[Objective] To investigate the effects of calcium ions on the gut microbiota of mice fed a high-fat diet. [Methods] Thirty 6- to 8-week-old male C57BL/6J mice were randomly divided into three groups: a standard diet control group （C group）, a high-fat diet group （M group）, and a high-fat diet supplemented with calcium chloride treatment group （D group）, with 10 mice in each group. The C group was fed a standard diet and given regular drinking water, the M group was fed a high-fat diet and given regular drinking water, and the D group was fed a high-fat diet and given drinking water supplemented with 1.5 g/100 mL calcium chloride. After 11 weeks of continuous feeding, fecal samples were collected from each group. The gut microbiota was sequenced using 16S rRNA high-throughput sequencing technology. Species richness, evenness, and diversity were calculated using Perl and R programming languages, and shared and unique OTUs were compared among samples. Alpha diversity （Shannon index） and richness （ACE and Chao1 indices） were analyzed using QIIME software. Differences in microbiota between groups were analyzed using the Wilcox test and LDA histogram from the R STATS package. The PICRUSt software was used to analyze the species composition information obtained from the 16S rRNA sequencing data, and in combination with the Kyoto Encyclopedia of Genes and Genomes （KEGG） database, the functional genes of the microbial communities in each group were classified and analyzed for enrichment differences. [Results] ①A total of 953 922 valid sequences were obtained from the sequencing of nine samples across the three groups. Analysis of the ACE index, Chao1 index, and Shannon index showed no significant differences in species richness and diversity among the groups （P>0.05）. ②Analysis of species relative abundance at the genus and species levels revealed that the dominant genera in the C, M, and D groups were Dubosiella, Lachnospiraceae NK4A136 group, and Ileibacterium, with relative abundances of 14.34%, 14.49%, and 21.69%, respectively. The dominant species in the C, M, and D groups were Clostridiales bacterium CIEAF 020, Ileibacterium valens, and Ileibacterium valens, with relative abundances of 1.36%, 7.24%, and 21.69%, respectively. ③ Analysis of microbiota differences between groups showed that the D group microbiota differed from the C and M groups, primarily characterized by Ileibacterium, Ileibacterium valens, Proteobacteria, Bacilli, Erysipelotrichales, and Erysipelotrichaceae. ④ PICRUSt prediction of functional gene composition revealed significant differences （P<0.05） between the D and M groups in functional gene pathways such as carbon fixation, pyruvate metabolism, and starch and sucrose metabolism, suggesting that calcium chloride treatment may influence gene expression in these metabolic pathways. [Conclusion] Adding calcium ions to a high-fat diet can change the structure of the intestinal microbiota of mice, increase the number of specific microorganisms, and may affect the metabolic pathways related to energy intake and fat accumulation, providing a new perspective for the application of calcium ions in the prevention of obesity.

[Objective] To isolate and identify Mannheimia haemolytica from sheep in Kaifeng City, Henan Province, analyze its biological characteristics, and understand its drug resistance and the presence of virulence genes. [Methods] A total of 530 nasopharyngeal swabs were collected from sheep with respiratory diseases in 8 sheep farms in Kaifeng City. Mannheimia haemolytica was isolated using Tryptic Soy Agar （TSA）. The isolated strains were identified through biochemical reactions, morphological observations, and detection of the specific gene LKT. Multiplex PCR was used for serotyping of the isolates. PCR was employed to detect virulence genes in the isolates. The sensitivity of the isolates to 12 antimicrobial agents was tested using the Kirby-Bauer （K-B） disk diffusion method. Pathogenicity tests of isolates were conducted using BALB/c mice. [Results] ①A total of 52 strains of Mannheimia haemolytica were identified from the 530 samples, with a detection rate of 9.81%. ②Serotyping of the isolated Mannheimia haemolytica revealed that 17 strains belonged to serotype 1, accounting for 32.69%; 28 strains belonged to serotype 2, accounting for 53.85%; and 7 strains belonged to other serotypes, accounting for 13.46%. ③Detection of 11 virulence genes in Mannheimia haemolytica showed that all genes were detected. The detection rates of gcp, lktC, and nanH were relatively high, at 73.08%, 67.31%, and 65.38%, respectively, while the detection rates of the remaining virulence genes ranged from 17.31% to 51.92%. ④The isolated strains were highly sensitive to cefotaxime, cephalexin, and ceftriaxone, with sensitivity rates of 86.54%, 78.85%, and 84.62%, respectively. The sensitivity rates to the remaining drugs ranged from 11.54% to 46.15%, among which the sensitivity rates to erythromycin, gentamicin, and ampicillin were lower than 20%. ⑤Pathogenicity tests in mice showed that the lethality rates of Mannheimia haemolytica of serotype 1 and serotype 2 were both 100% within 36 hours. [Conclusion] The Mannheimia haemolytica isolated and identified from sheep nasopharyngeal swabs in the Kaifeng region primarily exhibited two serotypes, carried multiple virulence genes, and demonstrated high pathogenicity. The research results provide data references for the rational use of drugs and scientific prevention and control of Mannheimia haemolytica infections in sheep in Kaifeng City.

