high mortality rate and early abnormal development of transgenic cloned pigs, we used anti-diarrhea transgenic (α1-fucosyl transferase gene, FUT1) positive and negative cloned pigs, as well as normal piglets as control, to analyze the expression levels of the imprinted gene insulin-like growth factor 2 (IGF2) in spleen, liver and leg muscle tissues via fluorescence quantitative RT-PCR assay. The results showed that in all three groups of pigs, there were differential expressions of IGF2 among tissues, expression level in liver tissue being the highest and that in the leg muscles being the lowest. Significant test indicated that the expression level of IGF2 in spleen tissue of FUT1 transgenic positive cloned pigs was significantly higher than that in negative cloned pigs (P<0.05), while it was significantly lower than that of negative cloned pigs in leg muscle tissue (P<0.05). Furthermore, the expression level of IGF2 in spleen of FUT1 transgenic negative cloned pigs was very significantly lower than that of normal pigs (P<0.01);However, it was very significantly higher than that of normal pigs in liver tissue (P<0.01). These results implied that the abnormal expression level of IGF2 in cloned pigs might influence their weak viability, however, its relationship with reduced survival rate of transgenic FUT1 gene cloned pigs was still needed to be defined.

In order to understand the codon characteristics of GnRHR gene and select the appropriate exogenous expression system, online tools CUSP, CHIPS and CodonW software were used to analyze the codon characteristics of GnRHR gene. GnRHR gene was compared to other genes of chicken, model animal genomes and GnRHR gene of other species.The results showed that ENc value of GnRHR gene in Jinghai Yellow chicken was small, which indicated strong codon bias. GnRHR gene was bias toward the synonymous codons with G and C at the third codon position. GC content was greater than AT content in CDS region of GnRHR gene. Analysis by CodonW software showed that in codons of GnRHR gene in Jinghai Yellow chicken, GCC, ATC, CTC, CTG, CGC, CGG, AGC, TCC and GTG were of strong bias and end with G/C. There were 12 bias codons with G/C at the third codon position in 31 genes of chicken. Codon bias comparison to other species showed that difference between GnRHR gene and the three species were very large, which indicated that GnRHR gene was not suitable for exogenous expression. GnRHR gene of poultry bias toward the synonymous codons contained G/C or end with G/C. GnRHR gene of our species had no strong codon bias. Result of clustering based on RSCU value showed that species with close genetic relationship tend to have similar codon bias.

In the assay, we used heat inactivation, ultrasonic cracking and ultraviolet irradiation three methods to prepare the death bacterial suspension of Mycobacterium tuberculosis, compared the effects of these three methods on the result of PMA-qPCR coupling technology. To choose the best preparation method of the dead bacterial suspension for subsequent experiments and explore the scopes of application and limitations of PMA-qPCR detection technology. The results showed that dead bacterial suspensions prepared by both methods of heat inactivation and ultrasonic cracking affected the changes of Ct values detected by PMA-qPCR. The dead bacterial suspension prepared by ultraviolet irradiation method had no effect on Ct values of PMA-qPCR detection technology.Heat inactivation method was the best method for the preparation of bacterial suspension of died Mycobacterium tuberculosis.PMA-qPCR coupling method was not suitable for the detection of dead bacteria prepared by the lethal method without cell membrane injury.

This study was aimed at cloning the full length cDNA of interleukin 1 beta (IL-1β) and providing full length cDNA information and experimental materials for further research on its biology function. The full-length cDNA of IL-1β from Small-tailed Han sheep was cloned according to the SSH cDNA library, using 5'-RACE technique. The full cDNA sequence was obtained and indexed in GenBank database with the number of KC425612.2. The results showed that the full-length IL-1β cDNA consisted of 1494 bp nucleic acids with the ORF of 801 bp encoding 266 amino acid residues of the predicted protein molecular weight of 30.622 ku, and the predicted protein IL-1β of Small-tailed Han sheep showed high homology with those of Moschus berezovskii, Bos taurus, Tursiops truncate and Orcinus orca.

This study was to identify the pathogen from calves which showed pneumonia symptoms occurred in a cattle farm of Kashi city in the South of Xinjiang. Three lung specimens were collected from the dead calves. Two isolates (designated as M.bovis-NJ-1 and M.bovis-NJ-2) were isolated from three pneumonic lung tissue samples of calves with Mycoplasma bovis special liquid medium and solid medium. Both isolates were identified as Mycoplasma bovis by the morphologic observation and specific PCR test, respectively. Colonies of two isolates growed on solid medium were typical fried-egg shape and Dienes staining was dark blue. An expected gene fragment of 448 bp specific for Mycoplasma bovis was amplified by PCR. In addition, the oppF genes of the isolates were amplified and sequenced, the homologies of which were 96.7% and 95.3% with reference strain Mycoplasma bovis PG45 available in the GenBank, respectively. The results indicated that Mycoplasma bovis was responsible for the calf pneumonia.

In order to study whether the internal transcribed spacers (ITS) sequence could be used as a molecular marker for the species identification of rabbit coccidian, the rDNA ITS of Eimeria intestinalis, Eimeria flavescens and Eimeria magna were amplified by polymerase chain reaction (PCR), and were cloned into pGEM-T Easy vector subsequently. The positive recombinant plasmids were identified by PCR and then sequenced. By sequence comparison and comparative analysis with the relative sequences of rabbit Eimeria spp. available in GenBank, the results showed that the lengths of Eimeria intestinalis, Eimeria flavescens and Eimeria magna were 1065, 1009 and 1047 bp, respectively, and the sequence homologies with the same species sequences were 99.2%, 99.0% and 94.5%, respectively, while were 55.3% to 82.1% compared with corresponding sequences of other different species sequences. The phylogenetic analysis using software Mega 5.0 showed that all rabbit coccidia clustered together in a clade, which was divided into two sister lineages, corresponding to the presence or absence of oocyst residuum. The result demonstrated ITS could be used as a molecular marker for the species identification of rabbit coccidia.

To establish a rapid detection of type O foot-and-mouth disease virus (FMDV) fluorescence quantitative PCR method, we selected FMDV structural protein gene 3D to design specific primers, after RNA extraction and PCR amplification, We amplified 180 bp gene fragment. The fragment was purified, cloned into pMD18-T vector, and transformed into competent Escherichia coli DH5α cells. Recombinant plasmid was identified by PCR, enzyme digestion and sequencing, and confirmed that it was the positive recombinant plasmid of FMDV. The recombinant plasmid was gradient diluted by 10 times, we established the standard curve of FMDV structural protein 3D and linear regression equation by fluorescence quantitative PCR method, and determined the optimal amplification temperature. The standard curve was Y=-3.727X+32.04, R²=0.980, and melting curve showed that there was a single peak.The detection limit of fluorescence quantitative PCR method was 1.2×10¹ copies/μL, and could only react with FMDV.These data suggested that the method had strong specificity and high sensitivity, which provided technical methods for the detection of content of FMDV in animal tissues and cells.

