[Objective] The aims of the present study were to isolate and identify lactic acid bacteria from camel milk in Hutubi County of Xinjiang Uygur Autonomous Region, and to evaluate their inhibitory effects on Staphylococcus aureus （S. aureus）. [Method] A total of 45 healthy camel milk samples were collected from a camel farm in Hutubi County. Lactic acid bacteria were isolated using MRS medium, and molecular biological identification was carried out using PCR amplification and sequencing targeting 16S rDNA sequence. Point inoculate method, agar spot method and Oxford cup double-layer agar diffusion method were used to screen the lactic acid bacteria with inhibitory effects on S. aureus ATCC 29213. The acid tolerance of the lactic acid bacteria was measured by adjusting pH value of MRS medium to 1-10. The bile salt tolerance of the lactic acid bacteria was assessed by adding 0-0.30% ox bile salt to MRS medium. The minimum inhibitory concentration （MIC） and subinhibitory concentration （SIC） of cell-free culture supernatant （CFCS） of the lactic acid bacteria against S. aureus ATCC 29213 were determined using micro-broth dilution method. Changes in inhibitory effect of CFCS on S. aureus ATCC 29213 under different pH value conditions and after enzymatic treatments were examined to preliminarily analyze the antibacterial active substances of CFCS. The inhibitory effect of CFCS on wild strains of S. aureus isolated from camel milk and dairy cow with mastitis were evaluated by Oxford cup double-layer agar diffusion method. [Result] A total of 20 lactic acid bacterial strains belonging to 5 species were isolated from the 45 camel milk samples, including Enterococcus faecalis （n=13）, Lacticaseibcillus rhamnsus （n=1）, Limosilactobacillus fermentum （n=3）, Lactobacillus paracasei （n=1） and Weissella confusa （n=2）. After screening with the above mentioned three methods, a strain of Lacticaseibcillus rhamnsus （L. rhamnsus, designated as KC4） exhibiting the strongest antibacterial effect on S. aureus ATCC 29213 was obtained. KC4 strain had good acid and bile salt tolerance, and showed normal growth in MRS medium with pH values adjusting to 4-7 and addition of ox bile salt at concentrations of 0-0.20%. The MIC and SIC of KC4 strain CFCS against S. aureus ATCC 29213 were 62.5 mg/mL and 7.812 5 mg/mL, respectively. Its antibacterial activity was still effective at pH values of 2-5, but reduced extremely significantly （P<0.01） after enzymatic treatments with pepsin, peroxidase, trypsin, peptidase, protease K, catalase and papain. It had good antibacterial effect on wild strains of camel and dairy cow derived S. aureus. [Conclusion] One strain of L. rhamnsus was obtained from the camel milk in Hutubi County, which had strong inhibitory effect on standard strain of S. aureus and wild strains of S. aureus isolated from camel milk and dairy cow with mastitis. It also exhibited high level tolerance to acid and bile salt, and the possible antibacterial active substances included acids, peroxides and proteins. The results obtained in this study provided potential bacterial resources for the development and utilization of lactic acid bacteria derived from camel milk.

