The use of biological feed as an antibiotic alternative has gained a lot of attention in light of the antibiotic ban in animal feed. Biological feed offers benefits including improving feed quality, enhancing animal production performance, boosting animal immunity and regulating animal gut microbiota, exhibiting an increasing market acceptance. This paper introduced the definition and classification of biological feed, summarized the research progress on the application of biological feed in cattle, sheep and pig production taking fermented feed and bacterium and enzyme synergistic fermented feed as examples, analyzed the problems in the current application of biological feed, and put forward relevant suggestions, in hoping to provide references for the development and application of biological feed.

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.

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] The aims of the present study were to assess the biological characteristics of Lactobacillus plantarum derived from Yichun forest pig and to comprehensively evaluate its application potential in the development of probiotic preparations. [Method] A lactic acid bacterial strain （P1M1） isolated from the feces of the healthy forest pig in Yichun City, Heilongjiang Province, was biochemically identified and then molecularly confirmed by using 16S rDNA PCR amplification and sequencing technology. The curves of growth and acid production of the strain were drawn, and its tolerance to acid （pH values at 2.0, 3.0 and 4.0） and bile salt （concentrations at 0.15% and 0.30%） were evaluated. The sensitivity of the strain to 13 antimicrobial agents and its inhibitory effect on Staphylococcus aureus （S. aureus） of porcine origin were examined. Tests were also conducted to assess the free radical scavenging ability, exopolysaccharides yield and safety to mice of the strain. [Result] Based on the biochemical and molecular identification results, P1M1 strain was identified as Lactobacillus plantarum （L. plantarum）. L. Plantarum P1M1 strain had glycolytic ability. Its logarithmic growth phase was 2-10 h of cultivation. After 18 h of cultivation, the pH value of its culture medium stabilized at 3.8-3.9. Its 3 h survival rates at pH values of 2.0, 3.0 and 4.0 were （48.97±0.61）%, （64.19±0.94）% and （78.44 ± 1.36）%, respectively, and those at bile salt concentrations of 0.15% and 0.30% were （53.86±1.14）% and （32.87±0.75）%, respectively. It was sensitive to erythromycin, enrofloxacin, norfloxacin, tobramycin, ampicillin, amoxicillin, cefoperazone, cefradine and ceftazidime, and had pronounced inhibitory effect on S. aureus of porcine origin. The scavenging rates of its cell-free supernatant against DPPH free radical, hydroxyl radical and ABTS free radical were （91.65±1.44）%, （87.32±0.22）% and （89.79±0.59）%, respectively, all significantly （P<0.05） higher than those of its intact cell suspension. Its exopolysaccharides yield was （796.73±2.43） mg/L. No death or organ damage was observed after continuous gavages of the L. plantarum P1M1 strain to mice for 2 weeks. [Conclusion] Forest pig derived L. plantarum P1M1 strain shows an early entrance into the logarithmic growth phase, has glycolytic characteristics, strong acid producing ability, and tolerance to acid and bile salt. It is sensitive to various antimicrobial agents and capable of inhibiting the growth of S. aureus of porcine origin. Furthermore, it has strong antioxidant capacity and high exopolysaccharides yield, and is safe for mice. Accordingly, it can be used as a candidate strain for the development of probiotic preparations.

Fermented Chinese herbal medicine combines the pharmacological effects of Chinese herbal medicine with the health benefits of probiotics. During the fermentation process, Chinese herbal medicine offers nutrients to microorganisms and promotes their growth, while the enzymes and metabolites produced by microorganisms stimulate the release of effective ingredients in Chinese herbal medicine, reduce the toxicity of derivative preparations, and also synthesize novel active ingredients to enhance the drug efficacy. The fermentation process also decompose the active macromolecules or polymers into small molecules, facilitating transmembrane transport and aiding in the absorption of active substances by the body. In addition, some microorganisms in fermented Chinese herbal medicine inhibit the proliferation of pathogenic bacteria and work synergistically with Chinese herbal medicine to jointly combat pathogens. Under the background of reducing antibiotics use and replacing antibiotics, fermented Chinese herbal medicine, as a type of green feed additive, has great utilization value and prospects in animal husbandry. This paper summarizes the research progress on the characteristics of fermented Chinese herbal medicine and application in animal production, in hoping to provide references for the further development and utilization of fermented Chinese herbal feed additives.

Long-acting preparations are medications with long-lasting therapeutic effects, which have the advantages of decreased administration frequencies, reduced dosages and less harmful side effects. Long-acting preparations of traditional Chinese medicine that can continuously release drugs are developed on the basis of conventional traditional Chinese medicine pharmaceutical technology by combining with the carrier materials through unique preparation procedures. This paper reviewed the research progress on long-acting preparations of traditional Chinese medicine and the application in exterminating ectoparasite, in hoping to provide references for future research and clinical application of anti-ectoparasitic long-acting preparations of traditional Chinese medicine.

[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 aimed to assess the research status, hotspots and trends of dairy industry development in China by bibliometric and visual analyses, so as to provide data supports for the domestic dairy industry development. [Method] China National Knowledge Infrastructure （CNKI） Database was used as the data source to retrieve literature in the field of dairy industry development research in China from 1992 to 2023. The knowledge graphs for the dairy industry development research field was created using the visualization analysis tool CiteSpace. In combination with bibliometric methods, the research status, hotspots and theme evolution in this field were then analyzed. [Result] According to the retrieve criteria, a total of 739 journal articles were included, with the highest annual publication volume in 2002, reaching 60 articles. The top three authors by publication quantity were LIU Yuman （17 articles）, LI Shengli （15 articles） and LIU Fang （15 articles）, and the top three institutions were Rural Development Institute of Chinese Academy of Social Sciences （19 articles）, Agricultural Information Institute of Chinese Academy of Agricultural Sciences （18 articles） and College of Economics and Management of Northeast Agricultural University （17 articles）. The dairy industry development research filed had formed a relatively tight and mature collaboration network. The institutions such as Agricultural Information Institute of Chinese Academy of Agricultural Sciences, College of Animal Science and Technology of China Agricultural University, Rural Development Institute of Chinese Academy of Social Sciences, Institute of Animal Science of Chinese Academy of Agricultural Sciences had higher cooperation densities and tighter connections with each other. Dairy industry and dairy industry development were the research hotspots in this field. Keywords such as dairy industry development, milk source base, dairy factory, dairy cattle industry and milk yield emerged earlier, while low-carbon development, regulatory approach and smart farming emerged recently. [Conclusion] The research hotspots on the theme of dairy industry development were dynamically changing, with high collaboration densities among researchers and institutions. There was regional heterogeneity in the distribution of collaboration networks. Low-carbon development and smart farming may be the focus of future research.

