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

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

[Objective] This study focuses on the functional effectiveness of China′s live hog futures market, and evaluate its price discovery efficiency and risk aversion efficacy, to provide a basis for government optimization of hog production capacity regulation and enterprise participation in market-based hedging, thereby maintaining producers′ production incentives and safeguarding consumer welfare. [Methods] Cointegration tests and vector error correction models were employed to reveal the long-term equilibrium relationship and short-term adjustment mechanisms between futures and spot prices. The information share model and permanent-transitory model were used to quantify the contributions of futures and spot markets to price discovery. An ordinary least squares （OLS） regression model and error correction model （ECM） were constructed to estimate the optimal hedging ratio and risk hedging efficiency. [Results] The findings indicate that China′s live hog futures market plays a leading role in price discovery, with a significant long-term equilibrium relationship between futures and spot prices, where short-term price deviations converge toward long-term equilibrium through the error correction mechanism. China′s live hog futures market demonstrates a certain degree of effectiveness in hedging, while also showing potential for further development as a tool for market-based management of hog price risk. [Conclusion] The study results suggest that the government can optimize threshold settings for reserve meat regulation using futures price signals, and the price discovery function of the futures market can provide forward-looking market signals for production capacity early warning mechanisms. Leading hog breeding enterprises can utilize dynamic hedging strategies to stabilize business expectations. These findings provide an empirical basis for improving China's agricultural futures market system and promoting innovation in agricultural risk management tools.

Ventilation in animal housing refers to the exchanging process of internal and external air, which is crucial for maintaining good air quality as well as regulating temperature and humidity in animal housing, and for reducing the risk of respiratory diseases in animals. The primary ventilation patterns in animal housing include natural and mechanical ventilation. Natural ventilation relies on natural forces and is suitable for open animal housing, while mechanical ventilation controls air movement within housing using machinery equipment, offering more flexibility. The factors such as animal species, layout and structure of animal housing, climate and geographical location should be taken into account in selection of ventilation patterns. The comfort of animal housing environment directly impacts the health status and production performance of animals. High temperature and high humidity environment may cause heat stress in animals, and further affects their feed intake, growth and immune function. Accordingly, scientific and reasonable ventilation management is of great significance for maintaining health and improving production efficiency of animals. This paper introduced the commonly used ventilation patterns in animal housing, expounded the impacts of different ventilation patterns on environmental factors, and reviewed the research progress on the effects of ventilation patterns on animals′ physiological and biochemical parameters and production performance, in hoping to provide theoretical basis for the design and construction of ventilation systems in animal housing.

Flavonoid compounds exist in a variety of plants in nature. They are a class of important natural active ingredients with a range of biological activities, such as anti-oxidation, anti-inflammation, antibiosis, anti-tumor, immune regulation, and have a wide range of application. The source, structure, classification, extraction techniques, biological activity of flavonoid compounds as well as their applications in medicine and animal production are reviewed, in hoping to provide references for further research and development of flavonoid compounds.

During the process of silage, the anaerobic environment can not be completely achieved by fermentation of silage raw materials alone, which not only results in the increase of pH value and ammonia nitrogen content as well as the decrease of lactic acid content in silage, but also may lead to the fermentation of undesirable microorganisms, affecting the effect of silage. To reduce the loss of nutrients during the fermentation process of silage and to improve the fermentation quality and nutritional value of silage, additives are commonly used in silage preparation. The frequently used additives for silage mainly include the following four types: bacterial inoculants, enzyme preparations, fermentation inhibitors and non-protein nitrogen. Different types of additives improve the fermentation quality of silage through varied ways, further ameliorating the nutritional value and feeding effect of silage. This paper reviewed the research progress on the impacts of different types of additives on sensory quality, fermentation quality and microbial diversity of silage, in hoping to provide a reference for the scientific selection of silage additives.

[Objective] Routine nutrient parameters with high reference value of Albas goat and Ordos fine wool sheep muscle were obtained, which provided reference for nutrition evaluation, product standard revision and publicity. [Methods] A total of 204 biceps femoris and longissimus dorsi muscles were collected from eight breeds of goats and sheep, including Ordos Albas goats, Ordos fine wool sheep, goats and sheep from Alxa, Ningxia and Shanxi. Four routine nutrient contents were determined, and descriptive statistics and orthogonal partial least squares discriminant analysis were performed. [Results] The protein, fat, moisture and ash contents （X±2SD, g/100 g） of Albas goat meat were （22.10±1.41）, （3.95±1.11）, （73.65±1.43） and （1.49±0.31） g/100 g, respectively. The protein content was significantly （P<0.05） higher than that of other breeds of goats and sheep;the fat content is lower than that of Alxa white cashmere goats and Hengshan goats, but the difference is not significant （P>0.05）; the moisture content is significantly higher than that of Hengshan goats （P<0.05）. Samples from core producing areas showed significantly （P<0.05） higher protein content than those from non-core producing areas. The protein, fat, moisture and ash contents of Ordos fine wool mutton were （20.25±1.63）, （5.68±2.16）, （72.61±2.18） and （1.59±0.46） g/100 g, respectively. Intramuscular fat content was significantly （P<0.05） higher than that of other breeds of goats and sheep. The protein content of Ordos fine wool sheep in Wushenzhao Town was significantly （P<0.05） higher than that in the other two towns. The supervised OPLS-DA results of routine nutrients showed that goats and sheep had a clustering separation tendency, with protein and ash being the major contributing factors. When fat was replaced by four comprehensive indicators of fatty acids, the clustering separation was more obvious, and the separation effect of breed/region was also better. The major contributing indicators were ash, saturated fatty acid （SFA）, polyunsaturated fatty acid （PUFA）, monoun-saturated fatty acid （MUFA） and trans fatty acid （TFA）. [Conclusion] Albas goats meat exhibited nutritional advantages with high protein, low fat and strong water-holding capacity. Ordos fine wool sheep showed significantly higher intramuscular fat content compared with other breeds of goats and sheep, indicating that the sensory quality was better. Further research should be carried out in terms of texture indicators.

