Genome-wide association studies have identified thousands of associations between common variants and common diseases(traits) in the last decade. Despite these discoveries, the missing heritability has attracted much concerns increasingly. Rare variants have become a key answer to explain the missing heritability, because GWAS focus on identifying the associations between common variants and phenotypes. The rapid advances in DNA sequence have made it possible to identify the associations between rare variants and common diseases(traits). A series of rare variants association analysis(RVAS) methods have been proposed and were applicated to many human diseases, however fewer investigations in livestock. In this review, we first briefly report the methods of sequence kernel association test(SKAT) and its family, which are representative. Then, we summary two methods which are used to improve the effectiveness in RVAS:extreme phenotype sampling and meta-analysis. Hereafter, we review the methods utilizing GWAS data to perform RVAS:imputation and rare haplotype associations analysis. Finally, we provide some guidelines for performing RVAS in livestock.

Tail analysis and genome-wide association studies(GWAS) were combined in this study to determine preliminary two tails selection criterions. A total of 2 000, 1 500, 1 000 and 500 samples and 20%, 15%, 12%, 10%, 8%, 5% of two tails were used to run GWAS to estimate the effects of the population size on GWAS and the effect of the proportion of two tails on GWAS, respectively. The results showed that the number of significant SNPs decreased with the reducing population size and the proportion of two tails. The preliminary selection criterions were:traits with heritability of about 0.38, the proportion of two tails of 8%, 10%, 10% and 20% from 2 000, 1 500, 1 000 and 500 samples, which were appropriate for two tails population for running GWAS, respectively. Further, the traits with heritability of about 0.50, the proportion of two tails of 5%, 5%, 10% and 15% from 2 000, 1 500, 1 000 and 500 samples were appropriate for two tails population for running GWAS, respectively. The present preliminary two tails selection criterions from populations with various sizes to run GWAS could detect significant SNPs effectively and also provide a strategy of reducing the cost of GWAS.

The aim of this study was to obtain the sequence of FTO gene of Tibetan chicken, analyze its sequence by bioinformatics, clarify its temporal-spatial expression characteristics, and reveal the relationship between the expression level of FTO gene and intramuscular fat content(IMF) at different developmental stages. Healthy Tibetan chickens in various ages(1-210 days of age) were selected, the tissue samples of heart, liver, spleen, lung, kidney, breast muscle, leg muscle and subcutaneous fat were collected for the total RNA extraction. The Reverse Transcription PCR(RT-PCR) was used to clone Tibetan chicken FTO gene sequence, the real-time quantitative PCR(qPCR) was used to detect the expression level of FTO gene in different tissues and developmental stages, and the correlation between the FTO mRNA expression and intramuscular fat content was analyzed. The results showed that the sequence of Tibetan chicken FTO gene was 1 585 bp (GenBank accession number:KY366175), containing 1 524 bp CDS, 35 bp 5' UTR and 26 bp 3' UTR, encoding 507 amino acids with a N-terminal domain and a C-terminal domain. There were 6 amino acid mutations between Tibetan chicken and Gallus gallus FTO amino acid sequences. FTO gene of Tibetan chicken was widely expressed in different tissues. The expression level of FTO gene was the highest in spleen, which was significantly higher than other tissues (P <0.01). FTO gene also kept a high expression level in adipose and lung tissues. The expression pattern of Tibetan chicken FTO gene in breast muscle and leg muscle were different, the expression level in breast muscle decreased gradually with the growth of Tibetan chicken, while in the leg muscle, the expression level increased first and then descended with the increasing age. The expression levels of Tibetan chickenFTO gene in different muscle tissues and different developmental stages presented diverse relationships with IMF content. The expression level of FTO in breast muscle of Tibetan chicken was negatively correlated with IMF content, and this correlation in hens was significantly stronger (P <0.05). In leg muscle, the expression level of FTO gene in cocks was positively correlated with IMF content(in period of 119-210 days, r=0.601, P <0.05), while in hens this relationship was opposite. The results suggest that FTO gene may play an important role in intramuscular fat deposition during the growth and development stage of Tibetan chicken. These results will facilitate the research on the structure and function of FTO gene in Tibetan chickens.

