[Objective] The aim of the present study was to screen the soybean varieties suitable for silage maize-forage soybean intercropping model in the low plain areas of eastern Hebei Province. [Method] A total of 35 soybean varieties were selected as experimental materials. Each variety was planted in a 35 m²（5 m×7 m）plot, with 10 cm plant spacing and 40 cm row spacing, and planting density of 170 000 plants/hm². The plots were randomly distributed and repeated three times. The time for flowering, pod setting and grain filling stages of all the soybean varieties was recorded and their growth periods （the number of days from sowing to grain filling stage） were calculated. The soybean were harvested at grain filling stage with fresh weight yield measured. Five soybean plants were randomly selected from each plot and variety, with contents of crude protein （CP）, acidic detergent fiber （ADF）, neutral detergent fiber （NDF）, crude ash （Ash） and crude fat （CF） measured after deactivation, drying and crushing. The entropy weight TOPSIS comprehensive evaluation function in SPSSAU software was used to comprehensively evaluate and rank the feeding quality of all the soybean varieties, and a comprehensive analysis chart for the comprehensive evaluation and ranking of the growth period, fresh weight yield and feeding quality of various soybean varieties was created. [Result] Ruidou No.1 had the longest growth period of 100 days. The growth periods of You 6019, Jindou 99 and Andou 109 reached 97 days, and that of Pudou 5110 was 95 days. The growth periods of Zhonghuang 78, Beidou 17, Beidou 30, Fengdou No.3 and Lindou No.10 were the shortest, only 85 days. Suike 23 （40.48 t/hm²）, Suike 9 （38.34 t/hm²） and Hedou 12 （38.06 t/hm²） were the three varieties with the highest fresh weight yield. Sudou 16 （10.29%） had the highest crude ash content, followed by Jindou 99 （9.80%）, Suike 9 （9.76%） and Shengdi No. 1 (9.57%). The crude protein contents of Wandou 37 （29.17%） and Jiakedou No.1 （25.38%） were significantly （P<0.05） higher than the other varieties. The crude fat contents of Andou 109 （6.33%）, Fengdou No.3 （5.93%） and Wandou 15 （4.97%） were significantly （P<0.05） higher than the other varieties. The ADF contents of Fengdou No.3 （24.05%）, Lindou 10 （24.38%） and Wandou 37 （24.46%） were significantly （P<0.05） lower than the other varieties. The NDF contents of Suike 12 （31.52%）, Jindou 99 （32.82%） and Pudou 5110 （33.39%） were significantly （P<0.05） lower than the other varieties. The top five soybean varieties in the comprehensive evaluation of feeding quality were Jindou 99, Pudou 5110, Andou 109, Suike 12 and Wandou 37. The comprehensive analysis chart based on the overall evaluation and ranking of the growth period, fresh weight yield and feeding quality of different soybean varieties showed that four soybean varieties, Ruidou No.1, Andou 109, Pudou 5110 and Jindou 99, performed well in all the three aspects. [Conclusion] Ruidou No.1, Andou 109, Jindou 99 and Pudou 5110 could be used as candidate varieties for silage maize-forage soybean intercropping model in the low plain areas of eastern Hebei Province.

[Objective] This study was conducted to preliminarily explore the possible regulative mechanisms underlying yellow beef fat of local cattle in Hulun Buir City of Inner Mongolia. [Method] A total of 72 local cattle were selected from Hulun Buir City, and their subcutaneous fat and liver tissues were sampled. The subcutaneous fat samples were subjected to color scoring with a 5-point subjective scoring scheme. Using liver tissues as experimental materials, the penta-primer amplification refractory mutation system （PARMS） was employed to assess the genotype and gene frequency distribution of BCO2 SNPW80X, BCMO1 SNP4, RDHE2 SNP2, ALDH8A1 SNP16 and PPARCG1A SNP12, which were considered as the crucial genes in the signaling pathways involved in the metabolic process of β-carotene. The non-targeted metabolomics analysis of the fat samples were performed by liquid chromatography-mass spectrometry （LC-MS） technology to identify the differential metabolites in different colored fat samples, and the differential metabolites were subsequently subjected to metabolic pathway enrichment analysis. [Result] The 72 subcutaneous fat tissue samples were predominantly white colored, with yellow colored ones （scoring 3 or above） accounting for 30.55%. The SNPs in BCO2, BCMO1, RDHE2 and PPARCG1A genes were observed in different samples, while these SNPs had no significant （P>0.05） correlation with fat color. Compared with the white colored fat samples, a total of 235 differential metabolites were identified in the yellow colored fat samples, which were enriched in the signaling pathways such as unsaturated fatty acid biosynthesis, primary bile acid biosynthesis, and bile secretion. [Conclusion] Comparing the yellow and white colored fat samples collected from the local cattle in Hulun Buir City, there were multiple differential metabolites involving in the signaling pathways closely related to fat formation, in vivo β-carotene transport and trans-membrane transport of β-carotene. In addition, they also directly or indirectly correlated with the β-carotene metabolism associated genes such as BCO2, BCMO1 and PPARCG1A. Further research may focus on the relevant molecular regulatory mechanisms, so as to provide a theoretical basis for the preparation of β-carotene containing feed and the targeted regulation of beef fat color.

[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 this study was to optimize the ultrasonic extraction process parameters of crude fat in feed. [Method] Using the grass carp expanded compound feed as experimental material, a single factor experiment design was adopted to investigate and analyze the effects of 4 factors （liquid to material ratio, soaking time, ultrasonic duration and ultrasonic frequency） at different levels on the determination of crude fat content in feed. In addition to the single factor experiments, a 4-factor and 3-level L9 （3⁴） orthogonal experiment was conducted to optimize the ultrasonic extraction process parameters of crude fat in feed. The crude fat content of grass carp expanded compound feed was measured using the optimized ultrasonic extraction process, and the results were compared to those obtained using the Soxhlet extraction method. The process was repeated 6 times to verify the optimal ultrasonic extraction process parameters. Following the determination of the ultrasonic extraction process parameters, the crude fat contents of 13 different feed samples were measured using both the ultrasonic extraction method and the Soxhlet extraction method with 6 repeated tests. The differences in crude fat content of the feed raw materials and common animal feed products between the two extraction methods were then analyzed and compared. [Result] The factors affecting the determination of crude fat content in feed was in the order of ultrasonic frequency>liquid to material ratio>ultrasonic duration>soaking time. The optimal ultrasonic extraction process parameters were liquid to material ratio of 37.5 mL/g, soaking for 0 min, ultrasonic duration for 30 min, and ultrasonic extraction twice. The crude fat content of grass carp expanded compound feed determined by the optimal ultrasonic extraction process was 4.76% （n=6）, whereas that determined by the Soxhlet extraction method was 4.77% （n=6）, proving that the ultrasonic extraction process was stable and feasible. The differences in crude fat content determination results of 13 different feed samples between the ultrasonic extraction method and the Soxhlet extraction method were not significant （P>0.05）. [Conclusion] The optimal process parameters for ultrasonic extraction of crude fat in feed determined in this study were stable and feasible.

