To assess the potential risk of toxicity in fish in the process of applying Buddleja officinalis Maxim. extract, zebrafish (Danio rerio) was selected as the model organism for developmental toxicity assessment. The nonlethal concentration (MNLC) of Buddleja officinalis extract for zebrafish was 21 & micro;g/mL, and the lethal concentration (LC10) was 34 & micro;g/mL. The extract showed no significant outcome on the zebra fish hatching rate at tested levels (2.3, 7, 21 and 34 & micro;g/mL) (P>0.05). The incidence of delayed yolk sac absorption increased in a dose-dependent manner (16.7% in control vs. 30.0%, 36.7%, 66.7% and 66.7% in treatment groups, respectively) (P<0.05). No obvious abnormalities were found in other organs or tissues. The Buddleja officinalis extract significantly increased the activity of CYP3A4 in zebrafish cytochrome P450 (CYP) at 21 mu g/mL and 34 mu g/mL, whereas 34 & micro;g/mL significantly increased the activity of CYP2D6. The extract had no significant effect on the activity of Caspase-3/7 in zebrafish at the experimental concentrations. The same situation was found regarding the morphology of zebrafish liver cells. The extract increased the ratio of Bcl-2/Bax at concentrations of 21 & micro;g/mL and 34 & micro;g/mL and inhibited apoptosis at concentrations of 21 & micro;g/mL and 34 & micro;g/mL. This study revealed that the extract has no obvious toxicity for the development of zebrafish and does not cause obvious damage to zebrafish liver tissue, which provides a possibility for further research and development of Buddleja officinalis extract to alleviate stress in fish.

Respiratory viruses, including the influenza virus (IAV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), pose significant health threats. As tissue-resident macrophages, alveolar macrophages (AM) are crucial for defending against respiratory viral infection by producing cytokines, engulfing virus-infected cells, and promoting wound healing. However, excessive inflammatory responses can lead to tissue injury. Growing evidence indicates that astragaloside IV (AST IV) regulates innate immune responses. Specifically, AST IV balances the inflammatory response to mitigate tissue damage and promote tissue repair. However, whether AST IV directly targets AM to alleviate lung damage induced by respiratory viral infection remains unclear. Our results demonstrate that AST IV treatment significantly reduces morbidity and mortality in mice during IAV infection. AST IV markedly decreases proinflammatory cytokine levels, mitigates lung injury and promotes lung recovery through enhancing the repair capacity mediated by alveolar type II cells. Mechanistically, AST IV suppresses the Wnt/β-catenin signalling pathway, which is critical for driving inflammatory responses in AM while maintaining mitochondrial fitness. Thus, our findings suggest that AST IV effectively targets AM to alleviate inflammation and lung damage caused by respiratory viral infections, highlighting its potential as a therapeutic agent for managing viral pneumonia.

Diarrhea is a serious health concern in livestock, affecting productivity and animal welfare. However, it remains a significant threat. Various practical therapies are being explored, such as prebiotics, probiotics, and organic acids, as well as chemical treatments including antibiotics, to combat this disorder. This study aims to explore the microbiome and metabolomic changes in rabbits with diarrhea. In the present study, diarrhea was induced in rabbits via oral gavage of Folium Sennae (FSAE), to assess body weights, diarrhea index, serum biochemical indicators, histopathology, microbiota, and metabolomics changes. Our study provides new insights into the mechanism of FSAE-induced diarrhea in rabbits and offers a novel mechanism for the interaction between gut microbiota, metabolomics, and gastrointestinal (GIT) dysfunction. Our results revealed that rabbits receiving FSAE showed a markedly higher diarrhea index and reduced body weight. Notably, levels of somatostatin, substance P, cholecystokinin, 5-hydroxytryptamine, vasoactive intestinal peptide, and acetylcholinesterase were significantly increased compared to control (P < 0.01). However, the levels of gastrin, motilin, enkephalin, and β-Endorphins were significantly decreased (P < 0.01). Microbial analysis revealed a significant reduction in microbial diversity (Shannon, Simpson, ACE, and chao1) and a decrease in Firmicutes, Campilobacterota, and Proteobacteria populations in FSAE-exposed rabbits. Additionally, 13 key metabolites associated with taurine and hypotaurine metabolism, alanine, aspartate and glutamate metabolism, starch and sucrose metabolism, histidine metabolism, and citrate cycle were identified in the colonic tissues. The present study concludes that FSAE-induced diarrhea in rabbits is associated with significant histopathological alterations in the colon, dysregulation of serum biochemical markers, and dysbiosis in metabolomics and gut microbiota. Our findings offer a novel model for investigating GIT dysfunction and its potential treatments.

