[Objective] To verify the role of β-defensin-1 in inhibiting the growth of colon cancer via circular RNA HAS-CIRCpedia-5280 by subcutaneous tumorigenesis experiments in nude mice. [Methods] Lentiviral transduction technology was performed to transduce human colon carcinoma HCT-116 cells with the overexpression lentivirus carrying HAS-CIRCpedia-5280 and empty-vector control lentivirus, respectively. After polybrene-assisted infection and puromycin screening for 2 weeks, HAS-CIRCpedia-5280 overexpression stably transduced HCT-116 cell line （HAS-CIRCpedia-5280 cells） and empty vector control stably transduced HCT-116 cell line （NC cells） were constructed. Thirty BALB/c-nu nude mice were divided into 6 groups[oe-NC group, subcutaneously injected with NC cells; oe-circRNA group, subcutaneously injected with HAS-CIRCpedia-5280 cells; oe-NC+PBS group, subcutaneously injected with NC cells and intraperitoneally injected with PBS; oe-circRNA+PBS group, subcutaneously injected with HAS-CIRCpedia-5280 cells and intraperitoneally injected with PBS; oe-NC+hBD-1 （human β-defensin-1） group, subcutaneously injected with NC cells and intraperitoneally injected with hBD-1; oe-circRNA+hBD-1 group, subcutaneously injected with HAS-CIRCpedia-5280 cells and intraperitoneally injected with hBD-1], with 5 mice in each group. The BALB/c-nu nude mice subcutaneous xenograft tumor model was established by subcutaneous injection of the above two kinds of stably transduced cells. The oe-NC+hBD-1 group and the oe-circRNA+hBD-1 group, the oe-NC+PBS group and the oe-circRNA+PBS group were intraperitoneally injected with 0.1 mg/（kg·BW） hBD-1 or an equal volume of PBS, respectively, for intervention, twice a week （Monday and Thursday）, and tumor volume was recorded every 7 days. All injections were completed within 4 weeks from the first administration. The nude mice were euthanized 72 h after the last administration, and the tumor tissues were dissected to measure tumor volume and weight. [Results] HAS-CIRCpedia-5280 overexpression （oe-circRNA） and empty vector control （oe-NC） stably transduced HCT-116 cell lines were constructed by lentivirus transduction. Fluorescence microscopy showed that most cells in the oe-circRNA group and oe-NC group exhibited clear green fluorescence, and the positive rate of cells was higher. The results of qRT-PCR showed that compared with the oe-NC control group, the expression level of HAS-CIRCpedia-5280 in the oe-circRNA group was extremely significantly up-regulated （P<0.01）. A subcutaneous xenograft tumor model of colon cancer in nude mice was constructed, and tumor growth was regularly monitored. The results showed that compared with the oe-NC group, the weight of transplanted tumor in the oe-circRNA group was extremely significantly increased （P<0.01）, and the volume was significantly increased （P<0.05）. qRT-PCR detection confirmed that the expression level of HAS-CIRCpedia-5280 in the oe-circRNA group was extremely significantly up-regulated compared with the oe-NC group （P<0.01）. An hBD-1 intraperitoneal intervention experiment was conducted on the colon cancer xenograft tumor model in nude mice. Compared with the oe-NC+PBS group, the weight of transplanted tumors in the oe-circRNA+PBS group was extremely significantly increased （P<0.01） and the volume was significantly enlarged （P<0.05）; the weight of transplanted tumors in the oe-NC+hBD-1 and oe-circRNA+hBD-1 groups was extremely significantly decreased （P<0.01） and the volume was significantly reduced （P<0.05）. qRT-PCR detection showed that, compared with the oe-NC+PBS group, the expression level of HAS-CIRCpedia-5280 in the oe-NC+hBD-1 group was significantly down-regulated （P<0.05）; compared with the oe-circRNA+PBS group, the expression of HAS-CIRCpedia-5280 in the oe-circRNA+hBD-1 group was significantly down-regulated （P<0.05）. [Conclusion] The experimental results indicate that overexpression of HAS-CIRCpedia-5280 promotes the growth of colon cancer xenograft tumors. Further studies found that hBD-1 treatment can effectively down-regulate the expression of HAS-CIRCpedia-5280 and inhibit the growth of xenograft tumors. It is therefore speculated that hBD-1 inhibits the progression of colon cancer through HAS-CIRCpedia-5280.