This experiment was aimed to study whether oyster crude polysaccharides could relieve the immune stress stimulated by LPS.Test randomly divided 30 rats into blank control group, stress control group, oyster crude polysaccharides low, medium and high dose groups.Blank control group and stress control group were fed with based diet, oyster crude polysaccharides low, medium and high dose groups were fed with based diet with 0.3%, 0.6% and 0.9% oyster crude polysaccharides.Test lasted for 28 d, the stress control group and oyster crude polysaccharides low, medium and high dose groups were intraperitoneal injected with 100 μg/kg LPS, blank control group with the same amount of saline injection, 2 h later, autopsied the rats and used relative fluorescence quantitative PCR to study the changes of the relative expression quantity of PPARγ mRNA which oyster crude polysaccharides acted on the immune stress rats.The results showed that in oyster crude polysaccharides high, medium, low dose groups and blank control group, the relative expression quantities of PPARγ mRNA in liver, spleen and lymph nodes were extremely significantly lower than that of stress control group (P<0.01), but in adrenal gland, the relative expression quantities of PPARγ mRNA of blank control group significantly decreased compared with stress control group (P<0.05).In adrenal gland and liver, there was no significant difference between oyster crude polysaccharides high and medium dose groups(P>0.05);but in spleen, there was significantly different between those two groups(P<0.05);in lymph nodes, there was extremely significantly different between those two groups(P<0.01).Adding oyster crude polysaccharides into the based diet could relieve the immunological stress from LPS, and the ease effect was better when adding amount was within the range of 0.3% to 0.6%.

A fluorescence quantitative PCR assay was developed using primers and probes designed according to a high conservative sequence of chicken infectious anemia virus (CAV). Detection of viral DNA copy number was determined by extrapolation from a CAV plasmid-based standard curve. The results showed that the estimated average viral copy number could detect 1.8×10¹ copies/μL of plasmid DNA with high reproducibility (CAV of the intra or inter) assay was below 2%. Furthermore, 1 day-old SPF chicken were inoculated with CAV and the virus loads were detected in multiple organs. The results showed that the virus could be detected in the brain, heart, liver, spleen, lung, kidney, thymus, bursa and serum and the virus loads in these organs showed no significant difference. No cross-reaction was detected with other avian virus.

To provide a preferential host system for gene expression and research gene function of classical swine fever virus (CSFV) structural and envelope protein E2, codon preference of this gene was analyzed by CHIPS and CUSP programs of EMBOSS software. The results showed that CAI and ENC values of E2 gene were 0.703 and 53.161 which had a strong bias in codon preference, and also with a strong bias towards the codons with G or C at the third codon position. There were distinct differences of 33, 25 and 25 codons frequencies in E.coli, yeast and human, respectively, comparing with CSFV E2. Besides, there were totally 34 rare codons in CSFV E2 gene and serial rare codons being strung together. The results showed that CSFV E2 was closest to yeast in codon usage pattern and yeast should be used as the most suitable expression system for CSFV E2 gene.

To establish a rapid, sensitive and specific method for evaluation of viral load of hog cholera lapinized virus (HCLV) vaccine, a Real-time RT-PCR assay was established using two pairs of primers and an internal TaqMan probe from the 5' non-structural region of HCLV genome. The sensitivity of the assay was 1.20×10⁵ copies/mL. The assay was specific and showed no application reaction with porcine reproductive and respiratory syndrome live vaccines, porcine epidemic encephalitis B live vaccines, swine paratyphoid and pseudorabies live vaccines. The coefficient of variation (CV) of 3 different vaccine samples of HCLV was 0.29% to 0.39% in intra-assay and 0.32% to 0.61% in inter-assay, respectively. Using this method to detect 7 different vaccines of HCLV from six different plants, the results showed that there were significant differences in viral loads among the selected HCLV vaccines. In conclusion, this Real-time RT-PCR was a highly sensitive, specific and stable method which could be applied to preliminarily evaluate the viral loads of HCLV vaccines.

To understand the distribution and spread of Salmonella isolated from cold fresh chicken production chain, we collected samples from a large-scale farm, and did the thorough research about serotype analysis, and pulsed-field gel electrophoresis (PFGE) typing analysis on the basic of identification. National standards and PCR were performed for the isolation and identification of Salmonella. The Salmonella detection rate of the kinds of farms, broiler farms, slaughterhouse and sales market were 1.46%(7/480), 7.00%(21/300), 62.86%(22/35), 54.67%(41/75), respectively. The detection rate in healthy chicks and dead embryos from hatchery were 1.11%(2/180), 12.00%(9/75), respectively. The PFGE genotyping of 102 Salmonella indicates yielded 24 PFGE types. Salmonella detection rate had increased along the production chain, slaughter and marketing might be the important part of Salmonella contamination. It was existing the phenomenon of Salmonella along the production chain horizontal spread.

The study was aimed to determine the differences between the N nucleoprotein of domestic pandemic kidney type avian infectious bronchitis virus (IBV) strains and other strains such as the ones already existed on the market and the abroad ones isolated in rencent years. Biological products research center of Tianjin RingPu bio-technology Co., Ltd. isolated a strain of new virus in renal tissue of chickens obtained from Shandong farm. It was finally identified to be a positive one belonging to IBV by PCR and named SD03. The primers were designed according to the conserved regions from NCBI. Then constructed the recombinant bacteria named pMD18-T-N/DH5α by RT-PCR and got the gene sequences of N domain through sequencing. The strain of SD03 was identified as kidney type IBV strain, and its homologies of nucleotide and amino acid to LDT3 and partridge/GD/S14/2003 strians (kideny type) were > 99.0% and its homologies of amino acid were 90.0% to 94.6% compared to classical kidney type strains such as Ma5, W93, Gray and Holte strains. While compared to the respiratory vaccine strains (H120, H52, M41) the homologies of amino acid were 89.7% to 91.0%. This research deeply analyzed the physicochemical properties of N domain protein of current reference epidemic strains through DNAStar software and ExPASY website (http://www.expasy.org/). This study provided a theoretical reference for N protein subunit vaccines expression and purification in different systems, and also laid some theoretical foundation for the prevention of IBV.

Through sequencing and analyzing of full-length genome of Hankou/99 strain of foot-and-mouth disease virus (FMDV), the study identified type of the strain, which had enriched gene library of FMDV and provided a solid foundation for study of molecular variation, infectious molecular cloning and pathogenesis. Five gene fragments of S, L, C, D and E covering full-length genome of Hankou/99 isolate of FMDV extracted from infected cell fluid were obtained by RT-PCR technique, which were cloned and sequenced finally. The results indicated that full-length genome of the strain was 8099 bp including 5'NCR of 1040 bp ORF of 6966 bp and 3'NCR of 93 bp with 30 bp poly(A) at end of the genome. Through application of biological softwares, the strain could be ranked in O serotype FMDV. The strain had common characteristic of deletion of 30 bp in 3A region with the OLZ and TW/97 strains. In addition, the phylogenetic tree derived from the nucleotide sequence of VP1 gene from the strain and other nine reference strains showed that the strain presented higher homology with the four strains of OLZ, TW/97, O/Akesu/58, O/OMⅢ, which indicated that they belonged to the same genotype.