[Objective] To investigate the effects of tributyrin （TB） and glycerol monolaurate （GML） complex on production performance, egg quality, serum biochemical parameters, and serum hormone levels in laying hens in the late laying period. [Methods] A total of 952 healthy 80-week-old Hy-Line Sonia laying hens were randomly divided into a control group （basal diet） and an experimental group （basal diet supplemented with 1,000 mg/kg TB and GML complex）. Each treatment consisted of 17 replicates, with 28 hens per replicate. The trial lasted for 8 weeks. Feed intake, egg number, and egg weight were recorded on a per-replicate basis to calculate average egg weight, laying rate, average daily feed intake, feed-to-egg ratio, and average egg production. At the end of the 4^th and 8^th weeks, egg samples were collected to assess egg quality parameters, and blood samples were collected to measure serum biochemical parameters and hormone levels. [Results] ① Dietary supplementation with the TB and GML complex showed a tendency to increase the laying rate from weeks 5 to 8 （P=0.098） and reduce the feed-to-egg ratio （P=0.055）. ②Compared to the control group, the experimental group exhibited a highly significant （P<0.01） reduction in water spot egg scores and a significant （P<0.05） improvement in eggshell strength at the 4^th week. ③Relative to the control group, dietary supplementation with the TB and GML complex significantly （P<0.05） reduced serum lactate dehydrogenase activity at the 4^th week and showed a tendency to decrease serum triglyceride levels （P=0.052）. At the 8^th week, the experimental group had significantly （P<0.05） higher serum levels of total protein, albumin, calcium, and total cholesterol compared to the control group.④Compared to the control group, the experimental group showed highly significant （P<0.01） increases in follicle-stimulating hormone （FSH） and luteinizing hormone （LH） levels, as well as a significant （P<0.05） increase in estradiol levels at the 4^th week. At the 8^th week, the experimental group exhibited highly significant （P<0.01） increases in FSH and estradiol levels and a significant （P<0.05） increase in LH levels. No significant （P>0.05） differences were observed in progesterone levels between the two groups. [Conclusion] In summary, dietary supplementation with the TB and GML complex improved serum hormone levels and eggshell quality in late-laying hens.

[Objective] To isolate and screen lactic acid bacteria capable of degrading condensed tannins from Onobrychis viciifolia （sainfoin） and to optimize their degradation conditions. [Methods] Naturally fermented Onobrychis viciifolia samples,collected from experimental fields in the grassland and animal husbandry park of the Horinger County,Inner Mongolia, were used to isolate and screen lactic acid bacteria that met the specified criteria. Initial screening was conducted using bacterial culture media,followed by secondary screening based on tannin degradation rates to select strains with superior degradation capabilities for condensed tannins from Onobrychis viciifolia. The selected strain was identified using 16S rDNA sequence analysis. Furthermore,the effects of varying inoculum amounts,culture time,and culture temperature on the degradation rate of condensed tannins from Onobrychis viciifolia were investigated to determine the optimal degradation conditions. [Results] Following fermentation of Onobrychis viciifolia,33 strains of lactic acid bacteria meeting the criteria were isolated. After initial and secondary screening, one strain YHD2-6,exhibited strong condensed tannin degradation ability and was identified as Lactobacillus plantarum. The optimal culture conditions for YHD2-6 were determined to be an inoculum amount of 10%,a culture time of 96 h,and a culture temperature of 37 ℃,under which the degradation rate of condensed tannins reached 76.73%. [Conclusion] This study successfully screened a strain of Lactobacillus plantarum with a robust ability to degrade condensed tannins from Onobrychis viciifolia. This strain not only enhances the nutritional value of tannin-containing feeds but also holds potential application value in the field of fine chemicals.