[Objective] This study was conducted to assess the effects of adding lactic acid bacteria and sugars on fermentation weight loss, fermentation quality and microbial community structure of wheat straw yellow storage at different compaction densities. [Method] Wheat straw was crushed into proper length and the initial moisture content was adjusted to 60%. After well mixing, it was randomly divide into two equal parts. One part was supplemented with the additives composed of a commercially available microbial agent containing 1×10⁵ CFU/g of Lactobacillus plantarum （5 g/t） and white sugar （10 kg/t）, evenly sprayed with 3% sterile water, and then compacted to prepare yellow storage at the densities of 450, 500 and 550 kg/m³ （additive treatment group）, respectively. The other part was evenly sprayed with 3% sterile water, and then compacted to prepare yellow storage at the densities of 450, 500 and 550 kg/m³ （control group）, respectively. Fermentation weight loss of the yellow storage of the two groups with different compaction densities were measured after fermentation for 1, 3, 6, 15, 35 and 200 d, respectively. At 200 d of fermentation, the yellow storage samples were taken to assess the fermentation quality, microbial quantity and microbial diversity. [Result] From 3 d to 200 d of fermentation, the fermentation weight loss of both groups increased significantly （P<0.05）. At 35 d and 200 d of fermentation, the fermentation weight loss of the additive treatment group was significantly （P<0.05） lower than that of the control group. Compared with the control group, the additive treatment group had significantly （P<0.05） lower pH value, significantly （P<0.05） higher lactic acid content, significantly （P<0.05） reduced ammoniacal nitrogen content, and significantly （P<0.05） elevated acid-base buffering capacity. The number of lactic acid bacteria and yeasts of the additive treatment group was significantly （P<0.05） lower than that of the control group. Lactiplantibacillus and Lentilactobacillus were found as the dominant bacterial genera in both groups, with relative abundance of 22.12%-49.18% and 1.45%-49.91%, respectively, and their total relative abundance exceeded 34.25%. At the compaction density of 450 kg/m³, the relative abundance of Leuconostoc and Enterobacter of the additive treatment group was significantly （P<0.05） lower than that of the control group. At the compaction density of 500 kg/m³, significantly （P<0.05） lower relative abundance of Lentilactobacillus and Leuconostoc as well as significantly （P<0.05） higher relative abundance of Enterobacter, Pantoea, Ralstonia and Weissella were observed in the additive treatment group compared with the control group. At the compaction density of 550 kg/m³, the additive treatment group had significantly （P<0.05） decreased relative abundance of Lentilactobacillus, Enterobacter and Leuconostoc as well as significantly （P<0.05） increased relative abundance of Bacillus and Paenibacillus than the control group. The relative abundance of Lentilactobacillus was negatively correlated with lactic acid content, the ratio of lactic acid to acetic acid, and acid-base buffering capacity （P>0.05）, positively correlated with acetic acid content （P>0.05）, significantly （P<0.05） positively correlated with pH value, and significantly （P<0.01） positively correlated with ammoniacal nitrogen content. The relative abundance of Enterococcus and Lactococcus was significantly （P<0.05） negatively correlated with lactic acid content, significantly （P<0.01） negatively correlated with the ratio of lactic acid to acetic acid as well as acid-base buffering capacity, and significantly （P<0.01） positively correlated with pH value. The number of lactic acid bacteria and yeasts was significantly （P<0.01） positively correlated with pH value and ammoniacal nitrogen content, and significantly （P<0.01） negatively correlated with the ratio of lactic acid to acetic acid. [Conclusion] Increasing compaction density and utilizing microbial additive can reduce the fermentation weight loss and ameliorate the fermentation quality of wheat straw yellow storage.

[Objective] The aims of the present study were to assess the optimal ratio of corn straw and spent Flammulina velutipes substrate as roughage in preparation of fermented total mixed ration （FTMR） for beef cattle, and to provide technical support for the high-value utilization of by-products such as mushroom bran. [Method] For the preparation of roughage, a total of 7 treatment groups with different mixing ratios of corn straw and spent Flammulina velutipes substrate were set up. Total mixed ration （TMR） were made from even mixing of corn straw and spent Flammulina velutipes substrate at the ratios of 8∶2 （T1 group）, 7∶3 （T2 group）, 6∶4 （T3 group）, 5∶5 （T4 group）, 4∶6 （T5 group）, 3∶7 （T6 group） and 2∶8 （T7 group） with addition of beef cattle concentrate supplement at a concentrate-roughage ratio of 4∶6 （fresh weight）. TMR samples from different treatment groups were placed into silage bags, and then compacted, sealed, vacuumized and stored in a dark room to naturally ferment for 60 days to prepare FTMR. The nutritional component and mycotoxin content of the prepared TMR and FTMR samples were measured and statistically compared. Furthermore, the fermentation parameters of FTMR were assessed to determine the optimal ratio of corn straw and spent Flammulina velutipes substrate. [Result]①As the ratios of corn straw to spent Flammulina velutipes substrate decreased, the DM content of TMR gradually reduced, the CP content gradually increased, the NDF and ADF contents generally elevated, and the EE content fluctuated. ②As the ratios of corn straw to spent Flammulina velutipes substrate decreased, the DM content of FTMR gradually reduced as well. Compared with the corresponding TMR, the FTMR in T4 group had the lowest DM loss rate. The CP content of FTMR in T3 and T4 groups were significantly （P<0.05） higher than that in the other groups. Compared with the corresponding TMR, the CP content of FTMR in T3 and T4 groups increased. No significant （P>0.05） differences in EE content of FTMR among different groups were observed. Compared with the corresponding TMR, the EE content of FTMR decreased in T1-T4 groups, but increased in T5-T7 groups. The NDF content of FTMR in T1-T5 groups were significantly （P<0.05） lower than that in T6 and T7 groups, with the lowest NDF content observed in T3 group. Compared with the corresponding TMR, the NDF content of FTMR in T3 and T5 groups decreased. The ADF content of FTMR in T1-T5 groups were significantly （P<0.05） lower than that in T6 and T7 groups. Compared with the corresponding TMR, the ADF content of FTMR in T4 and T5 groups decreased. ③The FTMR samples from all the treatment groups had acidic aroma and good fermentation quality. The pH value of FTMR in T3 group was the lowest, which was significantly （P<0.05） lower than that in the other groups. The pH value of FTMR in T4 group was lower as well. As the ratios of corn straw to spent Flammulina velutipes substrate decreased, the LA content of FTMR showed a trend of first increasing and then decreasing, with T4 group having the highest content, followed by T3 group, both of which were significantly （P<0.05） higher than the other groups. As the ratios of corn straw to spent Flammulina velutipes substrate decreased, the AA content of FTMR exhibited a trend of first increasing and then decreasing, with T5 group having the highest content, followed by T4 and T3 groups. Trace level of PA were detected in FTMR samples from all the treatment groups, and there were no significant differences （P>0.05） among the different groups. Trace level of BA were detected in FTMR in T6 and T7 groups, while the other groups were not detected. The AN/TN ratio of FTMR in T3 group was the lowest. FTMR in T6 and T7 groups had the AN/TN ratio exceeding 10%, while the other groups was less than 10%. The differences in AFB₁, ZEN and OTA contents of TMR and FTMR samples among different groups were not significant （P>0.05）. According to the Feed Hygiene Standard （GB 13078-2017）, the mycotoxin content of the TMR and FTMR samples did not exceed the threshold. ④The main effects analysis showed that the fermentation treatment significantly （P<0.05） reduced the ABF₁ and ZEN contents of TMR, while the treatment of the mixing ratios of corn straw and spent Flammulina velutipes substrate, as well as the combination effect of fermentation and mixing ratios, had no significant （P>0.05） effects on the ABF₁ and ZEN contents of the TMR and FTMR samples. In addition, the fermentation treatment, the treatment of the mixing ratios of corn straw and spent Flammulina velutipes substrate, and the combination effect of fermentation and mixing ratios had no significant （P>0.05） effects on the OTA content of the TMR and FTMR samples. [Conclusion] Based on the comprehensive analysis on nutritional component, mycotoxin content and fermentation quality, the preparation of FTMR with corn straw and spent Flammulina velutipes substrate as roughage was an efficient way to preserve and utilize the by-products such as straw and mushroom bran. Corn straw and spent Flammulina velutipes substrate mixed at the ratios of 6∶4 （T3 group） or 5∶5 （T4 group） had the better performance.

