Intramuscular fat (IMF) is a major determinant of meat quality, influencing tenderness, juiciness, flavor, oxidative stability, and nutritional value in livestock products. Increasing evidence indicates that IMF deposition is regulated by complex interactions between host genetics and gut microbial metabolism. This review summarizes current advances in the molecular and metabolic mechanisms linking host genetics and gut microbiota to IMF accumulation and meat quality traits. At the host level, IMF deposition is regulated by coordinated adipogenic networks involving PPARγ-C/EBPα signaling, lipogenic regulators, nutrient-sensitive pathways, and epigenetic modifications that control adipocyte differentiation and lipid storage. In parallel, the gut microbiota acts as an important metabolic regulator by producing bioactive metabolites, including short-chain fatty acids and secondary bile acids, which influence adipogenesis, inflammation, nutrient partitioning, and metabolic flexibility. Emerging evidence further demonstrates that microbial metabolites can modulate host transcriptional and epigenetic programs, thereby linking microbial activity with tissue-specific lipid metabolism. Integrative multi-omics approaches are increasingly revealing the mechanistic basis of host-microbiome interactions underlying variation in carcass composition and meat quality across livestock species. This review further highlights the translational potential of precision nutrition, microbiome modulation, and microbiome-informed breeding strategies for sustainable meat production.

Background Intramuscular fat (IMF) is a critical determinant of rabbit meat quality, influencing tenderness, juiciness, and flavor. miRNAs are crucial for IMF synthesis by regulating genes involved in lipid deposition, but the mechanisms by which miRNAs regulate IMF deposition in rabbits remain poorly understood. This study aimed to investigate the role of microRNAs (miRNAs) in IMF deposition in Hycole rabbits (HR) and Rex rabbits (RR) at three developmental stages (35, 75, and 150 days of age) using small RNA sequencing. Results A total of 195 differentially expressed (DE) miRNAs were identified in HR across the three stages, including 49 co-expressed DE miRNAs (e.g., ocu-miR-29c-5p, ocu-miR-382-3p, ocu-miR-29b-3p). In RR, 222 DE miRNAs were detected, with 45 co-expressed DE miRNAs (e.g., ocu-miR-182-5p, ocu-miR-486-5p, ocu-miR-370-5p). Comparative analysis between breeds identified 128 DE miRNAs, but none were co-expressed. GO and KEGG enrichment analyses showed DE miRNAs and their target genes were significantly enriched in pathways like PI3K-Akt, MAPK, Hippo, and HIF-1, which were closely associated with lipogenesis, metabolism, and obesity. Conclusions This study elucidates the transcriptional regulatory mechanisms of IMF deposition in rabbits and identifies key miRNAs influencing IMF accumulation. Our findings provide new insights into the molecular mechanisms underlying rabbit IMF deposition and offer important resources to support future genetic improvement and management strategies in rabbit production.

Rabbit meat is a high-protein, low-fat food with recognized nutritional benefits, often labeled as “healthy meat” and “nootropic meat.” However, its low-fat content leads to relatively poor flavor. Myofibers are the main components of rabbit meat, and their type composition determines the overall metabolic characteristics of the meat, which ultimately affects fresh meat quality. During the growth of rabbits, muscle fibers transform into one another. Nevertheless, the changes in the relative composition of myofiber types as domestic rabbits grow, and the molecular mechanisms behind myofiber transition, remain unclear. This study aimed to analyze the changes in the relative composition of myofiber types in rabbits of different ages and explore the roles of various potential molecules in rabbit myofiber transition at the transcriptional level using whole transcriptome technology. Significant differences were observed in the relative composition of gluteus (GLU) and gastrocnemius (GAS) muscle fiber types, which impacted rabbit meat color and taste. During growth, the relative composition of GLU muscle fiber types differed significantly between 1-day-old and 14-day-old rabbits. Transcriptome analysis of GLU muscle from these two age groups revealed extensive molecular changes during myofiber transition, including 3,194 differentially expressed mRNAs, 366 circRNAs, 1,394 lncRNAs, 343 miRNAs, 180 differentially expressed transcription factors, and 2,717 genes with significant alternative splicing. These differentially expressed molecules were associated with multiple signaling pathways involved in myofiber transition, such as the AMPK, calcium, PI3K-Akt, MAPK, Hippo, and mTOR pathways. Comprehensive co-expression and protein-protein interaction analyses identified an active interconnected module containing 38 co-expressed proteins related to myofiber transition. Based on the ceRNA (competitive endogenous RNA) theory and these 38 key molecules, a lncRNA/circRNA-miRNA-mRNA network was constructed, involving 9 mRNAs, 10 circRNAs, 18 lncRNAs, and 14 miRNAs. This study investigated how the relative composition and content of myofiber types change during different growth stages of rabbits, and revealed the complex dynamic biological mechanisms underlying myofiber transition in rabbits through whole transcriptomics. The results of this study can help identify appropriate targets for regulating myofiber transition, thereby facilitating the development of high-quality rabbit meat.