[Objective] To investigate the regulatory effect of homeobox A10（HOXA10） transcription factor on the balance of osteogenic and adipogenic differentiation of sheep bone marrow mesenchymal stem cells （BMSCs） and its molecular mechanism. [Methods] The dynamic expression of HOXA10 mRNA in sheep BMSCs during osteogenic and adipogenic induction was detected by qRT-PCR. The HOXA10 knockdown vector was constructed, and the effects of HOXA10 knockdown on osteogenic and adipogenic differentiation phenotypes were evaluated by Alizarin Red S staining and Oil Red O staining. The effects of HOXA10 knockdown on the expression of osteogenic and adipogenic marker genes were detected by qRT-PCR and Western blot. Combined with JASPAR database analysis, AlphaFold 3 structure prediction and dual-luciferase reporter assays, the regulatory mechanism of HOXA10 on LPL and FABP4 promoters was explored. [Results] ①The relative expression of HOXA10 mRNA initially increased and then decreased in osteogenic induction, and continued to decrease from the second day in adipogenic induction. ②After HOXA10 knockdown, the expression of HOXA10 mRNA and HOXA10 protein were extremely significantly decreased （P<0.01）. ③In terms of osteogenic differentiation, HOXA10 knockdown extremely significantly reduced the mineralization level （P<0.01）, and the mRNA expression of osteogenic marker genes RUNX2 （P<0.01）, ALPL （P<0.05） and OPN （P<0.05） and the protein expression of RUNX2 and ALPL were extremely significantly down-regulated （P<0.01）. In terms of adipogenic differentiation, HOXA10 knockdown extremely significantly increased lipid accumulation （P<0.01）, and the mRNA expression of adipogenic marker genes PPARG （P<0.05）, LPL （P<0.01） and FABP4 （P<0.01） and the protein expression of LPL and FABP4 were extremely significantly up-regulated （P<0.01）. ④The JASPAR database predicted three and six potential HOXA10 binding sites in the LPL and FABP4 promoter regions, respectively. AlphaFold 3 modeling showed that HOXA10 homeodomain could form stable binding interfaces with LPL PB1 and FABP4 PB3. The dual-luciferase reporter assays confirmed that the LPL and FABP4 promoter activities were extremely significantly increased after HOXA10 knockdown （P<0.01）. [Conclusion] HOXA10 may regulate the balance of osteogenic and adipogenic differentiation of sheep BMSCs by inhibiting the transcriptional activity of LPL and FABP4 promoters. HOXA10 knockdown can inhibit osteogenesis and promote adipogenesis, which provides a theoretical basis for the study of mesenchymal stem cell-related disease mechanism, sheep biomedical application and sheep germplasm improvement.

[Objective] To validate the targeting relationship between bta-miR-19b and the B-cell CLL/lymphoma 3 （BCL3） gene and to elucidate the molecular function and regulatory mechanism by which bta-miR-19b mediates immune regulation in bovine colostrum. [Methods] The intersection of TargetScan and miRanda predictions was used to screen the immune-related target genes of bta-miR-19b, and the minimum free energy （MFE） of binding between bta-miR-19b and immune-related candidate genes IL7R, EGFR, TNF, BCL3, NME7, MAPK8 and MAP3K1 was predicted using the RNAhybrid website. The wild-type （WT） and mutant （MT） fragments were synthesized using the predicted binding site of the 3′UTR of the BCL3 gene as template to construct pmirGLO luciferase reporter vectors. The bta-miR-19b mimics （chemically synthesized double-stranded RNA molecules that mimic endogenous miRNA functions） and NC control （NC-mimics） were synthesized and co-transfected with the reporter vector into 293T cells for target validation. The biological processes and key pathways of bta-miR-19b-BCL3 axis in the immune regulation of bovine colostrum were screened by bioinformatics methods. [Results] The binding free energy of bta-miR-19b with BCL3 was the lowest, suggesting that there was a potential binding of BCL3. The results of dual luciferase reporter gene assay confirmed that bta-miR-19b could specifically bind to the 3′UTR region of the BCL3 gene. The bta-miR-19b-BCL3 regulatory axis was enriched in 42 GO terms, of which 24 were immune-related biological processes. The KEGG pathways involving the bta-miR-19b-BCL3 regulatory axis included tumor necrosis factor TNF signaling pathway and C-type lectin receptor signaling pathway. [Conclusion] bta-miR-19b can target the 3′UTR of BCL3. Given that BCL3 is a regulatory factor of the NF-κB signaling pathway, it is speculated that the bta-miR-19b-BCL3-NF-κB-TNF regulatory axis may be one of the core molecular mechanisms for bovine colostrum to exert immune function, and the specific mechanism needs to be validated by functional experiments.