In this study, yak hypoxia adaptation and its related genetic molecular mechanism at the whole transcriptome level were analyzed using high-throughput RNA-Seq technology. Lung tissue samples were collected from yak and cattle, and RNA-Seq was performed on an Illumina HiSeq 2500 platform. A total of 54 720 968 filtered sequences containing 4 924 882 170 bp were obtained in the cattle sequencing library while 51 641 282 sequences containing 4 647 715 380 bp were obtained in the yak sequencing library. The basic transcriptome analysis showed that either the 5'-or 3'-ends of 8 123 genes in the yak genome were extended compared to the original yak genome. A total of 7 059 new transcripts were identified, of which 2 795 were predicted to have the ability to encode proteins. The GO analysis showed that a total of 14 764 genes were annotated in the cellular component, biological process and molecular function categories as well as 59 subcategories. Cell process and binding were the most enriched. The KEGG analysis showed that 14 485 genes were involved in 258 pathways. The metabolic pathway was the most enriched, followed by the focal adhesion pathway and then the amoebiasis pathway. A total of 39 positively selected genes were identified by Ka/Ks analysis based on a comparison between yak and cattle lung transcriptomes. The GO classification analysis results showed that, among the top 10 cellular component subcategories, those related to ribosome accounted for the highest proportion (4/10). Among the top 10 biological subcategories, those related to immunological cells accounted for the highest proportion (7/10). Among the top 10 molecular function subcategories, those related to enzymatic activities accounted for the highest proportion (5/10). The KEGG annotation results showed that the positively selected genes were involved in 56 pathways. Among the top 10 enriched pathways, 7 pathways were involved in sugar energy, vitamin and nucleic acid related metabolic pathways. Three of the top 10 enriched pathways were related to diseases, which might be attributed to the self-protective mechanism of yak. In conclusion, the normal transcriptome profile of yak lungs was successfully established by using RNA-Seq technology. It provided valuable data for further improving the yak genome database. Furthermore, the unique evolutionary process of yak hypoxia adaptation and its related genetic molecular mechanism were revealed by the positively selected genes identified in this study.

The aim of this study was to establish a simple and feasible in vitro culture system for high purity epididymal epithelial cells from cashmere goat. The primary cells were obtained from epididymal caput of 10-12 months cashmere goat using enzymatic dispersion and improved tissue-piece digestion method. The cells were identified by immunocytochemistry and immunofluorescence methods. Cell purity and proliferation were also investigated respectively by flow cytometry and CCK method. Ultrastructures of epididymal epithelial cells were observed under transmission electron microscope. The results showed that the cells obtained by both methods were in island-like clonal growth and good proliferation ability, and possessed active secretory and metabolic function. The expression of epithelial special cytokeratin 18 and epididymal special glutathione peroxidase 5(GPX5) and the result of flow cytometry showed that both methods could obtain high purity epididymal epithelial cells. The primary cells obtained by improved tissue-piece digestion method took a long culture time, compared to that the primary cells obtained by enzymatic dispersion method which took a short culture time with more cells. These results provided a good foundation for further study on the function of epididymal epithelial cells of cashmere goat.

It is important to determine the insemination time by using accurate estrous detection and ovulation prediction.In this study,10 multiparous Simmental cattle and 10 primiparous Holstein cows, which were 60 to 90 days postpartum, healthy and nonpregnant, were used as experiment animals. After estrus synchronization, the oestrus and ovulation time of cattle were detected by observation and rectal examination, and the corresponding activity and vaginal electrical resistance (VER) were measured by using pedometers in an interval of 30 min and estrus ovulation tester in an interval of 4 h, respectively. Results showed that, the VER in dioestrus ((300±12) Ω) was significantly higher than that in oestrus (P <0.05), and decreased rapidly 4 h before the onset of oestrus and dropped to the lowest ((220±27) Ω) 8-12 h after the onset of oestrus, and then gradually recovered to the dioestrus level after ovulating. The activity in dioestrus was lower than that in oestrus, and increased 10 times rapidly after the onset of oestrus, and then recovered to the dioestrus level after the end of oestrus. The oestrus duration, the time from onset of oestrus to ovulation and the time from end of oestrus to ovulation were (15.6±2.8) h, (26.8±4.2) h and (11.3±4.3) h, respectively. The ovulation occurred (15.0±1.3) h later after the lowest VER. The activity and VER variation could provide guidance to explore the techniques of accurate oestrus detection and insemination during oestrus and ovulation. The actvity combined with VER would improve oestrus detection efficiency and timing of ovulation predicted accuracy, which have significant value for developing the automatic technology of oestrus detection and ovulation prediction.

