In recent years, more and more studies on mitochondrial fusion and fragmentation mechanisms have been conducted, mitochondria are double-membrane organelles possessed by all eukaryotic organisms. In most cells, mitochondria are highly dynamic and maintain their homeostasis by continually fusing and dividing.Mitochondrial outer membrane and endometrial fusion were regulated, respectively by Mfn1, Mfn2 and a variety of forms of OPA1;DRP1 mediated epineurial division,at present the mechanism of endometrial fission is still unclear,may be mediated by S-OPA1 and MTP18. Research shows that a variety of objective factors through the impact of the degree of integration or division,thus affecting the mitochondrial fusion and fission,increased mitochondrial fusion or decreased mitochondrial fission will result in the cell into individual large, small number of mitochondria;On the contrary,will lead to mitochondria appear individual small, large number. In the future research process, this feature can be used to detect indirectly a change in mitochondrial morphology factors. On the basis of summarizing the results of previous studies, in the present review, we focus on the mitochondrial fusion and fission, some related proteins involved in mitochondrial fusion and fission, as well as the occurrence of mitochondrial disease.

In order to enrich basic date in goat (Capra hirus) CMKLR1 gene and investigate the correlation between CMKLR1 gene expression and intramuscular fat (IMF) content in muscles, the CMKLR1 gene was cloned from the goat of subcutaneous adipose tissue by RT-PCR, characterized by bioinformatics methods. The expression profiles of CMKLR1 gene of goat in various tissues were constructed liver was benchmark, the GAPDH (GenBank accession No.: AJ431207.1) as a reference gene.Then, the correlation between CMKLR1 mRNA expression and IMF content in muscles was analyzed. The results showed that the CMKLR1 gene CDS of goat (GenBank accession No.: KT165374) was 1 089 bp. Real-time PCR indicated that CMKLR1 was widely expressed in various tissues, including heart, liver, spleen, lung, kidney, adipose, longissimus dorsi, biceps femoris and triceps brachii, and was the highest in lung (P< 0.05). Similar expression variation trend of CMKLR1 was observed between the muscles from 1 to 3 and 24 months old goat, and was the highest in biceps femoris. Reversely, in 8 to 10 months old CMKLR1 was the highest in triceps brachii. The IMF of longissimus dorsi from 24 months old was the highest. Correlation analysis demonstrated that different correlations were observed between expression of CMKLR1 mRNA and IMF content in longissimus dorsi, biceps femoris, and triceps brachii in goat. The CMKLR1 gene did not participate in the deposition of IMF in goats. The research built the theoretical basis for further studies about the CMKLR1 gene.

To obtain the 3C protein of encephalomypcarditis virus (EMCV) and predict its structure,3C gene was amplified by RT-PCR with the RNA as template from HB10 strain. And the target gene inserted into pMD18-T vector. The plasmids were sequenced after verification by PCR and double enzyme digestion. The target gene was cleaved from the correct plasmid,and inserted into the pET32a vector. The recombinant pET32a-EMCV-3C was transformed into TranSetta (DE3) and then induced by IPTG. Then the size was identified by SDS-PAGE and the antigenicity was analyzed by Western blotting. According to the sequence results,the length of 3C gene was 615 bp,which encoded 205 amino acids. The results of SDS-PAGE showed that His-3C protein mainly existed in the form of inclusion body with the molecular of 40 ku. The Western blotting results verified that purified His-3C could react with rabbit anti-EMCV serum prepared with EMCV. Bioinformatics analysis indicated that 3C protein was non-secretory,and had multiple phosphorylation sites,but it had no transmembrane region. Thus,the 3C protein mainly involved in protein hydrolysis process.3C protease,as the only protease in the EMCV genome,played an indispensable role in viral replication. In this study,we successfully constructed the prokaryotic expression vector of 3C protein and predicted its structure,which provided a basis for further study of the role of 3C protein and catalytic mechanism.

The aim of this study was to clone the JHDM2A gene of porcine and study the expression of JHDM2A gene in porcine ovary. In this study, we cloned the porcine JHDM2A gene and constructed its eukaryotic expression vector, the expression of JHDM2A gene in porcine ovarian tissue was also analyzed. The results showed that the cloned CDS length of porcine JHDM2A gene was 3 945 bp, which encoded 1 315 amino acids. The results of multiple amino acid sequence comparison showed that the porcine JHDM2A shared 93.5%, 94.7%, 94.7% and 93.8% homologous compared with those of Bubalus bubalis, Bos taurus, Ovis aries and Homo sapiens, respectively. Phylogenetic tree analysis indicated that the JHDM2A gene was highly conservative in the evolutionary process. The pLVX-IRES-ZsGreen1-JHDM2A eukaryotic expression vector was constructed, and clear green fluorescent signal was observed when the plasmid was transfected into HEK293T cells by liposome method. The immunohistochemical results showed that the JHDM2A protein was expressed in porcine follicle of different development stages.The results showed that the porcine JHDM2A gene sequences was cloned, and the JHDM2A protein was highly expressed in porcine ovary, indicating that its function might be closely related to the development of porcine follicular.

In order to analyze the character of LSm1 gene and predict its biology function in this study,LSm1 gene from the Marc145 cells was amplified and cloned by nested PCR,and the secondary structure, B cell epitopes,conserved domain, transmembrane domain and signal peptide of LSm1 protein were predicted by bioinformatics softwares. The results showed that LSm1 gene sequence with 402 bp was successfully obtained,which could encode 133 amino acids. The nucleotide sequence of LSm1 gene from Marc145 cells was high similarity with human and primates,followed by marine mammals,terrestrial wild animal and livestock,the percent identity was from 92.8% to 99.8%.The encoding amino acid sequence similarity was from 97.8% to 99.3%. The results of phylogenetic tree showed that the LSm1 gene of Marc145 cells was closely relative with human which were in the same branch,followed by primates. The alpha helix and random coil were dominant in secondary structure ,which was 45.11% and 24.06%,respectively. It was predicted that there were 4 B cell dominant epitopes and a conserved domain of Sm superfamily in the LSm1 protein, and there was no transmembrane region and signal peptide region. In conclusion,the LSm1 protein might has low transcription and expression level in the intracellular,and nested PCR was needed to achieve the target band from cDNA of cells. The method provided a reference for the amplification of LSm1 gene. At the same time,the prediction results of it's biological function would lay a foundation for studying the LSm1 artificial expression protein,the antibody and the functional mechanism of LSm1 at the cellular level.