[Objective] To investigate the effects of compound probiotics fermented feed on growth performance, rumen fermentation parameters and serum biochemical indices of beef cattle. [Methods] Sixty healthy Simmental crossbred beef cattle with body weight of （320±15） kg were selected and randomly divided into four groups with 15 cattle in each group. The control group （group Ⅰ） was fed a basal diet, and the experimental groups Ⅱ,Ⅲ and Ⅳ were fed the basal diet supplemented with 3%, 6% and 9% compound probiotics fermented feed, respectively. The pre-experimental period lasted 14 days and the formal experimental period lasted 60 days. During the experiment, the growth performance, rumen fermentation parameters and serum biochemical indices of beef cattle were measured, and the suitable supplementation ratio of compound probiotics fermented feed was explored. [Results] Regarding growth performance, compared with group Ⅰ （control group）, the average daily gain （ADG） of group Ⅱ （3%） and group Ⅳ（9%） increased slightly （P>0.05）, and the average daily gain of group Ⅲ（6%） increased significantly （P<0.05）. The feed-to-gain ratio （F/G） of group Ⅱ（3%）, group Ⅲ （6%） and group Ⅳ （9%） decreased by 5.14%, 12.39% and 7.76%, respectively. Among them, the F/G of group Ⅲ decreased significantly （P<0.05）, and there was no significant difference in the other two groups compared with the control group （P>0.05）. There was no significant difference in average daily feed intake （ADFI） among groups （P>0.05）. Regarding rumen fermentation parameters, the pH value of rumen fluid in each group was maintained at 6.35-6.48; compared with the control group, the ammonia nitrogen （NH₃-N） level in group Ⅲ significantly （P<0.05） decreased by 18.50%, the total volatile fatty acid （TVFA） level significantly （P<0.05） increased by 25.62%, and the acetic acid/propionic acid （A/P） value significantly （P<0.05） decreased by 27.56%. There was no significant difference in NH₃-N, TVFA, propionic acid （PA）, butyric acid （BA） content and acetic acid/propionic acid between group Ⅱ （3%） or group Ⅳ （9%） and the control group （P>0.05）. Regarding serum biochemical indices, compared with the control group, the serum total protein （TP） and albumin （ALB） contents in group Ⅲ significantly increased by 12.06% and 14.27%, respectively （P<0.05）, while the serum total protein （TP） and albumin （ALB） contents in groups Ⅱ （3%） and Ⅳ （9%） showed no significant differences compared with the control group （P>0.05）; the blood urea nitrogen （BUN） and total cholesterol （TC） contents in group Ⅲ significantly decreased by 19.69% and 16.01%, respectively （P<0.05）, while the BUN and TC contents in groups Ⅱ （3%） and Ⅳ （9%） showed no significant differences compared with the control group （P>0.05）; alanine aminotransferase （ALT） and aspartate aminotransferase （AST） activities showed no significant differences among groups （P>0.05）. [Conclusion] In summary, supplementing 6% compound probiotics fermented feed to the basic diet can effectively improve the growth performance of beef cattle, optimize the rumen fermentation environment, improve the protein metabolism level of the body, and have no adverse effect on liver function, representing a suitable supplementation ratio in beef cattle production.

[Objective] To screen superior strains with the ability to inhibit the growth of toxigenic Aspergillus flavus and degrade aflatoxin B1 （AFB₁） from lactic acid bacteria isolated from the digestive tract of dairy goats. [Methods] With 30 strains of lactic acid bacteria from digestive tract of dairy goats as materials, the inhibition rate of cell-free fermentation supernatant （CFS） on spore germination of A. flavus was determined using 96-well plate method, and the degradation rate of AFB₁ by CFS was detected using ELISA method. Superior strains were screened based on the combined results of inhibition rate and degradation rate. The CFS and the antifungal activities of culture broth of the screened strains were evaluated using the agar diffusion method and double-layer plate method, respectively. The composition and changes of organic acids in CFS were analyzed using LC-MS. The effect of culture broth on the morphology of A. flavus was observed by scanning electron microscope （SEM）, and the removal effect of active and inactivated CFS and bacterial culture broth on AFB₁ was compared. [Results] Two superior strains were obtained: Lactobacillus plantarum R3 and Pediococcus pentosaceus I3. The inhibition rates of CFS against A. flavus spores of R3 and I3 strains were higher than 84 %, and the degradation rates of AFB₁ were 81.42% and 81.96%, respectively. The results of agar diffusion method showed that the antifungal activity of CFS of I3 was slightly stronger than that of R3. However, the results of double-layer plate method showed that the antifungal activity of the culture broth of R3 strain was stronger than that of I3 strain. Organic acid analysis showed that lactic acid and pyruvic acid were the main components of CFS, and the pyruvic acid content in the toxin group treated with R3 CFS after interaction with AFB₁ significantly decreased （P<0.05） compared with the R3 control group; after interaction with AFB₁, the DL-3-phenyllactic acid content in the toxin group treated with I3 CFS significantly decreased （P<0.05） compared with the I3 control group. The results of SEM observation showed that the culture broth of both strains resulted in the morphological deformation of A. flavus mycelium and the decrease of spore production. The AFB₁ removal experiment showed that after boiling water inactivation, the total removal rates of R3 and I3 strains increased to 54.36% and 51.65%, respectively. After being inactivated by boiling water, the degradation rate of AFB₁ by CFS of the two strains decreased. The total removal effect of R3 strain on AFB₁ was slightly better than that of I3. [Conclusion] In this study, lactic acid bacteria strains R3 and I3 were isolated from the digestive tract of dairy goats. Both of them can inhibit the growth of A. flavus and remove AFB₁ by producing organic acids. Among them, L. plantarum R3 exhibits stronger antifungal effect and ability to remove AFB₁.