Cottonseed, as a feed raw material with significant development potential, is rich in crude protein and can partially replace soybean meal in animal diets. However, anti-nutritional factors such as free gossypol present in cottonseed are toxic to animals, and issues including incomplete nutrient release and low nutrient utilization persist. Biological fermentation represents a safe detoxification technology that effectively degrades macromolecular nutrients, enhancing their digestibility and absorption by animals. To improve the utilization efficiency of feed raw materials and alleviate dependence on imported protein sources, the microbial fermentation of unconventional feed resources like cottonseed has become a critical strategy for the sustainable development of animal husbandry. This review summarizes the current research status on cottonseed as a feed, its nutritional components and anti-nutritional factors, the advantages of fermented cottonseed, fermentation techniques, and the progress in applying fermented cottonseed in animal production, aiming to provide a reference for the promotion and application of fermented cottonseed feed in animal production.

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

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

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

The total area of salinized grasslands in Hulunbuir City is approximately 460 100 hectares, primarily distributed across New Barag West Banner, New Barag East Banner, Prairie Chenbarhu Banner, and Ewenki Autonomous Banner （collectively referred to as the four pastoral banners）, accounting for 4.6% of the city′s total grassland area. This salinization diminishes grassland productivity and reduces available land, posing significant constraints on ecological development and the advancement of grassland-based animal husbandry in Hulunbuir City, and furthermore, impacting the ecological security of northern China. In light of this, this review presents a comprehensive review of the grassland resources, climatic conditions, and the current state of salinization within these four pastoral banners and summarizes the underlying causes of grassland salinization and relevant management strategies, aiming to provide a reference for optimizing salinized grassland management strategies and enhancing these degraded grassland resources in Hulunbuir City.

[Objective] This study was conducted to explore the ovum pick-up and in vitro fertilization （OPU/IVF） technology in cattle, and to establish a high-efficient in vitro embryo production system for cattle. [Method] The fresh ovaries of healthy cattle collected from slaughterhouses were used as experimental materials to perform oocyte maturation as well as fertilization and embryo culture under in vitro conditions, with focus on the effect of leptin supplementation in culture medium on blastocyst rate. Healthy Holstein dairy cows （n=10） and Wagyu cattle（n=10） aged 13 to 15 months were selected as donors, and ovum pick-up as well as oocyte maturation and embryo production under in vitro conditions were carried out. For both breeds, the number of available oocytes and blastocysts was recorded, and the cleavage rates and blastocyst rates were calculated. After thawing of the prepared frozen embryos of the donors, Holstein dairy cows were used as recipients for embryo transfering. The pregnancy rates of the recipients receiving the in vitro produced embryos of the Healthy Holstein dairy cows and Wagyu cattle were measured on day 45 after embryo transfering. [Result] Addition of 30 U/mL leptin in the culture medium significantly （P<0.05） increased the blastocyst rate of the in vitro cultured cattle embryos of slaughterhouse origin. For the donors, 7.5 and 8.1 usable oocytes were averagely obtained per Holstein dairy cow and per Wagyu cattle, respectively. The cleavage rates of Holstein dairy cow and Wagyu cattle were 84.00% and 82.71%, respectively, and there was no significant （P>0.05） difference between them. Under the in vitro conditions, 4.3 and 3.7 available blastocysts were averagely obtained per Holstein dairy cow and per Wagyu cattle, respectively, and the blastocyst rate of Holstein dairy cow （57.33%） was significantly （P<0.05） higher than that of Wagyu cattle （45.68%）. The pregnancy rates of Holstein dairy cow embryo group and Wagyu cattle embryo group were 54.17% and 55.79%, respectively, and no significant （P>0.05） difference was observed. [Conclusion] The established OPU/IVF system effectively improves the utilization efficiency of high-quality female cattle, reduces its production costs, and provides references for the optimization of in vitro embryo production system for cattle.