This study explored the effects of high-density rearing of pregnant ewes on the intestinal microbiota of their offspring. A total of 40 small-tailed Han sheep were distributed into two groups randomly including the high-density group (1 sheep/m(2)) and the control/ low-density group (1 sheep/2m2). Fecal samples from ewes and offspring were collected for high-throughput sequencing and multiple-significance analysis. We uncovered the response of gut microbiota in ewes and offspring to different rearing densities. The number of potentially harmful bacteria (Ralstonia pickettii, Ruegeria, Rhodobacteraceae, etc.) was increased in high-density groups, while the abundance of several probiotics (Oscillibacter, Akkermansia, Ruminococcaceae-UCG-010, etc.) was found significantly lesser than that of the control group (P<0.05). In addition, gut microbiota in the high-density groups exhibited more variability with age, indicating that an increase in the housing density has a significant correlation. Taken together, improper increase in the rearing density of pregnant sheep can harm themselves and their offspring, which not only fails to improve economic benefits but also produces harmful effects. This study may provide new ideas for healthy and sustainable sheep reproduction and farming.

Protocatechuic acid (PCA), a major active component found in Eucommia ulmoides Oliver, is involved in regulating oxidative stress and inflammation. Heat stress poses a significant threat to the poultry industry. In this study, we investigated the protective effect of PCA on intestinal homeostasis under heat stress. Our results indicated that PCA improved the growth performance of broilers during heat stress. Furthermore, PCA mitigated jejunal damage and attenuated the upregulation of inflammatory mediators, including TNF-α, IL-6, and IL-1β, triggered by heat stress. Concurrently, it restored the activity of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC). Furthermore, PCA maintained the jejunum function by increasing the levels of ZO-1, Claudin-1, and Occludin. Mechanistically, PCA inhibited the activation of TLR4/p38 MAPK and NF-κB pathways, thereby regulating the imbalance in oxidative stress and inflammatory responses caused by heat stress.

The coinfection of ALVs (ALV-J plus ALV-A or/and ALV-B) has played an important role in the incidence of tumors recently found in China in local breeds of yellow chickens. The study aims to obtain a better knowledge of the function and relevance of ALV coinfection in the clinical disease of avian leukosis, as well as its unique effect on the pathogenicity in Three-yellow chickens. One-day-old Three-yellow chicks (one day old) were infected with ALV-A, ALV-B, and ALV-J mono-infections, as well as ALV-A + J, ALV-B + J, and ALV-A + B + J coinfections, via intraperitoneal injection, and the chicks were then grown in isolators until they were 15 weeks old. The parameters, including the suppression of body weight gain, immune organ weight, viremia, histopathological changes and tumor incidence, were observed and compared with those of the uninfected control birds. The results demonstrated that coinfection with ALVs could induce more serious suppression of body weight gain (P < 0.05), damage to immune organs (P < 0.05) and higher tumor incidences than monoinfection, with triple infection producing the highest pathogenicity. The emergence of visible tumors and viremia occurred faster in the coinfected birds than in the monoinfected birds. These findings demonstrated that ALV coinfection resulted in considerably severe pathogenic and immunosuppressive consequences.