The unreasonable use and abuse of antibiotics in swine farming not only lead to bacterial antimicrobial resistance, but also result in antibiotic residues in animal tissues and animal-originated food, posing a great threat to food safety. Under the background of ′prohibition of antibiotics in feed′ and ′reduction of antibiotics in animal farming′, the screen and development of novel typed feed additives without toxic and side effects have become a hot topic for the relevant researchers. Micro-ecological preparations, especially probiotics, have gradually been considered as the ideal alternative to antibiotic additives due to their green and safe advantages. Probiotics are a type of active microbial feed additives and bring multiple benefits to the host animals mainly through regulating their gut microbial balance. This paper reviews the research progress on the action mechanisms of probiotics and their application in swine production, in hoping to provide references for the scientific utilization of probiotics in swine farming.

[Objective] This study was conducted to assess the effects of drought stress at different intensities on the growth and physiological characteristics of Amarunthus hypochondriacus seedlings, and to compare the drought resistance traits of different varieties of Amarunthus hypochondriacus seedlings. [Method] Three varieties of Amarunthus hypochondriacus, including Qiansuigu, American Grain Amaranth and Grain Amaranth N053 were selected as the experimental materials. Indoor pot experiment and artificial water control experiment were conducted, with 80% of the maximum soil moisture content as the control group （CK）. Mild, moderate and severe drought stress treatments were set up, with the soil moisture content of 60%, 40% and 20% of the maximum soil moisture content, respectively. The growth and physiological indicators of different varieties of Amarunthus hypochondriacus seedlings under different drought stress intensities were measured and statistically compared. The evaluation indicators were screened through principal component analysis, and subsequently the drought resistance of the three varieties of Amarunthus hypochondriacus seedlings was assessed using the membership function comprehensive evaluation method. [Result] The seedling growth indicators （plant height, number of leaves and stem width） of the three Amarunthus hypochondriacus varieties had gradually decreasing trends with the increase of drought stress intensities. Under the moderate and severe drought stress, the plant height, number of leaves and stem width of the three varieties of Amarunthus hypochondriacus seedlings were significantly （P<0.05） lower than those of CK and the mild drought stress. With the increase of drought stress intensities, the three varieties of Amarunthus hypochondriacus seedlings had generally decreased SPAD value, increased malondialdehyde （MDA） content, elevated proline （PRO） content, increased first and then decreased soluble sugar （SS） content, while the soluble protein （SP） content had no obvious change. As the intensities of drought stress increased, the leaf relative conductivity （RC） of American Grain Amaranth seedlings gradually decreased, the leaf RC of Qiansuigu seedlings gradually increased, and the leaf RC of Grain Amaranth N053 first increased and then decreased. The activities of superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD） of the three varieties of Amarunthus hypochondriacus seedlings demonstrated an overall trend of first increasing and then decreasing. Under the severe drought stress, the activities of SOD and POD of American Grain Amaranth seedlings were significantly （P<0.05） higher than those of Qiansuigu and Grain Amaranth N053 seedlings, and the CAT activity was also higher than that of the other two varieties. Principal component analysis revealed that the contribution rates of the first four principal components were 35.456%, 20.030%, 12.507% and 8.371%, respectively, with a cumulative contribution rate of 76.364%. The indicators with high absolute values of eigenvector in the first four principal components included plant height, number of leaves, stem width, MDA content, CAT activity, POD activity, SOD activity and SS content. These indicators were used as the source of comprehensive evaluation indicators for drought resistance. The membership function comprehensive evaluation showed that the average membership function values of the drought resistance associated indicators for American Grain Amaranth, Qiansuigu and Grain Amaranth N053 seedlings were 0.72, 0.53 and 0.29, respectively. [Conclusion] Through principal component analysis and membership function comprehensive evaluation of the growth and physiological indicators of Amarunthus hypochondriacus seedlings, the drought resistance of the three varieties seedlings from high to low was: American Grain Amaranth > Qiansuigu > Grain Amaranth N053.