Polysaccharide is the major component of bacterial cell that plays a significant role in the interaction between bacteria and their hosts. It aids the identification of bacteria, imparting virulence to the bacteria and adjusting host's immune response as well. Advance genomics research has deciphered several different bacterial polysaccharides sharing a common biosynthesis mechanism. The study of polysaccharides is mainly based on sequence analysis and prediction of genome in combination with metabolite analyses that still requires a detailed study. Researchers are now further focusing on their biosynthetic pathways to unveil the mechanisms underlying the diversity of these bacterial polysaccharides along with the host-pathogen interaction. It will open new doors for vaccine development and other therapeutic methods against pathogenic bacteria, and also provide technical support to control disease and cure at molecular level. This review states the mechanisms and relevant problems of biosynthesis and in vitro biosynthesis of peptidoglycan,O-antigen and capsular polysaccharides,and summarizes the application of bacteria polysaccharides in the aspects of searching for candidate antigens and controlling the targets of pathogenic bacteria and exploring genetic evolution of bacteria and biological synthesis.

In order to understand the characteristics of S gene of porcine epidemic diarrhea virus (PEDV) in Guizhou province, and grasp the genetic variation of PEDV, according to 3 pairs of specific primers designed in the test, S gene of 6 strains of PEDV from Guizhou were amplified by RT-PCR, cloned and sequenced. Nucleotide sequence and phylogenetic tree of 6 strains of PEDV from Guizhou and reference strains were analyzed by biological information software. The result showed that the length of S gene genome of 6 strains of PEDV from Guizhou was 4 161 bp, encoding 1 387 amino acids, and the nucleotide homologies of domestic and foreign PEDV reference were from 93.3% to 98.8%, the amino acid identity were from 91.6% to 98.9%. Phylogenetic tree analysis results showed that the 6 strains were close to the American strain, Vietnam strain and the Shandong strain.They were far from the CV777, LZC, Brl and 83P-5.The experiment showed that the S gene of PEDV in Guizhou had a certain degree of amino acid change in recent year with a trend of variation. The study provided a theoretical basis for the prevention and control of PEDV in Guizhou province.

In order to diagnose porcine reproductive and respiratory syndrome virus (PRRSV) early, a rapid, sensitive, simple reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay was established. Four primers targeting the ORF5 gene of PRRSV were designed. Reverse transcription and amplification of the viral cDNA using Bst DNA polymerase was optimal at a constant temperature of 65 ℃. The output of the RT-LAMP assay was visualized using 1.0% agarose gel electrophoresis and color change after the addition of the SYBR Green Ⅰ dye. The assay was also specific for PRRSV and did not cross react with classical swine fever virus (CSFV), porcine circovirus virus type 2 (PCV2), porcine parvovirus (PPV), porcine pseudorabies virus (PRV). The RT-LAMP method was approximately 100-fold more sensitive than RT-PCR for PRRSV detection. The clinical samples (n=10) were identified both by RT-PCR and RT-LAMP, and the coincidece rate was 100%. Thus, the novel RT-LAMP assay was a rapid, simple, sensitive, specific test for PRRSV, and it could potentially be applied in clinical settings.

In order to obtain TSATG7 gene sequence and analyze mRNA expression in tissue of Banna Mini-pig inbred line (BMI), we used TSARG7 gene mRNA sequence of pig and related species from GenBank as reference sequences to design specific primers and amplify BMI TSARG7 gene. The semi-quantitative was used to analyze the expression of TSARG7 gene in 10 important tissues, protein sequence was used to carry out functional bioinformatics analysis. A coding sequence of 1 371 bp (GenBank accession No.: KU950831, the corresponding amino acid sequence accession No.: AMY60405) of BMI TSARG7 was obtained, which encoded a protein of 456 amino acids, the protein molecular weight was 52.05 ku, and the isoelectric point was 9.28. Multiple tissue expression indicated that TSARG7 gene expressed highly in the testis, middle and low expression in the other tissues. Functional bioinformatics analysis indicated that TSARG7 protein contained one conserved domain, three transmembrane regions, and no signal peptide sequences;Its N-terminal was hydrophobic and C-terminal was hydrophilic;It had five kinds functional active sites and a 94.1% to located in cytoplasmic. The results of the study would lay a foundation for further study of the gene about its functions in pig spermatogenesis and sexual maturation.

The swine leukocyte antigen (SLA) genes in pigs were the important immune gene group in antigen presentation, and studing on SLA could provide the references for the prevention of some infectious diseases. Earlier studies found that SLA-1-632-TPK gene in ToPigs pig had a deleted base in its coding sequence (a single base "C" was lost in 632 bp from the 5' end of the SLA-1-632-TPK gene), which lead to frameshift mutation. In order to correct the SLA-1-632-TPK gene, two pairs of gene-correction's primers were designed to correct the gene by the splicing overlap extension PCR (SOE-PCR) in template of recombinant plasmid of SLA-1-632-TPK/pMD18-T. Firstly,the 5'and 3'ends of SLA-1-632-TPK gene were amplified, respectively, then both of them were spliced and amplified to form an intact SLA-1-632-TPK gene. After detected by agarose electrophoresis, the interest of the product was further cloned into pMD19-T Simple vector. The positive clones were screened by colony PCR and then sequenced. The result showed that the 5'and 3' ends of the SLA-1-632-TPK gene were all amplified successfully by SOE-PCR, with the products of about 650 and 590 bp, which were consistent with the theoretical value of 648 and 585 bp, respectively. After spliced, the intact sequence of SLA-1-632-TPK gene was obtained with the product of about 1 200 bp, which was close to the theoretical value of 1 223 bp. The colony PCR result showed that the corrected gene was successfully inserted into pMD19-T Simple vector . After the sequence was analyzed by GENETYX version 9.0, it was shown that the nucleotide "C" in 632 bp numbered from the 5'end of the gene was added and the SLA-1-632-TPK gene was coded correctly. In this study, the SLA-1-632-TPK was corrected successfully, and the recombinant plasmid SLA-1-TPK/pMD19-T was constructed, which would lay a foundation to further study the protein expression and associated function of SLA-1-TPK.

The difference of blood biochemical indicators between dogs in plateau and in plain was compared in this experiment, which would provide the basic data for understanding the plateau environment adaptability of the dogs. We collected blood samples of Kunming dogs and Malinois in plateau and plain areas, respectively.And 4 blood indicators including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), creatine kinase (CK) and lactate dehydrogenase (LDH) were tested. The results showed that compared with the Kunming dogs in plateau and plain, the difference of SOD and GSH-Px was significant (P< 0.05),the difference of LDH was extremely significant (P< 0.01), and the difference of CK was not significant (P> 0.05). Compared with the Malinoises in plateau and plain, the difference of SOD and LDH was significant (P< 0.05), the difference of GSH-Px was extremely significant (P< 0.01), and the difference of CK was not significant (P> 0.05). Compared with the Kunming dogs and Malinoises in plateau,the difference of GSH-Px and LDH was extremely significant (P< 0.01), the difference of CK and SOD was not significant (P> 0.05). It indicated that the Kunming dog had an altitude acclimatization, which provided a new idea for establishment of the animal model of plateau disease, and was more suitable for the working dog.

