Systemic chronic inflammation (SCI) is a key driver of non-communicable diseases. Early-life stressors disrupt intestinal homeostasis, promoting SCI, but the mechanisms are unclear. Using translational models, we identify dysregulated iron homeostasis as a pivotal disruptor of intestinal barrier integrity. Single-cell profiling reveals that neutrophils and macrophages mediate iron-dependent mucosal defense. Stress induces iron overload in gut epithelial cells and macrophages, a process governed by the transcription factor MITF. MITF-mediated iron dysregulation in macrophages is associated with neutrophil recruitment to the lamina propria, concomitant with elevated levels of the CXCL8, synchronizing with hepatic inflammatory and metabolic dysregulation via the gut-liver axis. Mechanistically, abnormal iron homeostasis couples with interferon signaling, and MITF modulates iron-related genes (FTH1, TFRC, and FRRS1). Therapeutic mitigation of iron dyshomeostasis preserves barrier function and attenuates systemic inflammation. Our findings identify MITF as a key regulator of gut-liver inflammatory cascades and nominate abnormal iron homeostasis as a target for early-life inflammatory disorders.

Abstract Background Early weaning is a key strategy to improve lamb production efficiency; however, it inevitably compromises intestinal barrier integrity and function. This study aimed to investigate the effects of epigallocatechin (EGC) on growth performance and intestinal barrier function in weaned lambs, using metagenomics, metabolomics, and intestinal transcriptomics to elucidate the underlying mechanisms. Results Weaning induced oxidative stress, inflammation, and metabolic disruptions in the jejunum. Supplementation with 12.5 mg/kg EGC (LE) significantly improved growth performance, reduced diarrhea incidence (P < 0.05), enhanced mucosal antioxidant capacity (P < 0.001), and strengthened anti-inflammatory ability (P < 0.001). Metagenomic analysis showed that the LE intervention enriched Ruminococcus spp. and reduced the abundance of Slackia. This microbial shift was associated with elevated luminal concentrations of valeric acid and microbial metabolites derived from EGC. Transcriptomic profiling revealed that the intervention upregulated the PPAR signaling pathway, which supports nutrient metabolism and barrier repair. Concurrently, it attenuated aberrant IL-17 signaling and promoted the restoration of mucosal immune homeostasis, indicating a resolution of excessive inflammatory responses. Conclusions Supplementation with 12.5 mg/kg EGC alleviates weaning stress by fostering a beneficial gut microbiota and promoting the production of specific metabolites. These changes reactivate PPAR mediated epithelial repair and dampen pathological immune activation. Low-dose EGC is an effective nutritional strategy to improve intestinal health and growth in weaned ruminants.

Hemoglobin metabolism disorder can result in systemic iron overload, leading to pigmentation in multiple organs. Although these disorders are often of genetic origin, the specific genes and mechanisms remain incompletely understood. Lanping black bone sheep (LP–BBS), a unique population from the high altitudes along the Hengduan Mountains in Yunnan province, exhibits hyperpigmentation in multiple tissues. Investigating the genetic and environmental factors underlying this phenotype provides a natural model to better understand hemoglobin metabolism disorder. LP-BBS were found to exhibit increased red blood cell counts, elevated hemoglobin levels, and systemic iron overload, evidenced by hyperpigmentation in various tissues. Histological and molecular analyses revealed that hyperpigmentation is driven by ferriheme overload, an inheritable quantitative trait influenced by both genetic variation and environmental factors. Genome-wide association studies identified FRRS1L as a candidate gene, with significant mutations in its 3′-untranslated region (3′-UTR) reducing FRRS1L expression. Functional assays demonstrated that insufficient FRRS1L expression promotes ferriheme accumulation in reticuloendothelial cells and macrophages, as confirmed in vitro using FRRS1L knockdown models. Ferriheme overload was associated with oxidative stress and systemic inflammation, causing pathological damage to critical organs such as the kidney, liver, and uterus. This study identifies FRRS1L as a key contributor to ferriheme overload through aberrant hemoglobin metabolism in LP–BBS. These findings offer new insights into the genetic basis and pathological mechanisms of iron overload disorders, providing a potential target for therapeutic intervention. Moreover, LP–BBS serves as a valuable natural model for studying hematogenous pigment disorders and their interplay with environmental factors.