[Objective] This study was conducted to assess the effects of different remediation measures on the restoration of degraded grassland. [Method] A restoration trial with three measures, including enclosure （TW）, enclosure+supplementary sowing （TB）, and enclosure+supplementary sowing+fertilization （TBS）, was performed on the moderately and severely degraded grasslands in Jarud Banner, Tongliao City, Inner Mongolia. Using the peripheral grazing plots as control （CK）, the vegetation height, coverage and above-ground biomass of the degraded grasslands were continuously monitored and compared under different remediation measures from 2016 to 2019. [Result] During the whole monitoring period, the vegetation height, coverage and above-ground biomass of TW, TB and TBS treatments were all significantly （P<0.05） higher than those of CK. In the current year of restoration （2016）, the vegetation height, coverage and above-ground biomass of TB and TBS treatments were significantly （P<0.05） higher than those of TW treatment, and the vegetation height and coverage of TBS treatment were significantly （P<0.05） higher than those of TB treatment. In 2017, the vegetation height and above-ground biomass of TBS treatment were significantly （P<0.05） higher than those of TW and TB treatments, and the vegetation coverage of TB and TBS treatments was significantly （P<0.05） higher than that of TW treatment. In 2018, the vegetation above-ground biomass of TB and TBS treatments was significantly （P<0.05） higher than that of TW treatment, and the vegetation above-ground biomass of TBS treatment was significantly （P<0.05） higher than that of TB treatment. In 2019, the vegetation coverage and above-ground biomass of TB and TBS treatments were significantly （P<0.05） higher than those of TW treatment. [Conclusion] The remediation measures of enclosure, enclosure+supplementary sowing, and enclosure+supplementary sowing+fertilization all had good restoration effects on moderately and severely degraded grasslands, with enclosure+supplementary sowing+fertilization having the best restoration effect.

[Objective] The aim of the present study was to comprehensively understand the development status and evolution trend of research on grassland ecological protection compensation in China. [Method] Using the China National Knowledge Infrastructure （CNKI） database as the data source, literature searches were conducted under the themes of ′Grassland Ecological Protection Subsidy and Incentive Policy′, ′Grassland Ecological Subsidy and Incentive′, ′Grassland Ecological Compensation′ and ′Grassland Compensation′. The time span was limited to 2000-2022, and the search scope were the papers published in the journals indexed in Peking University Core Periodical Catalogue and Nanjing University Chinese Social Sciences Citation Index （CSSCI）. CiteSpace （6.2. R4） software was used to perform visualization analyses on the publication years, source journals, authors and hotspots based on the 301 selected literature in this research field. [Result] ① From the perspective of the current research status, the relevant published literature on grassland ecological protection compensation exhibited a fluctuating upward trend since 2007. Journal of Arid Land Resources and Environment, Chinese Journal of Grassland as well as Heilongjiang Animal Science and Veterinary Medicine were the top three journals in terms of publication volume. JIN Leshan, ZHOU Shengqiang and GONG Fang had the higher number of published articles, and all of them published 11 articles. Cooperative relationship among different authors mainly manifested as an institution-based group collaboration mode. Collaborations among different institutions had obvious regional characteristics. Connections among institutions across regions were minor and the collaborations was limited. ② From the perspective of the research hotspots, keywords were classified mainly in three categories. The first category was involved in the policy′s subsidy and incentive standards as well as the compensation objects, and the corresponding keywords included ′compensation mechanism′, ′incentive mechanism′, ′farmers and herdsmen′, ′herdsmen′, etc. The second category was associated with the design of policy evaluation index system. Currently, researchers mainly constructed evaluation systems from the aspects of ecological benefits, economic benefits and social benefits. The third category was related to the effectiveness of policy implementation. Some researchers evaluated the effectiveness of policy implementation from the perspective of herdsmen, while others evaluated that from the perspective of grassland ecology. ③ From the perspective of the research hotspots′ evolution trend, the initially emerged hotspots were ′grassland′, ′ecological compensation′, ′compensation mechanism′ and ′incentive mechanism′, focusing on exploring the manners in which compensate and reward were implemented. Before and after 2010, the research hotspots predominantly concentrated in analyzing the policy itself, with emphasis on identifying problems and providing suggestions. In recent years, the research hotspots gradually shifted to evaluating the effectiveness of policy implementation. [Conclusion] The research on grassland ecological protection compensation in China has received widespread attention from scholars. The corresponding research results can provide scientific research support and references for the implementation of the relevant policies.