To reveal the effects of GSH supplemented in culture medium on lncRNA profiling of bovine embryos, the IVF embryos at 8-16-cell and morula stages were collected for high-throughput RNA sequencing (RNA-seq). Then co-expression analysis and cis-targeted genes prediction of differentially expressed lncRNAs (DElncRNAs), Gene ontology and KEGG pathway enrichment analysis of differentially expressed genes (DEGs) were performed. Additionally, qRT-PCR of 8 DElncRNAs was used to confirm the accuracy and validity of RNA-seq data. A total of 4 273 lncRNAs were obtained, and the qRT-PCR results confirmed the expression pattern of DElncRNAs from RNA-seq. Among those lncRNAs, 59 were differentially expressed. Among them, 23 DElncRNAs were up-regulated in control embryos while down-regulated in treated embryos, 36 DElncRNAs were down-regulated in control embryos while up-regulated in treated embryos. In control group(no GSH), 59 DElncRNAs were co-expressed with 754 DEGs which were involved in 47 GO terms and enriched in 5 pathways. In treated group, the co-expressed DEGs were 2 782 involving in 48 terms and participating in 13 pathways. Furthermore, 145 neighbor genes of 23 DElncRNAs and 154 neighbor genes of 36 DElncRNAs were participated in 35 and 43 GO terms, respectively. DEGs co-expressed with 14 lncRNAs were enriched in GSH metabolism pathways. Conclusively, GSH treatment could change the lncRNA profiling and improve the development of bovine IVF embryos.

The study was conducted to investigate the effects of dietary supplementation of Clostridium butyricum along with different dietary protein levels on the total tract apparent digestibilities (TTAD) of crude protein and amino acids, nitrogen balance, serum fatty acid composition and the serum biochemical indexs in growing pigs. A total of 24 healthy crossbred barrows (Duroc×Yorkshire×Landrace) with an average initial body weight of (39.07±1.80) kg were randomly assigned to 4 groups to conduct the 2×2 factorial experiment which included 2 dietary Clostridium butyricum levels (0, 100 mg·kg^-1) and 2 dietary protein levels (14%, 18%). Each gourp had 6 replicates with one pig. The experiment was divided into 2 periods including a 6-d pre-test and a 13-d test. Using total collection method, feces and urine of each pig were collected during the last 3 days of the experiment. Blood was sampled from each pig at the last day of the experiment. The results showed that the supplementation of Clostridium butyricum in diets decreased the TTAD of methionine (P <0.05), while increased the concentration of cis -5,8,11,14,17-eicosatrienoic acid in serum (P <0.05). Compared with control group, the low dietary protein level increased the nitrogen utilization efficiency, the TTAD of methionine and tryptophan(P <0.05), while decreased the urine nitrogen excretion, the TTAD of the most amino acids such as arginine and histidine, and the concentration of serum linoleic (P <0.05). Moreover, significant interactive effects were observed between Clostridium butyricum and dietary protein level on the concentration of total fatty acids, lignoceric acid, palmitoleic and arachidonic in serum (P <0.05). These results indicate that supplementation of Clostridium butyricum in diets decrease the TTAD of methionine, but increase the concentration of serum cis -5,8,11,14,17-eicosatrienoic acid. The Clostridium butyricum in diets shows a interactive effect with dietary protein level on the concentrations of total fatty acids, lignoceric acid, palmitoleic and arachidonic in serum.