[Objective] This study was conducted to characterize the prevalence and species distribution of Cryptosporidium in dairy cattle on a large-scale introduction farm in Kashgar Prefecture, Xinjiang Uygur Autonomous Region. [Method] A total of 190 fecal samples were collected from dairy cattle of different age groups in this farm. Targeting on the small subunit ribosomal RNA gene （SSU rDNA）, PCR assay combined with sequencing were used to detect the Cryptosporidium infection. The species of Cryptosporidium were identified through SSU rDNA sequence alignment. Chi-square （χ²） test was performed to compare the differences in the Cryptosporidium infection rates among dairy cattle of different age groups. The gp60 genes of C. parvum, C. bovis and C. ryanae were amplified by PCR assay, and the subtypes of the 3 Cryptosporidium species were identified by sequence alignment. In addition, phylogenetic trees were constructed to analyze their genetic evolutionary characteristics. [Result] Thirty-two fecal samples of dairy cattle were positive for Cryptosporidium, with an overall infection rate of 16.84% （32/190）. Four Cryptosporidium species, including C. parvum （n=8）, C. andersoni （n=10）, C. bovis （n=10） and C. ryanae （n=4）, were identified. A higher infection rate of Cryptosporidium was observed in the pre-weaned calves under 3 months of age at 28.00% （14/50）. There were significant （χ²=8.679, P<0.05） differences in the infection rates of Cryptosporidium among dairy cattle of different age groups. Seven gp60 subtype sequences were obtained from the 8 C. parvum positive samples, with 2 subtypes identified as ⅡdA15G1 （n=3） and ⅡdA19G1 （n=4）. Six gp60 gene subtype sequences were obtained from the 10 C. bovis positive samples, with 3 subtypes identified as ⅩⅩⅥb （n=2）, ⅩⅩⅥc （n=3） and ⅩⅩⅥe （n=1）. The 4 C. ryanae positive samples were successfully subtyped with gp60 gene, all of which were identified as subtype ⅩⅪb. The phylogenetic tree analysis showed that the obtained Ⅱd subtype sequences of C. parvum in this study were in the same subgroup as the sequences of Ⅱd subtype family of C. parvum derived from different hosts, and were in different subgroups with the sequences ofⅡa subtype family of C. parvum derived from different hosts in New Zealand. Both the obtained subtype sequences of C. bovis and C. ryanae in this study were in the same group as those of cattle derived C. bovis and C. ryanae from different regions of China. [Conclusion] The Cryptosporidium prevalent in this introduction farm was characterized by diverse genetic distribution. The Cryptosporidium infection in dairy cattle occurred after being introduced locally, suggesting that water and forage pollution may be the primary causes of Cryptosporidium infection.

[Objective] The aim of the present study was to assess the effects of different stresses on the agronomic traits, physiological indicators and endogenous hormones of Lotus corniculatus. [Method] Using Lotus corniculatus as the experimental material, 3 stress treatments, including low nutrition （LN）, high bicarbonate （HB） and low phosphorus （LP） were set up by preparing different nutrient solutions. Hoagland′s nutrient solution prepared with distilled water was used as blank control （CK）. Lotus corniculatus seedlings at 2-3 leaves stage were transplanted into bottles containing different nutrient solutions, with 5 seedlings in each bottle and 15 bottles for each treatment. The nutrient solutions were changed every 3 d. Plants were harvested after 1 month of cultivation. The agronomic traits, physiological indicators and endogenous hormone levels of Lotus corniculatus under different stress treatments were measured and statistically compared. Membership function analysis method was used to comprehensively evaluate the effects of different stress treatments on the agronomic traits, physiological indicators and endogenous hormone levels of Lotus corniculatus. The growth performance of Lotus corniculatus under different stresses were analyzed. [Result] The plant height of Lotus corniculatus was the highest under LP treatment. Compared with CK, the root length, rhizosphere diameter, stem thickness, root volume, number of branches, above-ground and under-ground fresh weights, and single plant fresh weight of Lotus corniculatus under the 3 stress treatments all decreased, while the above-ground and under-ground dry matter contents increased. The root to shoot ratios of fresh weight and dry weights were the highest under LN treatment. Under LN treatment, the taproot activity of Lotus corniculatus was the highest, and the fibrous root activity was significantly （P<0.05） higher than that under the other treatments. The leaf chlorophyll content under LP treatment was significantly （P<0.05） higher than that under the other treatments, and the stem chlorophyll content was the highest under HB treatment. Under the 3 stress treatments, leaf protein content of Lotus corniculatus was significantly （P<0.05） lower than CK, stem protein content was higher than CK, leaf malondialdehyde content was significantly （P<0.05） higher than CK, stem malondialdehyde content was significantly （P<0.05） lower than CK, and both leaf and stem proline contents were higher than CK. The 3 stress treatments significantly （P<0.05） reduced the stem superoxide dismutase and peroxidase activities of Lotus corniculatus, and significantly （P<0.05） increased the stem catalase activity and the leaf glutamine synthetase activity. HB and LP stress treatments significantly （P<0.05） reduced the leaf superoxide dismutase and peroxidase activities of Lotus corniculatus. LN and LP stress treatments significantly （P<0.05） reduced the leaf catalase activity and significantly （P<0.05） increased the stem glutamine synthase activity. Compared with CK, the contents of acetylene （ACC）, jasmonic acid and its derivatives （JA） in Lotus corniculatus significantly （P<0.05） decreased under the 3 stress treatments, while the contents of free cytokinin （CTK）, abscisic acid （ABA） and gibberellins （GAs） significantly （P<0.05） increased. Except for the ACC/BHA under LP treatment, the ratios of ACC to the other endogenous hormones in Lotus corniculatus decreased to varying degrees under the 3 stress treatments, with some ratios less than 1. The membership function analysis showed that the comprehensive growth performance of Lotus corniculatus was in the order of LP treatment>CK>HB treatment>LN treatment. [Conclusion] Based on the various indicators, low phosphorus stress had minor impacts on the growth of Lotus corniculatus, while high bicarbonate and low nutrient stresses had a greater impact. Under low phosphorus, high bicarbonate and low nutrient stresses, Lotus corniculatus can regulate its growth and development by adjusting the morphological structure, activating the antioxidant system and balancing endogenous hormones, thereby adapting to the adverse environments.