In the context of global climate change, extreme drought has been proven to pose significant impacts on the structure and function of ecosystems, especially on soil and vegetation characteristics. However, the impact level of extreme drought on ecosystems largely varied due to the ecosystem types. The grassland ecosystem is the largest terrestrial ecosystem in China, undertaking the prominent responsibility of economic and ecological sustainable development in pastoral areas. It is highly vulnerable to changes in precipitation patterns. Therefore, assessing the response of grassland soil and vegetation characteristics to extreme drought is of great significance for understanding the evolution laws of natural ecosystems, as well as preventing and reducing the losses resulting from future extreme climate events in the ecological environment and economic development. This paper reviews the research progress on the response of grassland ecosystems to extreme drought in the aspects of soil moisture, temperature, nutrients, mineralization and microorganisms, as well as vegetation community characteristics, vegetation phenology and functional traits, in hoping to provide references for investigating the selection and adaptation of grassland ecosystems to extreme drought climate under global climate change conditions.

Elymus nutans is one of the most extensively distributed high-quality forage grasses on the Qinghai-Tibetan Plateau. As a prominent grass species used for cultivation and utilization as well as replanting and improvement of degraded grasslands in the alpine region, it has important economic and ecological utilization value, and is essential for artificial grassland establishment and natural grassland vegetation restoration. This paper renders an overall review of the research progress on genetic diversity, seed germination characteristics, agronomic traits, cultivation and utilization, and stress resistance of Elymus nutans, in hoping to provide references for the future research and utilization of Elymus nutans.

[Objective] The present study was conducted to evaluate the quality grade of fresh dairy milk in different regions of Inner Mongolia, and to compare the milk yield and quality of dairy cows between agricultural and pastoral areas as well as between large-scale farms and scatter-feed households. [Method] In October 2023, a total of 120 batches of fresh milk samples were collected from large-scale farms in Hohhot City, scatter-feed households in Hohhot City, dairy farms in Hulun Buir City, and dairy farms in Xilin Gol League, with 30 batches each. Production record information of the dairy cows was also collected. The milk composition （milk fat percentage, milk protein percentage, total solids content, non-fat milk solids content, lactose content）, somatic cell count and total bacterial count of the samples collected from different regions were tested, and the samples were subsequently subjected to the quality grade evaluation according to the Quality Grading of Raw Cow Milk （NY/T 4054-2021）. Statistical methods were used to compare the average individual milk yield and milk quality of dairy cows between agricultural area （Hohhot City） and pastoral area （Hulun Buir City and Xilin Gol League）, as well as between large-scale farms and scatter-feed households in Hohhot City. [Result] The milk fat percentage and total bacterial count （6.16%, 83.10×10⁴ CFU/mL) of the samples collected from Xilin Gol League were significantly （P<0.05） higher than those collected from Hohhot City （3.96%, 14.05×10⁴ CFU/mL） and Hulun Buir City （4.15%, 38.94×10⁴ CFU/mL）. The milk somatic cell count of the samples collected from Hulun Buir City （399 900 cells/mL） was significantly （P<0.05） higher than those collected from Xilin Gol League （181 800 cells/mL） and Hohhot City （183 500 cells/mL）. According to the Quality Grading of Raw Cow Milk, the milk samples collected from Hohhot City were determined as extra-premium grade, and those collected from Hulun Buir City and Xilin Gol League were both determined as premium grade. The dairy cows in agricultural area had significantly （P<0.05） higher average individual milk yield and milk lactose content （29.07 kg/d, 5.14%） than those in pastoral area （16.56 kg/d, 4.85%）. The milk fat percentage, somatic cell count and total bacterial count of the samples collected from pastoral area （4.88%, 483 900 cells/mL, 49.52×10⁴ CFU/mL) were significantly （P<0.05） higher than agricultural area （4.05%, 202 000 cells/mL, 13.99×10⁴ CFU/mL）. Significantly （P<0.05） higher average individual milk yield as well as milk non-fat milk solids content and lactose content were observed in the dairy cows in large-scale dairy farms （34.46 kg/d, 9.44%, 5.19%） compared with scatter-feed households （20.71 kg/d, 9.21%, 5.07%） in Hohhot City, while significantly （P<0.05) higher milk somatic cell count was observed in scatter-feed households （232 400 cells/mL） compared with large-scale dairy farms （160 400 cells/mL）. [Conclusion] The quality of fresh dairy milk in Hohhot City was better than that in Hulun Buir City and Xilin Gol League. Dairy cows in agricultural area had higher milk yield and better milk quality than those in pastoral area. The milk yield and quality of dairy cows in large-scale farms were superior to those in scatter-feed households.