The objectives of the study were to explore the molecular mechanism of Visfatin regulating feed intake, and to further improve the theory of appetite regulation and energy balance in poultry.In this study, 20 healthy Roman Brown chicks at the age of 1 day old were randomly divided into 4 groups(group C, L, M, H). When the chicks grew up to the age of 10 days old fed with conventional commercial diet, they were intracerebroventricularly injected with various concentrations of human recombinant Visfatin(0, 40, 200, 400 ng) in hypothalamus, respectively. The cumulative feed intake was recorded after injection for 60 min. The chicks were then euthanized and the hypothalamus were collected. Metabolomics analysis was performed through GC-MS system. The PLS-DA model was built and the metabolic pathways of differential metabolites were constructed by KEGG. The results showed that the cumulative feed intakes of chicks in M and H groups were increased significantly compared to that in C group (P <0.05). A total of 73 differential metabolites, which were enriched in 51 pathways, were identified by GC-MS analysis.The differential metabolites in hypothalamus were closely related to carbohydrate, lipid and amino acid metabolism, and fatty acid biosynthesis pathway was one of the most significantly enriched pathways. The main reason for Visfatin promoting food intake is the change of steady state due to decrease of central nutrients.

The objective of this experiment was to investigate the effects of soybean cake substituted by oil cake of flax seed in diet on the growth performance, meat quality,fatty acid content and blood biochemical indicators of lambs. A total of 24 F1 Dorper×Small Tail Han sheep (5 month old, (26±1) kg) were randomly selected and equally assigned into 4 groups according to the proportion of flax cake substituting soybean meal (0, 1/3, 2/3 and 1):control group (CK group), treatment Ⅰ, Ⅱ and Ⅲ. The experiment lasted for 60 days. The result showed that:1) There was no significant difference in average daily gain between treatment groups and CK group (P >0.05). Compared with the CK group, the feed to gain ratio of group Ⅱ was significantly declined (P <0.05). 2) There was no significant difference in carcass weight and net meat weight between treatment and CK groups (P >0.05). The dressing percentage, net meat percentage and longissimus dorsi (LD) muscle area of group Ⅲ were significantly higher than those in control group (P <0.05). 3) The flax cake substituting soybean meal in diet effectively declined intramuscular fat content(P <0.05), whereas the pH, water holding capacity and cooked meat percentage were not significantly altered(P >0.05). 4) The flax cake substituting soybean meal in diet significantly increased the content of C20:5N3 in LD muscle(P <0.05), and had no significant effect on saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids (P >0.05). 5) Contents of TC, LDL and activity of SOD were not significantly different between treatment and CK groups (P >0.05). The contents of TG in group Ⅰ and Ⅲ were significantly lower than those in CK group (P <0.05). The content of HDL in group Ⅱ was significantly higher than that in other groups (P <0.05). The contents of UREA in group Ⅱ and Ⅲ were significantly lower than those in group CK and group Ⅰ (P <0.05). The MDA content of group Ⅲ was significantly lower than that of other groups (P <0.05). The activity of CAT in group Ⅲ was significantly higher than that in other groups (P <0.05). Dietary substitution of soybean meal by flax cake can reduce feed to gain ratio and improve the growth performance, reduce blood lipids and improve sheep antioxidant capacity. Therefore, oil cake of flax seed can be used as a protein source of sheep feed, the optimal substitution rate should be more than 2/3.

The objective of this study was to explore the effects of long-term feeding with high fat diet (HFD) on blood lipids, liver and gut microbiota in rats. Healthy adult SD rats were selected and divided into 2 groups:control group and HFD group (n=10). Rats in different groups were fed with normal diet and HFD for 13 weeks, respectively, and blood samples were collected on 8th and 13th week for blood lipids analysis. Liver tissues and cecal contents were collected to observe the changes of liver and gut microbiota on 13th week. Metabolic pathways related with gut microbiota were also predicted. The results showed that HFD could significantly increase the levels of TG, TCH and LDL (P <0.01) and result in serious steatosis in liver. Compared with the results on 8th week, prolonging time of HFD feeding increased the levels of TCH and HDL (P <0.01). Shannon and Chao indices were significantly lowered by HFD (P <0.001), indicating the reduction of gut microbiota richness. HFD also altered the composition of gut microbiota such as increasing Firmicutes and Actinobacteria and reducing Bacteroidetes (P <0.01). Results of PICRUSt showed that the metabolic pathways of control group were mainly associated with bacteria living and reproduction, while the pathways in HFD group were mainly associated with the metabolism of energy and amino acids. These changes of pathways might be related to the dyslipidemia and the decrease of gut microbiota richness. The study proved the harm of long-term feeding with HFD to blood lipids, liver and gut microbiota, and provided information for dyslipidemia and some guidance for diet management of pets.