Metabolomics has emerged as a transformative analytical platform for elucidating the biochemical mechanisms that underpin meat quality, nutritional value, and functional attributes. Rabbit meat is increasingly recognized as a viable alternative to conventional meats due to its lean composition, high-quality protein, and favorable lipid profile. Comparative evidence indicates that rabbit meat typically exhibits a polyunsaturated-to-saturated fatty acid (PUFA/SFA) ratio ranging from approximately 0.60 to >1.0, depending on breed and muscle type, values that consistently exceed those reported for beef and pork and are comparable to or higher than poultry, underscoring its nutritional advantage. Despite substantial advances, the practical deployment of metabolomics in rabbit meat research remains constrained by critical gaps, including the lack of standardized sample preparation and metabolite identification frameworks, incomplete metabolome coverage across analytical platforms, limited validation and transferability of candidate biomarkers, insufficient integration with genomics, transcriptomics, and proteomics, and the predominance of destructive, low-throughput methodologies that limit real-time industrial application.The unique contribution of this review lies in its systems-level integration of metabolomic drivers across the entire production continuum, from pre-harvest biological regulation (genotype, nutrition, and management) to post-mortem biochemical transformations and storage dynamics, coupled with a translation-oriented framework that bridges mechanistic discovery with emerging non-invasive technologies and industrial quality control strategies. By consolidating fragmented evidence into a coherent mechanistic and applied roadmap, this review provides strategic guidance for advancing reproducibility, predictive capability, and scalability of metabolomics in rabbit meat systems, thereby supporting the development of data-driven interventions to enhance meat quality, processing efficiency, and functional value.

Abstract Background Feed efficiency (FE) is a major determinant of productivity, economic sustainability, and environmental impact in livestock production. Although Pekin ducks constitute a substantial proportion of global poultry meat production, improvement of FE has progressed slowly, largely due to an incomplete understanding of its complex biological basis. In particular, how host genomic variation and gut microbial communities—especially across different intestinal segments—jointly contribute to FE remains poorly characterized in ducks. Results We integrated whole-genome sequencing (WGS) with segment-resolved microbiota profiles from 313 Pekin ducks to delineate host–microbiota architecture underlying feed conversion ratio (FCR), which exhibited moderate heritability ( h 2=0.23, P LRT = 2.53 × 10–2). Genome-wide association study (GWAS) identified two major genomic regions involving two genes ALG13 and TRPC5, which implicated in appetite regulation and energy balance to impact FE. Meanwhile, gut microbial communities exhibited spatial heterogeneity along the intestinal tract, with host genetics-associated taxa such as Solobacterium (cecum) and Eubacterium_eligens_group (jejunum) negatively correlating with FCR, likely via enhanced short-chain fatty acid production and improved energy harvest. Variation partitioning revealed that host genetics explained the largest FCR variance (36.96%), followed by cecal microbiota. Conclusions Our results highlight coordinated host–microbiota interactions influencing FE, offering targets for breeding and microbiota-based interventions.