The underdeveloped intestinal tissue and immature microbiota in neonatal lambs predispose to frequent diarrhea or even death, expanding the breeding losses. Yeast peptides are enzymatic products of yeast strains, recognized as antimicrobial peptides due to their demonstrated antimicrobial properties. This study aimed to investigate the impacts of yeast peptides supplementation on the incidence of diarrhea in neonatal lambs, as well as the underlying regulatory mechanisms involved. Thirty-two one-day-old lambs were randomly allocated to four treatments: CON, YP500, YP1000, and YP2000, receiving 0 mg/d, 500 mg/d, 1,000 mg/d, and 2,000 mg/d of yeast peptides, respectively. The dietary supplementation of yeast peptides elicited a significant reduction in fecal scores and the incidence of diarrhea (p < 0.05). The administration of yeast peptides to neonatal lambs markedly elevated the levels of anti-inflammatory factors (IL-4, IL-10) while concurrently suppressing the levels of pro-inflammatory factors (IL-1β, IL-6) in the colonic mucosa (p < 0.05). Furthermore, yeast peptides enhanced intestinal antioxidant capacity and ultimately strengthened colonic barrier function (p < 0.05). Supplementation with yeast peptides altered the colonic microbiota of lambs, characterized by a marked increase in Roseburia and a decrease in Staphylococcus and Escherichia_Shigella abundances. Correlation analysis revealed that the observed attenuation in inflammatory response and enhancement of barrier function were associated with the enrichment of Roseburia and the suppression of Staphylococcus and Escherichia_Shigella. In conclusion, yeast peptides demonstrate potential in ameliorating diarrhea of lambs through the modulation of microbial communities and the enhancement of barrier function in the colon of lambs. The recommended dosage of yeast peptides is 2,000 mg/d.

Flavor compounds are key determinants of food sensory quality, originating from natural sources, processing, or artificial additives. Although physical and chemical methods can effectively enhance food flavor, microbial fermentation and enzyme catalysis technology possess good potential in food flavor regulation due to their mild reaction conditions and high safety. In addition, the high efficiency and specificity of enzymes help to shorten the production cycle and accurately regulate food flavor. This review focuses on the application and regulation mechanism of bacteria, yeast, other fungi, and mixed microbe fermentation systems in flavor production. The utilization and catalytic reaction schemes of oxidoreductases, transferases, and hydrolases in flavor regulation are also deeply explored, and suggestions for the application of microbial fermentation and enzyme catalysis technology in flavor regulation are discussed.

The early weaning of lambs frequently leads to weakened immunity, impaired intestinal function, and increased susceptibility to intestinal disease. Lactobacillus plays a role in regulating immunity, enhancing antioxidant capacity, and maintaining intestinal health. This study aims to isolate a strain of Lactobacillus with favorable probiotic properties from sheep feces and investigate its effects on the intestinal health of early-weaned lambs. In this study, the growth characteristics, acid production capacity, bacteriostatic capacity, bile salt tolerance, gastrointestinal fluid tolerance, self-coagulation capacity, and surface hydrophobicity of Lactobacillus isolated from sheep feces were analyzed for in vitro probiotic properties. Lactobacilli with strong probiotic properties were used for in vivo validation. A total of 72 Hu lambs were allocated into four groups: a ewe-reared group (ER), early-weaning group (EW), low-dose Lactobacillus group (LL), and high-dose Lactobacillus group (HL). Early weaning was performed in the EW, LL, and HL groups at the age of 28 days. Lactobacillus johnsonii M5 (L. johnsonii M5), isolated from sheep feces, exhibited strong probiotic properties in vitro. Feeding EW lambs with a low dose of L. johnsonii M5 significantly reduced their diarrhea rate (p < 0.05). Its supplementation increased the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and total antioxidant capacity (T-AOC) in serum and jejunal mucosa and decreased levels of malondialdehyde (MDA) (p < 0.05). Compared to the EW group, serum immunoglobulin G (IgG) levels were significantly increased in the LL group (p < 0.05). Compared to the EW group, feeding with L. johnsonii M5 increased the content of anti-inflammatory cytokines, while reducing the content of pro-inflammatory cytokines in serum and jejunal mucosa (p < 0.05). Feeding early-weaned lambs with L. johnsonii M5 also decreased jejunal crypt depth and increased occludin and claudin-1 in jejunal mucosa (p < 0.05). These findings indicate that feeding early-weaned lambs with L. johnsonii M5 enhances their immunity and antioxidant capacity, improving intestinal health, and mitigates diarrhea in early-weaned lambs.