In 2014, cattle blood samples were collected from Guangdong province and vector-borne pathogens contained in them were detected in the present study. Samples which were detected as BTV positive by quantitative reverse transcription polymerase chain reaction (qRT-PCR) were isolated and identified. Embryonated chicken eggs were subsequently inoculated and their livers were harvested to passage on C6/36 and BHK-21 cells, respectively. Extensive cytopathic changes were observed. A subsequent qRT-PCR assay target with VP 7 gene and SEM observation results further confirmed the presence of BTV, and named as GD/ST2014. In addition, VP 2 gene fragment was used for genotyping. And combined with VNT test results, the genotype of the isolate obtained in the present study were identified as BTV-7. This was the first report that bluetongue virus serotype 7 field isolate was isolated from cattle in China.

This research was conducted to analyze the proteomic dynamic proteins of PRRSV-infected PAMs. In this study, Label-free LC-MS/MS was employed to quantitatively identify the differentially expressed proteins between PRRSV-infected PAMs and uninfected PAMs. Results were as follows:430 significantly altered proteins were identified after PRRSV infection. Among them, 171 proteins were up-regulated, and 259 proteins were down-regulated. These differentially expressed proteins are related to innate immunity, virus response and antigen presentation etc. Interestingly, many upregulated proteins were enriched in NF-κB, MAPK and RIG-1 signal pathway, including STAT1/2, OAS1/2, Mx1/2, ISG15/20, IFIT1/2/3/5; some proteins were enriched in MHCⅠand MHCⅡrelated signal pathways. Real-time quantitative reverse transcription polymerase chain reaction and Western blot analysis verifiedSTAT 1/2, OAS 1/2, CD 14, ISG, Mx1, IFIT genes and Mx1, IFIT3 proteins were significant up-regulated after PRRSV infection which were consistent with LC-MS/MS results. This study may accelerate our understanding of the mechanisms of PRRSV infection.

The objective of this study was to find an efficient method to isolate the exosomes from MARC-145 cells infected with PRRSV, and lay the foundations for explore the role of exosomes in PRRSV infection. Exosomes were isolated from MARC-145 cells using Total Exosomes Isolation. Exosomes were identified by using Western blot and electron microscopy. The rate-zonal centrifugation was designed to isolate the exosomes, its distribution range was identified by Western blot. Total Exosomes Isolation and immune magnetic bead capture technology were used to isolate the exosomes from MARC-145 cells infected with PRRSV, its characteristic were detected by Western blot. Results were as follows:CD63, Alix and Tsg101, three exosomal protein markers, were expressed in the purified exosomes from MARC-145 cells. EEA1, GRP94 and Cytochrome C did not expressed, which were not exosomal protein markers. The isolated exosomes were verified as small vesicles of approximately 30-100 nm in size by using the electron microscopy (TEM) assay. Using CD63 as an exosomes marker, we demonstrated that Optiprep^TM velocity gradients were efficient in isolating exosomes, with exosomes distributed in 7.2%-18% zones. The samples obtained by immunoaffinity capture were tested by Western blot, the results showed that isotype control magnetic beads did not express exosomal marker Tsg-101. These results indicated that exosomes are released into the extracellular space from MARC-145 cells, and suggested that the exosomes were successfully purified from MARC-145 cells infected with PRRSV by using immune magnetic bead capture technology.