[Objective] The aims of the present study were to isolate and screen cellulolytic bacteria derived from spent Flammulina velutipes substrate, to assess their biological characteristics and cellulolytic enzyme activities, so as to provide technical supports for the feed utilization of spent mushroom substrate resources. [Method] Spent Flammulina velutipes substrate samples were inoculated using plate dilution coating method. The cellulolytic bacteria were then isolated and cultured on nitrate cellulose sodium medium. The cellulolytic abilities of the isolated strains were preliminarily analyzed using Congo red medium. Candidate strains were selected through 16S rDNA sequencing analysis and biosafety prediction, followed by physiological and biochemical characteristics analysis, growth curve determination at different temperatures, and dynamic analysis of cellulolytic enzyme activities. [Result] A total of 30 independent colonies were isolated after screening culture with nitrate cellulose sodium medium. All of the strains formed clear transparent circles on Congo red medium, and some strains had strong cellulolytic abilities. The 16S rDNA sequencing analysis showed that the 30 isolated strains were identified as belonging to 9 bacterial species, including Pseudomonas koreensis, Advenella mimigardefordensis, Serratia rubidaea, and so on. Taking into account both biosafety prediction and the preliminary cellulolytic abilities screening results, Pseudomonas koreensis （JK-32）, Adrenella mimigardefordensis （JK-52）, Serratia rubidaea （JK-56）, Staphylococcus equiorum （JK-57）, Staphylococcus saprophytics （JK-62） and Serratia marcescens （JK-66） were selected as candidate strains for subsequent experiments. Physiological and biochemical characteristics analysis showed that all of the 6 candidate strains were determined as positive for contact enzyme activity test, and negative for methyl red test and diacetyl test. The growth of JK-62 strain was less affected by temperature, and the growth rate and final bacterial concentration performed better among all the candidate strains. Under the low cultivation temperatures （28-34 ℃）, the growth rate and final bacterial concentration of JK-56 strain were lower than the other candidate strains, while when the cultivation temperature increased to 40 ℃, its growth rate was similar to that of the other candidate strains and the final bacterial concentration was higher. On the 1^st to 7^th days of cultivation, the endoglucanase activity of JK-56 strain was the highest among all the candidate strains. On the 2^nd, 4^th, and 5^th days of cultivation, the endoglucanase activity of JK-66 strain was significantly （P<0.05） higher than that of the CK. The exoglucanase activity of JK-66 strain was higher among the candidate strains and was significantly （P<0.05） higher than that of the CK at different detection time points. On the 2^nd to 4^th days of cultivation, the exoglucanase activity of JK-56 strain was significantly （P<0.05） higher than that of the CK. The β-glucosidase activity of JK-66 strain was higher among the candidate strains. On the 3^rd to 7^th days of cultivation, the β-glucosidase activity of JK-56 strain was next to JK-62 and JK-66 strains among the candidate strains. On the 2^nd to 5^th days of cultivation, the filter paper enzyme activity of JK-56 strain was the highest among the candidate strains. On the 5^th day of cultivation, it was significantly （P<0.05） higher than that of the CK. During this period, the filter paper enzyme activity of JK-66 strain was also at a high level. [Conclusion] Serratia rubidaea JK-56 and Serratia marcescens JK-66 strains had high overall levels of cellulolytic enzyme activities, and prominent endoglucanase and exoglucanase activities, which could be used in combination with strains exhibiting strong β-glucosidase activity for the development and utilization of spent Flammulina velutipes substrate.

[Objective] This study aimed to assess the effects of gossypol on growth performance, serum antioxidant capacity, and renal pathological morphology of male broilers at different growth stages, so as to accumulate basic experimental data for the rational application of cotton seed meal in broiler breeding. [Method] A total of 48 healthy 1-day-old Liangfenghua male broilers from the same batch were selected and randomly allocated to 4 groups according to the principle of similar body weight, including a control group （C）, a low-dose group （L）, a medium-dose group （M）, and a high-dose group （H）. Each group had 4 replicates, with 3 broilers per replicate. The experimental broilers in different groups fed the same basal diet. In addition, the broilers in L, M and H group were orally administered 100, 150 and 200 mg/（kg·BW） gossypol once a day until 20-day-old, for a total of 20 days, respectively, while those in C group were orally given distilled water. During the experiment, the feed intake and weight gain of the broilers in each group were recorded, and the feed to weight gain ratio at different growth stages were calculated. Blood samples were collected at 6, 11, 16 and 21 days of age, and the serum activities of catalase （CAT） and glutathione peroxidase （GSH-Px） were measured. Kidney tissue samples were collected at 21 days of age, with HE staining sections prepared, and changes in renal histopathology observed. [Result] At 1-15 days of age, the feed to weight gain ratios of L, M and H groups were extremely significantly （P<0.01） higher than that of C group; at 6-15 days of age, the feed to weight gain ratio of M group was extremely significantly （P<0.01） higher than that of L group; at 16-20 days of age, the feed to weight gain ratios of L and H groups were extremely significantly （P<0.01） higher than that of C group, while that of M group had negative increase. At 6-21 days of age, the serum activities of CAT and GSH-Px in C group showed upward trends, while those in L, M and H groups all showed downward trends; at 11 days of age, the serum activities of CAT and GSH-Px in L group were significantly （P<0.05） lower than those in C group, while the serum activity of GSH-Px in M and H groups was extremely significantly （P<0.01） lower than that in C group; at 16 and 21 days of age, the serum activities of CAT and GSH-Px in L, M and H groups were all extremely significantly （P<0.01） lower than those in C group; at 21 days of age, the serum activity of GSH-Px in M group was extremely significantly （P<0.01） lower than that in L group. Pathological histology observations showed that the renal glomeruli of the broilers given gossypol by gavage were swollen, the renal capsule space became narrower, and the renal tubules were necrotic.The degree of renal tissue damage was M group>H group>L group. [Conclusion] Starting from 1-day-old, feeding male broilers with doses of 100, 150 and 200 mg/（kg·BW） of gossypol for 20 consecutive days by gavage reduced growth performance, decreased serum antioxidant capacity, and caused kidney damage. With the prolongation of gossypol feeding time, the above affects were the most obvious at the dose of 150 mg/（kg·BW）.

[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 explore the optimal plant spacing and row spacing for seed production of Bothriochloa ischaemum.[Method] Using Bothriochloa ischaemum ′Taihang′ seeds as the experimental materials and a two-factor split zone experiment design, four plant spacing levels （R₁=30 cm, R₂=45 cm, R₃=60 cm, R₄=75 cm） and four row spacing levels （L₁=30 cm, L₂=45 cm, L₃=60 cm, L₄=75 cm） were set up to assess the effects of different plant spacing and row spacing combinations on seed yield and its components of Bothriochloa ischaemum.[Result]Plant spacing and row spacing had extremely significant （P<0.01） interactions on the reproductive branch number, inflorescence length, plant height and shattering rate. The interactions between plant spacing and row spacing had extremely significant （P<0.01） effects on the actual seed yield of Bothriochloa ischaemum. Correlation analysis demonstrated that plant spacing was significantly （P<0.05） positively correlated with the reproductive branch number, spikelet number, theoretical seed yield and actual seed yield, and significantly （P<0.05） negatively correlated with the inflorescence length; the row spacing was significantly （P<0.05） positively correlated with the reproductive branch number, spikelet number, thousand grain weight, theoretical seed yield and actual seed yield, and significantly （P<0.05） negatively correlated with the inflorescence length. Principal component analysis showed that the cumulative contribution rate of the first two principal components was 81.946%. The main traits determining the first common factor were reproductive branch number, spikelet number, inflorescence length, shattering rate, thousand grain weight, theoretical seed yield and actual seed yield. The contribution rate of the second common factor was 20.994%. The comprehensive evaluation of yield indicators revealed that R₃L₃ （60 cm × 60 cm） had the highest score of 5.039.[Conclusion]To achieve the highest seed yield of Bothriochloa ischaemum, the optimal plant spacing and row spacing were 60 cm for both.