[Objective] This study aimed to determine the optimal extraction and processing method for total flavonoids from chickpea （Cicer arietinum）, and to evaluate the analgesic effect of chickpea total flavonoids （CTFs） on mice. [Method] The chickpeas produced in Xinjiang Uygur Autonomous Region were used as the experimental materials. The aluminum nitrate-sodium nitrite colorimetric method was employed to assess the contents of CTFs obtained through ultrasonic-assisted extraction, Soxhlet reflux extraction, micro-wave extraction, ultrasonic-assisted extraction+rotary evaporation treatment, Soxhlet reflux extraction+rotary evaporation treatment, ultrasonic-assisted extraction+freeze-drying treatment, respectively, to determine the optimal extraction and processing method for CTFs. Kunming mice were randomly assigned into 5 groups. The high, medium and low dose groups were gavaged with 60, 30 and 15 mg/(kg · BW) of CTFs. The positive control group was gavaged with 80 mg/（kg·BW） of aspirin. The blank control group was gavaged with 0.1 mL/（10 g·BW） of physiological saline. Each group was administered once daily for 3 consecutive days. According to the above grouping and administration scheme, the analgesic effects of different doses of CTFs on mice were evaluated using hot plate test （n=40, 8 mice in each group）, warm bath test （n=40, 8 mice in each group） and acetic acid twisting test （n=40, 8 mice in each group）. [Result] The CTFs obtained by different extraction and processing methods were as follows: ultrasonic-assisted extraction+freeze-drying treatment （51.18 mg/g）>Soxhlet reflux extraction （13.16 mg/g）>ultrasonic-assisted extraction （4.86 mg/g）>Soxhlet reflux extraction+rotary evaporation treatment （4.75 mg/g）>micro-wave extraction （3.03 mg/g）>ultrasonic-assisted extraction+rotary evaporation treatment （0.57 mg/g）. Hot plate test demonstrated that compared with the blank control group, CTFs high and low dose groups had extremely significantly （P<0.01） prolonged pain threshold at 10, 30 and 60 min after administration, while CTFs medium dose group exhibited significantly （P<0.05） prolonged pain threshold at 10 and 30 min after administration. CTFs medium and low dose groups had extremely significantly （P<0.01） prolonged pain threshold in warm bath test at 2 h after administration than the blank control group. CTFs high, medium and low dose groups had extremely significantly （P<0.01） reduced the frequency of twisting induced by acetic acid compared with the blank control group, with the pain inhibition rates of 35.44%, 35.44% and 61.37%, respectively. In addition, the frequency of twisting in CTFs low dose group was lower than that in the positive control group, with higher pain inhibition rate than that in the positive control group. [Conclusion] The optimal extraction and processing method for CTFs was ultrasound-assisted extraction+freeze-drying treatment. Different doses of CTFs had good analgesic effects on mice, with low dose [15 mg/（kg·BW）] having the best.