[Objective] The study focused on the degraded grasslands in West Ujimqin Banner, Inner Mongolia, aiming to explore the ecological restoration effects of different restoration measures on degraded grasslands and to provide a reference for the vegetation restoration and reconstruction of degraded grasslands in the local and surrounding areas. [Methods] From 2020 to 2022, the restoration measures of fencing enclosure and management and protection were adopted in the lightly degraded grasslands. The control area was a freely grazed grassland adjacent to the restoration area with a basically consistent background. In the severely degraded grasslands, the measures of sand barriers and reseeding （on the basis of fencing enclosure and management and protection） were implemented. The control area was a plot in the severely degraded sample site that was enclosed and managed and protected without the measures of sand barriers and reseeding. Indicators such as the height, coverage, above-ground biomass, and species number of the plant communities within the monitoring quadrats were monitored. [Results] Compared with the control area, after three years of implementing the restoration measures of fencing enclosure and management and protection in the lightly degraded grasslands, the height, coverage, and above-ground biomass of the plant communities in the restoration area increased highly significantly （P<0.01）. After three years of implementing the measures of sand barriers and reseeding in the severely degraded grasslands, the height and coverage of the plant communities in the sample plots increased significantly （P<0.05）, and the above-ground biomass increased highly significantly （P<0.01）. In terms of the plant species composition, within three years of the implementation of the fencing enclosure in the project implementation area, there was no obvious change in the number of species in the degraded grasslands. There was a trend of an increase in perennial forage species and a decrease in annual and biennial forage species in the species composition. [Conclusion] In summary, the adoption of different ecological restoration measures for grasslands degraded to different degrees has significantly improved the production performance of the grasslands and the characteristics of the plant communities.

[Objective] To clarify the nutritional value of leguminous plants in Hunan grasslands.[Methods] Seventeen germplasm resources of leguminous plants at the flowering stage were collected. The contents of crude protein （CP）, dry matter （DM）, ether extract （EE）, crude fiber （CF）, crude ash （Ash）, and nitrogen-free extract （NFE） were determined and analyzed. The nutritional value was comprehensively evaluated using the grey relational analysis method. [Results] The analysis of nutritional composition revealed that the DM content of the 17 germplasms ranged from 10.49% to 50.79%, the CP content from 7.49% to 19.17%, the EE content from 0.82% to 4.60%, the CF content from 23.76% to 42.57%, the Ash content from 5.33% to 15.54%, and the NFE content from 37.50% to 50.72%. Lespedeza pilosa exhibited the highest DM content （50.79%） and the lowest Ash content （5.33%）; Vicia hirsuta had the highest CP content （19.17%）; Albizia julibrissin showed the highest EE content （4.60%）; Vigna angularis had the lowest CF content （23.76%）; Caragana sinica had the highest NFE content （50.72%）. The rankings based on equal-weight and weighted grey relational degrees were largely consistent, with Albizia julibrissin （0.859 6, 0.864 4）, Vicia hirsuta （0.788 5, 0.798 4）, Vigna angularis （0.751 4, 0.773 3）, Lespedeza pilosa （0.741 7, 0.733 6）, Caragana sinica （0.737 1, 0.754 6）, and Mucuna lamellata （0.736 2, 0.745 5） ranking higher overall. [Conclusion] In summary, among the 17 leguminous plant germplasms at the flowering stage in Hunan grasslands, Albizia julibrissin exhibited the best nutritional quality, followed by Vicia hirsuta and Vigna angularis.