[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] 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 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 characterize the microbial community diversities in pig house environments, to understand the structural differences of bacterial communities in different types of pig house environments, and to identify the potentially pathogenic bacterial genera. [Method] Environmental microbial samples were collected from pregnant sow houses, nursery pig houses and farrowing houses in a large-scale pig farm using air sedimentation method. Three houses were sampled for each type of pig house, with a total of 9 samples. Using Illumina Miseq technology, the high-throughput sequencing was performed targeting on the V3-V4 variant region of bacterial 16S rDNA. The sequencing data were analyzed by QIIME2 software to compare the composition of microbial communities in different types of pig house environments. [Result] At the similarity threshold of 97%, a total of 29 126 OTUs were obtained from the 9 samples, covering 31 phyla, 66 classes, 160 orders, 320 families, 899 genera and 1 831 species of bacteria. The Chao1 index, Shannon index and phylogenetic diversity index of the farrowing houses and nursery pig houses were generally higher than those of the pregnant sow houses. Proteobacteria, Bacteroidota, Firmicutes and Actinobacteriota were the four dominant bacterial groups at the phylum level in the pig house environments. The relative abundance of Proteobacteria was the highest in all three types of pig houses, while the relative abundance of Firmicutes, Actinobacteria and Bacteroidetes varied greatly among different types of pig houses. Acinetobacter, Corynebacterium and Stenotrophomonas were the genera with the highest relative abundance in farrowing houses, pregnant sow houses and nursery pig houses, respectively. There were multiple genera of bacteria with potential pathogenicity to animals, such as Helcococcus, Streptococcus, Legionella and Serratia, in the air of pig houses. [Conclusion] The pig house environments were rich in microbial community diversities. Farrowing houses and nursery pig houses had higher bacterial diversity, evolutionary diversity and abundance than the pregnant sow houses. The potentially pathogenic bacteria found in this study provided references for the selection of disinfection drugs used in pig house environments.

[Objective] This study was conducted to characterize the expression pattern of antioxidant enzymes in sheep antral ovarian follicles with different diameters, so as to provide references for clarifying the regulatory mechanism of antioxidant function in ovarian follicles. [Method] The follicular fluids were sampled from sheep antral ovarian follicles with different diameters （large antra ≥ 6.0 mm, medium antra 2.0-6.0 mm, small antra ≤ 2.0 mm). The contents of reactive oxygen species （ROS） and total antioxidant capacity （TAC）, as well as the activities of superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GPX） and peroxidase （PRDX） were tested using the commercially available reagent kits. Real time fluorescence quantitative PCR （qPCR） assay was used to detect the relative mRNA expression levels of Cu/Zn-SOD, CAT, GPX3 and PRDX6 genes in the theca cells, mural granulosa cells and cumulus cells of small, medium and large antral ovarian follicles. [Result] There were no significant （P>0.05） differences in the contents of TAC and ROS in the follicular fluids of antral ovarian follicles with different diameters. The activities of SOD, GPX and PRDX in the follicular fluids decreased with the increase of ovarian follicle diameters. The small antral ovarian follicles had extremely significantly （P<0.01） higher activities of SOD, GPX and PRDX in the follicular fluids compared to the large antral ovarian follicles. The CAT activity in the follicular fluids elevated with the increase of ovarian follicle diameters. The large and medium antral ovarian follicles had extremely significantly （P<0.01） higher CAT activities in the follicular fluids than the small antral ovarian follicles. The relative mRNA expression levels of Cu/Zn-SOD, GPX3 and PRDX6 genes in the theca cells and mural granulosa cells of the small antral ovarian follicles were extremely significantly （P<0.01） higher than those of the medium and large antral ovarian follicles, while the relative mRNA expression levels of Cu/Zn-SOD, GPX3 and PRDX6 genes in the cumulus cells of the medium antral ovarian follicles were extremely significantly （P<0.01） higher than those of the small and large antral ovarian follicles. The large antral ovarian follicles had extremely significantly （P<0.01） higher relative mRNA expression levels of CAT gene in the theca cells and mural granulosa cells than the small and medium antral ovarian follicles, while the large and medium antral ovarian follicles had extremely significantly （P<0.01） higher relative mRNA expression levels of CAT gene in the cumulus cells than the small antral ovarian follicles. [Conclusion] There was no significant variations in contents of TAC and ROS in sheep antral ovarian follicles with different diameters, but the gene expression levels and the activities of antioxidant enzymes of SOD, CAT, GPX and PRDX in ovarian follicles with different diameters exhibited spatial specificity, indicating that the regulation of antioxidant function in sheep antral ovarian follicles was a synergistic process of multiple factors.

[Objective] The present study was conducted to assess the correlations between serum hormone levels and lactation performance in Alagxa Bactrian camels. [Method] A total of 65 Alagxa Bactrian camels with similar body conditions and parities in the early lactation stage were selected, and their serum hormone levels （estradiol, estriol, estrone, follicle-stimulating hormone, luteinizing hormone, progesterone, prolactin, growth hormone, cortisol, 5-hydroxytryptamine, epinephrine, norepinephrine, insulin, glucagon, leptin） as well as the lactation performance indicators （milk yield, milk protein rate, milk fat rate, lactose rate, ash content） were determined. Canonical correlation analysis between serum hormone levels and lactation performance was carried out: using lactation performance indicators as the X group variables, with V being the corresponding comprehensive variable; using serum hormone levels as the Y group variables, with W being the corresponding comprehensive variable; the overall correlation between the two groups of indicators were reflected by the correlation between the two comprehensive variables, and the correlations between serum hormone levels and various indicators of lactation performance were explored. [Result] In the X group of lactation performance indicators, the variation degree in the milk yield was the highest, followed by milk fat rate, while the coefficients of variation in lactose rate, ash content and milk protein rate were relatively small. In the Y group of serum hormone level indicators, progesterone had the highest coefficient of variation, followed by estradiol, luteinizing hormone, norepinephrine, follicle-stimulating hormone, 5-hydroxytryptamine, cortisol, estrone, prolactin, epinephrine, insulin, estriol, growth hormone, leptin and glucagon. The correlation analysis among the internal variables of serum hormone levels showed that serum levels of estriol were significantly positively correlated with those of estrone （r=0.88, P<0.001）, luteinizing hormone （r=0.70, P<0.001） and prolactin （r=0.59, P<0.001）. The canonical correlation analysis between lactation performance and serum hormone levels indicated strong correlation between milk protein rate and serum level of estriol. [Conclusion] The milk protein rate in the early lactation stage of Alagxa Bactrian camels is correlated with serum hormone levels of estriol, estrone, luteinizing hormone and prolactin.