With the hot phenol method to extract the capsular polysaccharide (CPS), CPS was detected by SDS-PAGE and silver stain, and subsequently made emulsion with Freund's adjuvant.The antiserum was prepared by immunizing rabbits, and examined by agar diffusion test and indirect hemagglutination assay (IHA).The results showed that a high concentration of CPS was obtained by hot phenol method, SDS-PAGE electrophoresis showed that bands were diffuse distribution and the molecular mass was about 55 ku. Agar diffusion test result was positive and red blood cells occurred up to 10 hole drop degrees by IHA.The extraction of CPS and preparation of antiserum of Haemophilus parasuis SC096 strain provided a preparation method and the theoretical basis for a variety of other bacteria containing capsule, and made the foundation for study of antigenicity and vaccine of bacterial CPS.

A polymerase chain reaction method was used to amplify the RaDtxR gene from the identified Riemerella anatipestifer serotype 2 RA-FJ strain, the target fragment was then cloned and sequenced, which included the encoding open reading frame (ORF) of RaDtxR gene. The nucleotide sequence and deduced amino acid sequence were analyzed by the bioinformatics software. The cloned sequence was 654 nucleotides in length, coding an ORF with 217 amino acids. The molecular weight, theoretical isoelectric point and instability index of the Riemerella anatipestifer RaDtxR gene were 24.82 ku, 5.69 and 38.45, respectively. The cloned RaDtxR gene shared the highest homology with Riemerella anatipestifer vaccine strain RA-CH-1 (GenBank accession number was CP003787), with 100.0%. Also, it shared 99.8% with other 4 Riemerella anatipestifer RaDtxR genes, which shared only a nonsense mutation at the position 186. No amplification was detected from other bacteria or virus, such as duck E.coli, avain Pasteurella multocida and Salmonella, the PCR results of Riemerella anatipestifer serotypes 1, 2, 3, 11, 13 were positive, which demonstrated that RaDtxR gene could be used as a diagnosis target gene for Riemerella anatipestifer.The results showed that we had successfully cloned the RaDtxR gene from Riemerella anatipestifer, which would lay a foundation for research of its function.

Dwarfing embryonated chicken eggs, HA and reverse transcription polymerase chain reaction (RT-PCR) methods were used in this test. And an infectious bronchitis virus (IBV) strain named SX01 was identified from a suspected farm in North China. The result showed that the isolate could cause a typical clinical symptom of chicken embryos. And there were no direct hemagglutination activity, but it could agglutinate chicken red blood cells after treatment with 1% trypisn. The sequencing analysis of M gene detected by RT-PCR showed that the homology of the nucleotide sequence of M genes between SX01 and GX-GL isolates was 99.4%, and with the 99.1% homology to SDZB0808 strain of QX genotype, but with lower homology in BJ/00/02 strain and H120 vaccine strain which were 90.6% and 90.0%, respectively. Analysis of the phylogenetic tree based on M gene showed that the isolate had the closed relationship with GX-GL, SDZB0808, CK/CH/LJL/110302, DY07 and IBVSX7, and were clustered into one group; but with the distant relatives from vaccine strain H120. The results suggested that SX01 was a kidney type IBV strain.

A pair of primers was designed base on the genome of porcine circovirus type 2 (PCV2) retrieved from GenBank, which could amplify the whole coding sequence of Cap gene. The PCR product was cloned into pFastBacHTA and then sequenced. Subsequently, the positive plasmid was transformed into DH10Bac cells and the recombinant plasmid with Cap gene of PCV2 (Bacmid-Cap) was identified by PCR method. The recombinant plasmid was extracted and transfected into sf9 cells and the recombinant baculovirus expressing Cap protein of PCV2 (rBacmid-Cap) was rescued, which established the basis for the further research on subunit vaccine against PCV2.

Using quantitative PCR investigate myostatin (MSTN) gene expression levels in different time of Yemnle sheep's muscle and fat (0 to 6 month), using 2^－ΔΔCt analysis of the different expression levels in different time, and aimed to understand the expression levels of Yemule sheep MSTN gene, provided genetic information for the selection of muscle growth traits. The results showed that MSTN gene expression levels in 3 month was significantly higher than the others months (P<0.05), and the others months had no significant differences in the muscle (P>0.05). In the fat , the expression level of MSTN gene present was lower in 0 month, With the growing increase, the expression levels in MSTN gene has increased, and MSTN gene expression levels was the highest in 5 month, then with the growing increase, the expression levels in MSTN gene had decreased. With the growing increase, MSTN gene expression levels had some certain rules, provided scientific basis for the selection of muscle growth traits.

The research aimed to study genetic variation and molecular biological characteristics of porcine reproductive and respiratory syndrome virus (PRRSV) from Liaoning hybrid wild boars. A virus strain was isolated by Marc-145 cells from blood of Liaoning hybrid wild boars with suspected porcine reproductive and respiratory syndrome (PRRS) infection. The isolation could induce regular cytopathogenic effects (CPE) on Marc-145 cells after six passages.ORF6 and ORF7 genes of PRRSV isolates were amplified by RT-PCR. The products were sequenced after cloning into pMD18-T vectors respectively. The sequences were analyzed and compared with other PRRSV isolates in GenBank.The results showed that ORF6 and ORF7 genes of the virus isolated shared 96.0% to 100.0%, 94.5% to 99.4%, sequence identities with that of American type strains at home and abroad, at nucleotide level and 89.6% to 100.0%, 87.3% to 98.7% respectively at the amino acid level. However, only 70.4% and 70.1% nucleotide, 48.8% and 49.7% amino acid homologies were found between ORF6, ORF7 genes and Europe type representative strains LV. It indicated that this isolate strain from Liaoning hybrid wild boars belongs to American type PRRSV.

The DNA sequencing technology, developing from the first generation to high-throughput sequencing (HTS) technology, has experienced a long and tortuous process amazing progress now. The technology has been used widely in the animal and plant genome with a great success. In addition, its also makes us to investigate the whole genome with lower cost, more in-depth. In this study, we had elaborated sequencing plaforms of HTS, such as Roche/454 sequencing, ABI/SOLID sequencing, Illumina/Solexa sequencing, single molecule sequencing and Ion Torrent sequencing technology. And we also had summarized the application of HTS in the genomics, transcriptomes, and epigenetics.

Under laboratory conditions, cultivable microbes with less than 1% of total microbes in nature, this is limited to understanding and utilization of environmental microbiota.Metagenomics break through the culturable method, and bring a new technology for study microbial diversity and functional genomics.This paper presents the concept and basic research methods, with emphasis on its application and achievement in gastrointestinal tract of an animal.At the same time, prospected the perspective of metagenomics.

