Scutellariae radix flavonoid extract (SFE) has been acknowledged for its antioxidant, anti-inflammatory and antimicrobial properties in enhancing gastrointestinal microbial communities and improving the host’s immunity. Nevertheless, the impacts of dietary supplementation with SFE on the gastrointestinal microbes and host metabolism in dairy cows remain uncertain. Therefore, the aim of this study was to assess the effects of dietary supplementation with SFE on the lactation performance, gastrointestinal microbes, and plasma biochemical parameters of dairy cows. Six ruminally and duodenally cannulated multiparous dairy cows were used in a crossover design over 28-d periods that included a 21-d adaptation and a 7-d sample collection period. Cows were fed a basal diet (CON group) or a basal diet supplemented with SFE at 25 g/d (SFE group). SFE supplementation tended to increase milk yield (P = 0.067) and milk urea N concentration (P = 0.079), and decreased the milk somatic cell counts (SCC, P = 0.036). Cows in the SFE group had lower plasma aspartate aminotransferase (AST), malondialdehyde (MDA), tumor necrosis factor (TNF-α), and interleukin-1β concentrations compared with the CON (P < 0.05). Meanwhile, SFE supplementation increased butyrate concentration in the rumen (P = 0.044). The microbial structure of rumen and duodenum were affected by SFE supplementation (P = 0.009 and P = 0.031; respectively), resulting in enrichment of Butyrivibrio in both parts of the SFE cows (P = 0.034 and P = 0.029; respectively). However, microbial structure and composition of feces were not affected by SFE supplementation. Overall, our study indicated that dietary supplementation with SFE could enhance lactation performance and milk quality in dairy cows by improving the gastrointestinal inner environment and health status.

The aims of the present study were to investigate the effects of dietary supplementation with rumen-protected taurine (RPT) on the whole-body protein turnover, the plasma metabolomics, and the whole blood cell transcriptomics in steers. Eight steers, averaging 220 ± 3.26 kg of liveweight, were allocated in a replicate 4 × 4 Latin square design. The experimental treatments consisted of four levels of RPT supplementation: 0, 25, 50, and 75 g RPT per day, added to a basal diet. The results showed that supplementation with RPT linearly decreased the fecal nitrogen (N) excretion (P = 0.001) and the ¹⁵N fractional recovery rate (P = 0.047), while it linearly increased the urinary excretion of taurine (P = 0.045) as well as the average daily weight gain (P = 0.003), the protein synthesis (P < 0.001), the protein degradation (P < 0.001) and the whole-body protein turnover (P < 0.001). Supplementation with RPT linearly increased the plasma concentrations of growth hormone (P = 0.005) and quadratically affected the plasma concentration of insulin-like growth factor-1 (P = 0.013), and it linearly decreased the plasma concentration of albumin (P = 0.022). Supplementation with RPT altered the whole blood cell mRNA expression and upregulated the expressions of the marker genes, including RPS6KB1, PRSS42, COL1A2, ENSBTAG00000013055 and ENSBTAG00000038159 which are related to protein metabolism. The plasma metabolomics profiling indicated that supplementation with RPT upregulated the plasma concentrations of taurine, lysine and methionine. The experiment revealed the impact and the mechanisms of taurine on driving whole-body protein turnover and protein accretion in steers. Two novel marker genes which could be related to body protein degradation in steers were identified.

Newborn goat kids exposed to environmental stress are susceptible to diarrhea due to immature intestinal functions and undeveloped gut microbiota. Butyrate-producing bacteria as next generation probiotics benefit the maintenance of intestinal health, but the mode of regulation is still unclear. Herein, a novel butyrate-producing strain was isolated from sheep rumen and identified as Clostridium beijerinckii (C. beijerinckii) R8, thereafter goat kids were treated with C. beijerinckii R8 to elucidate its regulatory mechanisms on diarrhea. Thirty-six goat kids were assigned to four groups: control (CON), low dose (LCB; supplementation with 5 × 10⁷ CFU/mL of C. beijerinckii R8, each with 10 mL/d), middle dose (MCB; supplementation with 5 × 10⁸ CFU/mL of C. beijerinckii R8, each with 10 mL/d), high dose (HCB; supplementation with 5 × 10⁹ CFU/mL of C. beijerinckii R8, each with 10 mL/d). The experiment lasted for 15 d, and 6 goat kids were randomly selected from each group for slaughter on the last day of the trial. The results showed that this isolate reduced the diarrhea rate (P < 0.001) and fecal scores (P < 0.001). In the gut, its supplementation inhibited inflammation, increased antioxidant capacity, and regulated intestinal flora. Meanwhile, C. beijerinckii R8 strengthened the intestinal barrier and altered the jejunum morphology. This evidence suggests that C. beijerinckii R8 may alleviate diarrhea in goat kids by regulating microbiota, which is directly related to intestinal barrier and immune capacity.