[Objective] To investigate the seed morphology, germination characteristics, and seedling growth of ten Poaceae species in the Hinggan League of Inner Mongolia Autonomous Region. [Methods] Seeds of ten wild Poaceae species （Digitaria sanguinalis, Phleum pratense, Poa annua, Chloris virgata, Elymus sibiricus, Leymus chinensis, Agrostis gigantea, Eragrostis pilosa, Elymus dahuricus and Agropyron cristatum） collected from the grassland area of the Hinggan League were used as materials. Seed length, width, thickness, thousand grain weight, germination rate, germination potential, germination index, vigor index, radicle length, and coleoptile length were measured and compared. Correlation analysis was conducted on these traits, and the quality of the seeds from the ten Poaceae species was comprehensively evaluated using the membership function method. [Results] The seed length and thousand grain weight of Elymus dahuricus were significantly （P<0.05） higher than those of the other Poaceae species. The seed width of Digitaria sanguinalis and Elymus sibiricus was significantly （P<0.05） greater than that of the other eight species. Agropyron cristatum had the thickest seeds, significantly exceeding the other nine species, followed by Elymus sibiricus and Elymus dahuricus. Except for Leymus chinensis, seeds of the other nine species began germinating on the second day. The germination rates of Digitaria sanguinalis and Phleum pratense exceeded 50% on the second day, with cumulative germination rates reaching above 90% from day 3 to day 7. By the end of the experiment, only Eragrostis pilosa and Leymus chinensis had germination rates below 50%. The germination rate, germination potential, germination index, and vigor index of Digitaria sanguinalis and Phleum pratense were significantly （P<0.05） higher than those of the other Poaceae species. Seedlings of Digitaria sanguinalis exhibited the longest radicles, while those of Elymus dahuricus had the longest coleoptiles. Correlation analysis revealed a highly significant （P<0.01） positive correlation among germination rate, germination potential, germination index, and vigor index across the different Poaceae species. Comprehensive analysis using the membership function method indicated that the top three species in seed quality were Digitaria sanguinalis, Phleum pratense and Elymus dahuricus. [Conclusion] This comprehensive study of seed morphology, germination characteristics, and seedling growth of ten Poaceae species collected from the Hinggan League region revealed that Digitaria sanguinalis, Elymus dahuricus, and Phleum pratense exhibited superior overall performance, demonstrating potential for cultivation and promotion in this region.