This study aimed to evaluate the impact of Hybridization on rabbit meat quality by comparing Hybrid rabbits (YH group) with Hyla rabbits (HL group) under identical rearing conditions. The results indicated that YH rabbits had a higher proportion of red muscle fibers and smaller muscle fiber area, which contributed to improved meat color and tenderness. Furthermore, YH rabbits exhibited increased total fatty acids, saturated fatty acids, and monounsaturated fatty acids, along with 8 unique fatty acids (e.g., C18:1 cis-9). Metabolomic analysis identified 108 volatile and 164 non-volatile differential metabolites enriched in lipid metabolism pathways, with strong correlations between these metabolites, fatty acids, and sensory traits. Electronic nose and tongue analyses confirmed enhanced flavor, while texture analysis showed decreased firmness and chewiness in YH rabbits. These findings demonstrate that Hybridization effectively improves rabbit meat quality, providing valuable insights for breeding high-quality and healthy rabbit meat.

Rabbit farming plays a crucial role in meeting the global demand for high-quality meat and sustainable agricultural practices. In recent years, significant attention has been directed toward the integration of Genomic-Assisted Selection (GAS) and Precision Nutrition (PN) as synergistic strategies to improve productivity and animal welfare in rabbit production systems. This integration is particularly critical given the intricate interplay between genetic predispositions and nutritional demands in optimizing rabbit farming outcomes. The present review systematically explores the genetic diversity inherent to rabbit breeds, examines the impact of key genetic traits on productivity and welfare metrics, and highlights advancements in genomic research and associated tools within the context of rabbit breeding practices. By examining the importance of personalized nutrition tailored to individual rabbit requirements, as well as nutritional strategies to optimize productivity and longevity. In this regard, we provide essential understanding for farmers and researchers in the rabbit farming industry. Our goal is to provide a new perspective on the significance of this integrated approach and its implications for future practices and research in rabbit production, emphasizing the need for continued efforts to harness the full potential of genomics and nutrition in enhancing rabbit farming practices.

This study investigates the impact of seven spices-ginger, garlic, Welsh onion, prickly ash, black pepper, star anise, and chili-on rabbit meat quality, focusing on sensory attributes, oxidative stability, and nutritional value. Using advanced techniques such as HS-SPME-GC-MS, E-tongue, E-nose, and GC-FID, we found that spices significantly enhanced flavor complexity, tenderness, juiciness, and oxidative stability compared to the control group (CG) (P < 0.05). Notably, garlic, star anise, and black pepper improved aroma intensity and overall acceptability, while ginger and prickly ash reduced undesirable flavor indices. This research presents a novel approach by integrating recipe data mining and sensory analysis, providing a scientific foundation for optimizing rabbit meat's flavor and health attributes. The findings highlight the potential of spices to reduce gamey flavors and enhance the nutritional profile, offering a strategy for healthier, more appealing meat products.

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.

Rex rabbit is famous for its silky and soft fur coat, a characteristic predominantly attributed to its hair follicles. Numerous studies have confirmed the crucial roles of mRNAs and non-coding RNAs (ncRNAs) in regulating key cellular processes such as cell proliferation, differentiation, apoptosis and immunity. However, their involvement in the regulation of the hair cycle in Rex rabbits remains unknown. In this study, we identified the hair follicle stages of Rex rabbits aged 3 to 5.5 months. Skin samples collected at 4, 5 and 5.5 months, representing the morphological features of the anagen, catagen and telogen stage separately, were finally selected for whole-transcriptome analysis. 25,736 mRNA, 8280 lncRNA, 24,885 circRNA and 1138 miRNA transcripts were identified. 6027 differently expressed mRNAs (DEGs), 2381 differently expressed lncRNAs (DELs), 438 differently expressed circRNAs (DECs) and 167 differently expressed miRNAs (DEMs) were detected in the anagen vs. catagen (AvC) comparison. 4092 DEGs, 1540 DELs, 356 DECs and 141 DEMs were detected in the anagen vs. telogen (AvT) comparison. 2290 DEGs, 779 DELs, 249 DECs and 92 DEMs were detected in the catagen vs. telogen (CvT) comparison. DEGs were primarily enriched in GO items including plasma membrane, integral component of plasma membrane and extracellular space. KEGG enrichment analysis revealed that DEGs were mainly enriched in PI3K-Akt signaling pathway, cell cycle and Wnt signaling pathway (p < 0.05). KEGG analysis showed trans-acting genes of DELs were significantly enriched in Hippo signaling pathway, PI3K-Akt signaling pathway and Melanogenesis. Target genes of DEMs were mainly enriched in MAPK signaling pathway, Wnt signaling pathway, ECM-receptor interaction and Signaling pathways regulating pluripotency of stem cells. Based on the ceRNA mechanism, lncRNA/circRNA-miRNA-mRNA networks were constructed involving 9 DECs, 437 DELs, 50 DEMs and 416 DEGs. Totally, this study provides comprehensive insights into the expression patterns of protein-coding genes and non-coding transcripts throughout the HF cycle, and enhancing the understanding of the regulatory mechanisms underlying mammalian hair fiber development.