According to the Brucella melitensis vaccine strain M5-90 outer membrane protein 10 (Omp10) genetic sequence in GenBank, a pair of primers was designed and the PCR technology was used to amplify Omp10 with its whole genome as the template. The Omp10 fragment which was 381 bp was obtained. Insert it into the plasmid pMD20-T, and it was transformed into E.coli DH5α. Recombinant prokaryotic expression plasmid, pET-28a-Omp10 was constructed, and transformed into E.coli BL21(DE3), and the fusion protein His-Omp10 was induced and expressed by IPTG, and identified with SDS-PAGE and Western blotting to analysis. The results showed that the recombinant protein was expressed successfully, which laid a solid foundation to the study of the animal immunization test profoundly.

The experiment was conducted to investigate the effect of biologics on growth performance, serum biochemical parameters and endocrine hormone in late fattening pigs of microbial fermentation bed system.A total of one hundred and twenty Suzhong pigs (70 kg) were randomly allotted to 2 treatments with 4 replicates per treatment, the control group was fed basal diet, the experimental group was fed the basal diet supplemented with biologics (including phytase, composite enzyme, Bacillus subtilis, yeast and Lactobacillus).There was a period of 7 days followed by an experimental period of 28 days.The results showed that compared with the control group, the average daily gain in experimental group was increased by 4.62%, and the gain to feed ratio was decreased by 6.53%, but the difference was not significant (P>0.05).Compared with the control group, the serum triglyceride (TG) content in experimental group was extremely significantly decreased (P<0.01), but there were no significant differences in the other parameters (P>0.05).Compared with the control group, the serum insulin (INS) and insulin-like growth factors-Ⅰ (IGF-Ⅰ) contents in experimental group was significantly and extremely significantly increased (P<0.05;P<0.01), respectively, the serum triiodothyronine (T3), thyroxine (T4) and growth hormone (GH) contents in experimental group had an increasing tendency, but the difference was not significant (P>0.05).In conclusion, adding biologics could improve the growth performance, the level of nutrient metabolism, the contents of IGF-Ⅰand INS, and the serum level of endocrine hormones, while it reduce the serum content of TG in pig, we suggested that the diets in late fattening pigs of microbial fermentation bed system might be added phytase, composite enzyme, Bacillus subtilis, yeast and Lactobacillus.

This experiment was conducted to study the effects of crude protein levels of starters on growth performance, serum biochemical and immune indexes of weaning lambs.Eighteen Dorper × Thin-tailed Han F1 lambs were randomly divided into three groups.Each group had 6 lambs, half rams and half ewes.Groups A, B and C were fed with three kinds of pelleted rations, respectively.They contained similar metabolizable energy, but the crude protein levels were different (10.40%, 13.00% and 15.70%).The body weight, withers height, body length, heart girth were measured and serum was collected before morning feeding on 0, 30 and 60 days of trial begins.The results showed that the lamb were fed with ration contained 13.00% crude protein, average daily gain was 248.67 g, higher than the other groups.The wither height, body length and heart girth among the three groups had no significant differences (P>0.05).Three groups had no significant differences in the serum concentration of GLU, TP, ALB, GLB, TCHO and ALB/GLB (P>0.05).The rations curde protein levels had significant effect on the serum concentration of BUN and TG (P<0.05).The serum IL-2 concentration of group B was significantly higher than that of A and C groups at 150 days of age (P<0.05), and the serum TNF-α concentration of group B was significantly higher than that of A and C groups at 180 days of age (P<0.05), the serum IgA of group B was significantly higher than that of group A at 180 days of age (P<0.05).In conclusion, the ration contained 13.00% of crude protein met the requirement of the optimum immune state and growth performance of Dorper × Thin-tailed Han crossbred lambs.

In order to find out the Shanma duck breeding in different seasons, a comparative analysis under different seasonal conditions between rearing on floor and in captivity of production performance were studied.The results showed that in the spring, laying rate and total egg weight of floor group were extremely significantly higher than that of captive group (P<0.01), while the feed ratio and malformation eggs rate in floor group were extremely significantly lower than that in captive group (P<0.01).In summer, laying rate of captive group was significantly higher than that of floor group (P<0.05) and the malformation eggs rate of captive group was extremely significantly lower than that of floor group (P<0.01), but there were no significant difference between the two groups on the total egg weight and feed ratio (P>0.05).In autumn, the laying rate of captive group was extremely significantly higher than that of floor group (P<0.01) and the feed ratio of captive group was significantly lower than that of floor group (P<0.05), but the total egg weight and malformation eggs rate were not significantly different with floor group (P>0.05).In winter, the laying rate and total egg weight of floor group was significantly and extremely significantly higher than that of captive group (P<0.05;P<0.01), respectively, and the malformation eggs rate was extremely significantly lower than that of captive group (P<0.01), but the feed ratio of floor group was not significantly different with captive group (P>0.05).In spring and winter, rearing on Shanma duck in floor method could improve the egg laying performance of ducks.In summer and autumn, rearing in captivity conducive was better for production performance.

This experiment was conducted to study the effect of dietary fatty acid composition on growth performance, nutrient digestion and nitrogen metabolism of Silver fox in growing period.Twenty male Silver foxes aged 12 weeks with a similar body weight were randomly divided into 2 groups with 10 replicates per group and 1 Silver fox per replicate, and they were fed diets supplementing 10% soybean oil (soybean oil group) and 10% mixture oil (chanterelle:soybean oil=1:1) (mixture oil group), respectively.The whole experiment period was 151 d, including two phases of days 90 to 145 (growing-furring period) and days 146 to 240 (winter fur-growthing period).The results showed that dietary fatty acid composition had no effect on the average daily feed intake and F/G (P>0.05), but the everage daily gain from soybean oil group was significantly higher than that from mixture oil group in the growing-furring period (P<0.05).Dietary fatty acid composition had no effect on the digestibility of protein and carbohydrate (P>0.05), but the digestibility of fat from soybean oil group was significantly higher than that from mixture oil group in the growing-furring period (P<0.05).Dietary fatty acid composition also had no effect on the N metabolism (P>0.05), but the biological value of protein and nitrogen retention in mixture oil group were significantly and extremely significantly higher than that in soybean oil group in the winter fur-growthing period (P<0.05;P<0.01), respectively.Considering all the factors, soybean oil was considered to be an optimal fat source in the diets for Silver foxes in the growing-furring period and oil mixture (chanterelle:soybean oil=1:1) was the optimal fat source for Silver foxes in the winter fur-growing period in terms of best growth performance.