This experiment was conducted to study the effects of the diets with different energy and protein levels on mRNA expression of glucose transporters in the small intestine and muscle of Tan sheep. A total of 112 healthy Tan sheep (half male and half female) with similar initial live weight were randomly divided into four groups with four replicates per group and seven sheep per replicate. According to the Feeding Standard of Meat-producing Sheep and Goats (NY/T 816—2004),each group was fed diet with different levels of energy and protein respectively:0.84×standard level (group Ⅰ),0.96×standard level (group Ⅱ),1.08×standard level (group Ⅲ) and 1.20×standard level (group Ⅳ). The test period were divided into two stages by body weight of sheep (29-35 and 36-40 kg). At the end of each stage,one sheep was slaughtered at each replicate,and small intestine and muscle samples were collected to study mRNA relative expression of SGLT1,GLUT4 and GLUT5 genes by Real-time PCR. The results indicated that:SGLT1 gene mRNA expression levels of group Ⅲ was significantly higher than other groups in small intestine at the end of 29-35 kg stage (P< 0.05);At the end of 36-40 kg stage,the SGLT1 gene mRNA expression levels had no significant difference among the four groups (P> 0.05).In muscle,the SGLT1 gene mRNA expression level increased with the rise of energy and protein levels at both stages ,and that of group Ⅳ were the highest.In small intestine,at the end of 29-35 kg stage,the GLUT4 gene mRNA expression levels had no significant difference among the four groups (P> 0.05);At the end of 36-40 kg stage,the GLUT4 gene mRNA expression level increased with the rise of energy and protein levels,and that of group Ⅳ were significantly higher than the other groups (P< 0.05).In muscle,the GLUT4 gene mRNA expression level were the highest in group Ⅳ at both stages,and significantly higher than group Ⅰ (P< 0.05). The GLUT5 gene mRNA expression did not show any regularity at both stages. In conclusion,diets with different levels of energy and protein could significantly affect the mRNA expression of SGLT1 and GLUT4 genes,and affect absorption of glucose in sheep.

In order to find the way to effectively utilize wheat straw,the effect of bacteria and enzyme treatments of wheat straw on growth performance and slaughter performance were studied.80 Dorper×Small-tailed Han crossbred male lambs with initial body weight of (24.00±2.42) kg were randomly divided into four groups with five replicates per group and four lambs per replicete, which were control group (dry wheat straw),treatment group Ⅰ (wheat straw with bacteria and enzyme compound preparations),treatment group Ⅱ (dry wheat straw with enzyme preparations),and Chinese wildrye group (Chinese wildrye).The experiment lasted for 60 d with 8 d of adaptation period.The results showed that the net gain and average daily gain of treatment groups Ⅰ,Ⅱ and Chinese wildrye group were significantly higher than those in control group (P< 0.05),and F/G were significantly lower than control group (P< 0.05),but those in the three groups were not significantly difference (P> 0.05);There were no significant differences of slaughter performance among different groups (P> 0.05).Compared with control group,the liver weight in the treatment groups Ⅰ,Ⅱ and Chinese wildrye group were increased 10.74% (P> 0.05),13.79% (P< 0.05),8.52% (P> 0.05), and the percentages of liver weight to live weight before slaughter were significantly higher than that in control group (P< 0.05).The other indexes of issues and internal organ (rumen,reticulum,omasum,abomasum,small intestine,large intestine,lung,kidney,head,feet and skin+wool) showed no significant difference (P> 0.05).The growth performance of sheep were significantly increased by wheat straw with bacteria and enzyme treating,while the slaughter performance and development of tissues and organs were not significantly affected. The nutrient value of wheat straw with biological treatment was close to Chinese wildrye.

The experiment was conducted to study the effects of yeast culture on growth performance, meat quality and intestinal microflora of broilers. A total of 432 1-day-old AA commercial broiler chicks with initial body weight of (41.73±0.15)g were randomly divided into 4 groups with 6 replicates per group and 18 broilers per replicate,receiving diets supplemented with 0,0.1%,0.2% and 0.3% yeast culture, respectively. The trial lasted for 42 days which was divided into two periods with 1 to 21 d and 22 to 42 d,respectively.The feed intake,body weight,death and culling rate were recorded in each period. At the end of the experiment,1 chickens in each replicate with the weight close to the average value were slaughtered after fasting for 12 h. The slaughter performance and intestinal microflora counts were determined.The results showed that compared with control group,the supplementation of 0.2% and 0.3% yeast culture significantly increased the body weight at 42 d and the average daily gain (ADG) during the whole trial (P< 0.05).The diet supplemented with 0.2% yeast culture significantly improved the ADG,decreased the F/G of broilers during 22 to 42 d (P< 0.05),and it also significantly increased the average daily feed intake (ADFI) and ADG (P< 0.05),decreased the F/G of the whole period (P< 0.05).Moreover,the supplementation of 0.2% yeast culture significantly decreased the drip loss of meat and the count of Escherichia coli (P< 0.05),and significantly increased the count of Bifidobacterium(P< 0.05). In summary, the supplementation of 0.2% yeast culture could significantly improve the growth performance and the muscle quality of broilers.The intestinal microflora in broiler cecum were effectively optimized after inclusion of yeast culture in the study.

In order to explore the changing rules of egg production and egg quality of Yufen Ⅰ commercial line,the Wood model,Yangning model and McMillan model were used to fit the curve of egg production rate,and the qualities of eggs at 32,36 and 40 weeks were analyzed. The non-linear equation of three kinds of model showed as follows:Wood model:y_t=0.327×2.2t×e^－0.067t;McMillan model:y_t=159.19×(1－e^{－0.199×(t－17.612)})×e^－0.019t;Yangning model:y_t=0.284×e^－0.284t/(1+e^{－0.302×(t－20.779)}),and the R² were 0.885,0.987 and 0.991,respectively.Compared with the actual production data,the fitting value of Yangning model was the closest to the observed value,and the fitting effect was the best.The results of egg quality analysis showed that the Haugh unit of Yufen Ⅰ was 82.61, reached the AA level.Eggshell strength reached 4.77 kg/m² with high strength.The color of egg yolk was 8.72,deeper than the ordinary eggs.These results indicated that Yangning model could be used to estimate and forecast the variation of laying rate of the strain in the actual production. It could provide reference for the breeding and management of new breed of local layers. The egg quality could be optimized in the later matching system.