Intramuscular fat (IMF) is a critical determinant of meat quality in rabbits, influencing attributes such as tenderness, juiciness, and flavor. A moderate increase in IMF content is associated with enhanced meat quality. In this study, we evaluated the growth performance, slaughter performance, and meat quality traits of the longissimus dorsi (LD) muscles in Hycole and Rex rabbits across various growth stages. Utilizing transcriptome sequencing, we identified and analyzed differentially expressed mRNAs (DE mRNAs) and long non-coding RNAs (DE lncRNAs), and constructed lncRNA-mRNA regulatory networks to investigate candidate genes influencing IMF content in Rex rabbits at different developmental stages. The results demonstrated an age-dependent increase in IMF content for both breeds, with Rex rabbits consistently exhibiting higher IMF levels compared to Hycole rabbits at equivalent ages. Through whole transcriptome sequencing, we identified several DE mRNAs and DE lncRNAs associated with fat deposition across various developmental stages and breeds. These include KCNQ5, POSTN, TMEM182, CASQ2, ME1, and COL6A6, as well as lncRNAs such as TCONS_00009631, TCONS_00082976, TCONS_00040377, TCONS_00051990, and TCONS_00069025. Enrichment analysis revealed that these genes are implicated in key signaling pathways related to fat deposition, including the Wnt, TGF-β, and PPAR signaling pathways. RNA sequencing data further revealed that age significantly impacts IMF deposition, with the most pronounced differences observed between 35-day-old and 150-day-old rabbits. Additionally, through comprehensive lncRNA-mRNA regulatory network, short time-series expression miner (STEM) analyses, and weighted gene co-expression network analysis (WGCNA), we identified 10 lncRNA-mRNA target gene pairs associated with IMF deposition, including critical genes implicated in fat accumulation such as STARD13, HSPB8, and CBLB. This work provided regulatory networks of rabbits and revealed STARD13, HSPB8, and CBLB as the key genes responsible for IMF deposition. Our findings highlight that IMF deposition in rabbits triggers dynamic transcriptional alterations. These findings provide a robust theoretical foundation for advancing genetic breeding strategies and elucidating the regulatory mechanism underlying adipose development in rabbits.

Runs of homozygosity (ROH) are continuous segments of homozygous genotypes inherited from both parental lineages. These segments arise due to the transmission of identical haplotypes. The genome-wide patterns and hotspot regions of ROH provide valuable insights into genetic diversity, demographic history, and selection trends. In this study, we analyzed whole-genome resequencing data from 117 rabbits to identify ROH patterns and inbreeding level across eleven rabbit breeds, including seven Chinese indigenous breeds and four exotic breeds, and to uncover selective signatures based on ROH islands. We detected a total of 31,429 ROHs across the autosomes of all breeds, with the number of ROHs (NROH) per breed ranging from 1316 to 7476. The mean sum of ROHs length (SROH) per individual was 493.84 Mb, covering approximately 22.79