Lycium barbarums are traditionally used as a homology of medicinal plants in China with a potent role in metabolism and immunomodulation. The current study was performed to explore the attenuation effect and microbiota regulation of Lycium barbarum polysaccharide (BLBP) on lipopolysaccharide (LPS)-induced intestine damage in mice. A total of 70 mice were randomly divided into five groups; negative control (GA), LPS (GB), both treated with an equal volume of normal saline, and BLBP treatment groups GC (100 mg/kg), GD (200 mg/kg), and GE (400 mg/kg) via gavage for 19 days. On Day 19, mice in groups GB, GC, GD, and GE were treated with 10 mg/kg LPS for 24 h and euthanized to collect intestine samples for pathological examination and microbiota sequencing. The results showed a non-significant difference in body weight gain among the five mouse groups; however, mice in the GC and GE groups showed decreased weight gain. An H&E examination revealed that the integrity of intestinal villi was destroyed by LPS, while BLBP supplement alleviated intestinal damage with an increase in villus height and a decrease in crypt depth. A total of over 59,000, 40,000, 50,000, 45,000, and 55,000 raw sequences were found in groups GA, GB, GC, GD, and GE, respectively. LPS challenge decreased alpha diversity indexes significantly ( p < 0.05), while a non-significant difference was found between different BLBP treatment groups and the GA group. A total of 8 phyla and 13 genera were found among five mouse groups, and BLBP partly restored the bacterial abundance in mice. LPS changed 282 metabolic pathways in KEGG L2, 77 metabolic pathways in KEGG L3, and 205 metabolic pathways in MetaCyc, respectively. The BLBP-supplemented groups, especially GE, showed reverse effects on those metabolic pathways. The current study revealed that BLBP can effectively decrease intestinal damage through the regulation of intestinal microbiota, which may provide new insights for the prevention of intestinal disease using food and medicine homologous of Lycium ruthenicum .

Staphylococcus aureus is a critical pathogen causing serious mastitis with huge economic losses in bovines. To reveal drug-resistant genes, a complete genome sequence of a multi-drug-resistant bacterium S. aureus derived from bovine mastitic milk was performed via High-throughput sequencing. Results revealed that the genome length of current S. aureus was 2.85 Mbp consisting of 2656 coding sequence genes, 60 tRNA, 19 rRNA, and 5 genomic islands. Functional annotation of S. aureus encoded proteins showed that 2090 (COG), 1586 (KEGG), 1600 (GO), 2648 (Refseq), 2300 (Pfam), 964 (SwissProt), and 1826 (TIGRFAMs) proteins were annotated. Antibiotic-resistant genes of tet, mepR, mepA, mgrA, norA, blaZ, arlS, arlR and LmrS in S. aureus genome were found via CARD annotation. More than 60 bacterial virulence factors including commonly known clfA, hla, hlb, fnbB, fnbA in S. aureus genome were uncovered through VFDB annotation. The current study may contribute towards effective treatment and developing new antibiotics against mastitis caused by S. aureus.

Haemonchus contortus is an important parasite that causes disease that seriously endangers ruminant animals cattle, sheep, goat, and camel. Here, we compared the proeomics analysis of three adult Haemonchus contortus isolates from mouflons (Ovis ammon). A total of 1,299 adult worm proteins were identified, and 461 proteins were quantified, of which 82 (108), 83 (97), and 97 (86) significantly upregulated (downregulated) differentially expressed proteins (DEPs) were detected among pairwise comparisons (1-vs.-3, 2-vs.-3, and 2-vs.-1). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and bioinformatic analysis indicated that these DEPs are mainly concentrated in cellular composition, molecular function, biological function, and catabolism pathways. In addition, Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were carried out to screen the DEPs. The main biological processes involved were nucleotide, nucleotide phosphate, ribonucleotide, purine-containing compound, purine ribonucleotide, single-organism, oxoacid, organic, carboxylic, oxoacid metabolic processes and single-organism catabolic processes. The majority of KEGG pathways were found to be related to metabolic pathways, biosynthesis of secondary metabolites, biosynthesis of antibiotics, carbon metabolism, and microbial metabolism in diverse environments. Moreover, we also found differences in the expression of some important or novel regulatory proteases, such as serine hydroxymethyl transferase (SHMT), dihydrolipoyl dehydrogenase (DLD), and transket pyr domain-containing protein (TKPD). In summary, label-free proteomic analysis of adult H. contortus worms displayed significant differences in three different individual isolates, which helps to improve our understanding of the growth and metabolic mechanisms of H. contortus in different individuals and relative natural environments and provides novel drug targets for the treatment of parasitic diseases.