This experiment was conducted to investigate the effect of feeding phytoestrogens on milk composition, blood biochemical index and antioxidant capacity of dairy cows.A total of 40 Holstein cows were selected and randomly divided into 4 groups by health, age and lactation stage. The cows in control group was fed total mixed rations(TMR), and the other in 3 trial groups were fed TMR supplemented with 2.5 g dainzein(group Ⅰ), 35 g formononetin (group Ⅱ), 1.25 g dainzein and 17.5 g formononetin (group Ⅲ), respectively. The total duration of the trial was 127 d, the first 7 d of the trial was the preliminary period and the formal trial lasted for 120 d. The milk samples were collected in the trial of 0, 30, 60, 90, 120 d, respectively, and determination of milk composition. The blood samples were collected by jugular vein in the trial, and plasma was separated by 15 min, 3 500 r/min centrifugation, and saved at －20 ℃ for later use. The result showed as follows: Compared with the control group, the milk yield and milk protein yield in groups Ⅰ and Ⅲ were significantly increased (P< 0.05),the lactose yield in groups Ⅰ,Ⅱ and Ⅲ were significantly increased (P< 0.05), the T-AOC activity of blood in group Ⅲ was significantly increased (P< 0.05), the GSH-Px activity of blood in groups Ⅱ and Ⅲ were significantly increased (P< 0.05), the MDA activity of blood in groups Ⅰ and Ⅱ were significantly decreased (P< 0.05), the milk fat yield,lactose rate and TP, ALB, GLB of blood were not significantly increased (P> 0.05),the CAT, SOD activity of blood in trail groups had a upward trent. It was concluded that feeding phytoestrogens could enhance the milk yield, milk protein yield, lactose yield, the body's antioxidant capacity and immune function of Holstein cows.

The experiment was aimed to study the effect of organic selenium and vitamin E (VE) on meat quality trait,blood biochemical indexes and antioxidant indexes of broiler chicken. 280 1-day-old AA broiler chicken were chosen and assigned to 7 groups with 40 broiler chicken per group. Group 1 was control group that did not adding organic selenium and VE,groups 2-7 were added with 100 IU/kg VE,0.15 mg/kg organic selenium and 100 IU/kg VE,0.30 mg/kg organic selenium and 100 IU/kg VE,200 IU/kg VE,0.15 mg/kg organic selenium and 200 IU/kg VE,0.30 mg/kg organic selenium and 200 IU/kg VE,respectively. The results showed that the organic selenium and VE had significant effects on eviscerated rate,slaughter rate and chest muscle rate (P< 0.05),while no significant effect was found on semi-eviscerated rate and leg muscle rate(P> 0.05). Adding 0.15 mg/kg organic selenium and 100 IU/kg VE could reduce drip loss,cooking loss,L^* and pH,and there were extremely significant difference or significant difference of cooking loss and L^* compared with control group (P< 0.01;P< 0.05),while this made little effect on a^*,b^* and shear force (P> 0.05). It could significantly or extremely significantly reduce the CHO and MAD contents (P< 0.05;P< 0.01),increase the content of GLU,T-AOC and GSH-Px,and there were extremely significant or significant differences of GLU and GSH-Px compared with control group (P< 0.01;P< 0.05).But there was no significant difference of HDL-C,LDL-C,CAT and SOD contents among all groups (P> 0.05).

In order to investigate the growth performance and apparent digestibility of Hetian sheep in fattening period response to adding reed in diet. Seventy-five Hetian sheep with 6 months old and body weight(30.59 kg±3.36 kg) were classified into 5 groups by single-factor completely random design of experiment, fifteen sheep were assigned to 0, 10%, 20%, 30% and 40% reed addition group. Each group was fed difference diet during the experimental period (75 d). The results showed that the DM intake of 20% and 40% reed addition groups were extremely significant higher than control group (P< 0.01), respectively. The daily gain of 20% reed addition group was significantly higher than control group (P< 0.05), the daily gain of 10%, 30% and 40% reed addition groups were higher than control group 10.09%, 5.64% and 10.87% (P> 0.05), respectively. The apparent digestibility of DM, CP, EE, NDF, ADF, crude ash, calcium and phosphorus in 20% reed addition group was relatively high. Each feed unit cost and total cost would be increase when the reed content of diet increase, the reed addition groups had a better weight gains economic efficiency than control group, and the 10% reed addition group was the best. The results suggested that the DM intake, daily gain and apparent digestibility of DM, CP and EE were better when the diet adding 20% reed. Considering that feed total cost, there were a better economic benefit when the diet adding 10% reed.

In this paper, the growth and development regularity of Suffolk lambs from 0 to 65 days of age were analyzed to improve the growth and development of meat sheep, and provide the theory of feeding and management of Suffolk lambs from 0 to 65 days of age. The experiment was carried out in Xinjiang Huaxing pasture breeding base, the donor ewes were purebred Suffolk sheep, the recipient ewes were Kazak sheep, and the body size indexes and body weight of the born Suffolk lambs were measured and recorded, the correlation of the average of each trait and the average weight were analyzed by SPSS 16.0 software. The results showed that the growth and development of characters were relatively fast at 30 days of age. The correlation coefficient between width and body weight of male lamb was 0.989, and the correlation coefficient between tube circumference and body weight was 0.638. The correlation coefficient between width and body weight of female lambs was 0.981, the correlation coefficient between tube circumference and body weight was 0.654. Suffolk lambs from the birth to 30 of age, the growth and development of male lambs were quicker than female lambs, and had the same growth rate from 45 to 65 days of age. Lambs grew from birth to 15 days of age, body length, chest circumference and body weight growth rate from the 30 to 65 days of age, body length, body weight and other parts of the growth rate was more stable;By analyzing the body size and body weight, the correlation coefficient between hip width and body weight was the largest, and the correlation coefficient between tube circumference and body weight was the smallest. The results showed that there was no difference in the growth and development of male and female lambs. To improve the growth and development of lambs, we should pay attention to the growth and development of lambs at all ages, and provide a reasonable basis for lambs, and improve feed quality and management level. In the future, the feed management of Suffolk lambs should focus on the feeding formula at different times and improve the breeding environment reasonably to maximize the growth potential.

The effects of pasteurized colostrum on growth performance and development of the gastrointestinal tract of calves were studied in this test. Twenty healthy newborn Holstein calves with similar body weight were randomly divided into two groups. The calves in control group were fed non-pasteurized colostrum while that in experimental group were fed on pasteurized colostrum. The experiment lasted for 90 days. The body weight,average body gain (ADG),average daily feed intake (ADFI),F/G and diarrhea rate were determined and at 0,30,60 and 90 days old,the body indexes were measured. The results showed that compared with control group,the ADFI and ADG of calves at 90 days old in experimental group were increased 1.74% and 2.33% (P> 0.05),and cannon circumference and body length were increased 2.68% and 1.41% (P> 0.05),while the diarrhea rate and F/G were decreased 0.67% and 2.40% (P> 0.05).There was no significant effect of pasteurized colostrum on the complex stomach weight,small intestine weight and small intestine length (P> 0.05). However,the ratio of complex stomach weight to body weight in control group was significantly higher than that of experimental group (P< 0.05). In conlusion,the pasteurized colostrum had a positive impact on growth performance for calves in 90 days old.