[Objective] The study aimed to screen high-quality and high-yield mixed sowing combinations suitable for establishing long-term artificial grasslands in the Hohhot region. [Methods] Sowing was carried out on May 8, 2021, at the Dry Farming Experimental Station of the Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences in Wuchuan County. Leguminous forages including Aohan alfalfa （A）, Zhongmu No. 3 （Z）, Zhongmu No. 1 （P）, and gramineous forages including Bromus inermis （W）, Elymus sibiricus （L）, and Elytrigia repens （Y） were selected as the research objects. They were sown separately first, and then mixed-sown in different combinations （AW: Aohan alfalfa + Bromus inermis; AL: Aohan alfalfa + Elymus sibiricus; AY: Aohan alfalfa + Elytrigia repens; ZW: Zhongmu No. 3 + Bromus inermis; ZL: Zhongmu No. 3 + Elymus sibiricus; ZY: Zhongmu No. 3 + Elytrigia repens; PW: Zhongmu No. 1 + Bromus inermis; PL: Zhongmu No. 1 + Elymus sibiricus; PY: Zhongmu No. 1 + Elytrigia repens） to establish artificial grasslands. On August 26, 2022, the height, density, and biomass of the grass population under different treatments were measured; the contents of dry matter, crude protein, crude fat, crude ash, neutral detergent fiber, and acid detergent fiber in the forages of each mixed-sowing combination were detected; the interspecific competition rate and interspecific compatibility were calculated. [Results] The experimental results showed that the characteristics of the vegetation community were better in mixed-sowing than in single-sowing. ①In terms of community characteristics: The forage height performed better in the mixed-sowing combinations ZW and ZL. After mixed-sowing, the height of Z increased by 18.29% compared with that in single-sowing, and the height of W increased by 12.87% compared with that in single-sowing. The density of forages after mixed-sowing ranged from 178.00 to 322.67 plants/m². Compared with the single-sowing of leguminous and gramineous forages, the density increased by 8.99%-35.33% and 11.24%-34.51% respectively, and there were significant differences （P<0.05） in the community density between the ZL combination and other mixed-sowing combinations. The biomass of forages after mixed-sowing ranged from 207.28 to 308.70 g/m². Compared with the single-sowing of leguminous and gramineous forages, the biomass increased by 13.24%-14.35% and 9.36%-12.95% respectively, and there were significant differences （P<0.05） in the community biomass between the ZL and ZW combinations and other mixed-sowing combinations except AW. ②In terms of nutritional quality: The dry matter content of forages in each mixed-sowing combination ranged from 88.67% to 89.38%. The dry matter content of forages in the ZL mixed-sowing combination was the highest, followed by that in the ZW mixed-sowing combination. The crude protein content ranged from 13.15% to 15.78%. The crude protein content of forages in the ZW mixed-sowing combination was the highest, followed by that in the ZL mixed-sowing combination. The crude fat content was between 1.57% and 2.30%. The crude fat content of forages in the AL mixed-sowing combination was the highest, followed by that in the ZL mixed-sowing combination. The crude ash content was between 7.96% and 9.90%. The crude ash content of the ZW mixed-sowing combination was the lowest, and that of the ZL mixed-sowing combination was the second lowest. The neutral detergent fiber content was between 47.45% and 53.01%. The neutral detergent fiber content of the ZL mixed-sowing combination was the lowest, and that of the ZW mixed-sowing combination was the second lowest. The acid detergent fiber content was between 33.70% and 39.43%. The acid detergent fiber content of the ZY mixed-sowing combination was the lowest, and that of the ZW mixed-sowing combination was the second lowest. ③ Interspecific competition rate and interspecific compatibility: Except for the AW and ZY mixed-sowing combinations, the relative yield total of the other different mixed-sowing combinations was greater than 1, ranging from 1 to 1.135, indicating that for all combinations except the AW and ZY mixed-sowing combinations, the interspecific interference was less than the intraspecific interference, and the coexistence of leguminous and gramineous forages in these combinations was good. In addition, except for the AY mixed-sowing combination, the interspecific competition ratio in all treatments was greater than 1, ranging from 1 to 1.754, indicating that the competitiveness of leguminous forages in all combinations except the AY mixed-sowing combination was better than that of gramineous forages. ④ Comprehensive evaluation: Based on the comprehensive evaluation using the grey relational degree and entropy weight-TOPSIS model, the ranking of each mixed-sowing combination from high to low was: ZL > ZW > PL > AL > PW > AY > PY > ZY > AW. [Conclusion] Considering all indicators, the ZL and ZW mixed-sowing combinations performed well in terms of vegetation community characteristics, forage nutritional components, interspecific competition, and community stability. Therefore, ZL and ZW are preliminarily selected as the best mixed-sowing combinations suitable for establishment in the Hohhot region.

The dairy industry is an important part of the animal husbandry industry, and the dairy product industry chain is one of the most complex food industry chains. Dairy product safety cannot be ignored and is a global issue. Through long-term practice, the Netherlands has established a relatively comprehensive dairy product safety supervision system. Based on this, this paper comprehensively analyzes the regulatory advantages of the Dutch dairy product industry chain from the development status and characteristics of the Dutch dairy industry and the food supervision system. Furthermore, it proposes development recommendations for the supervision of food safety in China′s dairy industry from three aspects: the quality of raw milk, regulatory authorities, and financial support, aiming to promote the high-quality development of dairy product safety supervision in China.