α-linolenic acid （ALA） is an n-3 polyunsaturated fatty acid （n-3 PUFAs） extracted from a variety of plants. As an essential fatty acid, ALA cannot be synthesized via endogenous metabolism in organisms and must be obtained from external diet or feed sources. It has been demonstrated to possess many important biological activities such as antioxidant and anti-inflammatory properties. In recent years, with the increasing emphasis on the concept of green and healthy livestock farming, ALA, as a natural and safe plant-derived feed additive, has attracted widespread attention from academia and industry in the field of livestock and poultry feed nutrition. This paper systematically reviews the chemical structural characteristics and basic physical and chemical properties of ALA, describes the main metabolic pathways and biotransformation mechanisms of ALA in animals in detail, discusses the key physiological functions and potential mechanisms of ALA in depth, comprehensively analyzes the specific regulatory effects and practical effects of ALA on various quality indicators of livestock and poultry products （including meat, eggs and milk）, and summarizes the research and application progress of ALA in different livestock and poultry production practices such as pigs, poultry and ruminants, aiming to provide a reference for the in-depth research and promotion and application of ALA in livestock and poultry production.

Under the dual background of the implementation of industrial policies on antibiotic reduction, restriction, and replacement, as well as the advancement of the global "dual carbon" strategy, rumen phages, as important regulatory factors of the rumen microbial ecosystem of ruminants, has become a research hotspot in ruminant microbiomics. Existing studies have shown that rumen phages have typical characteristics such as large population size, high community abundance, strong host specificity and unique genomic genetic diversity. They can regulate rumen fermentation metabolic efficiency, livestock and poultry production performance and rumen methane production, and demonstrate dual values of disease prevention and control and ecological emission reduction. At present, the research technologies of rumen phages has been upgraded from traditional pulsed-field gel electrophoresis and laser densitometry-based qualitative and quantitative detection to new technologies such as high-throughput metagenomic sequencing and single-cell sequencing, which have overcome the bottleneck of traditional technologies that cannot distinguish species. However, the existing technologies show a high dependence on the databases, and technical limitations such as difficulties in annotating novel viruses have not been completely resolved. This paper comprehensively reviews the latest research results in the field of rumen phage in ruminants from the four dimensions of rumen phage community structural characteristics, detection and analysis technologies, microbial regulatory mechanisms and community dynamic succession patterns. Diet composition and host physiological status are the core regulatory factors that determine the abundance and community composition of rumen phages. External dynamic conditions such as feeding cycles, seasonal changes, host growth stage and farming environment continuously drive the phage community to undergo phased replacement and succession. Prospects for subsequent key research directions of rumen phages are provided, aiming to offer theoretical support for the development of antibiotic-free and green farming technologies for ruminants and promote the low-carbon sustainable transformation of animal husbandry industry.