[Objective] The aim of the present study was to characterize the antimicrobial resistance profile as well as the prevalence of CTX-M gene and virulence genes of the Escherichia coli （E. coli） strains derived from cattle in Ta′e reclamation area, Xinjiang Uygur Autonomous Region. [Method] A total of 16 fecal samples of cattle with diarrhea were collected from a cattle farm in Ta′e reclamation area. The selective culture, Gram staining and microscopy, and 16S rDNA PCR amplification and sequencing were used to isolate and identify the E. coli strains. The PCR assay was used for the molecular typing （phylogenetic group and lipopolysaccharide core type） as well as the detection of antimicrobial resistance genes, CTX-M gene subtypes and virulence genes of the E. coli isolates. The K-B disk diffusion method as well as the CTX and TCL dual disk diffusion method were utilized for antimicrobial sensitivity test and ESBLs-producing E. coli identification, respectively. The biofilm formation ability of the E. coli isolates were semi-quantitatively analyzed using crystal violet staining method.[Result] Based on the colony growth feature, Gram staining characteristic and 16S rDNA sequencing result, a total of 16 E. coli strains were isolated and identified from the 16 fecal samples of the diarrhoeal cattle, with a separation rate of 100%. Most of the E. coli isolates belonged to the phylogenetic group B1 （14/16, 87.50%） and the lipopolysaccharide core type R1 （15/16, 93.75%）. The E. coli isolates exhibited high-level resistance to penicillin, rifampicin and compound sulfamethoxazole, with resistance rates of 100%, 68.75% and 68.75%, respectively, while they were sensitive to polymyxin, tigecycline and meropenem, with resistance rates all being 0. Twelve strains （75.00%） had multi-drug resistant phenotype, 11 strains （68.75%） produced ESBLs, and 15 strains （93.75%） were capable of forming biofilm. A total of 17 antimicrobial resistance genes were detected as positive among the 16 E. coli isolates, and the detection rates for 8 antimicrobial resistance genes such as CTX-M, ant （6′） and sul1 were 100%. Fourteen strains （87.50%） were identified as the CTX-M-1G gene subtype. In addition, a total of 12 virulence genes were detected as positive, among which, 5 virulence genes including iroN, ompA and yijP had 100% detection rate.[Conclusion] A high prevalence of CTX-M gene was observed in the cattle derived E. coli strains in Ta′e reclamation area of Xinjiang Uygur Autonomous Region. Furthermore, these isolates harbored multiple antimicrobial resistance genes and virulence genes, and had high-level antimicrobial resistance, which posed potential threats to the healthy farming of cattle in this region. Therefore,it is necessary to strengthen the monitoring of the CTX-M type E. coli prevalence in this region.

[Objective] This study aimed to characterize the changes in whole transcriptome expression profile of breast muscles during the growth process in Xichuan black-bone chicken before and after hatching. [Method] Breast muscle samples were collected from the Xichuan black-bone chicken embryos incubated for 14 d （marked as X-14 d） and the chicks freshly hatched for 1 d （marked as X-1 d）, respectively. Eukaryotic whole transcriptome sequencing analysis were performed around coding RNA （messenger RNA, mRNA） and non-coding RNA （lncRNA, circRNA and miRNA）. [Result] During the growth process of breast muscles in Xichuan black-bone chicken, the transcriptome levels of a large number of genes had significant changes. Compared with the chicken embryos incubated for 14 d, the chicks freshly hatched for 1 d （X-14 d vs X-1 d） had a total of 3 858 differentially expressed mRNA, including 1 054 upregulated genes and 2 804 downregulated genes. There were 371 differentially expressed lncRNA, including 222 upregulated genes and 149 downregulated genes; there were 316 differentially expressed circRNA, including 148 upregulated genes and 168 downregulated genes; there were 377 differentially expressed miRNA, including 159 upregulated genes and 218 downregulated genes. GO enrichment analysis showed that differentially expressed mRNA was involved in multiple biological processes, such as biological process regulation, stimulus response, localization, positive/negative regulation of biological processes, growth processes, immune system processes, etc. The KEGG pathway enrichment analysis of differentially expressed mRNA demonstrated that multiple signaling pathways were enriched, including adhesion junction, actin cytoskeleton regulation, amino acid biosynthesis, oxidative phosphorylation, carbon metabolism, citric acid cycle （TCA cycle）, tight junction, gap junction, metabolic pathway, focal adhesion, glycolysis/gluconeogenesis, pyruvic acid metabolism, melanogenesis, Notch signaling pathway, etc. The significantly differentially expressed genes were mainly related to multiple biological traits of Xichuan black-bone chickens such as growth trait, meat quality trait, lipid trait, melanogenesis trait, and immune system. [Conclusion] As important components of the transcriptome, mRNA, lncRNA, circRNA, and miRNA played crucial roles in the growth and development of Xichuan black-bone chicken. Our results provided references for analyzing the genetic regulation mechanism in the growth and development process of breast muscles in Xichuan black-bone chicken.

[Objective] This study was conducted to characterize the changes in whey protein profile during the fermentation process of traditional koumiss from Inner Mongolia. [Method] Traditional koumiss was prepared using mare milk collected from Xianghuang Banner, Xilin Gol League, Inner Mongolia, with fermentation temperature at （22±2） ℃, and manual mixing 5 times per day, 300 beats each time. The koumiss samples were taken every 12 h during the 0-96 h fermentation process, and whey protein was collected by centrifugation. Variations in Koumiss whey protein profile during the fermentation process were analyzed by the optimized SDS-PAGE. [Result] The optimized SDS-PAGE conditions were as follows: the concentrations of separation gel and spacer gel were 12% and 5%, respectively; the electrophoresis voltage for separation gel was 180 V, and the electrophoresis time was 300 min; the sample loading amount and concentration were 16 μL and 0.5 μg/μL samples, respectively; the gel was stained with modified Coomassie brilliant blue for 12 h and then decolorized for 12 h. Within 0-12 h of fermentation, the koumiss whey protein contents increased and peaked （5.12 μg/μL） at 12 h, and then fell with the extension of fermentation time, decreasing to 3.92 μg/μL at 96 h of fermentation. SDS-PAGE analysis showed that a total of 13 effective bands of whey protein within the molecular weight range of 10-70 kDa were observed. During the fermentation process, the contents of 3 types of whey protein, β-lactoglobulin, lysozyme C, and α-lactalbumin, fluctuated to varying degrees. The sum of their contents peaked at 72 h of fermentation, accounting for 85.73% of the total whey protein contents and maintained high levels during the fermentation process. It was indicated that they were the main components of whey protein in traditional koumiss within the fermentation process of 96 h. Among them, the content of β-lactoglobulin was the highest, accounting for an average of 38.92% of the total whey protein contents. The content of casein with the molecular weight range of 20-40 kDa began to decrease after 24 h of fermentation, and the corresponding bands disappeared till 60 h. The protein with a molecular weight of 10.33 kDa was depleted within 12 h of fermentation and reappeared at 60 h, and its content gradually increased with the extension of fermentation time and peaked at 84 h, accounting for 9.84% of the total whey protein contents. The protein with a molecular weight of 49.80 kDa began to appear after 72 h of fermentation, and its content reached 4.11% of the total whey protein contents at 96 h. Compared to the other whey protein components, the content of β-lactoglobulin and immunoglobulin had minor changes during the fermentation process. [Conclusion] The whey protein contents with the molecular weight range of 10-70 kDa in traditional koumiss from Inner Mongolia had regular increase and decrease within 96 h of fermentation. The main protein that was digested and decomposed was casein. There were some differences in the composition and content of whey protein in different fermentation stages of koumiss, while the original main components β-lactoglobulin, lysozyme C, and α-lactalbumin maintained higher levels. From the middle stage of fermentation, the proportion of peptides with relatively small molecular weight （10.33 kDa） in the whey protein of koumiss gradually increased. Our results showed that the traditional koumiss not only retained the original nutritional value of whey protein in mare milk, but also added some easily absorbed small molecular weight proteins through fermentation.