BACKGROUND:Yak (Bos grunniens) mainly inhabiting Tibet Plateau, displayed a high incidence of diarrhea due to harsh living environment and nutritional deficit. Gut microbial community has been reported to be closely related to many diseases including diabetes, obesity and inflammatory bowel disease, but information regarding diarrheic influence on gut microbiota in yaks remains scarce. Here, this study was performed to investigate the gut bacterial and fungal alternations of diarrheic yaks.RESULTS:Results revealed that the gut bacterial and fungal communities of diarrheic yaks showed a distinct decline in alpha diversity, accompanied by significant shifts in taxonomic compositions. Specifically, diarrhea caused a distinct increase in the relative abundance of 1 phylum and 8 genera as well as a distinct decrease in 3 phyla and 30 genera. Fungal taxonomic analysis indicated that the relative richness of 1 phylum and 2 genera dramatically increased, whereas the relative richness of 2 phylum and 43 genera significantly decreased during diarrhea. Surprisingly, 2 bacterial genera and 5 fungal genera even cannot be detected in the gut microbiota of diarrheic yaks.CONCLUSIONS:In summary, this study indicated that the gut bacterial and fungal compositions and diversities of yaks altered significantly during diarrhea. Moreover, these findings also contribute to understanding the gut microbial composition and diversity of yaks and developing strategies to alleviate and prevent diarrhea from gut microbial perspective.

Staphylococcus aureus is a leading source of foodborne poisoning in the human population also critically severe mastitis in livestock. A total of 671 serum samples were collected and tested through ELISA assays. The results revealed that the total prevalence of S. aureus infection in dairy cattle was 29.1% (95% CI: 25.6-32.7). In different farms, the prevalence ranged from 13.9% (95% CI: 8.8-20.5) to 36.6% (30.4-43.2). Similarly, the mean sero-prevalence was 17.0% (13.1-21.4) and 41.6% (36.3-47.2) in male and female animals, respectively. However, at different ages, the mean prevalence of Staphylococcus aureus was found to be 14.3% (7.4-24.1) to 38.5% (30.8-46.6). Although in different years, the sero-prevalence was 27.5% (22.2-33.4) in 2019, 19.6% (13.7-26.7) in 2020 and 36.5% (30.6-42.7) in 2021. According to conditional stepwise logistic regression analysis, different farms, gender, age and year were observed as the critical risk factors affecting the prevalence. Our results may contribute to development of prevention and control strategies against this zoonotic pathogen in farm animals in this region.