The purpose of this study was to gain insight into the mechanism of iron dextran (DexFe) absorption in the intestines. A total of 72 piglets (average BW = 7.12 ± 0.75 kg, male to female ratio = 1:1) weaned at 28 d of age were randomly divided into two treatment groups with six replicates for each group. The experimental diets included the basal diet supplemented with 100 mg/kg iron dextran (DexFe group) and the basal diet supplemented with 100 mg/kg FeSO₄·H₂O (CON group). The experiment lasted for 28 d. The piglets' intestinal iron transport was measured in vitro using an Ussing chamber. Porcine intestinal epithelial cell line (IPEC-J2) cells were used to develop a monolayer cell model that explored the molecular mechanism of DexFe absorption. Results showed that compared to the CON group, the ADG of pigs in the DexFe group was improved (P = 0.022), while the F/G was decreased (P = 0.015). The serum iron concentration, apparent iron digestibility, and iron deposition in the duodenum, jejunum, and ileum were increased (P < 0.05) by dietary DexFe supplementation. Piglets in the DexFe group had higher serum red blood count, hemoglobin, serum iron content, serum ferritin and transferrin levels and lower total iron binding capacity (P < 0.05). In the Ussing chamber test, the iron absorption rate of the DexFe group was greater (P < 0.001) than the CON group, and there was no significant difference between the DexFe group and the glucose group (P > 0.05). Furthermore, when compared to the CON group, DexFe administration improved (P < 0.05) SLC2A5 gene and glucose transporter 5 (GLUT5) protein expression but had no effect (P > 0.05) on SLC11A2 gene or divalent metal transporter 1 (DMT1) protein expression. Once the GLUT5 protein was suppressed, the iron transport rate and apparent permeability coefficient were decreased (P < 0.05) in IPEC-J2 monolayer cell models. The findings suggest the effectiveness of DexFe application in weaned piglets and revealed for the first time that DexFe absorption in the intestine is closely related to the glucose transporter GLUT5 protein channel.

The rumen is an important organ that enables ruminants to digest nutrients. However, the biological mechanism by which the microbiota and its derived fatty acids regulate rumen development is still unclear. In this study, 18 female Haimen goats were selected and slaughtered at d 30, 60, and 90 of age. Multi-omics analyses (rumen microbial sequencing, host transcriptome sequencing, and rumen epithelial metabolomics) were performed to investigate host–microbe interactions from preweaning to postweaning in a goat model. With increasing age, and after the introduction of solid feed, the increased abundances of Prevotella and Roseburia showed positive correlations with volatile fatty acid (VFA) levels and morphological parameters (P < 0.05). Epithelial transcriptomic analysis showed that the expression levels of hub genes, including 3-hydroxy-3-methylglutaryl-CoA synthase isoform 2 (HMGCS2), enoyl-CoA hydratase, short chain 1 (ECHS1), and peroxisome proliferator activated receptor gamma (PPARG), were positively associated with animal phenotype (P < 0.05). These hub genes were mainly correlated to VFA metabolism, oxidative phosphorylation, and the mammalian target of rapamycin (mTOR) and peroxisome proliferator activated receptor (PPAR) signaling pathways (P < 0.05). Moreover, the primary metabolites in the epithelium changed from glucose preweaning to (R)-3-hydroxybutyric acid (BHBA) and acetoacetic acid (ACAC) postweaning (P < 0.05). Diet and butyrate were the major factors shaping epithelial metabolomics in young ruminants (P < 0.05). Multi-omics analysis showed that the rumen microbiota and VFA were mainly associated with the epithelial transcriptome, and that alterations in gene expression influenced host metabolism. The “butanoate metabolism” pathway, which transcriptomic and metabolomic analyses identified as being upregulated with age, produces ketones that regulate the “oxidative phosphorylation” pathway, which could provide energy for the development of rumen papillae. Our findings reveal the changes that occur in the rumen microbiota, host transcriptome, and metabolome with age, and validate the role of microbiota-derived VFA in manipulating host gene expression and subsequent metabolism. This study provides insight into the molecular mechanisms of host–microbe interactions in goats and supplies a theoretical basis and guidance for precise nutritional regulation during the critical time window for rumen development of young ruminants.

This study aimed to compare the effects of dietary methionine (Met) and 2-hydroxy-4-(methylthio)-butanoate (HMTBA) on the eggshell quality of broiler breeder hens and elucidate the mechanism of Met in improving eggshell quality from the perspectives of eggshell microstructure and shell gland physiological function. A total of 720 WOD188 broiler breeder hens at 40 weeks old were assigned to 3 groups, with 8 replicates per group and 30 birds per replicate. Over 7 weeks, birds were fed a basal diet or the same diet supplemented with 0.15% Met or 0.17% HMTBA. Our findings revealed significant improvements in the Met group for egg shape index, shell thickness, breaking strength, and fracture toughness (P < 0.05), whereas the HMTBA group showed no significant improvements (P > 0.05). Met supplementation increased calcium and phosphorus levels in both serum and shell gland tissue (P < 0.05), and enhanced Ca²⁺ ATPase activity in shell gland tissue (P < 0.05). Histomorphological changes cluded enhanced mucosal fold dimensions and increased epithelial height in the shell gland (P < 0.05). Met also improved eggshell ultrastructure, resulting in a thicker effective layer and broader mammillae with fewer type B structures (P < 0.05). The mRNA levels for genes regulating eggshell ultrastructure, such as ovocleidin-116 (OC-116), calbindin 1 (CALB1), and integral membrane protein 2C (ITM2C), were significantly upregulated in the Met group (P < 0.05). Transcriptome analysis identified 248 differentially upregulated genes in the Met group, primarily linked to the non-canonical Wnt/Ca²⁺ signaling pathway, crucial for calcium ion transport and cellular proliferation. This research highlights that Met supplementation improves eggshell quality by enhancing calcium transport and cellular proliferation in uterine function, particularly through the modulation of Wnt family member 11 (WNT11) and CALB1, influencing calcium deposition and ultrastructural development.

