Bacterial communities in gastrointestinal tracts (GIT) play an important role in animal health and performance. Despite its importance, little information is available on the establishment of microbial populations in the goat GIT or on changes occurring during early development. Therefore, this study investigated the bacterial community dynamics of the rumen, duodenum, jejunum, ileum, cecum, and colon in 15 goats at five developmental stages (0, 14, 28, 42, and 56 days old) by using 16S rDNA sequencing and quantitative real-time PCR technology. 940 genera were found to belong to 44 phyla distributed along the GIT. As a whole, the microbial richness and diversity showed a clear increasing trend as the kids aged and alpha diversity differed significantly among GIT compartments mainly occurring at middle day ages (14 and 28 days). Principal coordinate analysis indicated that the bacterial community displayed distinct temporal and spatial specificity along the GIT in preweaning goats. As kids aged, the phylum Firmicutes was replaced by Bacteroidetes in rumen, whereas Proteobacteria in the large intestine was displaced by Firmicutes. The phylum Proteobacteria was mainly present in the small intestine in older animals. In the rumen, taxa, such as Bacillus and Lactococcus decreased and Prevotella, Treponema, Ruminococcus, and unclassified Prevotellaceae increased with the age of kids. Furthermore, a lower proportion of taxa, such as Lactobacillus and Bacteroides was observed with higher abundances of both Christensenellaceae_R_7 and Ruminococcus in duodenum and jejunum in older animals. In the large intestine, the microbiota displayed taxonomic dynamics with increases of Ruminococcaceae UCG 005, unclassified Lachnospiraceae, Barnesiella, and Blautia as kids aged. Predicted pathway analysis suggested that genes involved in amino acid metabolism, and translation were abundant in both rumen and duodenum, while genes involved in membrane transport and carbohydrate metabolism were enriched in the large intestine. These results indicate that both the microbial colonization process and potential function exert a temporal-spatial specificity throughout the GIT of goats. This study provides new insight into the temporal dynamics of GIT microbiota development during preweaning and will aid to develop strategies for improving animal health and downstream production.

Cashmere is a keratinized product derived from the secondary hair follicles (SHFs) of cashmere goat skins. The cashmere fiber stops growing following the transition from the actively proliferating anagen stage to the apoptosis-driven catagen stage. However, little is known regarding the molecular mechanisms responsible for the occurrence of apoptosis in SHFs, especially as pertains to the role of non-coding RNAs (ncRNAs) and their interactions with other molecules. Hair follicle (HF) degeneration is caused by localized apoptosis in the skin, while anti-apoptosis pathways may coexist in adjacent HFs. Thus, elucidating the molecular interactions responsible for apoptosis and anti-apoptosis in the skin will provide insights into HF regression. We used multiple-omics approaches to systematically identify long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and mRNAs expressed in cashmere goat skins in two crucial phases (catagen vs. anagen) of HF growth. Skin samples were collected from three cashmere goats at the anagen (September) and catagen (February) stages, and six lncRNA libraries and six miRNA libraries were constructed for further analysis. We identified 1122 known and 403 novel lncRNAs in the goat skins, 173 of which were differentially expressed between the anagen and catagen stages. We further identified 3500 gene-encoding transcripts that were differentially expressed between these two phases. We also identified 411 known miRNAs and 307 novel miRNAs, including 72 differentially expressed miRNAs. We further investigated the target genes of lncRNAs via both cis- and trans-regulation during HF growth. Our data suggest that lncRNAs and miRNAs act synergistically in the HF growth transition, and the catagen inducer factors (TGFβ1 and BDNF) were regulated by miR-873 and lnc108635596 in the lncRNA-miRNA-mRNA networks. This study enriches the repertoire of ncRNAs in goats and other mammals, and contributes to a better understanding of the molecular mechanisms of ncRNAs involved in the regulation of HF growth and regression in goats and other hair-producing species.

Adipose tissues are phenotypically, metabolically and functionally heterogeneous based on the sites of their deposition. Undesirable fat deposits in the body are often detrimental to animal and human health. To unravel the potential underlying mechanisms governing accumulation of adipose tissues in various regions of the body, i.e., subcutaneous (SAT), visceral (VAT) and tail (TAT), we profiled transcriptomes from Tan sheep, a Chinese indigenous breed with notable fat tail using RNA-seq. Upon comparison, we identified a total of 1,058 differentially expressed genes (DEGs) between the three adipose types (218, 324, and 795 in SAT/VAT, SAT/TAT, and VAT/TAT, respectively), from which several known key players were identified that are involved in lipid metabolic process, Wnt signals, Vitamin A metabolism, and transcriptional regulation of adipocyte differentiation. We also found that many elevated genes in VAT were notably enriched for key biological processes such as cytokine secretion, signaling molecule interaction and immune systems. Several developmental genes including HOXC11, HOXC12 and HOXC13, and adipose-expressed genes in the tail region, such as HOTAIR_2, HOTAIR_3 and SP9 were specially highlighted, indicating their strong associations with tail fat development in fat-tailed sheep. Our results provide new insight into exploring the specific fat deposition in tail, also contribute to the understanding of differences between adipose depots.

Carvacrol and thymol (CAT) have been widely recognized for their antimicrobial and anti‐inflammatory properties, yet their specific effects on colitis and the mechanisms involved remain insufficiently understood. This study establishes a causative link between CAT administration and colitis mitigation, primarily through the enhancement of Bifidobacterium pseudolongum abundance in the colon. This increase promotes the production of secondary bile acids, particularly hyodeoxycholic acid (HDCA) and 12‐ketodeoxycholic acid (12‐KCAC), which exert anti‐inflammatory effects. Notably, CAT does not alleviate colitis symptoms in germ‐free mice, indicating the necessity of gut microbiota. This research uncovers a novel regulatory mechanism where HDCA and 12‐KCAC inhibit colonic inflammation by reducing the expression of transmembrane guanylate cyclase 1A in the colonic epithelium. This downregulation elevates intracellular Ca²⁺ and cGMP levels, activating protein kinase G (PKG). Activated PKG subsequently suppresses the mTOR signaling pathway, thereby ameliorating dextran sulfate sodium (DSS)‐induced colonic damage. These findings highlight potential metabolites and therapeutic targets for preventing and treating colitis. Bifidobacterium pseudolongum, HDCA, and 12‐KCAC emerge as promising candidates for therapeutic interventions in colitis and related disorders characterized by impaired tight junction function.