[Objective] This study was conducted to assess the mechanisms underlying the protective role of honeysuckle extract against Newcastle disease virus （NDV） infection in pigeon. [Method] A total of 40 healthy 28-day-old American king pigeons without NDV vaccination were selected and subjected to a 7-day adaptive rearing. At the age of 35 days, the experimental pigeons were randomly assigned into a honeysuckle extract protective （KO） group （n=10） or a virus challenge control （OE） group （n=10）. The pigeons in KO group drank the water containing 1.2% honeysuckle extract for 7 consecutive days, and at the age of 42 days, they were intramuscularly injected with 0.5 mL NDV Pi/NJ/CH/4416/2016 strain of pigeon origin with HA potency of 5log2 . The pigeons in OE group drank the normal water and were challenged with the same NDV strain at the same dosage at the age of 42 days. Seven days after challenge, 3 pigeons were chosen from both KO and OE groups. The spleen samples were collected for paraffin-embedded tissue section preparation and for total RNA extraction to construct the transcriptome libraries. RNA-Seq was used to identify differentially expressed genes （DEGs） and to perform GO functional enrichment analysis as well as KEGG pathway enrichment analysis. Four randomly selected significant DEGs identified by RNA-Seq were verified by using qRT-PCR. [Result] The splenocytes of the pigeons in OE group had abnormally enlarged nuclei and white vacuoles, accompanied by a large number of granulocyte infiltration in splenic tissues, while those of the pigeons in KO group had many white vacuoles and minor granulocyte infiltration alone, and no abnormally enlarged splenocyte nuclei in splenic tissues were observed. A total of 374 DEGs were identified in the spleens of the pigeons in KO group by RNA-Seq, of which 112 were significantly up-regulated and 262 were significantly down-regulated. GO functional enrichment analysis demonstrated that 875 DEGs were enriched in 312 GO entries, of which 149 belonged to biological process, 33 belonged to cellular component, and 130 belonged to molecular function. KEGG pathway enrichment analysis revealed that 226 DEGs were enriched in 93 KEGG signaling pathways, including information transmission pathway, metabolic pathway, natural immunity related pathway, and apoptosis pathway. The qRT-PCR validation test showed that the relative mRNA abundance of the 4 randomly selected significant DEGs （LOC110360702, LOC110360688, SFRP5 and CHAD） had the same change trend as the RNA-Seq results. [Conclusion] Honeysuckle extract exerts protective role against NDV infection in pigeon by activating important physiological processes of host such as information transmission, metabolic regulation and immune response. The results obtained in this study provide a scientific basis for further investigation on the molecular mechanism of immune response to NDV infection in pigeon.

[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 present study was conducted to propose a method for organizing the knowledge of animal husbandry laws and regulations to achieve a more orderly organization of relevant knowledge. [Method] The online legal resources in the websites of flk.npc.gov.cn, pkulaw.com, lawyee.org, wkinfo.com.cn, and law.cnki.net were used as the data sources of animal husbandry laws and regulations, the relevant laws and regulations of animal husbandry were screened and obtained. Subsequently, the corresponding formulation authority, timeliness, effectiveness hierarchy, regulation category, issuing date, implementation date and year information were extracted, and the obtained data was preprocessed. The ontology was built, and the entities and relationships were defined. Using rule-based method, the entities and relationships from the obtained laws and regulations texts were extracted, and then temporarily stored in MySQL database. The SQLAlchemy database and py2neo database in Python were used to operate MySQL database and Neo4j Graph database to convert the data in MySQL into entity relationship triad, and then stored in Neo4j Graph database to complete the storage of knowledge graph of animal husbandry laws and regulations. [Result] A total of 287 laws and regulations related to animal husbandry were collected and classified based on whether the laws and regulations contained chapters. Among these, 211 laws and regulations contained chapters, totaling 1 470 chapters and 10 457 articles, whereas 76 laws and regulations did not contain chapters, totaling 2 145 articles. There were 10 types of entities defined, including ′laws and regulations′, ′issuing authority′, ′timeliness′, ′effectiveness hierarchy′, ′regulation category′, ′chapter′, ′article′, etc. There were 10 types of relationships defined, including ′the relationship of animal husbandry laws and regulations to category of laws and regulations ′, ′the relationship of animal husbandry laws and regulations to timeliness of laws and regulations′, ′the relationship of animal husbandry laws and regulations to issuing authority of laws and regulations′, and ′the relationship of animal husbandry laws and regulations to effectiveness hierarchy of laws and regulations′, etc. A knowledge graph of animal husbandry laws and regulations covering 14 936 entities and 16 339 relationships was constructed. [Conclusion] This method can be applied to organize the knowledge on animal husbandry laws and regulations, making the organization of knowledge more systematic and closely related.

With the continuous development of social economy and the steady improvement of people′s living standards, the public′s attention to the quality and safety of livestock products has also increased. The quality of livestock products reflects the development level of the animal husbandry industry, and the issue of livestock products quality and safety has become one of the critical issues restricting the healthy development of the animal husbandry industry. The livestock products quality and safety traceability system can trace the origin of livestock products and realize the sharing of information throughout the whole process from farm to fork. With the help of the livestock products quality and safety traceability system, the producers can achieve precise feeding and management as well as improve their breeding efficiency, the regulators can achieve precise supervision and improve their management efficiency, and the consumers can achieve worry-free consumption and improve their satisfaction. Accelerating the construction and application of the livestock products quality and safety traceability system is conductive to ensure the quality and safety of livestock products and promote the improvement of quality and efficiency of animal husbandry production. This paper introduced the application status of the livestock products quality and safety traceability system, analyzed the main problems in the application of the system, and put forward countermeasures and suggestions to accelerate the promotion of the system, in hoping to provide references for enhancing the supervision efficiency of livestock products quality and safety as well as helping the high-quality development of the animal husbandry industry.