The study was conducted to explore the role of ompW gene in the drug resistance of Gallibacterium anatis (G. anatis). The ompW gene knock-out mutant of G. anatis was constructed by natural transformation. The competent cells of G. anatis were induced following transfer of cells to M-IV medium from colonies on a blood agar plate. Then, transformation was performed by incubating the M-IV-compentent cells together with linear DNA fragment consisting of homologous arms and cmp^r gene. The transformants were identified by using PCR, SDS-PAGE and Western blot analysis. The MIC-determinations of 12 kinds of antibacterial agents were performed for both wild type and mutant ΔompW G. anatis using Mueller Hinton-Ⅱ. The ompW gene deletion strain ΔompW was successfully constructed. Comparing with wild type G. anatis, the MICs of terramycin and tetracycline for ΔompW were decreased to 1/8-fold (16/128) and 1/32-fold (4/128), respectively. The MICs of other drugs in this study showed no obvious change. In conclusion, ompW deletion strain of G. anatis was constructed by natural transformation for the first time in this study. OmpW plays an important role in the formation of tetracyclines resistance phenotype of G. anatis strains.

The aim of this study was to investigate the bacterial community structure and the characteristics of pathogenic bacteria in the air of sheepfold. We selected ten different sheep farms to take air samples. The Illumina MiSeq sequencing with 16S rRNA V3-V4 variable region was adopted to analyze the bacterial community structures of the air in sheepfold. A total number of 33 408 operational taxonomic units (OTUs) were obtained from air samples under the similarity level of 97%. We have got bacteria comprising groups of 25 phyla, 66 classes, 123 orders, 253 families, 547 genera, and 444 species. Analysis of microbial diversity and summarize pathogens with higher abundance in sheepfolds, which provides the basis for the disinfection and medication for sheep farm. The diversity, abundance, and characteristics of the main pathogens in air samples were analyzed in this study, which would be a helpful reference for disease prevention and control in sheepfold.

In order to study the biological characteristics and transmission routes of Salmonella enteritidis, 0.5 mL 7.09×10⁹ CFU·mL^-1SDBL-1 isolate from AA broiler chickens was administered to SPF chickens by perfusion in infection group, while the control group and the airborne group were fed with the same amount of physiological saline. The blood routine and lymphocyte subsets of the airborne group, the infection group and the control group were measured at different time after feeding. The bacteria were separated by the method of bacterial isolation. And Salmonella were isolated and identified from airborne oral swabs, cloacal swabs, feather follicles and dissecting organs. The Salmonella were determined in the environment (feed,drinking water, mosquitoes and flies), and the plate agglutination test was conducted to detect the antibody of the airborne group. The results were as follows:1) In the blood index, the ratio of lymphocyte in the airborne group and the infected group were decreased, the ratio of granulocyte, granulocyte and intercellular were increased, and the ratio of CD4⁺, CD8⁺ and CD4⁺/CD8⁺ in lymphocyte were decreased. 2) In the organ index of the airborne group, liver index increased significantly (P <0.05), and thymus index decreased significantly (P <0.05). 3) About infection situation, the airborne group was infected and the infected chickens were intermittently shedding virus by feces.Salmonella were separated from oral swab, feather capsule, cloacal swab and some organs, and the highest separation rate was from esophagus. Antibodies to Salmonella were firstly detected at the 4th day post infection (DPI) in the airborne group, and all chickens showed positive at the 14th DPI. 4) Detection of Salmonella in environmental samples revealed that Salmonella was isolated from waterline and feed, other than feathers and mosquitoes. These results showed that SDBL-1 isolates could infect chickens through air and cause infection, resulting in the inflammatory reaction, immune dysfunction and organ damage. The infected chickens could intermittently shedding virus by feces, oral cavity, and cloaca. There exist Salmonella in feed and waterline. This study explored the different routes of transmission of S. enteritidis, and provided references for controlling and preventing the prevalence and transmission of Salmonella.