Laccase, a member of the blue multicopper oxidase family, is widely distributed across diverse taxonomic groups, including fungi, bacteria, plants, and insects. This enzyme drives biocatalytic processes through the oxidation of phenolic compounds, aromatic amines, and lignin derivatives, underpinning its significant potential in the food industry, cosmetics, and environmental remediation. However, wild-type laccases face critical limitations, such as low catalytic efficiency, insufficient expression yields, and poor stability. To address these bottlenecks, this review systematically examines optimization strategies for heterologous laccase expression by fungal and bacterial systems. Additionally, we discuss protein engineering for laccase modification, with a focus on the structural basis and active-site redesign. The comprehensive analysis presented herein provides strategic suggestions for advancing laccase engineering, ultimately establishing a theoretical framework for developing high-efficiency, low-cost engineered variants for large-scale biomanufacturing and green chemistry applications.

The gut microbiome of domestic animals carries antibiotic resistance genes (ARGs) which can be transmitted to the environment and humans, resulting in challenges of antibiotic resistance. Although it has been reported that the rumen microbiome of ruminants may be a reservoir of ARGs, the factors affecting the temporal dynamics of the rumen resistome are still unclear. Here, we collected rumen content samples of goats at 1, 7, 14, 28, 42, 56, 70, and 84 days of age, analyzed their microbiome and resistome profiles using metagenomics, and assessed the temporal dynamics of the rumen resistome in goats at the early stage of life under a conventional feeding system. In our results, the rumen resistome of goat kids contained ARGs to 41 classes, and the richness of ARGs decreased with age. Four antibiotic compound types of ARGs, including drugs, biocides, metals, and multi-compounds, were found during milk feeding, while only drug types of ARGs were observed after supplementation with starter feed. The specific ARGs for each age and their temporal dynamics were characterized, and the network inference model revealed that the interactions among ARGs were related to age. A strong correlation between the profiles of rumen resistome and microbiome was found using Procrustes analysis. Ruminal Escherichia coli within Proteobacteria phylum was the main carrier of ARGs in goats consuming colostrum, while Prevotella ruminicola and Fibrobacter succinogenes associated with cellulose degradation were the carriers of ARGs after starter supplementation. Milk consumption was likely a source of rumen ARGs, and the changes in the rumen resistome with age were correlated with the microbiome modulation by starter supplementation. Our data revealed that the temporal dynamics of the rumen resistome are associated with the microbiome, and the reservoir of ARGs in the rumen during early life is likely related to age and diet. It may be a feasible strategy to reduce the rumen and its downstream dissemination of ARGs in ruminants through early-life dietary intervention.

Although early solid diet supplementation is a common practice to improve the growth and development in goat kids, its biological mechanism how solid diet induces rumen microbiota and epithelial development is still unknow. In this study, rumen fermentation parameters, 16S rRNA sequencing for rumen content and epithelial microbiota, transcriptomics and proteomics of epithelium were determined to classify the effects of solid diet supplementation. Here, we classified the changes of goat phenotypes (i.e., growth performance, rumen fermentation and development) and linked them to the changes of rumen microbiota, transcriptome and expressed proteins. The mechanism of solid diet improving rumen development was elucidated preliminarily. Moreover, different roles between the rumen content and epithelial microbiota were identified. Thess datasets expands our understanding of the association between the early diet intervention and rumen development, providing the useful information how nutrient strategy affects rumen function and subsequently improves the host growth. The generated data provides insights in the importance of rumen niche microbiota and microbe-host interactions, which benefits future studies.