[Objective] To analyze the immunomodulatory mechanism of miRNA in the MAPK signaling pathway of bovine milk and milk-derived exosomes. [Methods] Key immune miRNAs of MAPK signaling pathway in bovine milk and milk-derived exosomes were screened based on previous sequencing data. Target genes of these miRNAs were predicted using TargetScan and miRanda software, and their bioinformatics functions were analyzed. Finally, the miRNA-mRNA-KEGG regulatory network of immune-related key miRNAs was constructed. [Results] There were 80 key miRNAs in bovine milk and milk-derived exosomes. The target genes were significantly enriched in immune-related GO terms, including "regulation of inflammatory response" （GO:0050727） and "negative regulation of inflammatory response" （GO:0050728）. KEGG pathway analysis revealed enrichment in 335 pathways, with the top five being "Metabolism", "MAPK signaling pathway", "Pathways in cancer", "Endocytosis" and "Carbon metabolism". PDGFRA and PDGFRB genes in the regulatory network mediated immune functions of bovine milk and milk-derived exosomes through MAPK signaling pathway-associated miRNAs. [Conclusion] MAPK signaling pathway mediated the immune resistance in bovine milk and milk-derived exosomes via key miRNAs, such as bta-let-7i, bta-miR-155, bta-miR-34a, bta-miR-499b and bta-miR-106a_R+1_1ssIAC. PDGFRA and PDGFRB genes in the regulatory network regulated by multiple MAPK signaling pathway-associated miRNAs, might be the key genes in the immune regulation of bovine milk and milk-derived exosomes.

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

[Objective] 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] This study aimed to assess the effects of different saline-alkali stresses on seed germination and seedling growth of forage triticale（× Triticosecale Wittmack）. [Method] The solutions of NaCl, Na₂SO₄, Na₂CO₃ and NaHCO₃ were used to simulate the saline-alkali stress environments, with Na⁺ concentrations set at 0 （CK）, 50, 75, 100, 150 and 200 mmol/L for each solution. Seed germination experiments were conducted to evaluate the change patterns of germination percentage （Gp）, germination index （Gi）, mean germination time （MGT）, seedling vigor index （SVI）, embryonic root length and embryonic bud length of forage triticale under the stresses induced by different types of saline-alkali and concentrations of Na⁺, to reveal the response characteristics of seed germination and seedling growth to different saline-alkali stresses. [Result] Different types of saline-alkali, concentrations of Na⁺ and their interactions all had extremely significant （P<0.01） impacts on Gp, Gi, MGT, SVI, embryonic root length and embryonic bud length of forage triticale. With the increase of Na⁺ concentrations, Gp, Gi, SVI, embryonic root length and embryonic bud length of forage triticale decreased, while MGT elevated. Under the same Na⁺ concentration, forage triticale seed exhibited higher tolerance to neutral salt stress than alkaline salt stress. [Conclusion] With the increase of Na⁺ concentrations, the inhibitory effects of different saline-alkali stresses on seed germination and seedling growth of forage triticale enhanced. Alkaline salt posed stronger inhibitory effect than neutral salt. Forage triticale seed showed certain tolerance to the stress induced by the lower Na⁺ concentrations, indicating that it could be planted on the mild saline-alkali soils in China.

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.

[Objective] To investigate the effects of dietary supplementation with selenoglucose on growth performance, meat quality, serum immune indices, and serum antioxidant indices in broilers. [Methods] A single-factor completely randomized design was employed, with 288 one-day-old, weight-matched, healthy, male Cobb 505 white-feather broilers randomly assigned to four groups （A-D）, each comprising six replicates of 12 birds. Group A was fed a corn-soybean basal diet; groups B, C, and D received the basal diet supplemented with 0.15 mg/kg, 0.30 mg/kg, and 0.60 mg/kg selenoglucose, respectively. The trial lasted 42 days and was divided into two phases based on composition and nutritional levels of the basal diet: early stage （1-21 days） and late stage （22-42 days）. At the end of 21 and 42 days, growth performance was measured, and blood samples were collected from broilers in each group to determine serum immune and antioxidant indices. At day 42, breast muscle samples were collected for meat quality analysis. [Results] Regarding growth performance, from 1-21 days, the average daily gain （ADG） in groups B, C, and D was significantly （P<0.05） higher than that in group A; from 22-42 days, the ADG in group D was significantly （P<0.05） higher than that in groups A, B, and C, and the feed-to-gain ratio （F:G） in group A was significantly （P<0.05） higher than that in groups C and D; from 1-42 days, the ADG in group D was significantly （P<0.05） higher than that in groups A, B, and C, and the F:G in group A was significantly （P<0.05） higher than that in groups B, C, and D. In terms of meat quality, the drip loss in groups A and B was significantly higher （P<0.05） than in groups C and D; the shear force in groups A, C, and D was significantly higher （P<0.05） than in group B; the water-holding capacity in group A was significantly higher （P<0.05） than in groups B, C, and D; the cooking yield in group B was significantly higher （P<0.05） than in groups A, C, and D. Regarding serum immune indices, from 1-21 days, serum immunoglobulin A （IgA） levels in groups C and D was significantly （P<0.05） higher than in groups A and B; serum immunoglobulin G （IgG） and immunoglobulin M （IgM） levels in group C was significantly （P<0.05） higher than in groups A, B, and D; from 22-42 days, serum IgA levels in groups C and D was significantly （P<0.05） higher than in groups A and B; serum IgG levels in group C was significantly （P<0.05） higher than in groups A, B, and D; serum IgG and IgA levels in group A was significantly （P<0.05） lower than in groups B and D; serum IgM levels in groups A, C, and D was significantly （P<0.05） higher than in group B. For serum antioxidant indices, from 1-21 days, serum glutathione peroxidase （GSH-Px）, glutathione (GSH), and total antioxidant capacity （T-AOC） levels in groups C and D were significantly （P<0.05） higher than in groups A and B; serum GSH and T-AOC levels in group D were significantly （P<0.05） higher than in group C; from 22-42 days, serum GSH-Px levels in groups B, C, and D was significantly （P<0.05） higher than in group A; serum malondialdehyde （MDA） levels in groups B, C, and D was significantly （P<0.05） lower than in group A; serum superoxide dismutase （SOD） and GSH levels in group D were significantly （P<0.05） higher than in groups A, B, and C; serum T-AOC levels in groups B and C was significantly （P<0.05） higher than in group A. [Conclusion] The optimal dietary selenoglucose supplementation for broilers was determined to be 0.6 mg/kg. Under this condition, broilers exhibited the best comprehensive performance in terms of growth （ADG, F:G）, meat quality （drip loss）, immune function （IgA, IgG）, and antioxidant capacity （GSH-Px, GSH, SOD, T-AOC）.