ABSTRACT The forest musk deer (FMD) farming industry is currently experiencing rapid growth, yet the dietary energy requirements for FMD remain unclear. Therefore, we explored the optimal dietary digestible energy (DE) for growing phase FMD by providing three diets with different DE levels and analyzing changes in gut microbiota. A total of 20 six-month-old FMD were used in a 62-day trial. Animals were fed either traditional feed (CON, 10.38 MJ/kg DE) or pelleted diets with low (L, 8.87 MJ/kg), medium (M, 10.38 MJ/kg), or high (H, 11.86 MJ/kg) DE levels. The results showed that feeding pelleted diets significantly reduced the incidence of diarrhea ( P < 0.05). The average daily gain in the H group was significantly higher than in the M group, and the M group was higher than both the L and CON groups ( P < 0.05). Additionally, the H group showed the highest nutrient digestibility and the greatest increase in body measurements ( P < 0.05). Analysis of fecal microbiota revealed that α-diversity and the relative abundance of Firmicutes increased with higher dietary energy levels, while the relative abundance of Bacteroidetes decreased. Beneficial bacteria such as Akkermansia and Lachnospira were significantly enriched in the H group. In conclusion, our findings suggest that pelleted diets are suitable for growing phase FMD, with an optimal dietary DE level of 11.86 MJ/kg. IMPORTANCE This study underscores the significance of identifying the optimal dietary digestible energy (DE) for growing forest musk deer (FMD). Pelleted diets with a DE level of 11.86 MJ/kg enhanced growth performance, nutrient digestibility, and gut health, while reducing diarrhea and enriching beneficial gut bacteria, offering valuable insights for improving FMD farming practices.

Tibetan chicken (TBC) is one of the native poultry species that is well adapted to the high-altitude environment of the Qinghai-Tibet Plateau. To elucidate the genetic mechanisms underlying adaptation, the transcriptomes of five tissues (heart (HE), lung (LU), liver (LI), ovary (OV), and abdominal fat (AB)) were compared between TBCs and Roman chickens (RMCs) inhabiting the plateau for one year. Moreover, weighted gene co-expression network analysis (WGCNA) was applied to detect tissue-associated modules and hub genes. A total of 1105, 239, 400, 483, and 275 differentially expressed genes (DEGs) were identified in the LI, HE, LU, AB, and OV tissues, respectively. Fifteen tissue-specific modules were identified in TBC and thirteen in RMC. Analysis of transcription factor (TF) binding sites revealed nineteen hub TFs in TBC and twenty in RMC across the pool of hub genes in these two breeds. Functional enrichment analyses demonstrated that TBC exhibited robust capacity for oxygen transport, heme binding, oxidative phosphorylation, and antioxidant responses in high-altitude regions. Further investigation of the function of hub TFs indicated the involvement of ATF4, CEBPA, TCF7L1, and GFI1B in improving oxygen transport in TBCs. These hub TFs were associated with angiogenesis or hematopoiesis and likely linked to various regulatory functions and facilitate communication across multiple tissues. In conclusion, TBCs have developed a systemic adaptive mechanism to cope with high altitudes, involving the coordinated transcriptional regulation in multi-tissues to enhance oxygen transport and utilization, along with amelioration of oxidative stress.

Meat quality is a key factor influencing consumer purchasing decisions. Muscle composition consists of various types of myofibers (type I and type IIa, IIb, IIx myofibers), and the relative composition of fiber types has a significant impact on the overall biochemical properties and flavor of fresh meat. However, the relationship between biochemical changes in myofibers and their impact on meat quality remains underexplored. In this study, we compared the differences in meat quality by examining different muscles in rabbits, each containing different muscle fiber types. We focused on the adductor (ADD) and semitendinosus (ST) as our research subjects and investigated skeletal muscle metabolism at the individual myofibers level using Spatial metabolomics. Additionally, we utilized LC-MS and RNA-Seq to explore the molecular mechanisms underlying the metabolic differences between red and white muscle fibers. Our findings demonstrated that variations in myofiber composition significantly influenced meat color, pH, water content, and drip loss. Spatial metabolomics analysis identified 22 unique red and white muscle fingerprint metabolites, while LC-MS analysis revealed 123 differential metabolites, and these differential metabolites were mainly enriched in the pathways of ABC transporters, Biosynthesis of amino acids, glutathione metabolism, and arginine biosynthesis. To further elucidate the molecular mechanism of differential metabolism in ADD and ST, we identified 2248 differentially expressed genes (DEGs) by RNA-Seq and then combined DEGs with DMs for joint analysis. We found that red muscle exhibited higher levels of metabolites such as L-glutamic acid, glutathione, ascorbate, ornithine, oxidized glutathione, gamma-L-glutamyl-L-cysteine, cysteinylglycine, fumaric acid, gamma-aminobutyric acid. Additionally, related metabolic genes such as MGST1, ODC1, MGST3 and PRDX6 were highly expressed in ST muscle. These metabolites and genes were enriched in the glutathione and nicotinamide pathways, and had significant effects on meat color and drip loss. Moreover, red muscle contained more flavor compounds and nutrients, including adenosine monophosphate (AMP), ornithine, citrulline, taurine, acetyl phosphate, L-glutamic acid metabolites, as well as taurine and hypotaurine metabolites. Our results demonstrate that fresh meat with a higher proportion of red muscle fibers exhibited superior meat quality, enhanced flavor, and higher nutrient content. Furthermore, red muscle contains more antioxidant metabolites that can effectively prevent meat oxidation during the production process.