BACKGROUND:It is not uncommon for some individuals to retain certain primitive characteristics even after domestication or long-term intensive selection. Wild ancestors or original varieties of animals typically possess strong adaptability to environmental preservation, a trait that is often lacking in highly artificially selected populations. In the case of the Merino population, a world-renowned fine wool sheep breed, a phenotype with primitive coarse wool characteristic has re-emerged. It is currently unclear whether this characteristic is detrimental to the production of fine wool or whether it is linked to the adaptability of sheep. The underlying genetic/epigenetic mechanisms behind this trait are also poorly understood.RESULTS:This study identified lambs with an ancestral-like coarse (ALC) wool type that emerged during the purebred breeding of Merino fine wool sheep. The presence of this primitive sheep characteristic resulted in better environmental adaptability in lambs, as well as improved fine wool yield in adulthood. Reciprocal cross experiments revealed that the ALC phenotype exhibited maternal genetic characteristics. Transcriptomic SNP analysis indicated that the ALC phenotype was localized to the imprinted Gtl2-miRNAs locus, and a significant correlation was found between the ALC wool type and a newly identified short Interstitial Telomeric Sequences (s-ITSs) at this locus. We further confirmed that a novel 38-nt small RNA transcribed from these s-ITSs, in combination with the previously reported 22-nt small RNAs cluster from the Gtl2-miRNAs locus, synergistically inhibited PI3K/AKT/Metabolic/Oxidative stress and subsequent apoptotic pathways in wool follicle stem cells, resulting in the ALC wool type. The necessity of Gtl2-miRNAs in controlling primary hair follicle morphogenesis, as well as the wool follicle type for ALC wool lambs, was verified using intergenic differentially methylated region-knockout mice.CONCLUSION:The ALC wool type of Merino sheep, which does not reduce wool quality but increases yield and adaptability, is regulated by epigenetic mechanisms in the imprinted Gtl2-miRNAs region on sheep chromosome 18, with the maternally expressed imprinted gene responsible for the ALC phenotype. This study highlights the significance of epigenetic regulation during embryonic and juvenile stages and emphasizes the advantages of early adaptation breeding for maternal parents in enhancing the overall performance of their offspring.

Early weaning stress in lambs leads to decreased feed intake, damage to intestinal morphology, changes in the microbial flora structure, and subsequent complications. Yeast peptides are antimicrobial peptides with anti-inflammatory, antioxidant, and bacteriostasis effects. To study the effects of yeast peptides on relieving weaning stress in lambs, 54 lambs were randomly divided into three groups: ewe-reared (ER), yeast-peptide-treated (AP), and early-weaned (EW) lambs. The body weight and dry matter intake did not significantly differ among all groups. After weaning, the daily gain and feed conversion rate decreased significantly (p < 0.01), but AP showed an upward trend. In the EW group, immunoglobulin (Ig) levels changed significantly post-weaning (IgG decreased; IgA and IgM increased); the villi shortened, the crypt depth increased, and the villi height/crypt depth decreased (p < 0.001). The abundance and diversity of microflora among all groups were not significantly different. A column coordinate analysis showed significant differences in the intestinal microbial structure between the AP and EW groups. Lactobacillus, Aeriscardovia, Ruminosaceae_UCG-014, and Catenisphaera may play key roles in alleviating weaning stress in lambs. Our study provides new clues for alleviating weaning stress in lambs by describing the influence of yeast peptides on the intestinal microflora during weaning.