Heat stress affects the milking performance of lactating dairy cows through various routes, such as reducing feed intake, altering energy metabolism pattern, activating immune system and causing inflammation, and influencing mammary gland development and function. Alleviating measures against heat stress in dairy farms are usually taken from the aspects of nutrition, management and genetics, while the effect is limited. Understanding the potential mechanisms by which heat stress causes reduction in milk production in lactating dairy cows is crucial for controlling milk production losses resulted from heat stress. This paper reviewed the research progress on the influence mechanisms of heat stress on the milking performance of lactating dairy cows, in hoping to provide references for the scientific formulation of heat stress alleviating measures in dairy cow production.

[Objective] The aims of the present study were to establish an ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry （UHPLC-MS/MS） method for simultaneous detection of 64 drugs in compound feed, and to improve the detection efficiency of illegal additives. [Method] Waters HSS T3 column （2.1 mm×100 mm, 1.8 μm） was used for separation. Gradient elution was performed using 0.1% formic acid aqueous solution as mobile phase A and acetonitrile containing 0.1% formic acid as mobile phase B, respectively, with a flow rate of 0.40 mL/min and sample size of 2 μL. Positive-ion electrospray ionization （ESI） source scanning mode was used for detection, and multiple reaction monitoring （MRM） mode was used for signal acquisition. The recovery rates of the target drugs obtained with 4 kinds of sample extraction solvents and 2 types of solid-phase extraction column were compared to determine the optimal method of sample pretreatment. Detection of the 64 drugs in 100 batches of compound feed samples of different sources collected in Ningxia Hui Autonomous Region was carried out with the established UHPLC-MS/MS method. [Result] The compound feed samples were extracted with acetonitrile aqueous solution （acetonitrile∶water=8∶2, V/V） containing 0.2% formic acid after homogenization. Oasis PRiME HLB solid-phase extraction column was used to purify the samples. The recovery rates of most target drugs was above 60%. In the concentration range of 5.0-200.0 μg/L, a good linear relationship of the 64 drugs was observed, and their correlation coefficients （R） were all greater than 0.99. The limit of quantitation of different drugs was 5.0-10.0 μg/kg. The average recovery rates of 3 spiking levels at 5.0, 20.0 and 50.0 μg/kg ranged from 41.00% to 120.49%. The intra- and inter-assay relative standard deviations （RSDs） were 0.54%-15.94% and 1.25%-13.64%, respectively. No target drug was detected in the 100 batches of compound feed samples. [Conclusion] The established UHPLC-MS/MS method has good linear relationship, high recovery rate, good precision, high reproducibility and good operability, and can be used for screening the 64 drugs illegally added in compound feed.

[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] 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 mechanism underlying the response of plant functional groups in desert steppe to different grazing intensities, and to provide bases for the rational utilization of desert steppe. [Method] The desert steppe distributed in Sonid Right Banner, Xilin Gol League, Inner Mongolia was chosen as the research object. Three grazing intensity treatments were set up, including a non-grazing （NG） treatment, a moderate grazing （MG） treatment and a heavy grazing （HG） treatment. Each treatment had 3 replications, with a total of 9 experimental plots. The stocking rates of the NG, MG and HG treatments were 0, 1.92 and 3.08 sheep unit/（hm² · year）, respectively, and the corresponding actual number of grazing sheep was 0, 5 and 8, respectively. From 2018 to 2020, the density, coverage, height and above ground biomass of the plant functional groups in the desert steppe were annually surveyed in mid August. The differences in the quantitative characteristics of the plant functional groups under varied grazing intensities were statistically compared. Furthermore, the grey correlation analysis was conducted between plant functional group and community under different grazing intensities. [Result] The highest number of plant species was observed in MG treatment, followed by NG treatment and HG treatment, which were 27, 25 and 19 species, respectively. Grazing significantly （P<0.05） increased the density of perennial forbs and decreased the density proportion of perennial grasses. The coverage of perennial grasses, annuals and biennials, as well as shrubs and semi-shrubs gradually reduced with the increasing grazing intensities. Grazing significantly （P<0.05） reduced the coverage of shrubs and semi-shrubs. The coverage proportion of perennial grasses as well as annuals and biennials gradually decreased with the increasing grazing intensities, while that of perennial forbs elevated with the increasing grazing intensities. Grazing significantly （P<0.05） reduced the height of perennial forbs as well as shrubs and semi-shrubs, decreased the height proportion of shrubs and semi-shrubs as well as perennial forbs, and increased the height proportion of perennial grasses as well as annuals and biennials. Grazing significantly （P<0.05） reduced the above ground biomass of shrubs and semi-shrubs. Heavy grazing significantly （P<0.05） reduced the above ground biomass of all plant functional groups. Grazing increased the above ground biomass proportion of annuals and biennials as well as perennial forbs, and reduced that of shrubs and semi-shrubs as well as perennial grasses. In the NG treatment, perennial grasses as well as annuals and biennials were the functional groups that had the highest correlation with the community, both with correlation degrees of 0.76. In the MG treatment, the functional group showing the highest correlation with the community was perennial forbs, with a correlation degree of 0.77, followed by annuals and biennials, with a correlation degree of 0.75. In the HG treatment, the functional group exhibiting the highest correlation with the community was perennial forbs, with a correlation degree of 0.80, followed by annuals and biennials, with a correlation degree of 0.67. [Conclusion] Moderate grazing enriched the plant species in the desert steppe. Long-term heavy grazing significantly reduced the above ground biomass of all plant functional groups. Long-term grazing reduced the dominance of perennial grasses and increased that of perennial forbs in the community, converting the functional groups with the highest correlation with the community from perennial grasses as well as annuals and biennials to perennial forbs as well as annuals and biennials.