Rabbits display a wide range of coat colors, with yellow being a particular phenotype that aids in exploring the molecular mechanisms of coat pigmentation. The Fujian yellow (FJY) rabbit, as China's only indigenous breed with a yellow coat, serves as a valuable genetic resource. Fujian yellow rabbits have predominantly yellow fur, with a diluted white hue on the distal limbs and tail. However, the genetic mechanism underlying yellow coat color remains unclear. To address this, we conducted selection signature analysis to identify candidate genes and potential casual mutations underlying the yellow phenotype in rabbits. Utilizing whole-genome resequencing, a total of 22 486 177 high-quality SNPs were identified from 30 individuals belonging to three Chinese indigenous rabbit breeds featured with yellow or non-yellow phenotype. The results revealed that the ASIP gene on chromosome 4 and the SNAI2 gene on chromosome 3 were under strong selection pressure, both of which play pivotal roles in determining coat color phenotypes. The ASIP gene is involved in melanogenesis across various livestock species, while the SNAI2 gene is linked to hypopigmentation in the distal regions such as the limbs and tail. We further identified two SNP variants, g.23870943C>T in the fourth intron of the ASIP gene, which is closely associated with the yellow phenotype, and g.73725380A>G downstream of the SNAI2 gene, probably contributing to the white shading in Fujian yellow rabbits' limb and tail regions. These variants are key determinants in the development of the yellow coat color in rabbits. These findings advance the understanding of coat color pigmentation in domestic animals.

Early weaning is frequently accompanied by a significant increase in diarrhea and mortality rates, which reduces rabbits’ performance. Although antibiotics can reduce pathogenic bacteria, they also harm beneficial microorganisms and disrupt the normal intestinal microbiota balance. In order to find non-residue and non-toxic alternatives to antibiotics to ensure the safety of animal products, we conducted a study on the effect of compound microecological preparations supplementation on lactating female rabbits and their offspring. A total of 60 female rabbits were randomly assigned to four groups: CON, supplemented with probiotics at 3, 6, and 9 g/female rabbit/day from day 24 of gestation until weaning. We observed that probiotics supplementation significantly enhanced production performance (P < 0.05), immune and antioxidant function (P < 0.05), as well as intestinal flora composition in lactating rabbits and their offspring. Notably, compared with the control group, the experimental group exhibited a 19.23%, 44.22%, and 24.57% increase in milk yield (P = 0.002). Regarding rabbit growth performance, the average body weight of young rabbits in the experimental group showed a significant increase of 3.59%, 10.22%, and 6.74% at day 35 (P = 0.022), whereas the average daily gain (ADG) of rabbits aged between 21 and 35 days was significantly elevated by 4.94%, 17.06%, and 6.28% in the experimental group (P < 0.001). In conclusion, probiotics supplementation can significantly enhance lactation performance, promote growth and disease resistance in rabbits, as well as improve intestinal health when administered at a dosage of 6 g/day. Moreover, the limited sample size in this study may hinder the detection of subtle effects, and augmenting the sample size will bolster the reliability of the study findings. IMPORTANCE The intestinal environment of rabbits is fragile and susceptible to environmental influences, leading to inflammatory intestinal diseases. Adding antibiotics to rabbit feed can achieve the effect of preventing and treating inflammation, which can also lead to the imbalance of the gut microbiota and residual antibiotics in agricultural products. Composite probiotics are live microbial feed additives composed of various ratios of probiotics and have become the most promising alternative to antibiotics due to their residue-free and non-toxic properties. The aim of this study was to investigate the impact of compound probiotics on lactating female rabbits and their offspring. Our findings highlight the potential of compound microecological preparations as an effective strategy for enhancing lactation performance, immune function, and antioxidant capacity in rabbits. The supplementation of probiotics through rabbit milk offers a promising approach to optimize the growth and health outcomes of newborn rabbits.