[Objective] The aim of this study was to understand the prevalence as well as antimicrobial resistance and virulence gene distribution of Escherichia coli in sheep in a slaughterhouse in Aksu Prefecture, Xinjiang Uygur Autonomous Region. [Method] A total of 30 samples of lymph node, carcass swabs and feces were collected from the healthy sheep in a slaughterhouse in Aksu Prefecture. Escherichia coli was isolated using selective culture medium, and subsequently molecularly identified using Escherichia coli specific phoA gene. Multilocus sequence typing （MLST） of the isolates was performed by PCR amplification and sequencing. K-B disk diffusion method was used for antimicrobial susceptibility test of the isolates. The presence of the antimicrobial resistance and virulence genes of the isolates were detected by PCR assay. The 96-well plate micro-broth method was used to determine the biofilm formation ability of the isolates. [Result] A total of 14 strains of Escherichia coli were isolated from the 30 samples, with a separation rate of 46.67%. The 14 isolates belonged to 10 MLST types. High resistance rates to sulfamethoxazole-trimethoprim （100%）, penicillin （85.71%） and tetracycline （50.00%） were observed among the isolates. Nine isolates （64.29%） expressed multi-drug resistance phenotype. Twelve antimicrobial resistance genes, including bla_TEM （85.71%）, aph （3′） （71.43%）, tetA （64.29%）, sul1 （57.14%） and sul2 （57.14%） were detected in the 14 isolates, and 8 isolates （57.14%） harboured the typeⅠintegron int-Ⅰgene. Ten virulence genes, including fimH （100%）, yijP （92.86%）, mat （92.86%）, sheA （92.86%）, stx1 （35.71%） and ibeB （28.57%） were detected in the 14 isolates. Ten isolates （71.43%） had the ability to form biofilms. [Conclusion] The sheep derived Escherichia coli strains in the slaughterhouse had abundant intraspecific subtypes, increased antimicrobial resistance and the ability to form biofilms. They also carried multiple antimicrobial resistance and virulence genes, and thus posed a potential threat to animal food safety.

[Objective] This study aimed to understand the infection status and subgenotype distribution of Blastocystis in Hu sheep in large-scale farms in Hangzhou City, China. [Method] A total of 167 fresh fecal samples of Hu sheep were collected from four large-scale farms in Hangzhou City, and their whole genomic DNA were extracted. PCR assay targeting the small-subunit ribosomal RNA （SSU rRNA） gene was performed using the fecal DNA samples as templates, and the obtained positive amplification products were sequenced. The subgenotypes of Blastocystis were identified through sequence alignment. Phylogenetic tree was constructed to analyze their genetic evolutionary relationships. [Result] Among the 167 samples, 18 were positive for Blastocystis, with an infection rate of 10.78% （18/167）. Three farms had the prevalence of Blastocystis, with infection rates of 21.43% （3/14）, 21.21% （14/66） and 2.13% （1/47）, respectively. One farm had no Blastocystis detection. There were extremely significant （P<0.01） differences in the infection rates of Blastocystis among different farms. Seven subgenotypes of Blastocystis were identified, including ST7 （n=1）, ST10 （n=9）, ST21 （n=3）, ST23 （n=1）, ST24 （n=2）, ST26 （n=1） and ST30 （n=1）. ST10 was found as the dominant subgenotype （9/18, 50.00%）. Based on the phylogenetic tree analysis of the SSU rRNA gene of Blastocystis, it was found that six gene subgenotypes were clustered into one large group, with ST10 and ST23 clustering into one subgroup, ST21, ST26 and ST30 clustering into one subgroup, and ST24 clustering into one subgroup as well, while ST7 was clustered into another group. [Conclusion] Blastocystis infection in Hu sheep was common in Hangzhou City, and the subgenotypes of Blastocystis had genetic diversity. The results obtained in this study provided basic data for the investigation of sheep Blastocystis infection status in China.

[Objective] This study was conducted to understand the prevalence and genetic characteristics of porcine circovirus type 2 （PCV2） in Guangxi Zhuang Autonomous Region. [Method] The clinical samples collected from different areas of Guangxi Zhuang Autonomous Region were subjected to PCV2 detection and whole genome sequence amplification by PCR assay. The bioinformatics software including BioEdit, Mega 7.0, RDP 5 and SimPlot （ver 3.5.1） were used to perform nucleotide sequence similarity, genetic variation and recombination analyses on the while genome sequences of 24 PCV2 strains obtained. In addition, the variation sites on amino acid sequences of the Cap protein were analyzed. [Result] The genomic size of the PCV2 Guangxi strains were all 1 768 bp. Nucleotide sequence similarity analysis showed that the PCV2 Guangxi strains shared 44.7% to 99.7% similarity with the referential strains PCV1-PCV4, and had the lowest similarity with PCV3. The PCV2 Guangxi strains were determined as PCV2b and PCV2d subtypes, with PCV2d being the most prevalent. Whole genome sequence recombination analysis demonstrated that there were recombination events in selected PCV2 Guangxi strains. In comparison with the vaccine strains AY686764-PCV2b and HM641752-PCV2b, a total of 21 variation sites were observed on the amino acid sequences of the Cap protein of the PCV2 Guangxi strains. [Conclusion] PCV2d was the dominant subtype of the PCV2 Guangxi strains. Several strains had genomic recombination events and unique amino acid variations on some loci, indicating a clear genetic evolution trend. The research results provided basic data for the epidemiological investigation and genetic evolution analysis of PCV2 in Guangxi Zhuang Autonomous Region.