[Objective] This study was conducted to explore the effects of dietary supplementation of plant essential oils prepared with different processes on growth performance, intestinal digestive enzyme activity and serum immunoglobulin level of weaned piglets.[Method]A total of 198 heads of 21-day-old Duroc × Landrace × Yorkshire （DLY） healthy weaned piglets with an average weight of （5.687±0.761） kg were randomly assigned into 3 groups, with 11 replicates in each group and 6 piglets in each replicate. The control group fed a basal diet. The two experimental groups fed the same basal diet in which 300 g/t of a micro-encapsulated and control-released plant essential oil （MECR-PEO） or a mixed plant essential oil （M-PEO） were supplemented, respectively. The feeding experiment lasted for 21 days. The average daily feed intake, average daily weight gain and feed to weight gain ratio of the experimental piglets at 22-28 days, 29-35 days and 36-42 days of age, as well as the diarrhea rate at 22-42 days of age were calculated. On the 21^st day of the feeding experiment, the duodenal chyme was collected, and the activities of intestinal trypsin, amylase and lipase were measured. At the end of the feeding experiment, blood samples were collected with serum prepared. ELISA assay was used to detect the serum levels of IgG, IgM and IgA. [Result] At 22-28 days and 29-35 days of age, the dietary supplementation of the two types of plant essential oils had the trends of increasing the average daily weight gain and average daily feed intake, as well as reducing the feed to weight gain ratio （P>0.05） compared with the control group. At 36-42 days of age, the piglets received the dietary supplementation of MECR-PEO had significantly （P<0.05） higher average daily weight gain and significantly （P<0.05） lower feed to weight gain ratio than those in the control group; the piglets received the dietary supplementation of M-PEO had higher average daily weight gain and average daily feed intake （P>0.05）, as well as lower feed to weight gain ratio than those in the control group （P>0.05）. At 22-42 days of age, the diarrhea rates of the piglets in both plant essential oil supplementation groups were significantly （P<0.05） reduced compared with the control group. The MECR-PEO supplementation group exhibited a better performance, with a decrease in diarrhea rate of 67.79% compared to the control group. Piglets in the MECR-PEO supplementation group had significantly （P<0.05） higher activities of duodenal trypsin, amylase and lipase in comparison to those in the control group, and had significantly （P<0.05） higher lipase activity in comparison to those in the M-PEO supplementation group. Significantly （P<0.05） higher duodenal trypsin activity was observed in the M-PEO supplementation group compared to the control group. Significantly （P<0.05） elevated serum levels of IgG and IgM in the MECR-PEO supplementation group was found compared with the control group, and significantly （P<0.05） elevated serum IgM level in the M-PEO supplementation group was found compared with the control group. [Conclusion] Dietary supplementation of MECR-PEO and M-PEO had positive effects on improving growth performance as well as enhancing intestinal digestive enzyme activity and serum immunoglobulin level in weaned piglets. The effects of MECR-PEO were better.

[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.

[Objective] This study was conducted to investigate the prevalence of tick-borne spotted fever group Rickettsia （SFGR） on the body surface of cattle and sheep in Aksu Prefecture, Xinjiang Uygur Autonomous Region. [Method] A total of 574 ticks on the body surface of cattle and sheep were randomly collected from Aksu City （n=344）, Wensu County （n=93）, Xayar County （n=98） and Wushi County （n=39） in Aksu Prefecture. PCR assays targeting at Rickettsia outer membrane protein B gene （ompB） and surface cell antigen 1 gene （sca1） were utilized to detect the presence of Rickettsia and to determine the SFGR genotypes. The strong positive samples of the two genes were selected for sequencing. Phylogenetic trees were constructed by comparing the obtained sequences with the relevant gene sequences registered in the GenBank Database. The differences in Rickettsia infection rates in the ticks collected from the four regions were compared.[Result]The presence of 3 SFGR genotypes, Candidatus Rickettsia barbaria, Rickettsia sibirica and Rickettsia massiliae, were observed in the ticks on the body surface of cattle and sheep. The overall positive rate of Rickettsia in the tick samples was 15.16% （87/574）, with Wensu County having the highest positive rate of 23.66% （22/93）. Among the 3 detected SFGR genotypes, Candidatus Rickettsia barbaria was identified as the dominant species （Dr=44.83%, 39/87）. There were significant （P=0.001,χ²=15.834） differences in Rickettsia infection rate in the ticks among the four regions. [Conclusion]Aksu Prefecture is an endemic area for ticks and Rickettsia. It is advised to strengthen the prevention and control of tick and tick-borne diseases.

[Objective] This study aimed to investigate the effects of crossbreeding of Australian White sheep as paternal parents and Hulun Buir sheep as maternal parents on reproductive performance and reproductive hormone secretion during gestation period of ewes. [Method] A total of 392 Hulun Buir ewes were selected and randomly assigned into an experimental group or a control group according to the ram breeds. For the ewes in the experimental group （n=139）, Australian White sheep （n=7） were served as the breeding ram, while for those in the control group （n=253） , Hulun Buir sheep （n=13） were served as the breeding ram. After delivery, the reproductive performance indicators such as conception rate, miscarriage rate and twinning rate of the ewes in the two groups, as well as the birth weights of the lambs produced by the ewes in the two groups were statistically compared. Eight ewes were selected from each group, and blood samples were collected at mid-gestation period （60 d gestation）, late-gestation period （90 d gestation） and 10 d before the expected date of lambing, respectively. The serum levels of follicle-stimulating hormone （FSH）, luteinizing hormone （LH）, progesterone （P₄） and estradiol （E₂） were measured with ELISA kits.[Result] The ewes in the experimental group had significantly （P<0.05） lower conception rate and actual delivery rate, significantly （P<0.05） higher miscarriage rate, and extremely significantly （P<0.01） higher twinning rate compared with those in the control group. No significant （P>0.05） difference in lamb survival rate between the experimental group and the control group was observed. There were no significant （P>0.05） differences in the lamb birth weight, single-lamb birth weight and twin-lamb birth weight between the experimental group and the control group. At each observed time points during gestation period, the serum levels of FSH, LH, P₄ and E₂ of the experimental group ewes had no significant （P>0.05） differences with those of the control group ewes. For the ewes in the control group, there were no significant （P>0.05） differences in the serum levels of LH, FSH and E₂ among the three observed time points during gestation period, while the serum level of P₄ at 10 d before the expected date of lambing was significantly （P<0.05） higher than that at the mid- and late-gestation period. For the ewes in the experimental group, the serum level of E₂ at the late-gestation period was significantly （P<0.05） higher than that at the mid-gestation period and 10 d before the expected date of lambing; the serum level of E₂ at the mid-gestation period was significantly （P<0.05） higher than that at 10 d before the expected date of lambing; the serum level of P₄ at the late-gestation period and 10 d before the expected date of lambing was significantly （P<0.05） higher than that at the mid-gestation period. [Conclusion] Crossbreeding of Australian White sheep as paternal parents and Hulun Buir sheep significantly elevated the twining rate and thus improved the reproductive efficiency of ewes, indicating that Australian White sheep as paternal parents had heterosis in improving the reproductive performance of Hulun Buir sheep.