This study focused on the structural characteristics of Chinese ovine Babesia trap gene via sequencing the full-length sequence and bioinformatics analysis. And then a phylogenetic analysis was performed on the TRAP nucleotide and amino acid sequences, which provided the data for clarifying the taxonomic relationship of Chinese ovine Babesia. The conserved sequence fragments were obtained using published Babesia trap gene sequences to BLAST 2 of local genomic databases of Chinese ovine Babesia strains. The primers of PCR were designed with the fragment sequences as templates. The full-length trap gene sequences of 6 Chinese ovine Babesia strains were cloned and their structural characteristics were analyzed. The evolutionary relationship of these ovine Babesia strains was analyzed based on the comparisons of TRAP sequence similarities and constructed phylogenetic trees. The full-length gene sequences of trap were cloned from 6 ovine Babesia strains. The results of structural characteristics analysis showed that the trap gene of 6 ovine Babesia strains had 3 patterns of intron, 3, 4 and 5 introns and the predicted ORF sizes were 1 944, 2 100/2 142 and 2 286 bp, respectively. The analysis of amino acid sequences indicated that the predicted ovine Babesia TRAPs possessed all the distinctive domains of TRAP protein family, such as vWFA, TSR, transmembrane motif and CTD. Phylogenetic analysis showed that these Chinese ovine Babesia strains could be divided into 3 groups. The similarities of intra-group between the TRAP sequences were between 99.8% and 100%, and those of inter-group were from 43.6% to 74.6%. The 6 ovine Chinese Babesia strains were divided into 2 clades, Babesia sp. and B. motasi clades. In addition, the B. motasi clade were further divided into 2 sub-clades. The trap gene structure of 6 ovine Babesia strains are various, but the distinctive protein domains are conserved. These Chinese ovine Babesia strains belong to 2 Babesia species, and possibly there are 2 sub-species in the B. motasi species.

The present study aimed to evaluate the antibacterial activity and treatment effect of porcine beta-defensin 1 (pBD1) against E. coli in vitro and in sick chicken infected with E. coli. The inhibitory effects of pBD1 on three E. coli strains (O₁₄₁, SJZ1 and SJZ2) were detected through agar-gel diffusion method and micro-antibacterial assay in vitro, respectively. Then forty 11-day-old chickens were divided into 5 groups (n=8) randomly, including the defensin group (A), antibiotic group (B),defensin and antibiotic group (C), non-treatment group after infection (D) and negative control group (E).Group A, B, C and D were challenged with 1 mL E. coli O₁₄₁ (1.25×10⁹ cfu·mL^-1) via the neck subcutaneous injection and oral administration respectively, and Group E was inoculated 1 mL nutrient broth with the same administration routes. While theE. coli -infected chicken showing the clinical symptoms, the group A, B, C and D were given orally pBD1 (50 μg per chicken each time), ceftriaxone sodium (50 mg per kg of body weight), pBD1 (50 μg per chicken each time) and ceftriaxone sodium (50 mg per kg of body weight), and the same volume of sterilized saline water once a day, respectively, and the chickens in each group were continuously treated for seven days. The results showed that the recombinant pBD1 displayed clearly antibacterial activity against E.coli in vitro and this antibacterial effect increased as the concentration of pBD1 rose within certain ranges. Compared with the non-treatment group, the reduction were exhibited in clinical symptoms, pathological changes, morbidity and mortality of the three treated group (A, B and C). The body weights of the group A treated with pBD1 and the group C with defensin and antibiotic were significantly higher (P <0.01) than that of the non-treated group (D) in the later period of infection. These results showed that the recombinant pBD1 has obviously inhibitory effect on E. coli, and has effective therapeutic effects on the sick chicken suffering the colibacillosis. The treatment effect of pBD1 was superior to that of ceftriaxone sodium and helpful to refreshment of the sick chicken. The application of pBD1 combined with ceftriaxone sodium demonstrated the better treatment effect. This study could provide scientific basis for effective treatment of the colibacillosis and lay a solid foundation for the research and development of new type antibacterial agent of pBD1.