[Objective] The aims of the present study were to isolate and identify the Staphylococcus aureus （S. aureus） strain from fecal samples of lambs with diarrhoea, and to characterize the antimicrobial resistance and pathogenicity of the isolate. [Method] Four anal swab samples of diarrheic lambs were collected from a sheep farm in Emin County, Tacheng Prefecture, Xinjiang Uygur Autonomous Region, and S. aureus strain was selectively isolated with mannitol salt agar （MSA）. The isolate was identified by morphological observation and 16S rDNA sequence analysis. The in vitro susceptibility of the isolate to 11 antimicrobial agents belonging to 9 categories was analyzed by paper diffusion method. The presence of virulence genes of the isolate was detected by PCR assay. A model of abdominal infection in Kunming mice was established to evaluate the pathogenicity of the isolate. [Result] One suspected S. aureus strain was isolated from the four fecal samples of diarrheic lambs. It formed glossy, moderately raised, golden or lemon coloured colonies on MSA. Gram staining and morphological observation revealed that the isolate was Gram-positive and arranged in the form of grape bunches. The 16S rDNA sequence of the isolate was 100% similar to that of a S. aureus isolate of porcineluny origin from Changsha City, Hunan Province, China. Morphological observation and 16S rDNA sequence analysis confirmed that the isolate was S. aureus. The isolate was resistant to penicillin, clindamycin, cefotiamine, rifampicin and erythromycin, and was sensitive to gentamicin, azithromycin, chloramphenicol, norfloxacin, cefoxitin and cotrimoxazole. Out of the 20 virulence genes belonging to 8 classes tested, the presence of sea, seg, sei, eta, clfA and clfB genes was observed. The LD₅₀ of the isolate for Kunming mice was 2.24×10⁸ CFU/mL, with observable pathological changes in the organs of the dead mice. [Conclusion] One S. aureus strain was isolated and identified from the fecal samples of diarrheic lambs in a sheep farm in Emin County, which exhibited a multi-drug resistant phenotype, harbored multiple virulence genes and had certain pathogenicity. The results of this study provide references for the rational use of medication for the diseases caused by S. aureus infection in sheep in this region.

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

Mycotoxins are secondary metabolites produced by fungi in grains and are often present in the contaminated livestock and poultry feed and feed raw materials. The mycotoxins commonly found in the feed samples include aflatoxin B₁（AFB₁）, ochratoxin A （OTA）, zearalenone （ZEA）, deoxynivalenol （DON）, and fumonisin （FUM）. Mycotoxins damage the immune system and reproductive function of livestock and poultry, and cause pathological alterations in the organs such as kidney, liver, and intestinal tract, affecting the health of livestock and poultry. This paper introduces the types and contamination situation of the commonly observed mycotoxins in livestock and poultry feed and feed raw materials, summarizes the research progress in the toxic effects of mycotoxins on livestock and poultry, and proposes corresponding prevention and control measures, in hoping to provide references for minimizing the harm caused by mycotoxin contamination in livestock and poultry production.

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

[Objective] The aim of this study was to conduct bioinformatics analysis on the pS273R protein of African swine fever virus （ASFV）. [Method] Using bioinformatics tools, the sequence homology and genetic evolution of the pS273R gene of 43 strains of ASFV were analyzed, and predictions were made on the physicochemical properties, secondary structure, phosphorylation sites, glycosylation modifications, subcellular localization and tertiary structure of the pS273R protein. [Result] Different ASFV strains exhibited high homology in pS273R gene with 5 strains isolated from China sharing 100% sequence homology, and 38 strains isolated from other countries sharing 93.60% to 100% sequence homology. Phylogenetic analysis showed that the Chinese strains were genetically closely related to the European branch. The pS273R protein was hydrophilic and composed of 273 amino acids, with a predicted molecular weigh of 31.58 kDa. In terms of secondary structure, α-helix （Hh）, extended chain （Ee）, β-bend （Tt） and random coil （Cc） were mainly observed. It had 28 phosphorylation sites and 2 potential N-glycosylation sites. It most likely presented in the cytoplasm of the host cell （P=47.8%）. The tertiary structure was formed through biological processes such as rotation, folding and curling of the secondary structure of α-helix, β-bend, β-fold and random coil. [Conclusion] The results obtained in this study provide references for the in-depth analysis of structure and function of pS273R protein and the development of ASFV inhibitors.