[Objective] This study was conducted to assess the effects of dietary supplementation of soybean isoflavones and bile acids on production performance and serum physiological and biochemical indexes of green-shell laying hens. [Method] A total of 72 370-day-old green-shell laying hens were selected and randomly assigned into a control group or an experimental group, with 4 replicates in each group and 9 hens in each replicate. The control group were fed with a corn-soybean meal basal diet, while the experimental group received the same basal diet supplemented with 12.5 mg/kg soybean isoflavones and 60 mg/kg bile acids. The whole feeding experiment was consist of a 7-day preliminary trial and a 105-day formal trial. The feed intake, egg production and egg weight of each laying hen replicate during the experiment were recorded, and the average feed intake, feed to egg ratio and egg production rate were calculated. At the end of the experiment, egg samples were collected to measure egg quality indexes; blood samples were collected to prepare serum, and the serum physiological and biochemical indexes were measured. [Result] Compared with the control group, the average feed intake and egg production rate of the experimental group increased by 11.80% and 10.64%, respectively, with significant （P<0.05） differences. There were no significant （P>0.05） differences in the feed to egg ratio, egg shape index, egg weight, relative weight of eggshell, and relative weight of egg yolk between the experimental group and the control group, while there was an increasing trend in egg weight and relative weight of eggshell in the experimental group. The serum content of acetylcholinesterase （AChE） in the experimental group increased by 32.45% compared to that of the control group, with significant （P<0.05） difference. No significant （P>0.05) differences in serum contents of total protein （TP）, albumin （ALb）, glutamic pyruvic transaminase （GPT）, glutamic oxalacetic transaminase （GOT）, follicle-stimulating hormone （FSH）, and luteinizing hormone （LH） were observed between the experimental group and the control group, while increasing trends in serum contents of TP, ALb, FSH and LH as well as decreasing trends in those of GPT and GOT were observed in the experimental group. [Conclusion] Dietary supplementation of 12.5 mg/kg soybean isoflavones and 60 mg/kg bile acids for green-shell laying hens in the middle and late laying period improved the production performance and serum biochemical indexes.

[Objective] The aim of the present study was to characterize the molecular epidemiology and genetic variation of porcine reproductive and respiratory syndrome virus （PRRSV） in Guangxi Zhuang Autonomous Region. [Method] A real-time fluorescent RT-PCR kit for universal detection of PRRSV was utilized to detect the presence of PRRSV in a lung tissue sample collected from the clinically infected pig on a farm in Guangxi Zhuang Autonomous Region. Subsequently, a dual real-time fluorescent RT-PCR kit specific for the PRRSV American classic strain and NADC30-like PRRSV strain were employed to further identify the sample. The GP5 gene was amplified by PCR, and a homologous comparison was conducted between the obtained nucleotide sequence by sequencing and the GP5 gene sequences of both domestic and international PRRSV reference strains retrieved from the GenBank database. Additionally, a phylogenetic tree was constructed. The amino acid sequences derived from the GP5 gene were analyzed by sequence alignment. [Result] The sample was identified as NADC30-like PRRSV positive and designated as GXYL strain. Homologous analysis of the GP5 gene nucleotide sequences indicated that GXYL strain exhibited 61.9% to 93.2% similarity with both domestic and international PRRSV reference strains, sharing the highest homology with PRRSV NADC30 strain from the United States and the lowest homology with PRRSV LV strain of European type. Furthermore, phylogenetic tree analysis based on GP5 gene sequences placed GXYL strain within a branch alongside NADC30-like strains from China and NADC30 strains from the United States, indicating close relatedness among them within a larger branch containing other American type strains. Amino acid comparison analysis derived from GP5 gene sequences identified 7 mutation sites within GXYL strain, among which 2 sites were located at epitope A, 1 site was located at epitope B, and 4 sites were located at signal peptide region. No amino acid insertions or deletions were found. [Conclusion] GXYL strain is a NADC30-like PRRSV strain, suggesting that the surveillance of prevalence and genetic variation in PRRSV should be strengthened in this 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 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 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.

[Objective] The aims of the present study were to isolate and identify Staphylococcus aureus （S. aureus） strains from porcine milk in Aral City, Xinjiang Uygur Autonomous Region, and to characterize the virulence and antimicrobial resistance of the isolates.[Method] Six fresh porcine milk samples were collected from a large-scale farm in Aral City, and mannitol salt agar （MSA） was used to isolate S. aureus strains. The isolates were confirmed by phenotypic identification method and 16S rDNA sequence analysis. The biofilm formation ability of the isolates was determined. Antimicrobial sensitivity test was performed using K-B disk diffusion method. PCR assay was employed to detect the virulence and antimicrobial resistance genes.[Result]After isolation and molecular biology identification, two S. aureus strains were obtained from the milk samples, with a separation rate of 33.33% （2/6）. Both isolates had strong biofilm formation ability （+++）. The two isolates were sensitive to rifampicin and resistant to penicillin, cefoxitin, tetracycline, erythromycin, temicoxacin, clindamycin and sulfamethoxazole. Out of the five tested antimicrobial resistance genes, both isolates carried ant （4） gene and mecA gene. A total of six virulence genes were detected among the twenty tested virulence genes. Among these, both isolates carried seg, sei, hlb, fnbA and clfA genes. One isolate carried hla gene.[Conclusion]The porcine milk derived S. aureus strains in this farm had strong biofilm formation ability and carried multiple virulence and antimicrobial resistance genes, exhibiting multiple-drug resistance.