This study was aimed to prove up the effect on the quality of fermented ganodorma fungus chaff feed supplied by use the additive, and provided a theoretical basis for the production of high quality of fermented feed.Seven treatments such as 2 mL/kg fermented green juice, 2000 U/kg cellulase, 5000 U/kg xylanase, 2 mL/kg fermented green juice+2000 U/kg cellulase, 2 mL/kg fermented green juice+5000 U/kg xylanase, 2 mL/kg fermented green juice+2000 U/kg cellulase+5000 U/kg xylanase and to add distilled water as control group had been used in this experiment.Each treatment was repeated 3 times.The materials were ensiled at room temperature and opened 60 days later, chemical composition and fermented quality of fungus chaff feed were determined.The results showed that compared with the CON group, the WSC of FGJ, CEL and XYL groups was highly significantly increased (P<0.01), the pH, GLR, NDF, HC and AN of FGJ, CEL and XYL groups were highly significantly reduced (P<0.01).Compared with the FGJ group, the LA and AA of MIX1 and MIX2 groups were significantly or highly significantly reduced (P<0.05;P<0.01), respectively, the WSC of MIX1 and MIX2 groups was highly significantly increased (P<0.01), the AN of MIX1 and MIX2 groups was highly significantly reduced (P<0.01).Compared with the CEL group, the DMR and NDF of MIX1 group were highly significantly reduced (P<0.01), the WSC and AN of MIX1 group were highly significantly increased (P<0.01).Compared with the MIX1 and MIX2 groups, the pH and GLR of MIX3 group were highly significantly reduced (P<0.01), the ADF of MIX3 group was significantly reduced (P<0.05).In conclusion, the effect of adding cellulose and adding xylanase were better than the effect of adding fermented green juice, and the effect of mixed them were better than just one, especially the best of adding effect was MIX3.

This experiment was conducted to study the effect of different stocking density on slaughter performance and meat quality of fattening sheep in winter.A total of 144 6-month-old Aletai fat tailed sheep F1 hybrid generation were randomly divided into 4 groups with 36 sheep in each group.Each sheep respectively covered an area of 0.35, 0.70, 1.05 and 1.40 m² of groups 1, 2, 3 and 4.The whole experiment period was 45 d.The results showed that carcass weight, dressing percentage, net meat weight and net meat percentage decreased from group 4 to group 1.Compared with group 1, the carcass weight, dressing percentage, net meat weight and net meat percentage of group 4 were significantly increased by 20.65%, 11.00%, 30.40% and 19.73% (P<0.05), respectively.The scores of meat color for all groups was 3 to 4 points.The marbling was 1 to 1.1 points, the pH was the lowest, the shear force was the highest, the tenderness was the worst for group 1.In conclusion, under the condition of this experiment, the low breeding density (1.40 m²) had the better slaughter performance and meat quality, the high breeding density (0.35 m²) had the reverse effect.

16 healthy cats were randomly divided into two equal groups, a single dose of parallel test design was used. The pharmacokinetics of test substance and reference substance milbemycin oxime-praziquantel tablets were studied in cats by oral route (4 mg/kg·bw). The plasma concentrations of milbemycin oxime and praziquantel were determined by high-performance liquid chromatographic method, and pharmacokinetic parameters were calculated by kinetica program. The main parameters of reference substance were as follows, T_1/2β, T_max, C_max, AUC and MRT of milbemycin oxime were (20.08±7.57)h, 6.00 h, (764.43±251.40)ng/mL, (15.00±5.05)ng/(L·h) and (18.60±1.52)h, respectively; and T_1/2β, T_max, C_max, AUC and MRT of praziquantel were (6.27±5.26)h, (3.88±0.35)h, (1018.25±200.19)ng/mL, (8.69±2.07)ng/(L·h) and MRT (6.56±1.07)h, respectively. The main parameters of test substance were as follows, T_1/2β, T_max, C_max, AUC and MRT of milbemycin oxime were (15.07±4.05)h, (5.25±1.04)h, (806.65±299.01)ng/mL, (15.18±5.97)ng/(L·h) and (17.47±1.97)h, respectively, and the relative bioavailability was 101.20%; T_1/2β, T_max, C_max, AUC and MRT of praziquantel were (11.11±4.62)h, (5.25±1.04)h, (880.47±241.27)ng/mL, (9.64±2.76)ng/(L·h) and (10.52±1.52)h, respectively, and the relative bioavailability was 119.16%. Compared with reference substance, significant difference in T_1/2β was observed in milbemycin oxime (P<0.05), and significant difference in T_max was also observed in praziquantel (P<0.05), other parameters were no significant differences (P>0.05).The results showed that the test substance of milbemycin oxime-praziquantel tablets compared with the reference substance had similar pharmacokinetic characteristics in cats by oral route.

The objective of this study was to explore the method of isolation and cultivation of fibroblasts of Kunming dog in vitro. 12 fetus at 30th day in gestation of Kunming dog were obtained by laparotomy and the sex indentification of fetus were 7 males and 5 females. The body size and weight of fetus were measured. The results showed that male and female fetus of body length were 1.90 cm ± 0.14 cm and 2.00 cm ± 0.05 cm, body width were 0.90 cm ± 0.13 cm and 0.90 cm ± 0.15 cm, body weight were 0.68 g ± 0.17 g and 0.66 g ± 0.06 g, the difference was not significant (P>0.05). Additionally, the fetal fibroblast cell lines were successfully established by the method of collagenase digestion and cryopreservation. The research were designed to examine the biological characteristics of fibroblasts. The cells showed typical morphologic characteristics of fibrous and long spindle appearance. Analysis of the growth of the fibroblasts revealed a sigmoid curve with the population doubling time (PDT) of 36 h. Moreover, the average viability of the fetal fibroblasts was 96.1% before freezing and 94.6% after thawing. Karyotyping indicated the chromosome number of Kunming dog was 2n=78 (XY). In conclusion, the fetal fibroblast cell lines in Kunming dog were successfully established in vitro. It will not only preserve the genetic resources of Kunming dog at the cellular level but also provide valuable materials for further research.

In order to study the variation in different parts of adipose tissues deposition of Aletai sheep, 90 days (n=6) and 270 days (n=6) old ram of Aletai sheep were chosen in this study.The adipocyte area of perirenal fat, tail fat and subcutaneous fat were measured by using the method of oil red O staining on adipose tissue frozen section and Motic microscopic digital image processing system.Serum lipid metabolism related enzymes and hormones were measured by using radioimmunoassay and ELISA method. The results showed that in 90 days old Aletai sheep, the adipocyte area of tail fat was very significantly higher than adipocyte area of perirenal fat (P<0.01), in 270 days old Aletai sheep, adipocyte area of tail fat and subcutaneous fat were very significantly higher than adipocyte area of perirenal fat (P<0.01). Compared with 90 days old Aletai sheep, adipocyte area of perirenal fat in 270 days old Aletai sheep was significantly increased (P<0.05), and adipocyte area of tail fat was very significantly decreased (P<0.01). Serum leptin and hormone semitive lipase (HSL) concentrations of 270 days old Aletai sheep were very significantly lower than that of 90 days old Aletai sheep (P<0.01), and concentrations of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were very significantly higher (P<0.01). These results indicated that variation in different parts of adipose tissues deposition of different old Aletai sheep were inconsistent, this change might be related to serum leptin, HSL, AST and ALT levels.