The experiment was conducted to investigate the effects of the Bacillus subtilis on growth performances and serum biochemical parameters of weaned piglets. A total of 96 pigs(Duroc×Landrace×Yorkshire) were randomly allocated to four treatments, each treatment had three replicates of 8 pigs. The pigs in control group were only fed basal diet, and those in other groups(groups Ⅰ,Ⅱ and Ⅲ) were fed basal diet supplemented with 0.1%, 0.2% and 0.4% Bacillus subtilis, respectively. The experiment lasted for 40 d. The results showed that the average end body weight, average daily gain and average daily feed intake in group Ⅱ were significantly higher than that of control group (P< 0.05), and the F/G in group Ⅱ had no significant difference with that of control group (P> 0.05). The contents of ALB and TP had no significant differences in all groups, the activities of ALP, ALT and AST in serum had no significant difference in all groups too, and the contents of BUN in serum of group Ⅰ and group Ⅱ were significantly lower than that of the control group (P< 0.05).The contents of IgA, IgM and IgG in serum of all groups had no significant differences (P> 0.05). The content of serum superoxide dismutase was significantly higher with add 0.2% Bacillus subtilis to the diet of weaned piglets (P< 0.05).It was concluded that the growth performance and serum biochemical parameters of group Ⅱ was best in weaned piglets, and suggested that optimal dietary Bacillus subtilis level was 0.2%.

The objective of this study was to determine the effect of different carbohydrate sources on growth performance, body size indexes and nutrients apparent digestibility of beef calves. Twenty newborn Black Angus calves were randomly divided into 4 treatments,5 replications per treatment and 1 calve per replication. The calves in control group fed with milk,while that of groups A,B and C fed with glucose,whey powder and ripened corn powder as the main carbohydrate source of milk replacer,respectively. The test was start when the calves were 30 days of age,and the trial period lasted for 45 days. The body weight and body indexes of calves were measured at 30,45,60 and 75 days of age. Two digestion tests were arranged at 35-43 and 65-73 days of age,in addition,the incidence of diarrhea was documented daily. The results showed that the effect of different carbohydrate source on the calves was obvious in the first period. At 30-45 days of age,the average daily gain of group C was extremely significantly lower than that of control group (P< 0.01),and significant lower than groups A and B (P< 0.05),while that of group A was significantly lower than that of control group and group B (P< 0.05).The DM apparent digestibility rate of group C was significantly lower than that of groups A and B (P< 0.05),the apparent digestibility of CP was significantly lower than that of group A (P< 0.05) and extremely significantly lower than that of group B (P< 0.01),diarrhea rate was also high in this period. After 45 days of age,this influence decreased,the average daily gain of groups A and B began to increase,and there was no significant difference compared with control group (P> 0.05). The growth rate of group C increased rapidly,and there was no significant difference of average daily gain compared with group A at 75 days of age (P> 0.05).The nutrient apparent digestibility were improved in the second digestible test,and the diarrhea rate began to decrease which was 0 at the end of the test. During the whole experiment,the different carbohydrate source had little effect on the body indexes. In conclusion,whey powder showed the best effects in the experiment,flowed by glucose and the effect of ripened corn powder was poor in the early,but it became better with the increase of calves' age.

In order to understand the genetic diversity of Bactrian camel and the genetic evolutionary relationships between different populations,the genetic diversity of Alashan camel, Qinghai camel, Nanjiang camel, Beijiang camel, Subei camel and Sunite camel populations in China were analyzed using 10 microsatellite markers. By calculating heterozygosity (H), polymorphism information content (PIC), effective allele (Ne), Shannon information index, the genetic variation within populations were analyzed. By calculating the F-statistics, gene flow, genetic differentiation coefficient and genetic distance to analyze the genetic relationship between populations. The results showed that 89 alleles were tested at the 10 microsatellite loci,8.9 alleles were tested at every locus in average. All loci were medium-highly polymorphic loci (except YWLL08),the average PIC of the Bactrian camel population was between 0.488 to 0.752. The observed heterozygosity (0.355 to 0.448) of 6 Bactrian camel populations was lower than the expected heterozygosity (0.643 to 0.703). Almost all loci Shannon index was greater than 1,and most of loci were in Hardy-Weinberg disequilibrium. The genetic differentiation coefficient between groups (Fst) value was 0.059 and in the low degree of moderately differentiated state. The average Fis values of 6 Bactrian camel populations were positive which suggested 6 Bactrian camel populations had different levels of inbreeding. The standard genetic distance (D_S) and genetic distance T (D_A) clustering analysis showed that the Nanjiang camel and Beijiang camel jointed as one group, the Alxa camel, Qinghai camel, Subei camel, Sunite camel jointed as the other group. Research showed that Chinese Bactrian camel was abundant in genetic diversity, genetic variation within population was larger, and there was a phenomenon of inbreeding. There was a certain gene flow between populations, the differentiation of populations were mainly caused by genetic variation within population. 6 Chinese Bactrian camel populations were divided into two groups.

This experiment was aimed to study the growth development and fit the growth curve of Pietrain pig. The body weight records were collected by Osborne FIRE system to study its regularity growth development (122 boars and 129 sows).The rapid growth period was centralized between 110 and 150 d, and the growth of Pietrain pig was fitted the typical S-curve. The relative growth intensity was higher for younger pigs, then decreased gradually. Three non-linear models including Logistic,Bertalanffy and Gompertz were utilized to fit the growth curve of Pietrain pig, though all the three models had good fitness,and R² of the models (Logistic,Bertalanffy,Gompertz) for sow were 0.9815, 0.9589 and 0.9698, respectively. The results showed Logistic model played better for achieving the real observations. According to the fitting growth curve, the age of inflection value of boar and sow were 114.72 and 114.89 d,the weight of inflection value were 65.30 and 63.00 kg, the highest daily gain were 1.051 and 0.983 kg/d,respectively.