[Objective] This study was conducted to evaluate and compare the meat quality of different sheep breeds in Inner Mongolia. [Method] A total of 60 confined sheep belonging to 5 breeds, including Sonid sheep （selected from Sonid Right Banner, Xilin Gol League, n=12）, Ujimqin sheep （selected from East Ujimqin Banner, Xilin Gol League, n=12）, Chahar sheep （selected from Xianghuang Banner, Xilin Gol League, n=12）, Inner Mongolia fine wool sheep （selected from Zhenglan Banner, Xilin Gol League, n=12）, and Ordos fine wool sheep （selected from Uxin Banner, Ordos City, n=12） were randomly selected. After slaughter, 200 g longissimus dorsi muscle and 200 g biceps femoris samples eliminating fascia and fat were collected from each sheep, respectively. The physical indicators （color, cooked meat rate, shear force and water loss rate）, the contents of traditional nutritional components （water, fat and protein）, and the compositions and contents of amino acids （7 kinds of essential amino acids and 10 kinds of non-essential amino acids） of longissimus dorsi muscle and biceps femoris samples collected from the 5 sheep breeds were assessed and statistically compared. [Result] The longissimus dorsi muscle and biceps femoris of Ordos fine wool sheep and Sonid sheep had better perfomance in color. There were no significant （P>0.05） differences in cooked meat rates of longissimus dorsi muscle among the 5 sheep breeds. Chahar sheep had the highest cooked meat rate of biceps femoris. The water loss rates of longissimus dorsi muscle and biceps femoris of Ujimqin sheep were significantly （P<0.05） lower than those of the other 4 sheep breeds. The shear force of longissimus dorsi muscle and biceps femoris of Sonid sheep was relatively lower among the 5 sheep breeds. In longissimus dorsi muscle and biceps femoris, the highest water content, the lowest fat content and the highest protein content were observed in Chahar sheep, Ujimqin sheep and Sonid sheep, respectively. Ordos fine wool sheep had the highest total amino acid contents in longissimus dorsi muscle and biceps femoris, had higher contents of 7 kinds of essential amino acids in longissimus dorsi muscle, and had significantly （P<0.05） higher contents of 7 kinds of essential amino acids in biceps femoris than those of the other 4 sheep breeds. The ratios of essential amino acid to total amino acid （EAA/TAA） of longissimus dorsi muscle and biceps femoris of the 5 sheep breeds were all around 40%, and those of essential amino acid to non-essential amino acid （EAA/NEAA） were all above 60%, which met the recommended values for high-quality proteins by FAO/WHO. [Conclusion] Although the 5 sheep breeds in Inner Mongolia had differences in the main meat quality indicators, they were all high-quality protein sources due to the high content and balanced composition of EAA. Ordos fine wool sheep performed better in terms of meat TAA and EAA contents, while Ujimqin sheep had the characteristics of high-protein and low-fat meat.

[Objective] The aim of the present study was to analyze the research trend and hotspot of heavy metal passivation during organic waste composting process. [Method] The literature published from 2000 to 2022 and indexed by the Web of Science （WoS） core collection database on heavy metal passivation during organic waste composting process were used as the data source. CiteSpace 6.2.R6 and VOSviewer 1.6.18 bibliometric visualization software were employed to assess the number of publications and the corresponding countries （regions）, authors, institutions and keywords, and to clarify the research trend and hotspot in this research field. [Result] From 2000 to 2022, a total of 1 266 papers on heavy metal passivation during organic waste composting process were published, with an overall upward trend in annual publication volume. From 2020 to 2022, 345 papers were published, accounting for 27.25% of the total number of publications. Chinese scholars led the research field in terms of publication volume by countries （regions）, with 301 papers published, accounting for 23.78% of the total number of publications. From the perspective of publication volume and collaborative relationships among the authors, KALAMDHAD Ajay S and ZHANG Zengqiang had the highest number of publications, and both published 23 papers, accounting for 1.82% of the total number of publications. The highest number of collaborative authors were observed between the teams of ZHANG Jiachao and ZENG Guanming, indicating an intimate collaborative relationship. From the perspective of institutional publication volume and collaborative relationships, the Spanish National Research Council ranked the first with 96 papers published, accounting for 7.58% of the total number of publications. The Spanish National Research Council and the Chinese Academy of Sciences were the most active institutions in this research field and had the closest collaboration with the other institutions. The top 6 keywords with high occurrence frequency were heavy metals, sewage sludge, municipal solid waste, organic matter, soil and compost, with occurrence frequencies of 724, 441, 210, 187, 158 and 158, respectively. Among the top 10 keywords with high occurrence frequency, sewage sludge, bioavailability, growth, heavy metals, municipal solid waste and soil had intermediary centrality greater than 0.1, and their intermediary centralities were 0.78, 0.52, 0.42, 0.30, 0.25 and 0.18, respectively. A total of 10 categories of keywords were clustered in this research field, including sewage sludge, organic amendments, organic fraction of municipal solid waste, greenhouse gas, C/N ratio, heavy metals, organic waste, and so on. The keyword zinc had the highest burst strength at 16.57 and received attention from 2004 to 2015. Biochar, food waste, microbial community, transformation and organic amendments were the dominant burst keywords from 2017 to 2022. [Conclusion] This study clarified the research trend and hotspot of heavy metal passivation during organic waste composting process. The impacts of different organic wastes on heavy metal passivation, the form transformation and stability of heavy metals in organic waste composting, and the enrichment and transfer of heavy metals in composting products may be the focus of the future research.

[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.