[Objective] The purpose of this study was to screen the candidate lactic acid bacterial strains for preparing forage silage, so as to improve the fermentation quality of forage silage. [Method] Lactic acid bacterial strains were isolated from the leaves of 8 varieties of gramineous forages, including Pennisetum sinese, Eleusine indica, Imperata cylindrica and so on. On the basis of traditional microbiological identification techniques, molecular biological identification methods and 16S rDNA sequence diversity analysis were used to identify the suspected lactic acid bacterial strains isolated. The performance in growth, acid production and salt tolerance of the lactic acid bacterial strains was characterized. Their growth tolerance under pH value of 3.0, 3.5 and 4.0, as well as NaCl concentrations of 0.02, 0.04, 0.06, 0.08 and 0.10 mg/mL was assessed. Furthermore, their inhibitory effects against Candida, Staphylococcus aureus and Salmonella typhimurium were evaluated. [Result] A total of 30 suspected lactic acid bacterial strains were isolated from the surface of forage leaves. Following phenotypic identification and molecular biological identification, 10 strains of lactic acid bacteria were identified as belonging to the genera of Weissella, Pediococcus and Levilactobacillus, including 3 strains of L. brevis, 2 strains of P. pentosaceus, 2 strains of L. plantarum, 1 strain of W. cibaria, 1 strain of L. pentosus and 1 strain of L. coryniformis. The performance in growth rate and acid production varied among different strains. There were strain-specific salt and acid resistance as well as antibacterial property as well. By comprehensively comparing the biological characteristics of the 10 strains, L. plantarum Lab7 had better performance in salt and acid resistance, while L. brevis Lab1 and L. coryniformis Lab10 had good performance in growth rate, acid production ability, salt and acid resistance, and antibacterial property. [Conclusion] The naturally isolated lactic acid bacterial strains of forage origin, L. plantarum Lab7, L. brevis Lab1 and L. coryniformis Lab10 were screened as candidate strains for lactic acid bacterial preparation used in fermentation of forage silage, and had the potential for further development.

[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 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.

[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] 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.

[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] The aim of the present study was to characterize the succession of fungal community structure of traditional koumiss from Inner Mongolia at different fermentation stages. [Method] Traditional fermentation methods were used to prepare koumiss using the fresh mare′s milk collected from Xianghuang Banner, Xilin Gol League, Inner Mongolia, as the raw material. The traditional koumiss samples were collected at 0, 12, 24, 36, 48 and 96 h of fermentation, and their pH values were measured. Subsequently, high-throughput sequencing technology targeting on the fungal ribosomal DNA internal transcribed spacer （rDNA-ITS） sequence was used to characterize the changes of fungal community structure at different fermentation stages. [Result] The Chao1 index and Shannon-Wiener′s diversity index analysis demonstrated that in the early stage of fermentation （0-12 h）, the fungal community had decreased abundance and minorly changed diversity. The abundance and diversity of the fungal community increased simultaneously during 12-24 h of fermentation, decreased simultaneously during 24-72 h, and elevated simultaneously during 72-96 h. Both reached the initial level of fermentation at 96 h. Within 12 h of fermentation, the pH value of the fermentation system dramatically reduced. It decreased at a slower rate during 12-48 h, and continued to slow down and became gentle during 48-96 h. Two fungal phyla, Ascomycota and Basidiomycota, were identified in the traditional koumiss by high-throughput sequencing targeting on the fungal rDNA-ITS sequence, with the relative abundances of 99.77% and 0.02%, respectively. During the fermentation process, Ascomycota was absolutely dominant. A total of 9 fungal genera were observed, among which Kazachstania and Kluyveromyces were the dominant ones, with the relative abundances of 95.76% and 3.75%, respectively. During 12-96 h of fermentation, the change of relative abundance of Kluyveromyces displayed an alternating trend with that of Kazachstania, and both were present during the whole fermentation process of 96 h. In addition, Kazachstania unispora, Kluyveromyces lactis and Kluyveromyces marxianus were the dominant ones among the 9 fungal species identified, with the relative abundances of 95.76%, 2.10% and 1.63%, respectively. The relative abundances of the 3 dominant species changed in varied manners at the different fermentation stages. [Conclusion] This study clarified the dominant fungal species as well as the succession characteristics of diversity and structure of fungal community during the fermentation process of traditional koumiss from Inner Mongolia. Our results provided a reference for enriching the research on fermentation mechanism, optimizing the fermentation process and improving the fermentation quality of koumiss.

[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.

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

[Objective] The aims of the present study were to 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] 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] 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.

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

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

[Objective] This study 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] The aims of the present study were to fully exploit the application potential of cattle manure as organic fertilizer and to avoid potential heavy metal hazards to soil-crop ecosystem from excessive application of cattle manure. [Method] Five treatments were set up according to the different application ratios of cattle manure organic fertilizer and chemical fertilizer: a blank control （CK）, the single application of cattle manure organic fertilizer （CD）, the single application of chemical fertilizer （CF）, the combined application of cattle manure organic fertilizer with chemical fertilizer （DF1） at the ratio of 1∶1, and the combined application of cattle manure organic fertilizer with chemical fertilizer （DF2） at the ratio of 2∶1. Pot experiments were conducted using soil and silage maize as research subjects. The mass fractions of various forms of heavy metals of copper （Cu） and zinc （Zn） in soil under different fertilization treatments were measured and calculated. The correlations between the distribution rate of available Cu and Zn and soil pH value, organic carbon mass fraction were analyzed. The Cu and Zn contents in different parts of silage maize were compared. [Result] Combined application of cattle manure organic fertilizer with chemical fertilizer had significant （P<0.05） impacts on the total mass fractions and mass fractions of different forms of Cu and Zn in the soil. The application of cattle manure organic fertilizer promoted the transformation of residual form Cu to exchangeable form. The distribution rates of exchangeable Cu in CD and DF1 treatments increased from 15.86% in CK to 28.12% and 28.13%, respectively. Compared with CK, DF2 treatment had the largest increase in distribution rate of exchangeable Cu at 42.02%. The distribution rates of residual Zn in CD and DF1 treatments decreased from 53.40% in CK to 39.27% and 38.40%, respectively. In comparison with CK, the distribution rate of residual Zn in DF2 treatment decreased to 24.33%, which had the biggest change range. After the combined application of cattle manure organic fertilizer with chemical fertilizer, the soil pH value and organic carbon mass fraction had an upward trend. Among them, the soil organic carbon mass fraction had positive correlation with the distribution rates of available Cu and Zn in the soil, and the correlations reached extremely significant （P<0.01） and significant （P<0.05） levels, respectively. Furthermore, the distribution rate of soil available Zn was significantly （P<0.05） correlated with the change trend of soil pH value, while the correlation between the distribution rate of available Cu and soil pH value was not significant （P>0.05）. Compared with CK, the application of cattle manure organic fertilizer increased the contents of Cu and Zn in maize plants by 45.50% to 115.38% and 44.99% to 93.29%, respectively. [Conclusion] In addition to improving the physical and chemical properties of soil, the combined application of cattle manure organic fertilizer with chemical fertilizer activated the heavy metals of Cu and Zn in the soil, enhancing the heavy metal enrichment ability of the silage maize. Therefore, when applying cattle manure organic fertilizer, the appropriate application rate should be determined strictly following the soil testing and formula fertilization to limit the contamination risk of heavy metals in the soil environment and the feeding risk of silage maize.

The long-term and widespread use of antibiotics in the animal husbandry industry has led to serious problems such as drug residues and antibiotic resistance, which seriously threatens the health of animals and even humans. Bacteriophages are viruses that can invade and lyse bacteria, with the advantages of strong specificity, wide presence, and low research and development cost. With the continuous development of science and technology, the research of bacteriophages in the livestock and poultry industry has been deepened, and the use of bacteriophages is progressively gaining recognition as an alternative strategy to antibiotics. Starting from the biological characteristics of bacteriophages, this article elaborates on the research of bacteriophages therapy for bacterial infections in livestock and poultry as well as the development and application of bacteriophages in livestock and poultry breeding, food biological control, etc., in hoping to provide references for the application of bacteriophages in livestock and poultry production.