The genetic parameters of milk fat percentage (FP), milk protein percentage (PP), somatic cell score (SCS), milk yield of 305 days (MYD), age at first calving (AFC),calving interval (CI) and linear classification scores (LCS) were estimated using the DHI data of 2008 to 2016 in Ningxia area of 27 444 Holstein dairy cows and type records. With the aid of DMU v 6.0 AI-REML software, DMU combined with EM algorithm and multi character animal model was used to model the influence factors of the birth season, herd, year, parity and individual additive genetic effect. The results showed that FP, PP, SCS, MYD, AFC, CI and LCS's heritability were 0.14, 0.19, 0.19, 0.31, 0.37, 0.10, 0.07, respectively. At the same time, the breeding value, genetic correlation and CPI2 values of different traits were calculated. The genetic evaluation for dairy cows in Ningxia, could be more in-depth understanding of the basic situation of the herd, to provide basic data for the construction of dairy cow breeding matching selection, planning and selection index.

In order to study the different expression of HO-1 gene in different tissues of 70-weeks-old Changshun Blue-shelled chickens. We collected nine (3 of each genotype) Changshun Blue-shelled chickens of 70-weeks-old as samples. The brain, liver, kidney, ovary, fallopian tube and uterus were collected, and total RNA of every tissue was extracted and reversed transcription to cDNA.The expression of HO-1 mRNA in different samples were detected by quantitative Real-time PCR.We compared the expression in the same tissues of different genotypes and in the different tissues of the same genotype. The results suggested that there were differences among different tissues of the same genotypes and different genotypes of the same tissues. The expression of HO-1 gene was highest in the liver, and there were significant difference in different genotype (P< 0.01).The expression level in the uterus of White-shelled chicken was extremely significantly higher than other two genotypes (P< 0.01),there was no significant difference between homozygous and heterozygous Blue-shelled chickens (P> 0.05).

In order to understand the main pathogen of newborn piglets diarrhea in North Guangdong region, 31 diarrhea samples were collected from six pig farms in North Guangdong, the pathogen of porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV) and porcine rotavirus (PoRV) were detected by Real-time RT-PCR, meanwhile, ORF3 gene of PEDV amplified from positive samples were sequenced and analyzed. Pathogen detection results showed that 83.87%(26/31) samples were positive for PEDV, all herds and samples were negative for TGEV and PoRV. The sequence analysis revealed that the ORF3 gene of 5 epidemic strains of PEDV were all 675 bp, homologies of nucleotides were 98.7% to 100.0%, and homologies with reference sequences of nucleotides were 94.5% to 100.0%, and some gene mutation in common nucleotides site. The results of gene phylogenetic trees showed that PEDV could be divided into two groups, PEDV genetic relationship between field strains in North Guangdong and some regions in China, Southeast Asia, North America, Europe from 2013 to 2015 was closer, classed as a gene subgroup, from 2011 to 2012 main epidemic strains in our country and vaccine strains classed as other two gene subgroups. These results indicated that PEDV infection was the main pathogen of newborn piglets diarrhea in North Guangdong region, as time passed, the PEDV epidemic strains gene presented a tendency of evolution and variation.

Myogenin (MyoG) gene plays a central regulatory role in the process of muscle cell differentiation, which directly affects meat production capacity of animal. In this study, 6 sheep varieties including Large-tail Han sheep, Small-tail Han sheep, Yuxizhiwei sheep, Lanzhou fat-tailed sheep, Mongolia sheep and Tong sheep were selected as experimental materials to detect the polymorphism of MyoG gene exon 1 by non denaturing polyacrylamide gel electrophoresis, and analyze the association analysis between the polymorphism of MyoG gene exon 1 and meat quality traits in sheep. The results showed that 2 alleles (A, B) and 3 genotypes (AA, BB, AB) were detected in MyoG gene exon 1 of six sheep populations. The A allele frequency in Small-tail Han sheep, Large-tail Han sheep, Yuxizhiwei sheep, Lanzhou fat-tailed sheep, Mongolia sheep and Tong sheep were 0.5167, 0.2500, 0.4375, 0.6500, 0.5750 and 0.7125, respectively, the B allele frequency of six sheep populations were 0.4833, 0.7500, 0.5625, 0.3500, 0.4250 and 0.2875, respectively. MyoG gene exon 1 mainly affected the moisture and color of mutton, the moisture content of BB genotype was significantly higher than that of AB genotype (P< 0.01) and AA genotype (P< 0.05). The color of AB genotype was significantly higher than that of BB genotype (P< 0.01) and AA genotype (P< 0.05).

In order to rapid propagation of purebred Wagyu, the experiment were conducted to study the effects of high intensity superovulation, embryo sex identification and different breeds recipient cattle on calving, gestation period and calf birth weight. Wagyu were superovulated repeatedly for nine times with a 30 days interval. The results indicated that the average number of total embryos collected at the second time was 22.78, which was significantly higher than those of the fifth to ninth times (P< 0.05),and there was no significant difference between the other groups (P> 0.05).There was no significant difference between the number of transferable embryos in the first to third times (P> 0.05). The available embryos number of the second times superovulation were significantly higher than those of the fourth to ninth times (P< 0.05),and were remarkably significantly higher than those of the seventh and ninth times (P< 0.01). There were no observably differences of pregnant rate and calving rate between sex identified embryos, and regular embryos respectively (P> 0.05).The female calf percentage of sexed embryos was 95.56%. The calving rate of the Simmental-catalo receptors were higher than those of Wagyu-catalo and Holstein receptors (P> 0.05). The gestation period of Wagyu-catalo were remarkably significantly greater than those of Simmental-catalo and Holstein receptors (P< 0.01), however, there was no significant difference between Simmental-catalo and Holstein receptors (P> 0.05). The birth weight of female calves calved by Simmental-catalo receptors were higher than those of Wagyu-catalo (P< 0.05), which was extremely significantly higher than those of Holstein receptor (P< 0.01). The male calf birth weight was no significant difference in the three breeds receptors (P> 0.05). There were obvious differences between male and female calves in gestation and birth weight with in the same recipient breed.

In order to study the differences of CD46 gene expression in different tissues of Xinjiang Brown cattle and preliminarily master the expression regular pattern in different tissues, specific primers was designed in this study, and Real-time quantitative PCR technique was used to analyze the expression of CD46 gene in different tissues of Xinjiang Brown cattle like heart,liver,spleen,lung, kidney,small intestine,large intestine,stomach,muscle,ovarian and breast, respectively.The results showed that CD46 gene was expressed in all 11 samples of Xinjiang Brown cattle,and the expression in the liver was the highest, which was significantly higher than in lung,spleen,kidney, stomach,small intestine, large intestine, ovarian and breast (P< 0.05).By analyzing the results of CD46 gene expression in tissues of Xinjiang Brown cattle could provide information for studying the CD46 gene expression regulation pattern and biological function.