肠道黏膜氧化损伤与畜禽的生长发育和腹泻等疾病的发生密切相关,而褪黑素作为一种吲哚胺类化合物,具有明显抗氧化保护作用.为探究褪黑素对肠黏膜上皮细胞氧化损伤时的保护作用,本研究选取原代小鼠空肠黏膜上皮细胞,利用硫酸亚铁和过氧化氢处理建立氧化损伤模型,并通过添加不同浓度的褪黑素预处理上皮细胞,检测细胞损伤、氧化产物、抗氧化酶和炎性相关细胞因子的表达变化.结果发现,硫酸亚铁和过氧化氢处理后,黏膜上皮细胞明显受损,丙二醛含量显著增加、抗氧化酶表达水平降低.而褪黑素能明显减轻细胞氧化损伤程度、抑制丙二醛的产生并增加抗氧化酶的表达.同时,褪黑素还能显著减少炎性因子白介素-6 的表达,并增加趋化因子白介素-8 的表达.因此,褪黑素可以缓解自由基增加诱发的空肠黏膜上皮细胞氧化损伤,并能够减轻细胞损伤引起的炎症反应.

ABSTRACT The use of milk replacer (MR) is a modern strategy to ensure the health and growth of neonatal ruminants. Some studies have confirmed that dietary factors have significant effects on ruminal antimicrobial resistance genes (ARGs), which, as a potential threat to livestock, have received more attention. However, the effect of different milk sources (milk or MR) on the rumen resistome of yaks is still largely unknown. Here, using metagenome technology, we investigated the occurrence of ruminal ARGs in yaks and their relationship with rumen bacteria in response to different milk sources. The metagenomic result showed that MR feeding significantly increased the abundance of Prevotella members compared to milk feeding. A total of 138 rumen resistome-conveying ARGs to 17 different classes of antimicrobials were detected, of which tetracycline resistance was the predominant. MR feeding also drove the changes in the rumen resistome, and the predicted bacterial origins of ARGs had complex and various manifestations. Moreover, enzymes of butyrate metabolism and carbohydrate-active enzymes encoding carbohydrate and cellulose degradation were increased. This study revealed that MR feeding increased the abundance of beneficial bacteria Prevotella members, changed the microbial resistome, and promoted the metabolic function of volatile fatty acid biosynthesis in the rumen of yaks, which could provide beneficial evidence for the regulation of the rumen microbiome and the intervention of antimicrobial resistance in ruminants by dietary or nutritional methods. IMPORTANCE Yaks, as ruminants inhabiting high-altitude environments, possess a distinct rumen microbiome and are resistant to extreme living conditions. This study investigated the microbiota, resistome, and functional gene profiles in the rumen of yaks fed milk or milk replacer (MR), providing insights into the regulation of the rumen microbiome and the intervention of antimicrobial resistance in yaks through dietary methods. The abundance of Prevotella members increased significantly in response to MR. Tetracycline resistance was the most predominant. The rumen of yaks contained multiple antimicrobial resistance genes (ARGs) originating from different bacteria, which could be driven by MR, and these ARGs displayed intricate and complex interactions. MR also induced changes in functional genes. The enzymes associated with fiber degradation and butyrate metabolism were activated and showed close correlations with Prevotella members and butyrate concentration. This study allows us to deeply understand the ruminal microbiome and ARGs of yaks and their relationship with rumen bacteria in response to different milk sources.

With the rapid development of animal husbandry, intensive feeding and early weaning strategy comes into being. At the same time, all kinds of stress（such as heat stress, cold stress, weaning stress, transport stress, oxidative stress） increase, resulting in intestine injury of young farm animals whose immune system has not been fully established, which is life-threatening in serious cases. miRNA is a kind of endogenous non-coding single-stranded small RNA, which can regulate gene expression. As an important member of the gene family, miRNA was involved in almost all the signaling pathways in the body. miRNA could regulate the proliferation and differentiation of intestinal epithelial cells and mediate intestinal mucosal barrier injury. This review summarized the effect of stress on intestinal mucosal barrier function, the regulatory role and possible pathways of miRNA on intestinal mucosal barrier function of young farm animals. At the same time, the mode of miRNA participating in the action of exogenous additives was reviewed to provide a theoretical basis for nutrients targeted intervention to regulate the intestinal immune function of young farm animals, and was of great significance to improve the breeding of young farm animals.