[Objective] This study aimed to explore the biodiversity of yeasts in sour whey, a by-product of traditional cheese processing in the pastoral area of Xilin Gol League, Inner Mongolia. [Method] The yeasts were isolated and purified from two sour whey samples collected in Xilin Gol League, Inner Mongolia, using traditional isolation and culture technology of microorganisms. The species of the isolated yeast strains was determined by ITS gene sequence analysis, and a phylogenetic tree was constructed. [Result] A total of 18 yeast strains were obtained from the two sour whey samples, belonging to 4 different species, Saccharomyces cerevisiae （n=2）, Pichia fermentans （n=2）, Pichia kudriavzevii （n=2） and Kluyveromyces marxianus （n=12）. Among them, Kluyveromyces marxianus was the dominant flora in the sour whey samples. [Conclusion] Our results reveal the biodiversity of yeasts in sour whey collected in Xilin Gol League, Inner Mongolia, and provide references for the comprehensive utilization and industrial production of sour whey.

[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] To evaluate the safety and nutritional value of animal-derived protein hydrolysate prepared from meat and bone meal of disease-induced dead animals. [Methods] Meat and bone meal from different batches was processed through high-temperature and high-pressure treatment, degreasing, acid hydrolysis, distillative acid removal, neutralization and decolorization, concentration, and drying to collect animal-derived protein hydrolysate. The nutritional components （crude protein, crude fat, crude fiber, and protein digestibility, etc.）, mineral elements （calcium, total phosphorus, copper, iron, zinc, etc.）, heavy metals （arsenic, chromium, mercury, etc.）, prohibited drugs and antibiotics （clenbuterol, sulfonamides, quinolones, etc.）, microorganisms （Escherichia coli, Salmonella, etc.）, mycotoxins （vomitoxin, aflatoxin B₁, etc.）, and nucleic acids of major porcine pathogens （African swine fever virus, porcine reproductive and respiratory syndrome virus, etc.） were detected. Twenty-four healthy Duroc × Landrace × Yorkshire weaned piglets of similar age and body weight were selected and randomly divided into three groups. The control group was fed a basal diet, while experimental groups 1 and 2 were fed the basal diet supplemented with 0.1% and 0.5% animal-derived protein hydrolysate, respectively, for 35 days. Growth performance, diarrhea incidence, and serum immune, antioxidant, and biochemical parameters were measured. [Results] The animal-derived protein hydrolysate had a dry matter content of 94.04% and a crude protein content of 68.74%, with crude ash was rich in multiple mineral elements, including calcium, phosphorus, and iron exceeding 1 g/kg, and other trace elements exceeding 1 mg/kg. In terms of safety, the heavy metal mercury was not detected, and lead, cadmium, chromium, and total arsenic levels were below 1 mg/kg. No residues of prohibited drugs, harmful microorganisms, or nucleic acids of common porcine viruses were detected. Deoxynivalenol was detected at only 0.31 mg/kg, while other toxins were absent. The total bacterial count was 809 CFU/g, compliant with the Feed Hygiene Standard （GB 13078—2017）. In the weaned piglet trial, compared to the control group, diets supplemented with animal-derived protein hydrolysate significantly （P<0.05） increased average daily gain, significantly （P<0.05） reduced feed-to-gain ratio, and highly significantly （P<0.01） decreased diarrhea incidence. Additionally, it significantly （P<0.05） increased serum total protein and immunoglobulin A levels, highly significantly （P<0.01） increased immunoglobulin G levels, and significantly （P<0.05） enhanced the activities of glutathione peroxidase （GSH-Px）, superoxide dismutase （SOD）, and total antioxidant capacity （T-AOC） in plasma. [Conclusion] The animal-derived protein hydrolysate exhibits high safety and nutritional value, with the ability to modulate the body′s immune function.

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

Selenium is one of the essential trace elements for animals, which is involved in a series of biological processes such as anti-oxidation, immunity, reproduction and intestinal bacterial flora regulation. In recent years, among the selenium preparations from different sources, nano-selenium has attracted the attention of animal nutrition researchers both in China and abroad due to such advantages as low toxicity, high bio-availability, good safety and strong antioxidant property, becoming a hotspot in the research field of feed additives. This paper summarized the nature and characteristics, absorption and metabolism mechanism, and biological functions of nano-selenium, and reviewed the research progress on its application in animal production, in hoping to provide references for the development of nano-selenium feed additives and their scientific application in animal production.

[Objective] This study was conducted to characterize the change of functional gene expression of active microorganisms in different fermentation stages of koumiss. [Method] The koumiss samples were collected at the early （12 h）, middle （48 h） and late （96 h） stages of fermentation, and the metatranscriptomic libraries were prepared for high-throughput RNA sequencing. After assembly and functional annotation of the sequencing data, the differentially expressed genes （DEGs） were identified to determine the static enrichment of significant DEGs in GO and KEGG signaling pathways. [Result] The koumiss samples of the early, middle and late stages of fermentation generated 12.17 GB clean reads by metatranscriptomic high-throughput sequencing. Sequence assembly and data analysis demonstrated that the expression of genes involved in metabolic process played a dominant role in the fermentation process of koumiss. The identification and assessment of DEGs exhibited that the number of the down-regulated genes was more than that of the up-regulated genes in pairwise comparison of the koumiss samples collected at the three fermentation stages. GO functional enrichment analysis showed that the GO terms highly enriched by DEGs between the samples of early and middle fermentation stages associated with cellular process, metabolic process, organic ring compound binding, and heterocyclic compound binding. The GO terms highly enriched by DEGs between the samples of middle and late fermentation stages included cellular process and cellular macromolecule metabolic process. The GO terms highly enriched by DEGs between the samples of early and late fermentation stages mainly involved cellular process, organic substance metabolic process, nucleoside binding, ribonucleoside binding, and purine nucleotide binding. KEGG pathway enrichment analysis displayed that there was only one signaling pathway （ribosome） in which DEGs between the samples of early and middle fermentation stages significantly enriched. DEGs between the samples of middle and late fermentation stages significantly enriched in the signaling pathways of ether lipid metabolism, aminobenzoate degradation, mRNA surveillance pathway, and steroid biosynthesis. The signaling pathways of steroid biosynthesis, aminobenzoate degradation, mRNA surveillance pathway, ribosome and ethylbenzene degradation were significantly enriched by DEGs between the samples of early and late fermentation stages. [Conclusion] The differential expression of functional genes of active microorganisms was involved in the fermentation process and dynamically changed in different fermentation stages of koumiss. The results obtained in this study provide references for in-depth understanding the fermentation mechanism and optimizing the fermentation process of koumiss.