[Objective] This study aimed to assess the effects of parity, body condition score and backfat thickness on reproductive performance of sows in late pregnancy. [Method] A total of 654 Dannish sows in late pregnancy （109 d of gestation） were selected from the same production batch, and were grouped according to the parity （1-3 parity groups）, body condition score （1-5 score groups）, and backfat thickness （≤ 10 mm group, 11-15 mm group, 16-20 mm group, 21-25 mm group, and > 25 mm group）. The first parity group, body condition score 3 group, and backfat thickness 16-20 mm group were used as the control groups, and the other groups within the same indexes were used as the experimental groups. The data of body condition score, backfat thickness and parity as well as total number of piglets born, live litter weight, number of live piglets, number of healthy piglets, number of weak piglets, number of mummified fetus, and number of stillborn piglets were all entered and processed by the linear mixed model of IBM SPSS Statistics 26.0 statistical software. [Result] With the increased parities of the pregnant sows, the total number of piglets born, live litter weight, number of live piglets, and number of healthy piglets exhibited a significantly （P<0.05） increasing trend. When the backfat thickness of the sows in late pregnancy was in the range of 16-20 mm, the total number of piglets born, number of live piglets, and number of healthy piglets reached the maximum values, while the number of weak piglets and number of stillborn piglets reached the minimum values. When the backfat thickness of the sows in late pregnancy was in the range of 21-25 mm, the number of weak piglets, number of mummified fetus, and number of stillborn piglets were all elevated. When the body condition score of the sows in late pregnancy was 4, the total number of piglets born, number of live piglets, and number of healthy piglets were the highest. [Conclusion] Parity, body condition score and backfat thickness of sows in late pregnancy all have impacts on litter performance and can serve as important references for predicting sow reproductive performance.

[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 compare and analyze the fatty acid composition and content in fresh dairy milk from different regions. [Method] From May 2019 to March 2020, one large-scale dairy farm each from Henan Province, Hebei Province, and Shanxi Province was selected. A total of 36 fresh milk samples from healthy dairy cows were collected over the four seasons, with 12 samples coming from each of the three regions. Fatty acids were extracted and methylated using GC-MS method. The fatty acid composition and content were analyzed using CP-WAX 52 CB capillary chromatography column and gas chromatography-mass spectrometry analyzer. By comparing the retention time of 37 mixed standard substances of fatty acid methyl esters and searching in the NIST05 spectrum library, the fatty acid composition was qualitatively analyzed. The fatty acid content was calculated using area normalization method. [Result] A total of 28 fatty acids were detected in the fresh milk collected from Henan Province, among which 15 were saturated fatty acids. The contents of 5 saturated fatty acid methyl ester, including methyl decanoate, methyl laurate, methyl myristate, methyl stearate, and methyl palmitate, were relatively high, accounting for 57.03% of the total detected fatty acid content. Thirteen unsaturated fatty acid were detected, among which most had low levels, with only oleic acid/elaidic acid methyl ester having higher levels, accounting for 32.26% of the total detected fatty acid content. Thirty fatty acids were detected in the fresh milk collected from both Hebei Province and Shanxi Province, while the compositions were slightly different. The characterization of fatty acid content in the fresh milk collected from the two provinces were similar to that collected from Henan Province, with saturated fatty acid content accounting for around 60% of the total detected fatty acid content. The content of oleic acid/elaidic acid in the fresh milk collected from Hebei Province was 39.80%, which was the highest among the three regions. No linolelaidic acid methyl ester, γ-linolenic acid methyl ester, cis-15-carboenoic acid methyl ester, erucic acid methyl ester, and cis-4,7,10,13,16,19-docosahexaenoic acid methyl ester were detected in the fresh milk from all three regions. [Conclusion] The fatty acid content in the fresh dairy milk collected from the three regions were relatively rich, with saturated fatty acid as the main component. Oleic acid/elaidic acid had the highest contents among all the detected fatty acids, while there were also some regional variations in fatty acid composition and content.

[Objective] The aim of the present study was to screen the important signaling pathways and genes involved in carbon tetrachloride （CCl₄） induced intestinal injury in mice and in the treatment process with a traditional Mongolian medicine Honghua Qinggan 13 Flavor Pills. [Method] A total of 18 male C57BL/6 mice aged 6-8 weeks and weighing 20-22 g were randomly divided into three groups, a blank control group （n=6）, a model group （n=6）, and a treatment group （n=6）. The blank control group and model group were gavaged with physiological saline once a day at a dose of 10 mL/（kg·BW） for 7 consecutive days. The treatment group was gavaged with Honghua Qinggan 13 Flavor Pills once a day at a dose of 616.5 mg/（kg·BW） for 14 consecutive days. Four hours after the last gavage, the blank control group was intraperitoneally injected with olive oil, while both the model group and treatment group were intraperitoneally injected with CCl₄ and olive oil mixture （CCl₄∶olive oil=1∶4, V/V） at a dose of 10 mL/（kg·BW）. On the second day following the intestinal injury treatment, the duodenal tissues of the mice in the three groups were collected for high-throughput transcriptome sequencing. Using the obtained sequencing data, the differentially expressed genes were predicted, functionally analyzed, as well as KEGG signaling pathway enriched. The gene groups enriched in the significantly down regulated signaling pathway after the treatment with Honghua Qinggan 13 Flavor Pills were screened, and interaction analysis was performed with the target genes of Honghua Qinggan 13 Flavor Pills. [Result] ① Transcriptome sequencing analysis showed that compared with the blank control group, the model group and the treatment group obtained 1 419 and 2 875 differentially expressed genes, respectively. Compared with the model group, the treatment group obtained 2 288 differentially expressed genes, of which 1 139 were up regulated and 1 149 were down regulated. KEGG signaling pathways enrichment on the differentially expressed genes in the model group found that the activated signaling pathways included osteoclast differentiation, B cells, chemokines, inflammatory bowel disease, JAK-STAT, etc. KEGG signaling pathways enrichment on the differentially expressed genes in the treatment group found that the activated signaling pathways included FOXO, mTOR, longevity regulation, etc, while the inhibited signaling pathways included osteoclast differentiation, cell apoptosis, tumor necrosis factor, B cells, rectal and colorectal carcinoma, etc. ②Four genes with significantly different expression levels, JUN, STAT1, NFKBIA and FOS, were found in the transcriptome data via the gene groups enrichment in the significantly inhibited signaling pathway in the treatment group and interaction analysis between the target genes of Honghua Qinggan 13 Flavor Pills. [Conclusion] The main signaling pathways involved in CCl₄ induced intestinal injury in mice and the treatment process of Honghua Qinggan 13 Flavor Pills included chemokines, inflammatory bowel disease, JAK-STAT and longevity regulation, and the main genes included JUN, STAT1, NFKBIA and FOS. Our results provided references for clarifying the molecular mechanisms of prevention and treatment of intestinal injury with Honghua Qinggan 13 Flavor Pills.