The assay was aimed to evaluate the differences of prevalence and drug resistance of Enterococcus species among human, broilers and swines in Henan province, China. Totally 220 stool samples were collected, and identified by 16S rDNA sequence analysis and the Rapid ID 20 Strep System. There were significant differences among the total isolation rate of Enterococcus, isolation rate of E.faecalis, isolation rate of E.faecium in 3 different origins (P<0.05).A total of 156 (70.91%) Enterococcus spp. isolates were recovered. The isolation rate of Enterococcus from swine origin was the highest (86.00%), while human origin was the lowest (62.63%), There were significant differences between the isolation rates of swine and human origns (P<0.018). The most predominant specie was E.faecium (31.36%) in human, while in broilers and swines were E.faecalis (28.17% and 32.00%, respectively). All isolates were sensitive to vancomycin and teicoplanin. The resistant rate of many multidrug-resistant (MDR) of the isolates from human, broilers and swines were statistically significant (P<0.05).The resistant rates of isolates from human origin Enterococcus spp.to erythromycin (69.35%), ciprofloxacin (37.10%) and ampicilin (19.35%) were higher than those from broiler origin and swine origin. The isolates resistant rates to tetracycline (88.24%), florfenicol (11.76%) and chloramphenicol (21.57%) from broiler origin Enterococcus spp. were higher than those from the other two origins, respectively. The MDR rates of human (35.48%) and broiler (30.19%) origins isolates were higher than swine origin (7.84%). The observation in this study suggested that the prevalence and drug resistance of Enterococcus spp. from human, broilers and swines in Henan province were different, and the MDR isolates were prevalent in various origins Enterococcus. More attention should be given on investigation and research of the resistance of Enterococcus among human and animals to better understand the epidemic of the antidrug-resistant Enterococcus and minimize the spread of it effectively.

This experiment was aimed to compare immune enhancement activities of Astragalus polysaccharide (APS), Morus polysaccharide (MPS) and Chinese yam polysaccharide (CYPS) to chicken peripheral lymphocyte-T and spleen lymphocyte-B. The safe concentrations of the 3 polysaccharides to chicken embryo fibroblast were tested by enzymes detection method; the influence on proliferation of chicken peripheral lymphocyte-T by the 3 polysaccharides separate stimulating and coordinate stimulating with PHA were compared, the influence on proliferation of chicken spleen lymphocyte-B by the 3 polysaccharides separate stimulating and coordinate stimulating with LPS were studied. The results revealed that APS and MPS had higher safe concentrations. At 64 to 512 μg/mL, 3 polysaccharides showed excellent activity of promoting proliferation of peripheral lymphocyte-T and spleen lymphocyte-B. The results showed that the 3 polysaccharides had different influence on proliferation of chicken peripheral lymphocyte and spleen lymphocyte, and among them, the effect of APS was best, that of MPS was less, and CYPS was least.

The introduction of Bama minipigs from Guangxi Bama Yao autonomous county for breeding, we observed the change of adaptability and the blood physiological and biochemistry indicators in the Northeast environment.After two years observation and inspection, we confirmed that the introduced Bama minipigs had good adaptability, normal reproductive performance, sexual maturity of 2 to 3 months of age, pregnancy period of 114 to 120 days, the number of piglets of 3 to 7 primiparous head, and the number of multiparity of 5 to 10 piglets head.The numbers of piglets were significantly related to the weights of sow (R²=0.96).The values of WBC, HGB, AST, Urea, Cr, CK, LDH, GLU, T-Ch, TG, CHS, Na, Cl, AMS and CO2CP of Liaoning minipigs were lower than the data of original pig farm (P<0.05), other values were not significantly different (P>0.05).The results provided a reference for the test of Bama minipigs in Liaoning area.

Growth hormone (GH) has important physiological roles on animals in growth and development. GH plays a series of physiological effects after binding to growth hormone receptor (GHR). Our understanding of the mechanisms of action of GH and its receptor, the GHR, has advanced significantly in the last decade and has provided some important surprises. It is now clear that the GH-GHR axis activates a number of inter-related signalling pathways, not all of which are dependent on the intracellular tyrosine kinase, JAK2 as originally postulated. This paper summarizes the following aspects of signal transduction mechanisms progress under the GHR role:GHR structure and function;GHR signalling including JAK2-dependent signalling and JAK2-independent signalling; negative regulators of GHR signalling. Continued emphasis on elucidation of these complex mechanisms is critical to provide further insights into the animal diverse physiological and pathophysiological effects of GH.

In this experiment, genetic polymorphisms of growth hormone (GH), calcium-activated protease (CAPN1) and calpastatin (CAST) genes were studied by PCR-RFLP and analyzed their association with economic traits in Snow Dragon Black cattle by general linear model (GLM).The results showed that among the GH-P3, CAPN1 316 and CAST-UoG SNPs were moderate polymorphic.The GH-P3 SNP was very significantly associated with chuck short rib (P<0.01), significantly associated with the chuck flap and fat grade (P<0.05).The chuck short rib of AA genotype was 0.42, 0.60 cm thicker than that of AB and BB genotypes, respectively.The chuck flap of AA genotype was 0.52, 0.78 kg weightier than that of AB and BB genotypes, respectively.The fat grade of AA genotype was 0.95, 1.16 higher than that of AB and BB genotypes, respectively.The CAST-UoG SNP was significantly associated with chuck short rib and fat thickness (P<0.05).The chuck short rib of AA genotype was 0.32, 0.30 cm thicker than that of AB and BB genotypes, respectively.The fat thickness of AA genotype was 0.80, 0.47 cm thicker than that of AB and BB genotypes, respectively.CAPN1 316 SNP was no obvious association with economic traits studied (P>0.05).So we could choose AA genotype as molecular marker to benefit for the variety breeding of Snow Dragon Black cattle.

Blood samples were randomly selected from genomic DNA of 98 South Devon hybrid progeny to construct DNA pool, and sequence variations and polymorphism of growth differentiation factor 10 (GDF10) gene were analyzed by high resolution melting curve (HRM) analysis techniques and direct sequencing.SHEsis and PHASE were used to screen the SNPs in GDF10 gene by the wave height of sequencing map.The association between genotypes and body measurement was evaluated by SPSS 17.0.The results showed that three SNPs 1113 (G/A), 9569 (G/A) and 9628 (G/A) of GDF10 gene were identified in the population.Analysis of association of polymorphism with body measurement traits at all mutation loci showed that there were significant effects on body height, body length, chest circumference and cannon bone girth (P<0.05).There were 8 haplotype combinations in the cattle populations, in them AAA and GGA had significant effects on body height, body length, chest circumference and cannon bone girth (P<0.05).The results suggested that three SNPs and two haplotype combinations might have potential effects on production traits in the above mentioned cattle populations and could be used for marker-assisted selection.