[Objective] This study was conducted to understand the infection status and species distribution of Cryptosporidium in Bactrian camels in large-scale farms in Kalpin County, Aksu Prefecture, Xinjiang Uygur Autonomous Region. [Method] A total of 516 fecal samples were collected from 6 large-scale Bactrian camel farms in 4 townships or towns of Kalpin County, and were then subjected to genomic DNA extraction. PCR assay was carried out targeting the SSU rDNA of Cryptosporidium. After sequence alignment analysis, Cryptosporidium species were identified. The χ² test was used to statistically compare the infection rates of Cryptosporidium in Bactrian camels among different farms. DNA samples identified as Cryptosporidium parvum （C. parvum） positive were used to perform PCR assay targeting the gp60 gene. C. parvum subtypes were determined following sequencing alignment analysis. [Result] Out of the 516 fecal DNA samples of Bactrian camels, 34 samples were positive for Cryptosporidium, with an overall infection rate of 6.59% （34/516）. The NO.2 farm in Aqial Town had the highest infection rate of 9.57% （9/94）. There were statistically significant differences （χ²=5.497, P<0.05） in the infection rates of Cryptosporidium in Bactrian camels from different farms. Three species of Cryptosporidium, including Cryptosporidium andersoni （n=29）, Cryptosporidium rat genotype Ⅳ （n=1） and C. parvum （n=4）, were identified in the 34 samples positive for Cryptosporidium by the comparison analysis on SSU rDNA sequence. In addition, the 4 samples positive for C. parvum were identified as subtypeⅠd-like-A21 by the comparison analysis on the gp60 gene sequence, exhibiting unique genetic evolution characteristic. [Conclusion] A low infection rate of Cryptosporidium in Bactrian camels in Kalpin County was observed, and the subtype of the infected C. parvum was unique. The results obtained in this study offered fundamental data for characterizing the species distribution and genetic evolution of Cryptosporidium in Bactrian camels in China.

[Objective] This study was conducted to isolate and identify the common pathogenic bacteria associated with subclinical mastitis in dairy cows in Xinjiang Uygur Autonomous Region, and to evaluate the in vitro antibacterial effects of cefalonium and rifaximin against the clinical bacterial isolates. [Method] The subclinical mastitis in dairy cows in dry period in a dairy farm in Changji Hui Autonomous Prefecture, Xinjiang Uygur Autonomous Region was diagnosed using Lanzhou mastitis test （LMT）. The bacterial isolation and species identification of a total of 74 collected milk samples were performed using streak plate method and 16S rDNA sequence analysis method. The minimum inhibitory concentration （MIC） and minimum bactericidal concentration （MBC） of cefalonium and rifaximin against the clinical isolates were determined by micro-broth dilution method. [Result] A total of 103 pathogenic bacterial isolates belonging to 9 species were obtained from the 74 milk samples. Among them, Staphylococcus aureus （S. aureus, n=35）, Escherichia coli （E. coli, n=24） and Staphylococcus chromogenes （S. chromogenes, n=15） were found as the dominant species, accounting for 33.98%, 23.30% and 14.56% of the total number of the isolates, respectively. Staphylococcus simulans （S. simulans, n=10）, Staphylococcus epidermidis （S. epidermidis, n=6）, Enterococcus faecium （E. faecium, n=5）, Staphylococcus haemolyticus （S. haemolyticus, n=4）, Bacillus licheniformis （B. licheniformis, n=3） and Staphylococcus saprophyticus （S. saprophyticus, n=1） were also observed, accounting for 9.70%, 5.83%, 4.85%, 3.88%, 2.91% and 0.97% of the total number of the isolates, respectively. The in vitro antibacterial test showed that the MICs of cefalonium against S. aureus, E. coli, S. chromogenes, S. haemolyticus, S. epidermidis, S. saprophyticus, E. faecium, S. simulans and B. licheniformis were 0.12, 3.91, 0.98, 0.06, 0.98, 0.98, 3.91, 0.06 and 0.49 μg/mL, respectively, and the corresponding MBCs were 0.24, 7.81, 1.95, 0.12, 1.95, 1.95, 7.81, 0.24 and 1.95 μg/mL, respectively. The MICs of rifaximin against S. aureus, E. coli, S. chromogenes, S. haemolyticus, S. epidermidis, S. saprophyticus, E. faecium, S. simulans and B. licheniformis were 0.20, 6.25, 1.56, 0.78, 1.56, 1.56, 12.50, 0.20 and 0.20 μg/mL, respectively, and the corresponding MBCs were 0.78, 12.50, 3.13, 1.56, 3.13, 3.13, 12.50, 0.78 and 1.56 μg/mL, respectively. [Conclusion] The main pathogenic bacteria causing subclinical mastitis in dairy cows in dry period in this farm were S. aureus, E. coli and S. chromogenes. Both cefalonium and rifaximin had good antibacterial effects against the clinical isolates.