The differences between the high-starch diet commonly used in rabbit farming and the natural feeding habits of rabbits may pose certain health risks. In our study, we replaced part of the starch in the feed with soybean oil and conducted a 4-wk feeding trial with weaned Rex rabbits. The results indicated that rabbits fed the oil-supplemented diet had a lower incidence of diarrhea, improved growth performance, and higher feed conversion efficiency, along with increased absorptive capacity of small intestine. Additionally, the composition of the cecal contents and fermentation patterns were altered; the concentration of ammonia in the cecum and the proportion of acetate among volatile fatty acids decreased, while the proportion of butyrate increased. Furthermore, the concentration of ammonia nitrogen in the cecum decreased, along with reductions in hepatic urea synthesis activity and urinary nitrogen excretion. These findings suggest that replacing part of the dietary starch with oil can enhance the production efficiency of Rex rabbits.

Musk secreted by the musk glands in male forest musk deer (FMD; Moschus berezovskii) is highly valued for its pharmaceutical and perfumery applications. However, the regulatory mechanisms underlying musk secretion are not well understood. This study aimed to investigate the genes and transcription factors involved in musk secretion across different periods and ages. We analyzed the musk glands of adult male FMD during the non-secretory and secretory periods, as well as juvenile and adult male FMD during the secretory period, using single-cell multiome ATAC+gene expression technique. Our analysis identified 13 cell types, including acinar cells of Types 1 and 2. Chromatin accessibility analysis and gene expression data confirmed that the genes Map3k2, Hsd17b12, and Jun are critical for musk secretion. Additionally, EHF, NR4A2, and FOXO1 proteins play crucial regulatory roles. Weighted gene co-expression network analysis (WGCNA) highlighted the importance of GnRH signaling pathway in musk secretion. Gene set enrichment analysis (GSEA) showed that the steroid hormone biosynthesis pathway is notably enriched in acinar cells. Furthermore, intercellular communication appears to influence both the initiation and maintenance of musk secretion. These findings provide valuable insights into the molecular pathways of musk secretion in FMD, offering potential avenues for increasing musk production and developing treatment for inflammation and tumors.

Intramuscular fat (IMF) content is a predominant factor recognized to affect rabbit meat quality, directly impacting flavor, juiciness, and consumer preference. Despite its significance, the major interplay of genetic and epigenetic factors regulating IMF in rabbits remains largely unexplored. This review sheds light on this critical knowledge gap, offering valuable insights and future directions. We delve into the potential role of established candidate genes from other livestock (e.g. PPARγ, FABP4, and SCD) in rabbits, while exploring the identified novel genes of IMF in rabbits. Furthermore, we explored the quantitative trait loci studies in rabbit IMF and genomic selection approaches for improving IMF content in rabbits. Beyond genetics, this review unveils the exciting realm of epigenetic mechanisms modulating IMF deposition. We explored the potential of DNA methylation patterns, histone modifications, and non-coding RNA-mediation as fingerprints for selecting rabbits with desirable IMF levels. Additionally, we explored the possibility of manipulating the epigenetic landscape through nutraceuticals interventions to promote favorable IMF depositions. By comprehensively deciphering the genomic and epigenetic terrain of rabbit intramuscular fat regulation, this study aims to assess the existing knowledge regarding the genetic and epigenetic factors that control the deposition of intramuscular fat in rabbits. By doing so, we identified gaps in the current research, and suggested potential areas for further investigation that would enhance the quality of rabbit meat. This can enable breeders to develop targeted breeding strategies, optimize nutrition, and create innovative interventions to enhance the quality of rabbit meat, meet consumer demands and increase market competitiveness