Experiments were designed to investigate the factors of influencing superovulation in Wagyu.These factors included season, times of repeated superovulation and paternal line.All donors received 120 mg NIH of Folltropin-V in a conatant dose, twice daily IM schedule over 4 days.The results showed that:①There were no difference of the mean number of embryos (7.1, 7.8, 8.3 and 7.7) and of transferable embryos (5.2, 4.7, 5.2 and 5.2) in the spring, summer, autumn and winter(P>0.05).The mean number of untransferable embryos (3.2 and 3.1) in summer and autumn were significantly higher than in spring (1.9) (P<0.05).②Repeated superovulation (1 to 10)was applied to superovulation of Wagyu.There were no difference among the mean number of embryos (7.5 to 9.3), of transferable embryos (4.6 to 6.1) and of untransferable embryos (2.7 to 3.4) (P>0.05).③The mean number of recovered embryos in the WESFA0107 line (11.1)was significantly higher than in the GOSFZ0302、BYWFA0015、BYWFY0342、BYWFY0350 and TFWFW06290 lines (P<0.05).The mean number of recovered transferable embryos in the WESFA0107 line (6.2)was significantly higher than in the BYWFY0350 line (3.6)(P<0.05).The mean number of recovered degenerate embryos in the WESFA0107 line (3.3) was significantly higher than in the BYWFA0015, BYWFY0350 and TFWFW06290 lines (1.8, 1.1 and 1.7) (P<0.05).The mean number of recovered unfertilized ova in the WESFA0107 line (1.6)was significantly higher than other lines (P<0.05).The mean numbers of recovered embryos and transferable embryos in the BYWFY0350 line (5.3 and 3.6) were the least among the paternal lines.In summary, avoiding hot seasons, repeated superovulation and selecting dornors of appropriate paternal line could enhance the production of embryo in Wagyu.

In this study, Gaojiao chickens, Weining chickens, Wumeng black-bone chickens (including blue-shell chickens and white-shell chickens) from three local breeds of Guizhou were selected for research subjects. By constructing DNA pools to amplify the all sequences of extron 1 and the segmental sequences of intron 2 on NKX2-5 gene. Taking direct sequencing method to detect the single nucleotide polymorphisms on NKX2-5 gene of three varieties (four groups). By bioinformatics software to predict the effects of different polymorphism loci on mRNA, protein secondary structure of NKX2-5 gene. The results showed that 5 SNPs including G108A, T288C, C400T, T420G and G429A were discovered. And among these SNPs, G108A was located in non-coding regions, T288C and C400T were located in extron 1, T420G and G429A were located in intron region. T288C and C400T were missense mutations, T288C mutation leaded to serine (Ser) into proline (Pro), C400T mutation leaded to alanine (Ala) into valine (Val), and SNPs sites had some effects on mRNA secondary structure, protein secondary structure of NKX2-5 gene.

The research measured body size traits and slaughter performances and carried out the significance test and correlation analysis for 100 ten weeks old Xingyi ducks. The results indicated that the difference of body size traits was significant from different sex ducks (P<0.05), the slaughter performances had no significant difference except that the lean meat percentage of male were significantly lower than female and weight of leg bone and muscular stomach were significantly higher than female (P<0.05);The correlation analysis showed that all body size traits had a significant correlation, the majority of slaughter performances showed a significant correlation (P<0.05), and lung showed a little correlation with other traits in Xingyi ducks;The majority of body size traits showed significant correlation with slaughter performances (P<0.05);The weight of pectorales showed significant negative partial correlation with stank length and stank girth (P<0.05), the weight of muscular stomach showed significant positive partial correlation with length from beak to hip all, keel bone length and stank girth (P<0.05). These results will provide a fundamental statistics for study on Xingyi ducks in the future and as a insight for selection of Xingyi ducks.

CoQ₁₀ is a quinone ring compound, existing in flora and fauna extensively, some biologists named it vitamin Q as it play a part in oxidative phosphorylation, regulation of apoptosis, radical scavenging, enhancing immunity and so on.The polymorphism of genes encoding CoQ₁₀'s synthase influence the level of CoQ₁₀ and this makes it possible that treating the genes as markers in breeding of Black cattle.The mechanism of CoQ₁₀ in oxidative phosphorylation and regulation of apoptosis, location and structure of the genes encoding CoQ₁₀'s synthase were summarized in this article.These materials provide reference for beef breeding in molecular marker technology.

In order to understand the relationship between single nucleotide polymorphism sites(SNPs)of myostatin(MSTN) gene and slaughter traits in Xingyi duck, MSTN gene was used as a candidate gene for slaughter traits. The polymorphisms of the exon of MSTN gene in Xingyi duck were detected by direct sequencing of PCR products and gene cloning. The results showed that there were 8 single nucleotide polymorphism sites (SNPs) in 60 Xingyi ducks, there were 5 mutations in exon 1 of SNP1(G77A), SNP2(A91G), SNP3(G130A), SNP4 (C325T), SNP5(C331T), there was no mutation in exon 2, and there were 3 mutations in exon 3 of SNP6(C206T), SNP7 (A235G), SNP8 (C256A). By correlation analysis between the 8 SNPs and slaughter traits, it showed that there were no significant associations between the genetype and slaughter traits of Xingyi ducks (P>0.05). The result of this study could enrich MSTN gene research data and provide reference for duck breeding.

This experiment was to study the effect of cold stress on the lipoprotein lipase (LPL) gene mRNA expression in Altay sheep, tissue samples of six part were collected before and after cold stress, LPL mRNA expression levels were detected using RT-PCR method.The results showed that the LPL mRNA expression of Altay sheep was significantly or extremely significantly increased after cold stress (P<0.05;P<0.01), and the highest expression after cold stress was intramuscular fat of the neck and tail fat, suggested that the Altay sheep's strong mobilization of adipose tissue at low temperatures so that their body heat production increased to resist cold stress.

In order to provide some reference on scientific training and determination of horse trot training race, experiment was conducted on analysis of speed characteristic of Yili horse trot training race. The grade of 7 Yili horses 1000 m trot training race and the speed per 50 m were measured, which was used as a research object and sample, by statistical analysis, correlation analysis, the difference of the linear regression method for quantitative analysis. It was resulted that between subsection speed (2 to 18) and average speed were significantly or extremely significantly correlated (P<0.05;P<0.01), the 9^th subsection speed had the highest relevancy; 6 high correlation subsection speeds were choosed for regression analysis, equation:Y=4.039X₉+2.256X₈－2.653X₁₆－1.361X₅－3.739X₁₃+2.529X₁₉－0.728. The experiment preliminary proved the difference among every subsection speed of 1000 m speed training race and the correlation between subsection speed and average speed, establishing a regression equation of subsection speed and average speed.

This paper was aimed to study the growth and development of Hu sheep, and had a preliminary discussion in growth curve model and made a trend analysis. It could provide a basis for the Hu sheep breeding and the feeding management improving which was based on the growth curve for the model, then the best growth point and listing point of Hu sheep could be found. 31 Hu sheep were chosen, which were breed on wood high bed, to detect the weight of 7-day-old, 14-day-old, 1-month-old, 2-month-old, to 12-month-old. The growth curves of Hu sheep was analyzed with three kinds of nonlinear models (Logistic, Gompertz and Von Bertalanffy). Finally, we found that the growth curves were appropriately fitted with Logistic and Gompertz models. The values of R² were higher than 0.97, and the Gompertz model had the best effect on fitting with the growth curves of Hu sheep. Furher study also showed that the day of growth inflexion of Hu sheep was around 2 month age by using the best fitting model.