ZBED6, a key transcription factor, plays an important role in skeletal muscle and organ growth. ZBED6 knockout (ZBED6-/-) leads to the upregulation of IGF2 in pig and mice muscle, thereby increasing muscle mass. However, the effects and mechanism of Zbed6 single-allele knockout (Zbed6+/-) on mice muscle remain unknown. Here, we reported that Zbed6+/- promotes muscle growth by a new potential target gene rather than Igf2 in mice muscle. Zbed6+/- mice showed markedly higher muscle mass (25%) and a markedly higher muscle weight ratio (18%) than wild-type (WT) mice, coinciding with a larger muscle fiber area (28%). Despite a significant increase in muscle growth, Zbed6+/- mice showed similar Igf2 expression with WT mice, indicating that a ZBED6-Igf2-independent regulatory pathway exists in Zbed6+/- mice muscle. RNA-seq of muscle between the Zbed6+/- and WT mice revealed two terms related to muscle growth. Overlapping the DEGs and C2C12 Chip-seq data of ZBED6 screened out a potential ZBED6 target gene Barx2, which may regulate muscle growth in Zbed6+/- mice. These results may open new research directions leading to a better understanding of the integral functions of ZBED6 and provide evidence of Zbed6+/- promoting muscle growth by regulating Barx2 in mice.

β-catenin is a conserved molecule that plays an important role in hair follicle development. In this study, we generated skin-specific overexpression of ovine β-catenin in transgenic mice by pronuclear microinjection. Results of polymerase chain reaction (PCR) testing and Southern blot showed that the ovine β-catenin gene was successfully transferred into mice, and the exogenous β-catenin gene was passed down from the first to sixth generations. Furthermore, real-time fluorescent quantitative PCR (qRT-PCR) and western blot analysis showed that β-catenin mRNA was specifically expressed in the skin of transgenic mice. The analysis of F6 phenotypes showed that overexpression of β-catenin could increase hair follicle density by prematurely promoting the catagen-to-anagen transition. The results showed that ovine β-catenin could also promote hair follicle development in mice. We, therefore, demonstrate domestication traits in animals.

The health of young ruminants is highly dependent on early rumen microbial colonization. In this study, the effects of milk replacer on growth performance, rumen fermentation, and the rumen microflora in yak calves were evaluated. Sixty yak calves (body weight = 22.5 ± 0.95 kg, age = 30 ± 1 d) were assigned to the CON group (breastfed) or TRT group (milk replacer fed) and evaluated over 120 d. At 120 d, ruminal fluid samples were collected from 14 calves and then conducted for rumen fermentation and microbiota analyses. There was no difference in growth performance; however, calf survival was higher in the TRT group than in the CON group. The concentration of total volatile fatty acids and the molar proportion of butyric acid and lactic acid were increased with milk replacer feed in the TRT group (p < 0.05), but iso-valeric acid concentration was highest in the CON group (p < 0.05). Firmicutes and Bacteroidetes were the most dominant phyla in the CON and TRT groups, respectively. In the TRT group, Bacteroidetes, Prevotellaceae, Bacteroidia, Bacteroidetes, and Prevotella_1 were the dominant flora in the rumen of calves. The relative abundances of various taxa were correlated with rumen fermentation parameters; the relative abundance of Quinella and iso-butyrate levels were positively correlated (r = 0.57). The relative abundances of the Christensenellaceae_R-7_group and A/P were positively correlated (r = 0.57). In summary, milk replacer is conducive to the development of the rumen microflora, the establishment of rumen fermentation function, and the implementation of early weaning in yaks.