[Objective] To investigate the effects of dietary supplementation with different levels of red yeast rice powder on the growth performance, immune performance, and serum biochemical indices of yellow-feathered broilers, and to provide a reference for its rational application in broiler production. [Methods] A total of 240 one-day-old slow-growing yellow-feathered broilers were randomly divided into 4 groups, with 3 replicates per group and 20 birds per replicate. The control group was fed a basal diet, while the experimental groups were fed the basal diet supplemented with 2%, 4% and 6% red yeast rice powder （designated as the 2% group, 4% group and 6% group, respectively）. All experimental yellow-feathered broilers were vaccinated with Newcastle disease-infectious bronchitis-avian influenza （H9） triple inactivated vaccine at 10 days of age. The experimental period lasted 42 days. During the experiment, body weight and feed intake of the broilers were regularly measured, and average daily gain, average daily feed intake and feed-to-gain ratio at each stage were calculated. Serum samples were collected at 21 d and 42 d to determine Newcastle disease （ND） and avian influenza H9 subtype （AI H9） antibody titers as well as related serum biochemical indices. At 21 d and 42 d, three chickens were randomly selected from each group, weighed and sacrificed, and the liver, stomach, intestine, bursa of Fabricius, thymus and spleen were separated to calculate organ indices. [Results] From 1 to 21 d, there were no significant differences in growth performance indices among the groups （P>0.05）. From 22 to 42 d, the average daily gain of all experimental groups was lower than that of the control group, and only the 6% group showed a significant difference compared with the control group （P<0.05）; there were no significant differences in average daily gain between the 2% group or 4% group and all other groups （P>0.05）. The average daily feed intake of the 2% group and 6% group was significantly higher than that of the control group （P<0.05） and extremely significantly higher than that of the 4% group （P<0.01）, while the average daily feed intake of the 4% group was significantly lower than that of the control group （P<0.05）. The feed-to-gain ratio of all experimental groups was higher than that of the control group; the feed-to-gain ratio of the 6% group was significantly higher than that of the control group and the 4% group （P<0.05）, and there were no significant differences among the 2% group, control group and 4% group （P>0.05）. Throughout the entire experimental period （1-42 d）, there were no significant differences in average daily gain or feed-to-gain ratio between the experimental groups and the control group （P>0.05）; the average daily feed intake of the 4% group was significantly lower than that of the 2% group and 6% group （P<0.05）, and there were no significant differences among the control group, 2% group and 6% group （P>0.05）. At 21 d and 42 d, there were no significant differences in digestive organ indices or immune organ indices among the groups （P>0.05）; there were no significant differences in avian influenza H9 subtype antibody （AI H9 Ab） titers or Newcastle disease antibody （ND Ab） titers among the groups （P>0.05）. At 21 d, the serum total protein （TP） of the three experimental groups was extremely significantly higher than that of the control group （P<0.01）; the serum globulin （GLB） content of the 2% group and 4% group was extremely significantly higher than that of the control group （P<0.01）, and the GLB content of the 6% group was significantly higher than that of the control group （P<0.05）. The alanine aminotransferase （ALT） activity of all experimental groups was lower than that of the control group; the ALT activity of the 6% group was extremely significantly lower than that of the control group （P<0.01） and significantly lower than that of the 4% group （P<0.05）, while the ALT activity of the 2% group showed no significant difference with any group （P>0.05）. There was no significant difference in alkaline phosphatase （ALP） activity between any experimental group and the control group （P>0.05）, but the ALP activity of the 6% group was significantly lower than that of the 2% group and 4% group （P<0.05）. The total cholesterol （T-CHO） content of all experimental groups was lower than that of the control group, among which the T-CHO content of the 4% group was significantly lower than that of the control group （P<0.05）, and there were no significant differences in T-CHO content among the control group, 2% group and 6% group （P>0.05）. The low-density lipoprotein cholesterol （LDL-C） content of all experimental groups was lower than that of the control group; that of the 2% group was extremely significantly lower than that of the control group （P<0.01）, that of the 4% group was significantly lower than that of the control group （P<0.05）, and that of the 6% group showed no significant difference with any group （P>0.05）. At 42 d, the ALT activity of the 6% group was extremely significantly higher than that of the control group （P<0.01）, that of the 4% group was significantly higher than that of the control group （P<0.05）, and that of the 2% group also showed a certain increase compared with the control group （P>0.05）; there were no significant differences in ALT activity among the experimental groups （P>0.05）. The ALP activity of the 2% group was extremely significantly higher than that of the control group （P<0.01） and significantly higher than that of the 4% group （P<0.05）. There were no significant differences in malondialdehyde （MDA） content among the experimental groups （P>0.05）, and the MDA content of all three groups was extremely significantly lower than that of the control group （P<0.01）. The T-CHO content of the three experimental groups was lower than that of the control group, among which the T-CHO content of the 2% group was significantly lower than that of the control group （P<0.05）, that of the 4% group was extremely significantly lower than that of the control group （P<0.01）, and that of the 6% group showed no significant difference with any group （P>0.05）. [Conclusion] Dietary supplementation with 2%-6% red yeast rice powder shows no obvious promoting effect on the growth performance and immune performance of yellow-feathered broilers from 1 to 42 d. Long-term high-dose supplementation of red yeast rice powder has potential risks of inhibiting broiler growth and increasing hepatic metabolic pressure. Supplementation with 2% and 4% red yeast rice powder can reduce blood lipids and improve antioxidant capacity. Comprehensively considered, it is recommended that the addition level of red yeast rice powder in the diet of yellow-feathered broilers from 1 to 42 d should not exceed 2%; when utilizing its antioxidant and lipid-lowering functions, the addition dosage should be strictly controlled or a staged feeding strategy should be adopted, and liver function monitoring should be strengthened.