为分析早期断奶对沂蒙黑山羊羔羊生长性能、盲肠短链脂肪酸含量和菌群多样性影响,选用0d沂蒙黑山羊羔羊36只,分为2组,对照组和试验组,每组18只羔羊.母乳组(B组)羔羊哺喂母乳,代乳粉组(R组)于8 d起断奶,10 d完全哺喂代乳粉,15 d开始两组均饲喂开食料.在8、10、15、25、45和75 d时每组随机屠宰3头羊并收集盲肠内容物,采用GC-MS检测方法分析短链脂肪酸含量以及高通量测序技术分析菌群多样性.结果表明:1)15 d时R组羔羊体重极显著低于B组(P＜0.01),而75 d时显著高于B组(P＜0.05),并且R组11～15 d间日增重极显著低于B组(P＜0.01),且在25 d之后日增重均显著高于B组(P＜0.05).2)R组25 d时乙酸、丙酸、丁酸、戊酸和异戊酸含量显著高于15 d时(P＜0.05),而 B组45 d时各类短链脂肪酸含量均显著高于25 d时(P＜0.05).3)R 组 15 d 时 Sobs、Ace,Chao 1 和25 d 时 Shannon 及 Simpson 均显著低于 B 组(P＜0.05).在门水平上,R组Firmicutes门相对丰度在25 d时低于B组差异显著(P＜0.05);Proteobacteria门相对丰度在10和45 d时极显著高于B组(P＜0.01);Bacteroidetes门相对丰度在75 d时差异显著低于B组(P＜0.05).在属水平上,Butyri-cicoccus属相对丰度10d开始两组均显著减少(P＜0.05),25d时极显著下降(P＜0.01);R组Lactobacillus属相对丰度在 15 d 时差异显著低于 B 组(P＜0.05),25 d 时厚壁菌门中 PeptoclostridiumClostridium_sensu_stricto_1,Romboutsia、Intestinibacter、Terrisporobacter 和 Lachnos piraceae_NK3A20 group 属类与日增重、短链脂肪酸生成密切相关.综上,早期断奶能够降低沂蒙黑山羊羔羊日增重和盲肠菌群多样性,而断奶后15 d时可加快羔羊盲肠内容物中短链脂肪酸的生成,并且断奶35 d后促进杆菌属和瘤胃球菌属等有益菌定植,改善羔羊营养物质代谢.

Mastitis is an economically important disease in the dairy industry, which is caused by various infectious pathogens. There is limited information known about the situation of drug resistance and virulence factors of Staphylococcus aureus (S. aureus) in mastitis bovine milk in Anhui. Therefore, a total of 125 fresh milk samples from clinically mastitis-positive bovine animals were collected. The bacteria pathogens were identified via bacterial culture, Gram staining, biochemical analysis, DNA extraction, 16s rRNA amplification, and phylogenetic analysis. Drug resistance analyses were performed through drug-resistant genes and virulence genes amplification. Results showed that a total of 24.8% (31/125) bacterial isolates were isolated and identified as S. aureus by Gram straining, biochemical reactions, and 16 s rRNA genes blasting. Multiple sequence alignment analysis found that the current isolates were highly similar (96.9–100.0%) to previous isolates. Phylogenetic analysis demonstrated that S. aureus was similar with MK809241.1 isolated from food in China and wCP030426.1 isolated from a person in the United States. The bacterial isolates were detected resistant to 11 antibiotics, such as Penicillin G, SXT, Ciprofloxacin, Norfloxacin, Polymyxin B, Levofloxacin, Chloramphenicol, Clindamycin, Clarithromycin, Erythromycin, and Spectinomycin. Drug-resistant genes of blaZ, ermC, rpoB, and ant (4')-la were successfully amplified. Virulence genes of hla, nuc, clfa, and eta were found in S. aureus bacteria. The current study isolated S. aureus from milk samples and revealed its drug-resistant situation, drug-resistant genes, and virulence genes. Hence, regular monitoring of S. aureus in milk samples from dairy cows may contribute to the prevention and treatment of public health concerns causing bacteria in this region.

为了解山东沂蒙草鸡禽白血病病毒(ALV)感染情况,本试验从2个沂蒙草鸡规模化养殖场采集血浆样品184份,经DF-1细胞分离后利用ELISA试剂盒检测ALV-p27抗原.结果 显示,有5份样品为ALV阳性(阳性率2.71％).经分型引物鉴定,4份样品为A亚群禽白血病病毒,1份样品为J亚群禽白血病病毒.对J亚群禽白血病病毒(命名为SDLYU1901)进行了全基因序列测定及分析,结果发现,J亚群病毒全基因组序列与江苏蛋鸡分离株JS09GY3相似性最高,为96.4％.分离株gag 、pol基因较为保守,而env基因和3'UTR基因变异程度较大.其中gp85基因与ALV-J参考株核苷酸相似性为89.7％～95.8％.3'UTR在rTM区以及DR1区域共出现205 bp的缺失.U3区序列分析结果显示,其与ALV-J原型株HPRS-103相似性最高,相似性为97.3％.试验结果表明沂蒙草鸡存在ALV感染,同时可为分析沂蒙草鸡ALV-J毒株分子特征及变异趋势提供数据支持.