[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 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] 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] This study aimed to thoroughly analyse the development history, hotspot and trend of the research filed of community diversity in desert steppe in China and abroad, and to provide visualized data support. [Method] The relevant literature information on community diversity in desert steppe indexed in Web of Science Core Collection and published from January 1991 to December 2022 was used as the research object. By CiteSpace software, the change trend of annual publication volume, and the publication quantities of journals and authors were assessed. In addition, co-occurrence analysis and cluster analysis were performed on countries, institutions, authors, keywords and cited literature, and the obtained results were then visually presented. [Result] Under the set retrieval criteria, a total of 1 122 English literature on community diversity of desert steppe were obtained. From January 1991 to December 2022, the domestic and international publication quantities in this research field exhibited an overall upward trend. The articles published by Chinese authors or institutions had the highest citation frequency and academic impact, followed by those published by American authors or institutions. Journal of Arid Environments had the highest publication quantity, and Chinese Academy of Sciences had a higher academic impact. The research directions included but not limited to species diversity, climate change, ecosystem of desert steppe and human production activities. [Conclusion] From January 1991 to December 2022, this research field focused on the restoration of desert steppe in the context of global climate change, and the response mechanism of community diversity in desert steppe to human intervention. Exploring the factors influencing plant diversity in desert steppe and the impacts of global climate change on biodiversity in desert steppe are the future hotspots.

[Objective] This study was conducted to investigate the status of intestinal parasitic infection in sheep in Yuxi City, Yunnan Province, to analyze the infection risk factors, and to provide references for the scientific prevention and control of sheep intestinal parasitic diseases in this region. [Method] A total of 1 339 fresh fecal samples of 4 sheep breeds were collected from 88 farms （households） in 9 counties （districts） of Yuxi City. Parasite eggs were screened by saturated saline floating method and subsequently identified by morphological method. The differences in intestinal parasitic infection rates in sheep in different counties （districts） and of varied breeds were compared. The relevance between intestinal parasitic infection and age, gender of sheep, as well as altitude, temperature differences of the sampling regions were analyzed by epidemiological method. [Result] The overall infection rate of parasite eggs/oocysts in the collected fresh sheep fecal samples was 93.43% （1 251/1 339）. The positive rates of nematode eggs, Eimeria oocysts and mixed infection of nematode eggs/Eimeria oocysts were 24.42% （327/1 339）, 69.01% （924/1 339） and 20.09% （269/1 339）, respectively. No trematode eggs were detected. The positive rates of nematode eggs, Eimeria oocysts and mixed infection of nematode eggs/Eimeria oocysts among sheep in different counties （districts） and of varied breeds had differences. Risk factor analysis revealed that age of sheep as well as altitude and temperature of the sampling regions had moderate relevance with the single or mixed intestinal infections of nematode eggs and Eimeria oocysts, while gender of sheep had no relevance. [Conclusion] A high prevalence of intestinal parasitic infection was observed in sheep in Yuxi City, Yunnan Province, with the dominant infected species being nematodes and Eimeria. The intestinal parasitic infection rates varied by counties （districts） and sheep breeds. The age of sheep as well as the differences in altitude and temperature were the risk factors for the high prevalence.

[Objective] This study was conducted to monitor the quinolone residues in poultry egg products in Bijie City, Guizhou Province, and to assess the risk of quinolone residues.[Method]A total of 231 batches of poultry egg products were randomly collected from poultry farms, supermarkets and agricultural markets in Bijie City from January to November 2023. A solid phase extraction-liquid chromatography/tandem mass spectrometry method was used to detect the residue levels of 7 quinolones （enrofloxacin, ciprofloxacin, defloxacin, norfloxacin, ofloxacin, lomefloxacin and pefloxacin）. The safety of quinolone residues in poultry egg products was evaluated by point assessment in exposure assessment combined with the index of food safety （IFS）.[Result]The 7 quinolones had good linear correlation in the concentration range from 0.005 to 0.1 μg/mL, with correlation coefficients （R²） all greater than 0.990. The recovery rates at 3 spiking levels （2, 6 and 10 μg/kg） ranged from 64.2% to 106.0%, with relative standard deviation （RSD） less than 15% （n=6）. The detection limit and quantification limit of the method were 0.02-0.33 μg/kg and 0.07-1.10 μg/kg, respectively. The used method was proved to be simple and fast, to have high accuracy, good precision and strong selectivity, and met the detection demands of quinolone residues in poultry egg products. Among the 231 batches of poultry egg products sampled, the residues of enrofloxacin and ciprofloxacin was observed in 15 batches, with a detection rate of 6.5% and a residue range of 0.94-15.1 μg/kg. Among these, 3 batches had enrofloxacin residue that exceeded the maximum residue limit （10 μg/kg） specified in the National Food Safety Standard-Maximum Residue Limits for 41 Veterinary Drugs in Foods （GB 31650.1-2022） of China, with a exceeding rate of 1.3%. The average, minimum and maximum values of IFS for quinolone residues in poultry egg products in Bijie City were 5.23×10^-4, 1.39×10^-4 and 8.61×10^-4, respectively, and these values were far less than 1.[Conclusion]The quinolone residues in poultry egg products in Bijie City had minor impacts on human health and the risk was acceptable. Supervision and random inspection should be strengthened.