[Objective] To analyze the research trends and hotspots in the regulation of methane emissions in ruminants by plant extracts. [Methods] Relevant literature published from 2003 to 2023 in the field of methane emission regulation in ruminants by plant extracts in the Web of Science （WoS） Core Collection database was collected. Bibliometric visualization tools CiteSpace 6.2.R6 and VOSviewer 1.6.18 were employed to analyze publication volume, contributing countries （regions）, authors, institutions, and keywords, thereby identifying research trends and hotspots in this field. [Results] From 2003 to 2023, a total of 1,145 articles were published in this field of methane emission regulation in ruminants by plant extracts, with an overall upward trend in annual publication volume. Between 2021 and 2023, 374 articles were published, accounting for 32.66% of the total. In terms of countries （regions）, the United States ranked first, with 198 articles （17.29% of the total）. Among authors, WANAPAT M had the highest number of publications （39 articles, 3.41% of the total）. In terms of institutional contributions, Agriculture and Agri-Food Canada ranked first, with 62 articles （5.41% of the total）, and exhibited the highest level of activity and strongest collaboration with external entities. Keywords with high betweenness centrality （>0.1） and frequency included "plant extracts" "in vitro" and "fermentation" indicating their central role in the keyword network and their close connections with other keywords, as well as their significance as core topics in this research field. The literature keywords were clustered into 10 categories: "beef cattle" "Yucca schidigera" "essential oil" "methane emission" "condensed tannin" "meat quality" "greenhouse gas" "plant secondary metabolites" "essential oils" and "natural plant extracts" .The keyword "sheep" had the highest burst strength （14.60） and was a focus during 2007—2013, followed by "populations" （burst strength: 8.98）, which was a hotspot during 2013—2017. Keywords such as "reduce methane emissions" and "nutrient digestibility" were prominent during 2017—2023. [Conclusion] The research trends and hotspots in the regulation of methane emissions in ruminants by plant extracts were clarified. The effects of different types of plant extracts on methane emissions in ruminants and the synergistic effects among various plant essential oils are likely to be key research directions in the future.

[Objective] To systematically evaluate the effects of heat-clearing Chinese herbal extracts on the production performance of heat-stressed dairy cows, providing guidance and references for alleviating heat stress in dairy cows. [Methods] Published literature on the effects of heat-clearing Chinese herbal extracts on heat-stressed dairy cows was retrieved from four databases: PubMed, CNKI, CQVIP, and WanFang, with the search period spanning from the establishment of each database to August 2024. A systematic review method was used to conduct a Meta-analysis of the literature. Review Manager 5.4 software and the SPSAU website were used to analyze the data of the production performance indicators of dairy cows under heat stress, including milk yield, milk fat percentage, milk protein percentage, lactose percentage, and somatic cell count （SCC）. Then, sensitivity analysis, subgroup analysis, and publication bias analysis were carried out. [Results] Based on strict inclusion and exclusion criteria, 10 research articles meeting the conditions of randomized controlled trials （RCTs） were selected, involving 423 dairy cows. The addition of heat-clearing Chinese herbal extracts significantly increased milk yield [SMD=0.87, 95% CI: （0.63, 1.11）, P<0.000 01] and milk fat percentage [SMD=0.43, 95% CI: （0.02, 0.84）, P=0.04] in heat-stressed dairy cows. Additionally, it significantly reduced somatic cell count in milk [SMD=-1.31, 95% CI: （-1.68, -0.95）, P<0.000 1]. No significant effects were observed on milk protein percentage or lactose percentage （P>0.05, P=0.67, 0.49）. Sensitivity analysis confirmed the stability and reliability of the meta-analysis results, and no significant publication bias was detected. [Conclusion] Heat-clearing Chinese herbal extracts can effectively enhance the production performance of heat-stressed dairy cows.

[Objective] To screen low-temperature cellulose-degrading bacteria suitable for efficient composting of manure and straw in the Inner Mongolia region. [Methods] Using sodium carboxymethyl cellulose （CMC-Na） as the carbon source, bacterial strains were isolated and preliminarily screened from deciduous humic soil, naturally composted sheep manure, and cattle manure in Inner Mongolia under 18 ℃ culture conditions. Further screening was conducted using the cellulose Congo red degradation zone test, and the taxonomic identity of the isolates was determined via 16S rDNA sequence analysis. The filter paper strip degradation test was employed for additional screening of the isolates. The carboxymethyl cellulase （CMCase） activity of the screened cellulose-degrading strains was measured using the 3,5-dinitrosalicylic acid （DNS） colorimetric method. Finally, low-temperature strains with high cellulose degradation capabilities were obtained. [Results] Under 18 ℃ culture conditions, 30 cellulose-degrading bacterial strains were initially isolated. Following the cellulose Congo red degradation zone test, 15 strains with superior cellulose degradation abilities were selected, belonging to the classes Bacilli, Gammaproteobacteria, Actinobacteria, Flavobacteria, and Betaproteobacteria. Among these, Bacilli and Gammaproteobacteria were the primary dominant groups, with Actinobacteria as the secondary dominant group. At the genus level, Bacillus was the primary dominant genus, followed by Pseudomonas as the secondary dominant genus. Further screening of the 15 isolates using the filter paper strip degradation test yielded 7 strains with enhanced cellulose degradation capabilities. After culturing at 18 ℃, the CMCase activity of these strains was measured, identifying three highly efficient low-temperature cellulose-degrading strains: F-1-1 （Bacillus）, Y10 （Bacillus）, and T11 （Pseudomonas）, with CMCase activities of （29.25±0.98）, （20.73±0.27）, and （20.60±0.14） U/mL, respectively. These three strains also exhibited higher CMCase activity than other strains when cultured at 30 ℃. [Conclusion] This study elucidates the diversity and cellulose degradation capabilities of culturable cellulose-degrading bacteria in certain regions of Inner Mongolia under low-temperature conditions.The three low-temperature strains with high CMCase activity identified in this study represent promising candidates for the development of microbial agents for efficient low-temperature cellulose degradation in manure composting fermentation.