[Objective] To explore the single nucleotide polymorphisms （SNPs） in the promoter region and the first exon of the growth differentiation factor 9（GDF9） gene in Sonid ewes and its association with litter size traits, and to screen molecular markers related to high fecundity of Sonid ewes, aiming to provide data support for genetic improvement of reproductive traits of Sonid ewes, molecular marker-assisted breeding and improvement of large-scale breeding efficiency of mutton sheep. [Methods] A total of 95 healthy Sonid ewes were selected as experimental animals, including 48 single-lambing individuals and 47 twin-lambing individuals. Blood samples were collected and total DNA was extracted using a blood genomic DNA extraction kit. Specific PCR primers were designed according to the GDF9 gene sequence of sheep. The promoter region and the first exon region of GDF9 gene were amplified using PCR, and the genotyping was performed using Sanger sequencing. MegAlign and Chromas software were used for sequence assembly, alignment and genotype determination. The genotype frequency and allele frequency of each mutation site were counted, and the population genetic parameters （homozygosity Ho, heterozygosity He, effective number of alleles Ne, polymorphism information content PIC） were calculated. Chi-square test was used to analyze the Hardy-Weinberg equilibrium state of each locus, and the association between GDF9 gene polymorphisms and litter size traits of Sonid ewes was analyzed. [Results] Five SNP polymorphic loci were successfully detected in the GDF9 gene of Sonid ewes, including chr5: 41769149, chr5: 41768729, chr5: 41768538, chr5: 41768521 and chr5: 41768463, respectively. The results of population genetics analysis showed that the polymorphic information content （PIC） of chr5: 41769149, chr5: 41768538, chr5: 41768521 and chr5: 41768463 was less than 0.25, which were low polymorphic loci; the PIC value of chr5: 41768729 locus was between 0.25 and 0.5, which was a moderately polymorphic locus. Chi-square equilibrium test showed that the loci chr5: 41768521 and chr5: 41768729 significantly deviated from Hardy-Weinberg equilibrium （P<0.05）, while the remaining three loci were in equilibrium （P>0.05）. Trait association analysis showed that the dominant genotype of chr5: 41768521 was CC and the dominant allele was C, and the allele frequency of twin-lambing ewes （0.93） was significantly higher than that of single-lambing ewes （0.84）. The dominant genotype of chr5: 41768729 locus was AA and the dominant allele was A, and the allele frequency of twin-lambing ewes （0.84） was significantly higher than that of single-lambing ewes （0.73）. The polymorphisms of the above two loci were significantly associated with litter size traits of Sonid ewes and the remaining three loci were not significantly associated with litter size traits. [Conclusion] The polymorphisms of chr5: 41768521 and chr5: 41768729 loci of GDF9 gene in Sonid ewes are significantly associated with litter size traits, which can be used as effective molecular markers for the breeding of high fecundity traits in Sonid ewes. The results enrich the molecular genetic research of sheep reproductive traits, and provide a reference for the improvement of reproductive performance of Sonid ewes, the construction of molecular breeding system and the high-quality development of mutton sheep industry.

[Objective] To explore the effects of different transplanting methods on the establishment survival rate of Puccinellia distans in saline-alkali patches and the improvement of soil physicochemical properties. [Methods] In June 2024, the saline-alkali patches of Hulun Buir grassland was taken as the research object. After completing the seedling raising of P. distans using seedling pots, soil was improved through the combined application of organic fertilizer, deep plowing and harrowing and amino acid water-soluble fertilizer （on June 28, 2024, organic fertilizer was applied at 3 kg/m² to Treatment Ⅰ, Ⅱ, Ⅲ, CK1 and CK2, followed by uniform deep plowing to 30 cm and harrowing. CK3 received only deep plowing to 30 cm and harrowing without organic fertilizer application. On July 5, 2024, amino acid water-soluble fertilizer was applied via drip irrigation at 0.02 L/m² to Treatment Ⅰ, Ⅱ, Ⅲ, and CK1, while CK2 and CK3 received no water or fertilizer applications）. Three transplanting methods of P. distans were set up[Treatment Ⅰ：hole depth of 10 cm, with a distance of 1 cm below the ground level after soil covering （the soil level was lower than the ground level, the same below）; Treatment Ⅱ：hole depth of 15 cm, with a distance of 3 cm below the ground level after soil covering; Treatment Ⅲ：hole depth of 20 cm, with a distance of 5 cm below the ground level after soil covering] and the control （CK1, CK2, CK3）. Through field experiments, the effects of different transplanting hole depths and soil covering distances on the survival rate of P. distans and the soil physicochemical properties were compared and analyzed. [Results] ① In terms of survival rate of P. distans：the survival rate of P. distans in Treatment Ⅱ（96.66%） was significantly （P<0.05） higher than that in Treatment Ⅰ （71.33%） and Treatment Ⅲ （86.00%）. ② In terms of soil physicochemical properties：compared with the three controls, the three transplanting methods significantly （P<0.05） reduced the pH value, electrical conductivity, contents of exchangeable potassium, exchangeable sodium and available phosphorus of saline-alkali patch soil, and Treatment Ⅱ and Treatment Ⅲ significantly （P<0.05） increased soil organic matter, alkali-hydrolyzable nitrogen and available potassium content. The soil pH value and exchangeable sodium content of Treatment Ⅱ were significantly （P<0.05） lower than those of Treatment Ⅰ and Treatment Ⅲ, and the organic matter content of Treatment Ⅱ was significantly （P<0.05） higher than that of Treatment Ⅰ and Treatment Ⅲ. [Conclusion] In the saline-alkali patches, the transplanting method with the transplanting hole depth of 15 cm and a distance of 3 cm below the ground level after soil covering （Treatment Ⅱ） has the best effects on the survival rate of P. distans and the improvement of soil physicochemical properties. The optimized transplanting technology can effectively promote the rapid recovery of saline-alkali patch vegetation, enhance grassland productivity, improve the grassland ecological environment, and provide a feasible technical approach for ecological restoration of saline-alkali land.