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

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

[Objective] To understand the production performance advantages of the F₁ generation crossbreds between Huang-huai Meat Sheep and Hu Sheep, providing a reference for the promotion of new Huang-huai Meat Sheep breed resources. [Methods] 90 purebred Hu ewes, ranging from 2 to 4 parities, were selected and synchronized for estrus. Subsequently, 35 randomly selected purebred Hu ewes were artificially inseminated with semen from Huang-huai Meat Sheep rams, resulting in 29 parturient purebred Hu ewes producing 61 Huang-Hu F₁ lambs （experimental group）. The remaining 55 Hu ewes were artificially inseminated with Hu rams, resulting in 53 parturient purebred Hu ewes producing 103 purebred Hu lambs （control group）. Growth traits, including birth weight, weaning weight, weaning survival rate, average daily gain （ADG） from 0-55, 55-90, 90-120, 120-150, and 0-150 days, as well as body height, body length, chest circumference, and cannon bone circumference at birth, 55, 90, 120, and 150 days, were measured and analyzed for both groups. [Results] Regarding birth weight, weaning weight, weaning survival rate, and ADG across different age periods （0-55, 55-90, 90-120, 120-150, and 0-150 days of age）, the single-birth weight of F₁ generation Huang-hu lambs in the experimental group was significantly （P<0.01） higher than that of Hu lambs in the control group; the multiple-birth weight （twins or more） of F₁ generation Huang-hu lambs in the experimental group was significantly （P<0.05） higher than that of Hu lambs in the control group; the weaning weight, weaning survival rate, and ADG across all measured age periods （0-55, 55-90, 90-120, 120-150, and 0-150 days of age） of F₁ generation Huang-hu lambs in the experimental group were significantly （P<0.01） higher than those of Hu lambs in the control group. For body measurements, at birth and weaning, the body height, body length, and chest circumference of F₁ generation Huang-hu lambs in the experimental group were significantly （P<0.01） higher than those of Hu lambs in the control group; the cannon bone circumference of female lambs at birth in the experimental group was significantly （P<0.05） higher than that of female Hu lambs in the control group; at 90, 120, and 150 days, the chest circumference of F₁ generation Huang-hu lambs in the experimental group was significantly （P<0.01） higher than that of Hu lambs in the control group; the cannon bone circumference of female lambs at 120 days in the experimental group was significantly higher （P<0.01） than that of female Hu lambs in the control group; the cannon bone circumference of male lambs at 150 days in the experimental group was significantly higher （P<0.01） than that of male Hu lambs in the control group; the cannon bone circumference of female lambs at 150 days in the experimental group was significantly （P<0.05） higher than that of female Hu lambs in the control group. [Conclusion] Using Huang-huai meat sheep as the sire and Hu sheep as the dam for crossbreeding, the F₁ generation lambs show obvious heterosis in birth weight, weaning weight, weaning survival rate, and chest circumference, and prominent meat production traits, and are therefore suitable for promotion and application in large-scale sheep farms.

[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.

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.

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

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

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

[Objective] 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 explore the effects and possible mechanisms of citric acid and acetic acid on the contraction of isolated mouse intestinal smooth muscle, and to provide references for the development of organic acid products that helps regulate gastrointestinal motility disorders in humans or animals. [Method] A biological signal processing system was used to monitor the effects of two-fold increasing concentrations of citric acid （0.02-0.64 mmol/L） or acetic acid （0.13-2.00 mmol/L） as well as their corresponding bolus effective concentrations on the contractile amplitude, ension, and peak of the isolated intestinal segment in mice. [Result] Both citric acid and acetic acid dose-dependently reduced the contractile amplitude and tension of the intestinal smooth muscle （P<0.01）, with the effective inhibitory concentrations of 0.32 mmol/L and 1.00 mmol/L, respectively. Both acids with effective inhibitory concentrations did not affect the contractile peak of the intestinal tissue caused by 25 mmol/L KCl （P>0.05）, while the citric acid treatment significantly （P<0.05） alleviated the decrease in intestinal contractile amplitude induced by bethanechol chloride, an M-receptor agonist. [Conclusion] Both citric acid and acetic acid can inhibit the contraction of isolated intestinal smooth muscle in mice, and may not affect the depolarization process of smooth muscle cell membrane. However, citric acid may have spasmolytic effect on gastrointestinal smooth muscle via partially affecting the role of M-receptor.