This experiment was conduced to express and purify the recombinant NSP2 protein of PRRSV. The NSP2 gene was amplified using PCR method, and then it was subcloned into pET-28a(+) vector and expressed in E.coli. The molecular weight of the recombinant protein was 29 ku. The result of SDS-PAGE indicated that the expression efficiency of the recombinant protein was induced by 1 mmol/L IPTG for 8 h at 37 ℃.Western blotting result showed that the recombinant protein had high immunogenicity and could be recognized with positive serum of PRRSV. In this study, we expressed and purified the recombinant NSP2 protein of PRRSV, and the results laid the foundation for the further development of ELISA methods coated with NSP2 protein.

In order to gain an insight of the transcriptomes difference in E.coli O157:H7 strains of different virulence,enrich the E.coli O157:H7 transcriptome data,two E.coli O157:H7 strains of different virulence were selected,then the transcriptome libraries of the strains were constructed using Illumina HiSeq^TM 2000 sequencing technique.The bioinformatics methods were used subsequently,such as sequencing assess and gene function annotation. The results showed that 3 113 118 reads were obtained in the high virulence strain,and 2 944 912 reads were obtained in normal virulence strain.83.76% and 78.97% reads could be compared to the E.coli O157:H7 reference genome sequence,respectively. Comparison with the transcriptome of normal virulence strain,941 differentially expressed genes were found in the high virulence strain,including 637 up-regulated genes and 304 down-regulated genes.GO function annotation classifications indicated that the differentially expressed genes were divided into different function categories,in which many functional categories were mainly involved,such as catalytic activity,binding,transporter activity,receptor activity,enzyme regulator activity,localization,biological regulation,locomotion. KEGG analysis showed 425 genes were annotated to 160 metabolic pathways. Metabolic,ribosome,flagellar assembly,pyrimidine metabolism,starch and sucrose metabolism,bacterial chemotaxis pathways were significantly enriched. The transcriptome study of E.coli O157:H7 strains of different virulence using high-throughput sequencing technology revealed the number of differentially expressed genes in different virulence,obtained the function,classification and metabolic pathway of differentially expressed genes,which enriched the transcriptome information of E.coli O157:H7,and laid a foundation for the study on related genes with virulence traits and molecular mechanisms in E.coli O157:H7.

Dairy cow mastitis is one of the most costly diseases affecting the development of the world dairy industry. It causes a serious economic loss to dairy farming, and affects the yield and quality of milk, endangers human health. The cause of dairy cow mastitis is complex, but the main cause is pathogen infection, particularly Staphylococcus, Streptococcus and intestinal bacterial infection. The rapid diagnosis of pathogenic bacteria of mastitis is crucial for the effectively treatment of the dairy cow mastitis. In order to provide theoretical basis for developing rapid, specific and sensitive of dairy cow mastitis pathogens diagnosis, the author summarized the microbiological and biochemical assay method in routine used of dairy cow mastitis pathogen diagnosis, automatic microbial identification system, resazurin trace plate method, immune diagnosis method, the nucleic acid probe hybridization, 16S rRNA gene sequences of sequencing, PCR, gene chip and LAMP etc, and analyzed the advantages and disadvantages of these methods.

An indirect ELISA for detecting the IgA antibody against porcine foot-and-mouth disease virus (FMDV) type A was developed by using purified FMDV structural protein VP1 as coating antigen, mouse anti-pig IgA monoclonal antibody as second antibody and HRP-conjugated goat anti-mouse IgG as third antibody.The concentration of coating antigen was optimized as 3.50 μg/mL,the dilution and reaction time of second antibody and third antibody were optimized as 1:10 000 and 30 min, respectively.There was no cross-reactivity with anti-CSFV, PRRSV and other pathogen specific IgA antibodies.The positive detection rate of FMDV type A infectedsamples was above 90%.The coefficient variation of intra-and inter-assay was ranged from 3.16% to 9.76%.The ELISA method described in this study was proved to be specific and rapid for the detection of FMDV specific IgA antibody.It was potential to be applied for detection the level of FMDV specific IgA and evaluate the effect of mucosal immunity.Besides,it provided a new method for clinical diagnosis of foot-and-mouth disease.

To investigate the epidemics of Streptococcus suis in Guangdong province, 228 samples from infected pigs,and 698 samples from healthy pigs including 243 samples from tonsils of slaughtered pigs and 455 nasal swabs of healthy pigs were analyzed.The results showed that the positive rate of Streptococcus suis of infected,healthy and slaughtered pigs were 82.02%(187/228),42.20%(192/455) and 32.10%(78/243),respectively.187 strains of Streptococcus suis were isolated from infected pigs and serotyped in 11 serotypes,including serotype SS1,SS2,SS3,SS4,SS7,SS8,SS9,SS16,SS19,SS29 and SS31, in which serotype SS2(16.58%),SS3(9.63%) and SS19 (7.49%) were dominant,flowed by SS7(6.95%)and SS9(5.34%),and 48.66% strains were non-typabled.Meanwhile,154 strains of Streptococcus suis from healthy swine(including farms and slaughter houses) were classified into 17 serotypes,including serotype SS2,SS3,SS4,SS5,SS7,SS8,SS9,SS10,SS12,SS15,SS16,SS17,SS19,SS21,SS23,SS29 and SS30,in which SS2(18.83%) and SS29(14.94%)were dominant,flowed by SS16(6.50%) and 31.82% strains were non-typabled.

In order to understand the virulence genes and drug resistance genes carried by E.coli strains from dairy cows with mastitis in large-scale dairy farms in Liaoning region, and also provide improved programs for control and treatment of mastitis to dairy farmers, 66 strains of E.coli isolated from milk of dairy cows with clinical mastitis in several large-scale farms in Liaoning region were examined to detect 4 virulence genes and 4 drug resistance genes using PCR methods. The results showed that none of the target genes was detected in only one strain, while at least 2 and up to 7 target genes were detected in the rest of 65 strains. The detection rates of the virulence genes stx2e, eaeA, K99 and astA were 56.1%, 47.0%, 34.8% and 31.8%, respectively. In addition, the detection rate of dual virulence gene reached 43.9%, in which the genotype with the highest detection rate was eaeA/stx2e. The detection rates of the drug resistance genes sul3, sul1, cmlA and aacA4 were 87.9%, 83.3%, 40.9% and 28.8%, respectively. And the dual resistance gene detection rate was 36.4%, in which the highest detection rate was sul1/sul3 genotype; Triple drug resistance gene detection rate was 37.9%, and cmlA/sul1/sul3 presented the highest detection rate. These results confirmed that the E.coli isolated from dairy cow mastitis in large-scale dairy farms in Liaoning region had high detecting rates of sulfonamide resistance genes and chloramphenicol resistance genes, which was directly related to the drug resistance of the E.coli. These results provided important guiding significance for the prevention and control of dairy cow mastitis in Liaoning region as well as the safety of public health.