In order to validate the synergistic immune-enhancing action of selenizing Codonopsis pilosula polysaccharide (sCPP) and garlic polysaccharide (GP) and the efficacy of their compound sCPP-GP and offer theoretical evidence for developing new-type immunopotentiators, the immune-enhancing activities of these three kinds of polysaccharide were compared. In vitro test, the effects of three polysaccharides on chicken peripheral lymphocytes proliferation and mRNA transcription of IL -2 and IFN -γ were determined respectively by MTT method and Real-time quantitative PCR technique. In vivo test, the chickens were injected with three polysaccharides when vaccination of Newcastle disease vaccine, the dynamic changes of chicken peripheral lymphocytes proliferation, serum HI antibody titer, IL-2 contents and IFN-γ contents were determined. The results of in vitro test showed that the three polysaccharides at appropriate concentrations could significantly promote lymphocytes proliferation and mRNA transcription of IL -2 and IFN -γ, and the effects of compound were significantly stronger than those of two constituents; The results of in vivo test showed that at four time points after vaccination three polysaccharides could promote lymphocytes proliferation and enhance serum HI antibody titer and contents of IL-2 and IFN-γ at different degrees, and the efficacy of compound were significantly stronger than those of constituents. These results indicate that sCPP and GP can synergistically enhance the immunological efficacy of chicken peripheral lymphocyte and Newcastle disease vaccine, sCPP-GP compound's action is stronger than its two constituents, and can be a candidate of new-type immunopotentiators.

In order to reveal the mechanism of the immunosuppressive effect of Fusarium toxin zearalenone (ZEA), this experiment had studied the effects of ZEA on the activation and proliferation of mouse T lymphocytes stimulated by concanavalin A (Con A) in vitro. After being treated with different concentrations of ZEA (0, 10, 20, 40 μmol·L^-1), CCK-8 method was used to detect the proliferation of T lymphocytes. At the same time, the expression levels of the early activation antigen CD69 and metaphase activation antigen CD25 were evaluated by flow cytometry. Results were as follows:Cells were cultured for 48, 72, 96 h, compared with group of cell blank, the group of Con A had obvious proliferating phenomenon (P <0.01). Compared with the group of Con A only, group of ZEA 10 μmoL·L^-1 had an obvious phenomenon of Inhibition of proliferation (P <0.05). When ZEA concentration was 20, 40 μmol·L^-1, the proliferation of T lymphocytes was further inhibited. The proliferation of T lymphocytes stimulated by Con A decreased obviously with the increased concentration of the ZEA which showed in a dose-dependent manner (P <0.01). Cells were stimulated by Con A for 6 or 30 hours. Compared with group of cell blank, the group of Con A had obvious activated phenomenon (P <0.01). Compared with the group of Con A only, group of ZEA 10 μmol·L^-1 had an obvious phenomenon of Inhibition of activation (P <0.01). When ZEA concentration was 20, 40 μmol·L^-1, the expression of CD69 and CD25 was further inhibited. The expression levels of the early activation antigen CD69 and metaphase activation antigen CD25 were significantly inhibited after being treated with the ZEA which showed in a dose-dependent manner (P <0.01). The immunosuppressive effect of ZEA to animals is related to its directly inhibition to the activation and proliferation of T lymphocytes in mouse.

The aim of this experiment was to study the effects of the self-developed functional compound additive on the growth performance, nutrient digestibility and blood parameters of weaned piglets. According to the initial body weight, thirty-two Duroc×Landrace×Yorkshire piglets weaned at 21 days of age with an initial body weight of (7.08±0.47) kg were randomly divided into two groups (n=16/group) gave ordinary water (control group) and water added functional compound additive (additive group, additive:water was 1 g:4 L), respectively for 14 days. The results showed that:1) Supplementing the functional compound additive in the drinking water significantly reduced the F/G in 8-14 days (P <0.05), tended to decrease F/G in 1-14 days (P=0.07). 2) Supplementing the functional compound additive in the drinking water significantly increased the digestibility of crude protein, calcium and ash (P <0.05). 3) Supplementing the functional compound additive in the drinking water significantly reduced urea nitrogen, interleukin 6, interleukin 1 and triglycerides levels in serum on day 14 (P <0.05). These results suggest that supplementing the functional compound additive in the drinking water tend to increase growth performance via improving nutrient digestion and utilization, and adjusting immune status of piglets.