Muscle tissue from livestock such as cattle, sheep, and pigs possesses excellent nutritional value and desirable eating characteristics, making it one of the most important sources of animal protein for humans. However, how to further enhance the meat quality of these livestock remains a focal point for researchers and practitioners in the animal husbandry industry. Livestock muscle tissue is composed of different types of muscle fibers, and the muscle fiber type and its dynamic transformation processes significantly affect the meat's texture, flavor characteristics, and nutritional composition. Muscle fiber transformation is a complex biological process synergistically regulated by multiple factors, including genetics, nutrition, and environment. Therefore, an in-depth exploration of the composition characteristics and transformation mechanisms of livestock muscle fibers, and their effects on meat quality, holds significant theoretical importance. This review aims to systematically elaborate on the research progress regarding the muscle fiber types and their transformation mechanisms in livestock, providing a scientific basis for the improvement of meat quality.

[Objective] This study aimed to analyze the structure and function of African swine fever virus （ASFV） pI215L protein. [Method] A total of 29 pI215L gene sequences of different ASFV strains were downloaded from the African Swine Fever Virus Database （ASFVdb）. Bioinformatics tools were used to analyze the homology and genetic evolution of pI215L gene of different ASFV strains, and to predict the physicochemical properties, secondary structure, linear epitope, and three-dimensional spatial location of pI215L protein. [Result] The pI215L gene sequences had high homology among different ASFV strains. The pI215L protein was unstable and hydrophilic. Its secondary structure mainly contained four forms, including α-helix, extend strand, β-turn, and random coil, and had a domain of E2 Ubiqutin-conjugating enzyme. A total of 16 peptide fragments were potential linear epitopes. SWISS-MODEL was used to complete homology modeling of the tertiary structure of pI215L protein, and its homology with 6NYO.1 （ubiquitin-conjugating enzyme E2 R2 and ubiquitin） in the PDB database was 46.06%. The PyMOL software was used to predict the conformational epitopes of pI215L protein to accurately locate the distribution of the predicted three-dimensional spatial position of the epitopes in the model. [Conclusion] Our results provided references for unravelling the structure and function of pI215L protein, as well as developing vaccines and drugs for prevention and control of ASFV.

[Objective] This study was conducted to assess the effects of ellagic acid on growth performance, antioxidant function and intestinal barrier function in mice fed aflatoxin-containing diets. [Method] A total of 30 healthy female Kunming mice weighted 18 to 22 g were randomly assigned into a control group, a toxin group or an ellagic acid treatment group, with 10 mice in each group. The control group fed a basal diet, the toxin group fed the basal diet containing 250 μg/kg aflatoxin, and the ellagic acid treatment group fed the basal diet supplemented with 250 μg/kg aflatoxin and 100 mg/kg ellagic acid. The feeding experiment lasted for 35 days. The mice were individually weighed at the beginning and end of the experiment, and the weight gain were calculated. At the end of the experiment, the blood samples of the mice were collected with ophthalmectomy. The serum antioxidant indexes such as total superoxide dismutase （T-SOD） activity, total antioxidant capacity （T-AOC） and malondialdehyde （MDA） content as well as the intestinal barrier function indexes such as diamine oxidase （DAO） activity and D-lactic acid content were determined by using ELISA assay. The jejunal tissue samples of the mice were collected to prepare paraffin section. The morphological structure of jejunal mucosa, jejunal villus height and jejunal crypt depth were observed with HE staining, and the ratio of villus height to crypt depth was calculated. [Result] The final body weight and the weight gain of toxin group were extremely significantly （P<0.01） lower than control group. While the final body weight of ellagic acid treatment group was not significantly （P>0.05） different from toxin group, the weight gain of ellagic acid treatment group was extremely significantly （P<0.01） higher than toxin group. Toxin group had significantly （P<0.05） decreased serum T-AOC activity and extremely significantly （P<0.01） reduced serum T-SOD activity in comparison to toxin group. Ellagic acid treatment group had extremely significantly （P<0.01） elevated serum T-SOD activity compared with toxin group, while no significant （P>0.05） difference in serum T-AOC activity was found between these two groups. An extremely significantly （P<0.01） higher serum MDA content was observed in toxin group than control group, and an extremely significantly （P<0.01） lower serum MDA content was observed in ellagic acid treatment group than toxin group. Toxin group had extremely significantly （P<0.01） higher serum DAO activity and D-lactic acid content compared with control group. Ellagic acid treatment group had significantly （P<0.05） reduced serum DAO activity compared with toxin group,while no significant （P>0.05） difference in serum D-lactic acid content was found between these two groups. The jejunal villi and crypt of the mice in control group exhibited complete morphology, and no abnormal pathological changes were observed. Serious pathological damages were observed in jejunal tissues of the mice in toxin group：the arrangement of jejunal villi was neither neat nor tight, the intervillous space enlarged and even break, and the arrangement of jejunal crypt was also not neat. The jejunal villus height and the ratio of villus height to crypt depth of toxin group was extremely significantly （P<0.01） decreased compared with control group, while no significant （P>0.05） difference in jejunal crypt depth was found between these two groups. The mice in ellagic acid treatment group exhibited alleviated pathological damages in jejunal tissues compared with toxin group：the morphology of jejunal mucosa was basically restored to normal, the villi breakage was ameliorated, and the jejunal crypt arranged more neatly. The ellagic acid treatment group had extremely significantly （P<0.01） increased jejunal villus height and the ratio of villus height to crypt depth than toxin group, while no significant （P>0.05） difference in jejunal crypt depth was found between these two groups. [Conclusion] Ellagic acid alleviates the damages induced by aflatoxin in mice via inhibiting the body weight reduction, enhancing serum antioxidant function and improving jejunal mucosa barrier function.