This experiment was aimed to cultivate Fasciola gigantica metacercariae, the development process and the clinical, pathological changes of Fasciola gigantica in the intermediate host were studied. Fasciola gigantica eggs were artificially cultured and hatched. Fasciola gigantica miracidium were used to infect intermediate host, Galba pervia. The collected metacercariae were used to infect mice, the results showed that the liver had a different degree of pathological changes, and liver surface and essence contained Fascola gigantica larvae. The results indicated that Fasciola gigantica larvae could survive 7 to 8 weeks when they were raised in mice, and could cause regular pathological changes and even death. So we could use the mouse as experimental animal of Fasciola hepatica infection for the study of early diagnosis, immune prevention, treatment and other aspects of Fasciola hepatica disease.

Coccidiosis was the major parasitic disease in chickens and caused huge losses in poultry industry. The approach of anti-chicken coccidiosis was medication, but the resistance strains were emerged after mass and long term used medication, environmental pollution was severe, so anticoccidial vaccine became the first method for anti-chicken coccidiosis. Cytokines as immunoadjuvant could enhance specific immunity response of vaccine, and had a crucial role in parasite vaccine's research.This paper summarized the research progress on mechanisms of action and application of cytokine against chicken coccidiosis.

The healthy Pelteobagrus fulvidraco were artificially infected with Yersinia enterocolitica (Y.enterocolitica) strain GM2402 by intraperitoneal injection to test the median lethal concentration (LC₅₀).The histology changes of Pelteobagrus fulvidraco were studied by histopathological methods.These results showed that the challenged fish indicated abdomen swelling, pectoral fin and ventral fin bleeding, swelling and bleeding on anus after intraperitoneal injection.The LC₅₀ value of Y.enterocolitica in Pelteobagrus fulvidraco was 3.0×10^6.2 CFU/mL.The main histopathological changes of organs indicated that swelling and degeneration of hepatocyte were observed in the liver.In the kidney, swelling and degeneration were showed in renal tubule epithelial cell.A large number of erythrocyte emerged in spleen. Gill lamella showed mild congestion and swollen.The ultrastructures indicated that there were distinct changes in liver and intestine, especially in mitochondria.The cristaes of mitochondria were disordered and disappeared. In conclusion, Y.enterocolitica strain GM2402 was pathogenic to Pelteobagrus fulvidraco.

There are more and more mycotoxin-contaminated crops around the world, which not only results in huge economic losses, but also has adverse effects on animal and human health.Flow cytometry has become an available tool in cytotoxicity of mycotoxins studies in recent years for the rapid and accurate analysis of single cells in a mixture.The author reviewed the application of flow cytometry to determination of mycotoxins and research of its cytotoxic effect in order to provide references for further research of mycotoxin toxicity mechanism.

Clostridium difficile is a G⁺ anaerobic and one of the most important pathogenic bacteria in human intestinal infection. Its major pathogenic factors are toxin A (enterotoxin) and toxin B (cytotoxin).After the cell damage caused by toxin A, toxin B can invade the intestinal mucosa, cause cell lesion, lead to cytopathy and a series of clinical manifestations in infection.Meanwhile, Clostridium difficile toxin is also an important factor causing diarrhea in pigs, chickens and other livestock. Exploring the damage of Clostridium difficile toxin to the body is helpful to reveal the pathogenesis of Clostridium difficile, which provides a theoretical basis for prevention and control of Clostridium difficile.

Bacteria were isolated from the duck organs of six duck farm in Guizhou province.According to the bacteria culture characteristics, gram stain's and microscope and biochemical properties, 137 strains bacteria of 7 genus were isolated, Escherichia, Staphylococcus and Riemerella were 3 main bacteria.Selecting main pathogenic bacteria to dilute into 10⁹ CFU/mL bacteria suspension, BALB/c mice were intraperitoneal injected 0.3 mL each, pathogenicity was analysed by statisticsing its mortality rate, observing its clinical symptoms and autopsy lesions.The results showed that the Escherichia and Staphylococcus caused the BALB/c mice to die and clearly visibled the autopsy lesions, fatality rate were 23.3% and 16.7%, respectively, while there was on pathogenicity and fatality rate was 0 when injected Riemerella, the control group was 0.The results indicated that there exists mixed infection in the 6 duckery, the Escherichia and Staphylococcus have pathogenicity to mice, however Riemerella has no pathogenicity to the mice.

In order to investigate extended spectrum beta-lactamases (ESBLs) production and drug resistance of Escherichia coli strains isolated from chickens in Taizhou areas, 13 strains of Escherichia coli isolates were tested. ESBLs were examined and minimum inhibitory concentrations (MICs) of different drugs against ESBLs producing strains and non-ESBLs-producing strains were detected by broth microdilution method. The results showed that 5 out of the total 13 isolates were identified as ESBLs producing strains, and the positive rate was 38.5%. And drug resistance of ESBLs producing strains to β-lactam antibiotics was extremely serious with apparently higher drug-resistance rate than those of the non-ESBLs-producing strains, resistance rate of the ESBLs producing strains and non-ESBLs-producing strains to ampicillin were 100% and 62.5%, respectively; resistance rate to ceftiofur were 100% and 12.5%, respectively; resistance rate to ceftriaxone were 80% and 20%, respectively. To other antimicrobial resistance rates were apparently higher than those in non-ESBLs-producing strains.Ampicillin and shubatan (2:1) combined with the single ampicillin compared to ESBLs producing strains MIC value reduced to single ampicillin at 1/16 to 1/8, whereas no significant changes happened on non-ESBLs-producing strains. Ampicillin and Amikacin (1:1)combined compared to any kind of both, on ESBLs producing bacteria and non-ESBLs-producing strains MIC values were reduced to a single drug 1/16 to 1/2.The results showed that, the clinica choice of mixed preparation of betalactam and beta lactamase inhibitors to treat ESBLs producing chicken Escherichia coli infection, the drugs of different kinds or different mechanism were also combincated to treat chicken Escherichia coli infection, especially drug resistance chicken Escherichia coli infection.

Antibiotics were important to control diseases of human and animal.However, the widely use of antibiotics in animal husbandry caused serious drug resistance and drug residue, which were harmed to the health of human and animal, so antibiotic alternatives became a new research trend.Here the antibiotic alternatives were summarized and the mechanism of immune regulation were reviewed.

One bacterium was isolated from a large-scale Shandong Long-hair rabbit farm with the main clinical features of rhinitis and purulent pneumonia disease in June 2012. After bacterial culture, it was verified as capsular serotype A Pasteurella multocida through staining, biochemical test, PCR identification and animal test. The drug sensitivity test results showed that the bacterium was sensitive to tilmicosin, enrofloxacin, florfenicol, ceftiofur sodium and amoxicillin. 3 experimental groups (Pasteurella vaccine trial group, enrofloxacin group, Pasteurella vaccine and enrofloxacin combined group), each group with 500 Long-hair rabbits, were designed, the results showed that Pasteurella vaccine and enrofloxacin combined group had ideal effect on the prevention and control of the disease after 30 days.