The goose is one of the earliest domesticated poultry species, which possess multiple values such as meat, egg and down production. China is one of the core producing countries of the global goose industry. In recent years, driven by multiple factors such as technological innovation, policy support, and consumption upgrading, the goose industry has continued to expand and develop in China. To promote the development of the goose industry, this paper systematically reviews the development status of goose industry based on literature survey, market investigations, and industry practices. The study found that the industry has formed a regional development trend of "retreating in the east and advancing in the west, moving north and expanding south", and Yangzhou Goose, Tianfu Meat Goose, Jiangnan White Goose and other new varieties （supporting lines） have successively passed official evaluation, effectively meeting the market demand; the farming models continue to develop toward scale and intensification; the construction of disease prevention and control systems has been gradually improved; the consumption patterns continue to innovate. However, China′s goose industry still faces many challenges: genetic resource degradation is serious, and breeding progress lags behind the needs of industrial development; the price of main feed raw materials continues to rise, resulting in rising farming costs; goose viral diseases and bacterial diseases are concurrent and prevalent, and the problem of antibiotic residues is prominent; low-price competition is common, and product homogenization is severe; and the pressure of environmental protection compliance and rectification of small and medium-sized farming entities is great. In response, the paper proposes development countermeasures such as accelerating the breeding of new varieties, strengthening the protection of genetic resources, broadening the sources of feed raw materials, accelerating the intelligent upgrading of farming models, deepening the integrated development of the whole chain, and improving the utilization system of manure resources, aiming to promote the transformation of the industry from scale expansion to high-quality development and contribute to rural revitalization.

Astragalus membranaceus is a perennial herb belonging to the genus Astragalus of the Fabaceae family. It is mainly produced in Inner Mongolia, Gansu, Xinjiang, Shanxi, Shaanxi, Heilongjiang and other regions in China. A. membranaceus has functions such as consolidating the exterior to arrest sweating, tonifying qi and raising yang, as well as promoting diuresis to alleviate edema. As a natural plant with dual medicinal and edible values, it is widely applied in clinical traditional Chinese medicine and health care. In recent years, it has attracted extensive attention from the farming industry due to the multiple functions of its active ingredients in animal health care and nutritional regulation. A. membranaceus is rich in bioactive substances including polysaccharides, flavonoids and triterpenoid saponins, and exhibits various physiological functions such as anti inflammation, antioxidant, anti stress and immunomodulation. By systematically discusses the research progress on the application of A. membranaceus in ruminant production, this paper reviews relevant studies on its abundant active substances and biological functions, as well as recent research regarding growth performance and feed efficiency, immunoregulation and disease resistant effects, antioxidant and anti stress capacity, gastrointestinal microenvironment regulation and livestock product quality improvement in ruminants. Combining the industrial background of antibiotic restriction, antibiotic substitution and healthy farming in the current farming industry, this paper further analyzes the application prospects and limiting factors of A.membranaceus as a natural plant additive, aiming to provide references for the research and application of A.membranaceus in ruminant farming.

Unconventional feedstuffs are an important supplement to ruminant diets. With the rapid expansion of the scale of the cattle and sheep industries, the supply of conventional feedstuff raw materials is difficult to meet the demand. China is rich in unconventional feedstuffs resources. Using unconventional feedstuffs to replace conventional feedstuff can not only alleviate the pressure of insufficient feedstuff supply in China, but also reduce feedstuff costs and bring higher economic benefits to farmers. This paper classifies and outlines the application status of four categories of unconventional feedstuffs, including miscellaneous oilseed meals, woody plants, wild herbaceous plants, and agricultural by-product residues, summarizes the common shortcomings of such raw materials, such as high contents of anti-nutritional factors and poor palatability, and puts forward key technical points for the efficient utilization of unconventional feedstuffs from aspects such as raw material screening and addition ratio control, removal of anti-nutritional factors, improvement of diet palatability, and scientific combination of feedstuff additives, aiming to broaden the sources of ruminant feedstuff, balance the supply of feedstuff, and provide references for healthy and green farming of cattle and sheep.