This experiment was conducted to study the protein expression of F gene of Newcastle disease virus (NDV) type Ⅶ by baculovirus expression system.The F gene was amplified by RT-PCR and cloned into pFastBac HT A plasmid, and then the recombinant plasmid was transformed into DH10Bac competent cells to get the positive recombinant bacmid.After 72 h transfection of Sf9 cell with recombinant bacmid, the expression of interest protein was detected by indirect immunofluorescence assay (IFA), SDS-PAGE analysis and Western blotting. Serum antibody titers of immunized SPF chickens were determined by ELISA and the protective properties were determined by protection test. The results showed that F gene was expressed in Sf9 cells infected with the recombinant baculovirus. The expressed protein could induce high titer specific antibody against NDV. The protective rate of recombinant F protein group was 90%, which was significantly higher than that of the negative control group. These results laid a foundation for study on NDV subunit vaccine.

A new assay for the detection of swine influenza virus (SIV) was developed with a novel nucleic acid probe——Molecular beacon in this study. The specific primers and molecular beacon probes were designed according to the conserved region of H3 and N2 genes of SIV H3N2 subtype. A digital RT-PCR assay was developed for detection of SIV H3N2 subtype. The results showed that SIV H3N2 subtype could be identified simultaneously on this microarry with high sensitivity and reproducibility,which could reach to 10⁶ dilute viruse. The conclusion was that the digital RT-PCR method could analyze quantitatively the RNA templates.On the identification of H3N2 SIV,the digital RT-PCR method was much more scientific than Real-time quantitative PCR method.

Florfenicol-hydroxypropyl-β-cyclodextrin was prepared by colloid mill technique using orthogonal experiment technology to improve its solubility. The inclusion rate and getting ratio of the complex were taken as indexes to analyze the effect. The optimum preparation procedure was the proportion of 1:1 for HP-β-CD to florfenicol, the concentration was 6 mg/mL and the time was 1 h. Its structure was proved by DSC and IR, which suggested that the florfenicol was wrapped by HP-β-CD. The inclusion rate was 83.74% and the getting ratio was 98.48%. The solubility of florfenicol was increased from 1.25 mg/mL to 40.76 mg/mL.Thus, it showed that the process was suitable for batch preparation of florfenicol-hydroxypropyl-β-cyclodextrin inclusion complex.

In order to establish the determination method of ivermectin (IVM) in the ivermectin microemulsion injection by high performance liquid chromatography (HPLC), Hypersil ODS2 colunm (5 μm,4.6 mm×250 mm) was used in this study. The mobile phase composed of methanol, acetonitrile and water (35:60:5,V/V/V) at a flow rate of 1 mL/min. The detection wave length was set at 244 nm and the column temperature was 30 ℃. The results showed that the HPLC system suitability of IVM was good. A good linear correlation of IVM was observed within the concentration range 80 to 320 μg/mL, and the average recovery rate was 101.90%±2.94% with RSD was 2.88%, the regression equation was Y=22 700X+2 510 (R²=0.9998). The RSD of IVM content in ivermectin microemulsion injection was 1.86%. The method was accurate and reliable,reproducible,easy to operate, which could be used in new type of ivermectin microemulsion injection. The method could be used as the basis of quality control and establishing a quality standard, and to provide basis for quality evaluation, also can provide reliable reference for safe veterinary clinical application in the future.

Synthetic antibacterial agents are widely used in prevention and treatment of animal diseases. However, the irrational drugs use has caused severe drug residues issues and bacteria resistance.Therefore,it is particularly important to develop the rapid detection technology.The antibodies rapid detection technology has broad prospects because of its high sensitivity, simplicity, and low cost. The author reviewed the latest research on antibodies preparation and rapid detection methods for sulfonamides,fluoroquinolones, quinoxalines, nitrofurans and nitroimidazoles. It is great significant for the development of antibody rapid detection methods on the veterinary drug residues.

The utilization of Astragalus resource was often limited to the root, while the stem and leaf had always been discarded, causing serious waste of traditional Chinese medicine resources. This experiment was aimed to study the changes of the content of active ingredients such as Astragalus polysaccharides, flavonoids and saponins in Astragalus root, stem and leaf by probiotic fermentation. A strain of FGM probiotic isolated from chicken intestines was used in this experiment for the fermentation of Astragalus root, stem and leaf. The results showed that, after fermentation, the crude polysaccharide contents of Astragalus root, annual stem, two years stem, annual leaf, two years leaf increased by 177.46%, 227.27%, 207.11%, 170.61% and 182.28%, respectively, the total flavonoids contents increased by 55.67%, 33.68%, 30.04%, -8.17% and -6.57%, respectively, and the total saponins contents increased by 68.50%, 55.91%, 55.71%, 40.93% and 46.13%, respectively. FGM probiotic fermentation made the main component contents of Astragalus increased, which would help for the further utilization of different parts of Astragalus, and efficient utilization of traditional Chinese medicine resources.

In recent years, the constantly emerging of drug resistant Mycobacterium tuberculosis brings unprecedented pressures to treat tuberculosis. In recent studies, it has found that not only bovine-type Mycobacterium tuberculosis can infect people, but human-type Mycobacterium tuberculosis can also infect cattle, which is also brings threats and challenges to the development of the cattle industry. And how to establish quick, handy, sensitive, highly specific and inexpensive resistance testing methods is the key to control the spread of the disease.In this review, it introduced not only the mechanism of action of isoniazid, rifampicin, streptomycin, ethambutol, pyrazinamide and so on, but also the traditional detection methods of drug resistance of mycobacteria (luciferase system, microscopic observation of drug susceptibility, proportion method, Bactec MGIT 960 System)and molecular detection methods (reverse hybriditation-based line probe assay (LiPA), Gene Xpert automatic detection system, PCR-single-strand conformation polymorphism analysis(PCR-SSCP),PCR-restriction fragment length polymorphism(PCR-RFLP), DNA sequencing, gene chip, RNA/RNA mismatch assay, which may be helpful to the further and clinical treatment and research for tuberculosis.

The objective of this study was to explore the antibacterial mechanism of baicalin on Escherichia coli. Based on the determination of baicalin on Escherichia coli minimum inhibitory concentration (MIC) and growth curve, the influence of baicalin on Escherichia coli cells permeability was researched by measuring the conductivity and alkaline phosphatase (AKP) content of bacterial solution. The experimental results showed that baicalin had significantly inhibitory effect on Escherichia coli, and its MIC was 6.25 mg/mL.Baicalin could significantly increase the conductivity and AKP content of Escherichia coli bacteria solution.The results suggested that baicalin on antibacterial activity was mainly due to the changes of the cell membrane permeability and the damage of the cell wall.