Background Colonization of intestinal microbiota in ruminant during the early life is important to host health, metabolism and immunity. Accumulating evidence revealed the ameliorative effect of milk replacer administration in the gut microbial development of early-weaned ruminants. Yimeng black goats (YBGs) inhabiting Shandong, China show a complex intestinal microbial ecosystem, but studies of their gut microbiota are still insufficient to report. Here, this study was performed to investigate how the gut microbiota develops in weaned YBGs with the effect of age and milk replacer. Results Results indicated that both age and milk replacer were important factors to change the gut microbiota of YBGs. Although the alpha diversity of gut microbiota did not change with the age of YBGs, the taxonomic compositions significantly changed. The relative abundance of some beneficial bacteria such as Lachnospiraceae , Ruminococcaceae , Ruminiclostridium , Eubacterium and Barnesiella significantly decreased and subsequently increase with age, which contributes to maintain the stability of intestinal environment and realize the diversity of intestinal functions. The relative abundance of Porphyromonas , Brevundimonas , Flavobacterium , Stenotrophomonas , Propionibacterium , Acinetobacter , Enterococcus and Clostridium belong to pathogenic bacteria in milk replacer-treated YBGs was significantly decreased. Additionally, some beneficial bacteria such as Ruminococcus , Ruminococcaceae , Christensenellaceae and Ruminiclostridium also display a trend of decreasing first followed by gradually increasing. Conclusions This study first revealed the gut bacterial community alterations in YBGs with the effect of age and milk replacer. This study also characterized the gut microbial distribution in YBGs with different ages and provided better insight into microbial population structure and diversity of YBGs. Moreover, milk replacer may serve as a good applicant for improving gut microbial development in early-weaned YBGs.

Hexavalent chromium [Cr (VI)] is a hazardous heavy metal that pollutes soil, water and crops. Moreover, its prolonged exposure can harm the gastrointestinal system, liver and respiratory tract in different species, but knowledge regarding Cr (VI) influence on gut microbiota in chickens remains scarce. Therefore, this study was performed to investigate the impact of Cr (VI) on gut microbiota in chickens. Results revealed that the gut microbiota in Cr (VI)-induced chickens exhibited a distinct reduction in alpha diversity, accompanied by significant shifts in microbial composition. Specifically, Firmicutes and Bacteroidetes were the most dominant phyla in the control chickens, whereas Firmicutes and Actinobacteria were observed to be predominant in the Cr (VI) induced populations. Moreover, the types and relative abundances of predominant bacterial genus in control and Cr (VI)-induced chickens were also different. Bacterial taxonomic analysis revealed that the relative abundances of 3 phyla and 7 genera obviously increased, whereas 8 phyla and 30 genera dramatically decreased during Cr (VI) induction. Among them, 1 phylum (Deferribacteres) and 5 genera (Butyricicoccus, Butyricimonas, Intestinimonas, Lachnospiraceae_FCS020_group and Ruminococcaceae_V9D2013_group) even could not be found in the gut microbial community of Cr (VI)-induced chickens. Taken together, our study indicated that the long-term exposure to Cr (VI) dramatically alter the gut microbial diversity and composition in chickens. Notably, it represents a breakthrough in understanding the impact of Cr (VI) on the intestinal microbiota of chickens.