[Objective] The aim of this study was to assess the mechanism by which Honghua Qinggan 13 Flavor Pill （HHQG）, a traditional Mongolian medicine, alleviated liver injury in mice through inhibiting inflammatory cell infiltration. [Method] A total of 54 male C57BL/6 mice aged 6 to 8 weeks were selected and randomly divided into control group （n=18）, model group （n=18） and HHQG liver protection group （n=18）. The HHQG liver protection group was intragastrically administered 0.616 5 g/（kg·BW） of HHQG once a day for 7 consecutive days, while the control group and model group were intragastrically administered the same volume of physiological saline once a day. On the 7^th day, 4 hours after the administration, the control group received 0.1 mL/（10 g·BW） of olive oil by intraperitoneal injection, while the model group and HHQG liver protection group received an equal dose of a CCl₄ and olive oil mixture （CCl₄∶olive oil=1∶4, V/V） in the same manner. On the 2^nd, 5^th and 7^th days after modeling, the prepared liver injury model and the alleviating effect of HHQG on liver injury were evaluated by detecting serum aspartate aminotransferase （AST） and alanine aminotransferase （ALT） activities as well as observing liver tissue pathological changes （HE staining and Masson staining）. The neutrophil and monocyte/macrophage infiltration in liver tissue was observed using immunohistochemical assay. The expression of the inflammatory factor TNF-α in liver tissue at both protein and gene levels were assessed using immunohistochemical assay and reverse transcription real-time fluorescence quantitative PCR （RT-qPCR）. The effects of HHQG on the expression levels of adhesion molecule genes in liver tissue were analyzed by transcriptome sequencing （RNA-seq） and RT-qPCR. [Result] According to the multiple evaluation indicators, the model group mice exhibited obvious symptoms of liver injury, indicating the successful preparation of CCl₄ induced liver injury model. Compared with the model group, on the 2^nd day after modeling, the serum AST and ALT activities in the HHQG liver protection group were extremely significantly （P<0.01） reduced. HHQG intervention inhibited the inflammatory cell infiltration such as neutrophil and monocyte/macrophage in liver injury areas, alleviated collagen fiber deposition and promoted liver tissue repair by cell proliferation. HHQG liver protection group had reduced expression level of TNF-α in the liver injury areas. Compared with the model group, on the 2^nd and 7^th, as well as the 5^th days after modeling, the relative mRNA expression levels of TNF-α gene in the liver tissue of HHQG liver protection group were extremely significantly （P<0.01） and significantly （P<0.05） reduced, respectively. RNA-seq analysis showed that HHQG intervention significantly downregulated the gene groups of adhesion molecules associated with neutrophil and monocyte/macrophage infiltration in liver injury mice. RT-qPCR validation results demonstrated that HHQG liver protection group had extremely significantly （P<0.01） reduced relative mRNA expression levels of VCAM-1 gene in the liver tissue than the model group on the 5^th and 7^th days after modeling. In addition, in comparison to the model group, significantly （P<0.05） and extremely significantly （P<0.01） decreased relative mRNA expression levels of ICAM-1 gene in the liver tissue of the HHQG liver protection group were observed on the 2^nd as well as the 5^th and 7^th days after modeling, respectively. [Conclusion] Through inhibiting the inflammatory cell infiltration dominated by neutrophil and monocyte/macrophage, HHQG downregulated the expressions of the inflammatory factor TNF-α and adhesion molecules in the liver injury areas, and alleviated inflammation after liver injury, thereby exerting anti-inflammatory and hepatoprotective effects in mice.

[Objective] This study was conducted to reveal the molecular mechanism underlying the hepatoprotective effects of Honghua Qinggan 13 Flavor Pill （HHQG）, a traditional Mongolian medicine, by improving liver function via activating hepatocyte nuclear factor 4α （HNF4α）. [Method] A total of 45 C57BL/6J mice were randomly assigned into control group, CCl₄ injury group and HHQG group, with 15 mice in each group. The mice in HHQG group were given HHQG at a dose level of 0.616 5 g/（kg·BW） by gavage once daily for 7 consecutive days, and those in control group and CCl₄ injury group were given an equal volume of sterile distilled water by gavage. Four hours after the last gavage, the mice in control group were intraperitoneally injected with 5 mL/（kg · BW） of olive oil, and those in CCl₄ injury group and HHQG group were intraperitoneally injected with the same dose of a CCl₄ and olive oil mixture （CCl₄∶olive oil=1∶4, V/V） for liver injury modeling. Blood and liver tissue samples from mice in each group were collected on the 2^nd, 5^th and 7^th days after modeling. The body weights of the mice were monitored during the experiment period. The serum activities of aspartate aminotransferase （AST）, alanine aminotransferase （ALT） and total superoxide dismutase （SOD） were measured. HE staining and Masson staining were used for observing liver histopathological changes. Differential gene enrichment pathways were analyzed by transcriptome sequencing （RNA-seq）. The expression of HNF4α protein in liver tissue was detected using immunohistochemical assay. [Result] Compared with control group, the body weight of CCl₄ injury group significant （P<0.05） or extremely significant （P<0.01 or P<0.001） dropped on the 1^st to 4^th and 6^th to 7^th days after modeling, respectively. In comparison to CCl₄ injury group, the body weight of HHQG group significant （P<0.05） or extremely significant （P<0.01） rose on the 4^th and 6^th to 7^th days after modeling, respectively. On the 2^nd day after modeling, CCl₄ injury group had extremely significantly （P<0.001） increased serum activities of ALT and AST than control group, while significantly （P<0.05） decreased serum activities of ALT and AST were observed in HHQG group compared with CCl₄ injury group. HE staining and Masson staining demonstrated that the liver damages in HHQG group were obviously ameliorated compared with CCl₄ injury group on the 2^nd , 5^th and 7^th days after modeling. KEGG signaling pathway enrichment analysis showed that the signaling pathways such as peroxisome proliferator-activated receptor, fatty acid degradation and fatty acid metabolism in the liver tissue of HHQG group mice were upregulated, while ribosome, glycerophospholipid metabolism, thyroid cancer and some others were downregulated compared with CCl₄ injury group. In comparison to CCl₄ injury group, the gene groups associated with liver differentiation （such as HNF4α, ATF5 and Cebpb） in the liver tissue of HHQG group were significantly upregulated. Immunohistochemical analysis showed that HHQG group had obviously elevated HNF4α expression level in liver tissue than CCl₄ injury group on the 2^nd and 5^th days after modeling. [Conclusion] As a mechanism underlying the hepatoprotective effects, HHQG ameliorated liver injury in mice by inhibiting liver oxidative damage, promoting liver tissue repair and maintaining liver function via activating HNF4α .

Canada is one of the earliest nations to carry out the conservation of livestock and poultry genetic resources, and has a high level of conservation and utilization of these resources. Through systematic analysis of the current status of livestock and poultry genetic resources, gene bank construction, conservation subjects, and relevant laws and regulations in Canada, it was discovered that the high level of conservation and utilization of these resources were largely due to the established livestock and poultry pedigree registration systems, animal heritage resource information systems, advanced livestock and poultry resource preservation technology, and sound legal systems. By comparing the relevant practices and systems in China, five rationalization suggestions were proposed, including establishing pedigree registration systems and optimizing the preservation technology of livestock and poultry resources, in hoping to provide useful references for improving the conservation and utilization level of livestock and poultry genetic resources in China.

With the development of medical laboratory technology, people have gained deeper understanding of respiratory tract micro-ecology and begun to explore the relationship between microbiome and respiratory diseases. More and more evidence suggested that the respiratory tract microbiota is associated with the stability of the pulmonary environment and the occurrence of pulmonary diseases. The current research focused on exploring the causality and potential mechanisms between dysbiosis of respiratory tract microbiota and respiratory diseases such as chronic obstructive pulmonary disease, asthma, and lung cancer. Phlegm, as the preferred sample for respiratory tract micro-ecology research, contains rich micro-ecological information and is easily accessible. This paper summarizes the detection methods of respiratory tract bacterial flora, reviews the research progress of respiratory tract micro-ecology in recent years, and explores the relationship between respiratory tract micro-ecology and the occurrence and progression of respiratory diseases, in hoping to provide new ideas for the specific diagnosis and treatment of respiratory diseases.