[Objective] To analyze the bioinformatics characteristics of the IutA protein from Klebsiella pneumoniae of ovine origin, providing a theoretical basis for its research as a candidate subunit vaccine protein. [Methods] Bioinformatics software was utilized to predict the physicochemical properties and structural characteristics of the IutA protein. Using the genomic DNA of K. pneumoniae as a template, the IutA gene was amplified via PCR. The recombinant expression plasmid pET-32a-IutA was constructed. Positive recombinant vectors were identified by double-enzyme digestion electrophoresis and gene sequencing. The verified plasmid was transformed into Escherichia coli BL21 （DE3） to induce recombinant protein expression. SDS-PAGE and Western blot were employed to detect protein expression. [Results] Bioinformatics prediction results indicated that the IutA protein consists of 731 amino acids, with a relative molecular mass of approximately 80.72 kDa and a theoretical isoelectric point of 4.80, classifying it as a stable hydrophilic protein. The protein contains one signal peptide and 22 transmembrane β-barrel domain. The amino acids at positions 44-731 belong to the conserved domain of the TONB-dependent siderophore receptor. The protein possesses 28 B-cell epitopes. Enzymatic digestion and sequencing confirmed the correct construction of the recombinant plasmid. SDS-PAGE and Western blot analyses revealed a specific target protein band of approximately 91 kDa, with the expression products predominantly present in inclusion bodies. [Conclusion] The physicochemical properties and structural characteristics of the IutA protein were obtained through bioinformatics prediction. The recombinant plasmid pET-32a-IutA was successfully constructed, and IutA protein expression was achieved in E. coli BL21 （DE3）, with the expression products existing mainly in the form of inclusion bodies. This study provides a foundation for subsequent evaluation of the immunogenicity of the IutA protein and the development of its subunit vaccine.

[Objective] To understand the species composition, drug resistance and pathogenicity to mice of yeast-like fungi isolated from pigeons. [Methods] Yeast-like fungi were isolated and purified from the crop samples of meat pigeons. The isolated strains were identified to the genus and species levels by colony morphology observation and ITS sequence analysis, and the drug resistance and pathogenicity of the isolated strains were analyzed. [Results] A total of 28 yeast-like fungi were isolated from 30 samples, belonging to 7 genera and 7 species, including 14 strains of Candida albicans （Candida）, 4 strains of Saccharomyces cerevisiae （Saccharomyces）, 3 strains of Trichosporon asahii （Trichosporon）, 3 strains of Diutina catenulata （Diutina）, 2 strains of Cutaneotrichosporon cutaneum （Cutaneotrichosporon）, 1 strain of Debaryomyces hansenii （Debaryomyces）, and 1 strain of Wickerhamomyces anomalus （Wickerhamomyces）. All the 7 yeast-like fungi were susceptible to nystatin and clotrimazole, but resistant to other antifungal drugs to varying degrees. C. albicans showed strong pathogenicity to mice, T. asahii exhibited moderate pathogenicity to mice, and the remaining yeast-like fungi displayed opportunistic pathogenicity to mice. [Conclusion] C. albicans is the predominant yeast-like fungal species isolated from pigeons, which exhibits strong pathogenicity, posing a considerable potential threat to the meat pigeon industry. Therefore, prevention and control measures against C. albicans should be strengthened in pigeon farms.

Mycoplasma is an important zoonotic pathogen. As a cell-wall-free prokaryote, its genome is highly streamlined and is an ideal model for synthetic biology and genome minimization research. Gene editing is a core tool for analyzing the biological characteristics of mycoplasma. This paper systematically summarizes three major categories of mainstream operational technologies: Tn transposons, homologous recombination and CRISPR/Cas systems, and explains the principles of action, technical characteristics and optimization and improvement strategies of each technology;Among them, the CRISPR/Cas systems is subdivided into CRISPR/Cas9, CRISPR interference （CRISPRi）, base editing, SURE editing and other derivative tools. Different editing techniques have their respective applicable scenarios, and have been widely used in mycoplasma gene functional verification and pathogenic mechanism analysis, development of attenuated vaccines, rapid detection of pathogens, and construction of synthetic biology chassis cells and other applications: Tn transposons and CRISPR/Cas9 are suitable for pathogenic mechanism mining and vaccine development, while CRISPR-derived diagnostic techniques have unique advantages in rapid detection of pathogens. In summary, after integration and improvement, different types of gene editing tools have become the core technology system for basic research and application development of mycoplasma, which can provide key support for the prevention and control of mycoplasma diseases and the innovation of biological technology.