Background The characterization of colonization and dynamic changes related to gut microorganisms might be vital, as it presents an opportunity to quantify the co-variation between stocking densities and gut microbiome of dynamic distribution. The objective of this study was to determine the stocking density on physiological performance and dynamic distribution of gut microbiome (including bacterial and fungal communities) of Langya laying hens in the two development stages. Methods A randomized design with 2 × 3 factorial controls consisting of two development stages (24, 43 weeks-old) with three different stocking densities was performed. Three different stocking densities were allocated to a total of 300 11-week-old Langya laying hens (450 cm 2 /bird, 675 cm 2 /bird, 900 cm 2 /bird). Three housing densities were accomplished by raising different chickens per cage with the same floor size. The dependent variables of stocking densities at each sampling point were; growth performance, organs index, egg quality and the changes of dynamic gut bacterial and fungal communities in the cecum. Results Results showed that the stocking density didn’t affect liver index, eggshell thickness, breaking shell strength and egg shape index. Hens from the highest stocking density had the lowest body weight, fallopian tube index, egg weight and yolk colour score. Except for the yolk colour score, the measurement changes caused by age followed the opposite pattern as stocking density. We observed a substantial rise in taxa linked with health threats when stocking density was increased, including Talaromyces , Oscillospiraceae_UCG-002 , Oscillospira , and Dielma . The opposite was observed with Bacteroides , Bifidobacterium , Lachnoclostridium , Eisenbergiella , and Kurtzmaniella . Also, most taxa were linked to polymicrobial infection in clinical cases, especially species whose percentage declined as the hens aged, such as Terrisporobacter , Faecalicoccus , Dialister , Cylindrocarpon etc. Whereas Sellimonas , Mitsuokella , Eurotium , Wardomyces and Cephalotheca had the opposite trend. Conclusion We speculated that excessive high density drove the abundance of bacteria and fungi connected with health problems. Where the gut microecology gradually reach a mature and balance status with age. Overall, this study demonstrates gut microbiome ecological processes in Langya layers at various stocking densities and finds possible connections between stocking density, microbiome and production performance. Our study will contribute to new insights associating suitable density patterns and production performance in laying hens by harnessing such a relative microbiome.

Mounting evidence revealed the importance of gut microbiota in host metabolism, immunity and physiology, and health. Yimeng black goats (YBGs) mainly distributed in Shandong province of China, displayed a complicated intestinal microecosystem, but studies of its gut microbiota are still insufficient to report. Therefore, this study was performed with an objective to characterize the intestinal microbial community structure and diversity in the small intestine (duodenum, jejunum and ileum) and cecum of YBGs and investigated the variability of gut microbiota of different intestinal segments. A total of 12 intestinal samples were collected from YBGs for high-throughput sequencing analysis based on V3-V4 variable region of 16S rRNA genes. Our results revealed alterations in gut microbial composition with obvious differences in relative abundance between the different intestinal segments. Additionally, small intestine including duodenum, jejunum and ileum not only displayed higher species abundance and diversity than cecum but also showed a significant difference among the main components of gut microbiota based on the analytical results of alpha and beta diversities. At the phylum level, Firmicutes and Proteobacteria were the most preponderant phyla in all the samples regardless of intestinal sites. Moreover, the microbiota in small intestine was significantly different from cecum, which were characterized by the higher relative abundance of Butyrivibrio_2, Megasphaera, Halomonas, Delftia, Hydrogenophaga, Limnobacter, Pseudoxanthomonas, Novosphingobium, Janibacter and Erythrobacter, whereas the levels of Butyricicoccus, unidentified_Lachnospiraceae, Fusicatenibacter, Akkermansia, Ruminococcaceae_NK4A214_group and Lactobacillus were lower. Overall, this study first characterized the profile of gut microbiota composition in different intestinal sites and provide better insight into intestinal microbial community structure and diversity of YBGs.