It is well known that solid diet supplementation in early life can significantly promote rumen development and metabolic function in young ruminants. However, the changes in the expressed proteome and related metabolism in rumen epithelium in response to a supplemented solid diet remain unclear. In this study, rumen epithelial tissue from goats in three diet regimes including milk replacer only (MRO), milk replacer supplemented concentrate (MRC), and milk replacer supplemented concentrate plus alfalfa pellets (MCA) were collected for measurement of the expression of epithelial proteins using proteomic technology (six per group). The results showed that solid diet significantly improved the growth performance of goats, enhanced the ability of rumen fermentation, and promoted the development of epithelial papilla (p < 0.05). Proteome analysis revealed the distinct difference in the expressed protein in the MRC and MCA group compared with the MRO group (42 upregulated proteins and 79 downregulated proteins in MRC; 38 upregulated proteins and 73 downregulated proteins in MCA). Functional analysis showed that solid diet supplementation activated a variety of molecular functions in the epithelium, including protein binding, ATP binding, structural constituent of muscle, etc., in the MRC and MCA groups. Meanwhile, the expression of proteins related to fatty acid metabolism, the PPAR signaling pathway, valine, leucine, and isoleucine degradation, and butanoate metabolism were upregulated, being stimulated by solid feed. In contrast, the proteins associated with carbohydrate digestion and absorption and glycosaminoglycan degradation were downregulated. In addition, the protein expression of enzymes involved in ketone body synthesis in the rumen was generally activated, which was caused by solid feed. In summary, solid feed promoted the development of rumen epithelium by changing the expression of proteins related to fatty acid metabolism, energy synthesis, and signal transduction. The ketone body synthesis pathway might be the most important activated pathway, and provides energy for rumen development.

Early life intervention is important to shape the gut microbiome profiles of adult animals due to the tremendous alteration of diet components. Nevertheless, there is still no unified understanding about its long-term effects in lambs. In this study, sixty 20-day-old lambs were assigned into ewe-rearing (ER) and artificial-rearing (AR) treatments to evaluate the effects of AR strategy on ruminal microbiota, fermentation, and morphology of pre-weaning lambs (from 20 to 60 days of age) and its long-term effects in the fattening stage (from 61 to 180 days of age). During the pre-weaning stage, ER lambs were breastfed and supplemented starter, while AR lambs were artificially fed with milk replacer and starter. During the fattening stage, all lambs in both treatments were fed with the same fattening diets. At 60, 120 and 180 days of age, 6 lambs from each group were slaughtered to collect rumen content and tissue samples. Compared with ER lambs, the dry matter feed intakes of AR lambs increased (P<0.05) from 20 to 180 days of age, companying an increased average daily gain (ADG) from 61 to 120 days of age (P<0.05) and from 121 to 180 days of age (0.05 0.05), it was higher (P<0.05) in AR lambs compared with ER lambs at the fattening stage. The rumen keratin layer of AR lambs was thinner (P<0.05) than that of ER lambs. Along with lamb growth from 60 to 180 days of age, the differences in rumen bacterial diversity between AR and ER treatments grew more distinct (P<0.05). Compared with ER lambs, AR lambs increased (P<0.05) rumen bacteria abundance, such as phylum Spirochaetes and genus Treponema at 60 days of age, phylum Actinobacteria and genus Succiniclasticum at 120 days of age, and phylum Proteobacteria at 180 days of age, but decreased genus Selenomonas from 60 to 180 days of age, and Anaerovibrio at 180 days of age. In summary, the early interventions before weaning could improve dry matter feed intake of lambs, which triggered robust rumen development and produced positive long-term effects on rumen fermentation and noticeable weight gain of fattening lambs. It suggests that the artificial rearing strategy is effective in improving rumen fermentation and microbial maturity of intensive fattening lambs.

Early feeding regime has a substantial lifelong effect on lambs and weaning ewe's milk can lead to the intestinal injury of lambs. To explore the molecular regulatory mechanism of intestinal injury of lambs under weaning stress, the jejunum was conducted transcriptome and then integrated analyzed with our previous proteome data. A total of 255 upregulated genes and 285 downregulated genes were significantly identified. These genes showed low overlapping with differentially expressed proteins identified by isobaric tags for relative and absolute quantification (iTRAQ). However, according to their functions, the differentially expressed genes (DEGs) and proteins with the same expression trend were enriched for the similar Gene Ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as intestinal lipid absorption, urea cycle, peroxisome proliferator-activated receptor (PPAR) signaling pathway, and ferroptosis. Furthermore, the DEGs, including FABP2, ACSL3, APOA2, APOC3, and PCK1, might play essential roles in intestinal lipid absorption and immune response through the PPAR signaling pathway and ferroptosis. This study could provide new insights into early lamb breeding at the molecular level.