[Objective] The aims of the present study were to isolate and identify Pasteurella multocida （Pm） from sheep, and to assess the biological characteristics of the isolate. [Method] On site dissection was performed on sheep with typical respiratory disease symptoms from a family farm in Togtoh County, Hohhot City, Inner Mongolia Autonomous Region. The pathological changes of the main respiratory organs and spleen were observed and the pathological sections of lung tissue were prepared. Lung tissue sample was aseptically collected for bacterial isolation and culture. After phenotypical identification, molecular biological identification and capsular serotype identification of the isolated strain were performed. PCR assay was used to detect the virulence genes. Disc diffusion method was used to test the sensitivity of the isolated strain to 11 antimicrobial agents. The pathogenicity of the isolated strain to mice was evaluated using intraperitoneal injection method. [Result] The diseased sheep had adhesions of the lungs to the pleura and pericardium, necrotic lesions in the lung tissues, enlarged lymph nodes in the hilum of the lung, and bleeding sites in the spleen. After isolation and purification, one bacterial strain was obtained and designated as 2021-TX-06. This strain appeared as a tiny, circular and white colony with slight protrusion on TSA medium containing 5% horse serum. It was a Gram negative bacterium that conformed to the biochemical characteristics of Pm and was capable of fermenting and utilizing mannitol, sorbitol, trehalose, xylose and glucose. After 16S rDNA PCR amplification and sequence alignment, the 2021-TX-06 strain was identified as Pm. Following capsular serotyping, it was identified as capsular serotype D, carrying 15 virulence genes such as ptfA, fimA, Fur, etc. It was sensitive to the antimicrobial agents including tetracycline, ceftriaxone, gentamicin, polymyxin B, and resistant to norfloxacin, enrofloxacin, and chloramphenicol. Seventy-two hours after the intraperitoneal injection with 5 × 10⁸ CFU/mL bacterial suspension of 2021-TX-06 strain, a 100% mortality rate was observed in the experimental group mice. A strain consistent with the challenging strain was recovered from the lungs of the dead mice. [Conclusion] A Pm prevalent strain belonging to capsular serotype D was isolated from the lung tissue of sheep with typical respiratory disease symptoms. This strain harbored multiple virulence genes, showed resistance to some antimicrobial agents, and had strong pathogenicity to mice.

As a fundamental link of the modern grassland governance system, digitization of grassland ecological production is crucial for preserving ecological balance, increasing productivity, and fostering the transformation and upgrading of the pastoral economy. Currently, although digital technology is being widely used in monitoring and management of grassland ecological production at all levels, its overall development and implementation is still lagging behind. With a particular focus on the digitization process of grassland ecology and production activity, this paper analyzed the development status, main accomplishments and primary problems in this field at both the national and Inner Mongolia Autonomous Region levels. Furthermore, a series of countermeasures on the digital development of grassland ecological production were made from the perspective of national strategy in response to the numerous shortcomings of the current digital construction of grassland ecology, in hoping to lay a strong technological foundation for the realization of the ecological civilization construction goal of ′green mountains and clear waters are invaluable assets′, as well as for the development of new quality productive forces in grassland.

[Objective] This study aimed to screen the suitable mixed sowing combinations of forage grasses for saline-alkali grassland reseeding in Songnen Plain. [Method] The experiment was conducted on the saline-alkali grassland in Qiqihar City, Heilongjiang Province. Hordeum brevisubulatum, a variety of saline-alkali tolerant forage grass widely distributed in Songnen Plain, was used as the dominant forage grass for reseeding. The mixed sowing treatments were set with 4 indigenous varieties of saline-alkali tolerant forage grasses in Songnen Plain, including Puccinellia tenuiflora, Elymus dahuricus, Leymus chinensis and Calamagrostis epigejos. A single sowing treatment with Hordeum brevisubulatum was set as well. In the 4 mixed sowing treatments, the sowing amount of Hordeum brevisubulatum was 30 kg/hm², and that of the other forage grasses was all 15 kg/hm². In the single sowing treatment of Hordeum brevisubulatum, the sowing amount of Hordeum brevisubulatum was 45 kg/hm². Each of the above treatment had 3 reduplicates with 1 plot for each reduplicate. A plot without reseeding （CK） was included. Accordingly, a total of 16 plots were included in this study, and each plot covered an area of around 0.4 hm². Under the condition of minimizing disturbance to the native vegetation, no-tillage reseeding was performed on the experimental plots in 2021. Starting from the second year of reseeding, the soil physical and chemical properties such as bulk density, pH value, salt content （conductivity）, organic matter content, alkali-hydrolyzable nitrogen content, available phosphorus content and available potassium content, as well as the important value of vegetation community of the experimental plots were determined for two consecutive years. [Result] In the second year （2022） of reseeding, compared with CK, the soil bulk density, pH value and conductivity of the mixed sowing treatments and the single sowing treatment decreased to varying degrees, while the soil contents of organic matter, alkali-hydrolyzable nitrogen, available phosphorus and available potassium increased to varying degrees. Compared with the second year of reseeding, the mixed sowing treatments and the single sowing treatment had decreased soil bulk density, pH value and conductivity as well as elevated soil contents of organic matter, alkali-hydrolyzable nitrogen, available phosphorus and available potassium in the third year （2023） of reseeding. The effectively improved soil physical and chemical properties were observed in the mixed sowing treatments and the single sowing treatment in the third year of reseeding. Specifically, the soil bulk density, pH value and conductivity were significantly （P<0.05） lower than those of CK, the soil contents of alkali-hydrolyzable nitrogen, available phosphorus and available potassium were significantly （P<0.05） higher than those of CK, and the soil organic matter content was significantly （P<0.05） higher than CK except for the mixed sowing treatment of Hordeum brevisubulatum+Leymus chinensis. In addition, the lowest soil bulk density, pH value and conductivity were observed in the mixed sowing treatment of Hordeum brevisubulatum+Leymus chinensis, while the highest soil contents of organic matter, alkali-hydrolyzable nitrogen, available phosphorus and available potassium were found in the mixed sowing treatment of Hordeum brevisubulatum+Elymus dahuricus. Compared with CK, there were minor differences in the important values of Poaceae plants and other forbs among the varied mixed sowing treatments and the single sowing treatment in the second year of reseeding, with the highest observed in the mixed sowing treatment of Hordeum brevisubulatum+Elymus dahuricus at 0.60. Compared with the second year of reseeding, the important values of Poaceae plants in various mixed sowing treatments and the single sowing treatment elevated in the third year of reseeding, and they were all higher than those in CK. Furthermore, the highest important value was also observed in the mixed sowing treatment of Hordeum brevisubulatum+Elymus dahuricus at 0.71. [Conclusion] The mixed sowing of Hordeum brevisubulatum+Leymus chinensis had the best performance in ameliorating the soil bulk density, pH value and salt content, and was a preferable mixed sowing combination for improving the severely saline-alkali grasslands. The mixed sowing of Hordeum brevisubulatum+Elymus dahuricus exhibited the best effects on ameliorating the soil contents of organic matter, alkali-hydrolyzable nitrogen, available phosphorus and available potassium as well as vegetation community, and was a superior mixed sowing combination for improving the mild and moderate saline-alkali grasslands as well as the degraded grasslands.