Colonization and development of the gut microbiome during early life is important in establishing a host-microbial symbiotic relationship. It contributes to maintaining health and well-being throughout the life span. To date, early longitudinal development of intestinal microflora in the ileum micro-ecology of the Yimeng black goats (YBGs) is rare. The purpose of this research was to study the effect of milk replacer with age on the ileal microbiota growth and maturation in YBGs throughout the post-weaning phase. The newborn YBGs (n = 24) were divided into two groups, i.e., milk replacer (R group) and control group (B group). The microbiome of Ileum was observed on days 15, 25, 45, and 75. When compared with baseline (B group), the R group's alpha diversity was lower (day 15, 25, 45), but it gradually approached and exceeded the baseline in the later stages (day 75). On the time axis, the richness of intestinal microflora was increased with age, but there was no statistically significant difference. The relative abundances of Proteobacteria, Firmicutes, Peptoclustridium, Lachnospiraceae, and Prevotellaceae showed a continuous trend of increase initially. They then decreased except Ruminococcaceae, which reflected the gradual maturity of intestinal microbial development. Milk replacer treatment temporarily increased the abundance of Actinomycetes (day 25 and 45), while the relative proportion of several intestinal bacteria such as Parasutterella, Megasphaera, Prevotellaceae, Akkermansia, and Subdoligranulum species were significantly higher in R group than in B group. The major changes in gut microflora composition might reflect positive effect of milk replacer on the development and maturation of the intestine during the early stage, connecting with substrate availability in the gut. Our study provides an effective strategy to promote the development of the gut microbiome, which is helpful for a smooth transition during the early-weaning period in YBGs.

[目的]探讨影响琅琊鸡及其配套系蛋壳质量和钙代谢的差异因素,为琅琊鸡品种资源保护及开发提供理论依据.[方法]选取240日龄琅琊鸡及其浅麻羽色、深麻羽色配套系各180只,各品系随机分为6个重复,每个重复30只,在相同饲养条件下饲养至300日龄时各重复随机收集鸡蛋30枚,各重复随机选取6只,翅下静脉采集血样、屠宰后收集左腿胫骨及十二指肠、蛋壳腺、肾脏等组织样,用于检测蛋壳质量、钙、磷相关指标及钙结合蛋白CaBP-D28k mRNA的表达量.[结果]浅麻羽色配套系的蛋重显著低于深麻羽色配套系(P<0.05),而蛋壳重低于其他品系(P>0.05);另外,蛋壳厚度和蛋壳比率显著高于深麻羽色配套系(P<0.05),蛋壳强度显著高于其他品系(P<0.05);浅麻羽色配套系的蛋黄、蛋壳、胫骨中钙含量显著高于深麻羽色配套系(P<0.05),蛋壳、胫骨中磷含量显著高于其他品系(P<0.05);蛋壳中灰分含量浅麻羽色配套系最高,其次为琅琊鸡、深麻羽色配套系,而胫骨中灰分含量和胫骨重浅麻羽色配套系最高,其次为琅琊鸡、深麻羽色配套系,品系间均差异显著(P<0.05);浅麻羽色配套系的体重、胫骨长度显著低于深麻羽色配套系(P<0.05);浅麻羽色配套系的血钙、降钙素含量显著低于其他品系,而浅麻羽色配套系的血磷、碱性磷酸酶、甲状旁腺素含量显著高于其他品系,且品系间均差异显著(P<0.05);浅麻羽色配套系的钙结合蛋白含量显著低于深麻羽色配套系(P<0.05),而两个配套系的骨钙素显著高于琅琊鸡(P<0.05);浅麻羽色配套系的十二指肠部位钙结合蛋白CaBP-D28k mRNA表达量显著高于其他品系(P<0.05),而蛋壳腺部位表达量显著高于深麻羽色配套系(P<0.05),肾脏部位钙结合蛋白表达量显著高于琅琊鸡(P<0.05).[结论]在240—300日龄产蛋期,浅麻羽色配套系的血磷、碱性磷酸酶、甲状旁腺素、骨钙素等相关活性物质及十二指肠、肾脏、蛋壳腺部位钙结合蛋白CaBP-D28k mRNA表达水平高于其他品系,可能促进其小肠上段对钙磷的吸收和骨钙的释放、转运能力,影响蛋黄、蛋壳中矿物质的沉积和改善蛋壳、胫骨质量.