[Objective] To understand the prevalence and genotypic characteristics of infectious bronchitis virus （IBV） in chickens in Yanggu County, Liaocheng City, Shandong Province. [Method] 266 disease samples were collected from 27 chicken farms in four townships with large breeding volume in Yanggu County from 2022 to 2023. RT-qPCR was applied to detect IBV, and then the S1 gene sequences of some positive samples were amplified using RT-PCR to analyze the genotypes and genetic variation. [Result] The study found that IBV infection was present in chicken farms in all four townships. Forty-two IBV nucleic acid-positive samples were detected from 266 diseased samples, and the positive rate of farms and positive rate of samples were 51.85% （14/27） and 15.79% （42/266）, respectively. Among the samples from large-scale egg farms, large-scale broiler farms and free-range chicken farms, the highest positive rate and sample positivity rate were found in free-range chicken farms, which were 57.14% （8/14） and 21.30% （23/108）, respectively. Spring and winter samples had higher IBV detection rates of 24.53% （26/106） and 12.05% （10/83）, respectively. The highest positivity rate of 33.75% （27/80） was found in samples from chickens below 1 month of age. The S1 gene sequences of the seven IBV-positive samples were amplified, sequenced and analyzed, and it was found that five belonged to the GI-19 lineage and two to the GI-22 lineage. [Conclusion] There is an epidemic of IBV in Yanggu County, and spring and winter are the high infection periods. The risk of infection was higher in flocks under 1 month of age and free-range flocks, and GI-19 as well as GI-22 were the dominant lineages of IBV in this area.

[Objective] To investigate the prevalence of echinococcosis in sheep in Yuxi City, Yunnan Province, to provide a scientific basis for its prevention and control in the region. [Methods] A total of 304 serum samples from non-immunized sheep were collected from six districts, cities, counties, or ethnic autonomous counties in Yuxi City, including Jiangchuan District, Chengjiang City, Huaning County, Yimen County, Eshan Yi Autonomous County, and Yuanjiang Hani, Yi and Dai Autonomous County. The enzyme-linked immunosorbent assay （ELISA） was employed to detect serum antibodies against Echinococcus spp., and statistical differences in antibody positivity rates were analyzed across various factors, including sampling locations, farming scales, age groups, rearing modes, breeds, and sexes. [Results] Of the 304 sheep serum samples, 14 tested positive, yielding an overall antibody positivity rate of 4.61%. Jiangchuan District exhibited the highest positivity rate （7.50%）, while Chengjiang City showed the lowest （0）, with no significant differences in positivity rates among the districts, cities, counties, and autonomous counties （P>0.05）. The positivity rate in free-range sheep （7.14%） was higher than that in large-scale farm sheep （2.00%）, with significant differences （P<0.05）. Sheep aged ≥3 years had the highest positivity rate （8.57%）, while those aged ≤1 year had the lowest （0.95%）, with significant differences across age groups （P<0.05）. Small-scale grazing sheep showed the highest positivity rate （8.06%）, while barn-fed sheep had the lowest （1.20%）, with significant differences among rearing modes （P<0.05）. Sheep exhibited a higher positivity rate (9.41%) than local goats （2.74%）, with a significant difference between breeds （P<0.05）. The positivity rate in male sheep （6.00%） was slightly higher than in female sheep （4.33%）, though the difference was not significant （P>0.05）. [Conclusion] With the exception of Chengjiang City, where no positive samples were detected, echinococcosis infection was confirmed in sheep across the remaining five districts, cities, counties, or autonomous counties of Yuxi City surveyed （Jiangchuan District, Huaning County, Yimen County, Eshan Yi Autonomous County, and Yuanjiang Hani, Yi and Dai Autonomous County）. Higher infection rates were observed in free-range sheep, older sheep （≥3 years）, small-scale grazing sheep, and wool sheep. Comprehensive prevention and control measures should be implemented in this region to effectively reduce the incidence of sheep echinococcosis.