[Objective] This study was conducted to measure and compare the electrical resistance of vaginal mucus （ERVM） of beef cows in different reproductive physiological periods and with different types of reproductive disorders, and to provide references for the assistant detection of estrus and gestation as well as the diagnosis of reproductive disorders in cows based on the obtained relevant basal data. Meanwhile, it also aimed to assess the applicability of animal estrus and ovulation tester, and to render technical support for improving the reproductive efficiency in cows. [Method] A total of 297 reproductive beef cows were selected from 21 cattle farms or households. According to the reproductive records and rectal examination results, the cows were subjected to reproductive physiological periods （anestrous period, estrus period, gestation period) determination or reproductive disorders diagnosis. Based on the above records and results, the 297 cows were assigned into the following four groups: an anestrous period group （n=76）, an estrus period group （n=48）, a gestation period group （n=106）, and a reproductive disorders group （n=67）. The 106 heads in the gestation period group were further classified based on the gestation days: 44 heads with ≤60 days of gestation, 24 heads with 61-120 days of gestation, 31 heads with 121-180 days of gestation, and 7 heads with >180 days of gestation. In accordance with the reproductive physiological processes, 42 heads at the luteal phase, 13 heads at the follicular phase and 24 heads at the gestation phase were selected from the cows in the anestrous, estrus, and gestation periods, respectively. The 67 heads in the reproductive disorders group were further divided based on the types of reproductive disorders: 8 heads with ovarian cysts, 57 heads with persistent corpus luteum, and 2 heads with freemartinism. The ERVM of the cows in different reproductive physiological periods and with different types of reproductive disorders was measured using a fully automated animal estrus and ovulation tester, and was statistically compared and analyzed. [Result] The lowest ERVM was observed in the cows in the estrus period, which was 17.91% （P<0.01） and 28.38% （P<0.01） lower than that in those in the anestrous and gestation periods, respectively; the ERVM in the anestrous period was 12.76% （P<0.01） lower than that in the gestation period. The highest ERVM was observed in the cows with ≤ 60 days of gestation, followed by those with 61-120 days of gestation; both were extremely significantly （P<0.01） higher than those with >180 days of gestation; the ERVM in the cows with 121-180 days of gestation was significantly （P<0.05） higher than that in those with >180 days of gestation. The ERVM in the cows at the follicular phase decreased by 35.85% and 37.05% compared with that in those at the luteal and gestation phases, respectively, reaching extremely significant （P<0.01） levels; the ERVM at the luteal phase was similar to that at the gestation phase （P>0.05）. The ERVM in the cows with freemartinism was the highest, and was 36.12% higher （P<0.01） than that in those with ovarian cysts; the ERVM of the cows with persistent corpus luteum was 22.42% higher than that in those with ovarian cysts （P>0.05）. [Conclusion] The variations in the ERVM of beef cows in different reproductive physiological periods and with different types of reproductive disorders were characterized. The average ERVM of the cow populations evidently varied among the anestrous, estrous and gestation periods as well as the different types of reproductive disorders, and also exhibited apparent individual differences. Moreover, there was partial overlap in the ERVM of cows under different reproductive physiological conditions. A ERVM less than 180 Ω was indicative for the determination of estrous period. Additional diagnostic techniques, such as rectal examination and verification of reproductive records, were necessary when using ERVM to identify gestation and anestrous periods and to diagnose reproductive disorders in cows.

Cymbopogon citratus contains a variety of bioactive components such as terpenes, aldehydes, alcohols, flavonoids and polyphenols, exerting the bioactive functions of bacteriostasis, antivirus, immune regulation, anti-inflammation, antioxidation, regulation of intestinal health and so on. It also has significant improvement effects on the growth performance, antioxidant stress capacity, anti-parasitic ability and product quality of livestock and poultry. This article reviews the nutritional value, bioactive function and application of Cymbopogon citratus in livestock and poultry production, in hoping to provide references for the development and promotion of Cymbopogon citratus.

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

[Objective] This study was conducted to screen the high-yield and good-quality annual forage grass varieties suitable for planting and promoting in the Mu Us Sandy Land. [Method] A total of 12 forage grass varieties such as Juncao, forage sweet sorghum and forage maize were used as experimental materials, and their phenophase, agronomic traits and nutritional qualities were observed and measured. The adaptability of the varieties was comprehensively evaluated through variance analysis, correlation analysis and membership function. [Result] All of the 12 tested varieties exhibited adaptability to the local growth environment, completed vegetative growth phase and harvested forage grass. The fresh yield of Giant Juncao （Cenchrus fungigraminus） was the highest, followed by the forage sweet sorghum cultivar Lyujuren. The performance of the tested varieties in the hay yield was similar to that in the fresh yield. Giant Juncao had the highest crude protein yield, followed by the Juncao cultivar Lyuzhou No.1. Among the primary traits of the 12 introduced forage grass varieties, the plant height was extremely significantly （P<0.01） positively correlated with the fresh and hay yields, and the plant height and hay yield were significantly （P<0.05） negatively correlated with the crude protein content and relative feed value. The varieties with top three scores in membership function analysis from high to low were Giant Juncao, annual Melilotus officinalis, and Sorghum Hybrid Sudangrass cultivar Julang. [Conclusion] Comprehensive evaluation and analysis demonstrated that among the 12 tested forage grass varieties, the adaptability of Giant Juncao, annual Melilotus officinalis and Sorghum Hybrid Sudangrass cultivar Julang was better. The research results provided references for introducing suitable forage grass varieties in the Mu Us Sandy Land.

Giant Juncao （Cenchrus fungigraminus） has been widely used in cultivation as high-quality herbage and ecological management material due to its advantages such as fast growth, large biomass, strong stress resistance and wide adaptability. In particular, good results have been achieved in the restoration of the ecologically fragile areas and the heavy metal pollution areas. However, due to its late introduction into China, few studies have been conducted on molecular aspects. In this paper, we review the molecular research progress of Giant Juncao in the aspects of genetic molecular markers, transcriptomics, stress resistance and so on, as well as its application in ecological restoration and management, in hoping to provide references for deep exploration of the feeding value and ecological restoration value of Giant Juncao.

[Objective] The purpose of this study was to determine the optimal harvesting height for hybrid Broussonetia papyrifera and the processing parameters for preparation of hybrid Broussonetia papyrifera silage fermented with microbial agents. [Method] The optimal harvesting height was determined by analyzing the nutritional component and biological yield of hybrid Broussonetia papyrifera at different growth heights. Using hybrid Broussonetia papyrifera at the optimal growth height as raw materials, and Lactobacillus plantarum, Pediococcus acidilactici, and Lactobacillus buchneri as fermentative strains, the silage processing parameters such as combinative ratio of bacterial strains, molasses addition amount, cellulase addition amount, and fermentation duration were screened by orthogonal experimental design. The optimal combination of processing parameters for preparation of hybrid Broussonetia papyrifera silage were determined based on indicators of sensory evaluation, chemical composition, aerobic stability, and nutritional component. [Result] The highest biological yield and nutritional value of hybrid Broussonetia papyrifera were obtained when harvested at the height of 1.2 meters. The optimal processing parameters for preparation of hybrid Broussonetia papyrifera silage obtained through orthogonal experimental design were as follows: the ratio of Lactobacillus plantarum, Pediococcus acidilactici, and Lactobacillus buchneri was 4∶1∶1, the molasses addition amount was 3%, the cellulase addition amount was 9×10³ U/kg, and the silage duration was 60 d. [Conclusion] This study determines the optimal harvesting height and the processing parameters for preparation of hybrid Broussonetia papyrifera silage, providing references for the feed utilization of Broussonetia papyrifera.

Constant body temperature is crucial for maintaining life activities. Homeostatic animals require endogenous heat sources. The direct consequence of hypothermia in animals under cold conditions is the inhibition of protein synthesis at the overall cellular level, while the expressions of cold-inducible RNA binding protein （CIRP）, RNA-binding motif protein 3 （RBM3）, uncoupling protein （UCP）, heat shock proteins （HSPs） and a few cytokines are elevated, which ensures the homeostasis and survival of cells in cold environments. This paper summarizes the recent research progress on cold-inducible proteins and related molecules in animals, in hoping to provide insights into the in-depth research of cold-inducible proteins.