[Objective] To investigate the infection status and molecular genetic characteristics of bovine rotavirus in neonatal calves from an introduced dairy farm in the Kashgar region of the Xinjiang Uygur Autonomous Region. [Methods] Fecal samples were collected from 50 calves under three months of age at the dairy farm in Kashgar. The presence of bovine rotavirus was detected using RT-PCR, and the resultant sequences were subjected to genotype determination and phylogenetic analysis. [Results] Based on VP6 gene detection, 6 tested positive for bovine rotavirus, yielding an infection rate of 12.00% （6/50）. Sequence analysis of the VP7 gene from the six positive samples revealed two genotypes: G6 （n=4） and G8 （n=2）. Analysis of the VP4 gene indicated that all 6 positive samples belonged to the P[5] type. Consequently, two bovine rotavirus genotypes were identified at the dairy farm, namely G6P[5] （n=4） and G8P[5]（n=2）. Phylogenetic analysis demonstrated that the G6 genotype was closely related to bovine rotavirus strains from Turkey, whereas the G8 genotype showed closer genetic proximity to human rotavirus strains from Japan; the P[5] genotype was most similar to bovine rotavirus strains from Iran. [Conclusion] The bovine rotavirus detected in the calves of this dairy farm exhibits considerable genetic diversity, with the G6P[5] genotype being predominant. The study is the first to report the presence of the G8P[5] genotype in bovine rotavirus in the Kashgar region of Xinjiang, thereby providing valuable insights for the prevention and control of bovine rotavirus infections in southern Xinjiang.

[Objective] To monitor the antibiotic resistance profiles and the epidemiological distribution of virulence genes in Escherichia coli isolates from selected meat duck farms in Shandong Province. [Methods] A total of 240 cloacal swab samples were collected from four large-scale duck farms in Shandong Province. E. coli was isolated and identified using differential culture media and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS）. The susceptibility of E. coli isolates to 11 antibacterial agents was determined using the broth dilution method. Polymerase chain reaction （PCR） was employed to detect the presence of resistance genes and virulence genes in the isolates. [Results] A total of 212 E. coli strains were isolated, with an isolation rate of 88.33% （212/240）. All isolates exhibited resistance to doxycycline and were sensitive to meropenem. High resistance rates were observed against ampicillin （99.05%） and amoxicillin/clavulanic acid （97.64%）. The multidrug resistance （MDR） rate among the isolates was 93.40%. Resistance spectrum analysis revealed that 63 strains were resistant to 9 antibacterial agents, 51 strains to 8 agents, and 47 strains to 10 agents. Among the 21 resistance genes tested, the detection rates of aadA2, strA, strB, bla_TEM, qnrS, mcr-1, and tetA ranged from 52.83% to 94.34%, while qnrD, tetG, and aadA were not detected, with strains co-carrying eight resistance genes being the most prevalent （60 strains）. Among the 18 virulence genes analyzed, yijp, ibeB, OmpA, mat, iucD, fimC, and vat showed detection rates ranging from 54.25% to 98.58%, with strains co-carrying seven virulence genes being the most common （71 strains）. The predominant virulence gene pattern was ibeB-yijp-mat-OmpA-fimC-iucD （14.62%）. [Conclusion] E. coli isolates from meat ducks in certain farms in Shandong Province exhibited severe antibiotic resistance, with a prevailing pattern of co-carrying seven virulence genes. These findings suggest that the isolated duck-derived E. coli may possess significant pathogenic potential, highlighting the need for enhanced monitoring of antibiotic resistance in duck-derived E. coli in this region.