Heat stress poses a significant threat to the global livestock industry, particularly impacting dairy cows due to their higher metabolic heat production and increased susceptibility. The rumen microbiota plays a crucial role in regulating heat stress in dairy cows. Moreover, the rumen-mammary gland axis has been recently unveiled, indicating that rumen bacteria and their metabolites can influence mammary gland health and function. Extracellular vesicles, cell-derived vesicles, are known to carry various biomolecules and mediate intercellular communication and immune modulation. This review proposes the hypothesis that heat stress poses a threat to dairy cows via the rumen-mammary gland axis by regulating rumen microbiota and their secreted extracellular vesicles. It summarizes existing knowledge on bacterial extracellular vesicles and the rumen-mammary gland axis, suggesting that targeting the rumen microbiota and their extracellular vesicles, while enhancing mammary gland health through this axis, could be a promising strategy for preventing and alleviating heat stress in dairy cows. The aim of this review is to offer new insights and guide future research and development efforts concerning heat stress in dairy cows, thereby contributing to a deeper understanding of its pathogenesis and potential interventions.

Dietary sanguinarine (SAN) can enhance the growth performance of poultry and livestock, but the regulatory mechanism of the SAN monomer on intestinal homeostasis and how it promotes growth performance has not yet been clarified. In this study, 200 chickens were divided into four groups and fed different doses of SAN (0, 0.225, 0.75, 2.25 mg/kg) for transcriptome and microbiota analysis. The data showed that different doses of SAN supplementation increased the feed conversion rate (FCR) of 22 to 42 d old and 1 to 42 d old broilers (P < 0.01), and 0.225 mg/kg SAN reduced the contents of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (CREA) and blood urea nitrogen (BUN) in serum (P < 0.01). Dietary SAN increased the villus height and the villus height/crypt depth (V/C) ratio in the ileum (P < 0.01). The levels of tight junction proteins (zonula occludens-1, occludin and claudin-1) were up-regulated in the ileum and cecum (P < 0.01) and the levels of immunoglobulin (Ig) A, IgM, IgG, interleukin (IL)-4, IL-10 and interferon (IFN)-γ were up-regulated in the serum and ileum (P < 0.01). RNA-seq analysis revealed 385 differentially expressed genes (DEGs) (|log₂ fold change| ≥ 1, FDR < 0.05) between the SAN group and CON group. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed 15 pathways mostly associated with the immune system. Additionally, the reverse transcription-PCR results showed that the relative mRNA expression of β-defensin and mucin 2 were up-regulated (P < 0.01) and Toll-like receptor (TLR2 and TLR4) mRNA expression were down-regulated by SAN (P < 0.01), which was consistent with the transcriptomic analysis. Western blot analysis also showed that SAN reduced the expression of inflammatory proteins such as TLR4, nuclear factor-kappa B and IL-1β in the ileum (P < 0.01). In addition, at the genus level, SAN significantly increased the relative abundance of bacteria (Bacteroides, unclassified_f__Lachnospiraceae, Lactobacillus and Romboutsia) involved in acetate and butyrate production in the cecum, which are associated with enhanced intestinal immune function and maintaining intestinal health. In conclusion, SAN ameliorates the growth performance of broilers, enhances intestinal immune function, regulates the structure of microbiota and maintains intestinal health.

The aim of this study was to investigate the effect of dietary supplementation with 25-hydroxyvitamin D₃ (25(OH)D₃) on productive performance, lipid metabolism and gut microbiota in aged laying ducks. A total of 432 healthy Longyan ducks at 60-week of age were randomly allotted to 6 groups, each with 6 replicates of 12 ducks. Ducks were given a basal diet (without added 25(OH)D₃) or that diet supplemented with 800, 1600, 2400, 3200, or 4000 IU/kg 25(OH)D₃ for a total of 16 wk. Dietary supplementation with 25(OH)D₃ improved egg production, egg mass and average daily feed intake, and decreased the feed conversion ratio (FCR) of ducks during the whole trial period (linear, quadratic; P < 0.05). Supplementation with 25(OH)D₃ decreased very low-density lipoprotein (VLDL) content in yolk (P = 0.008), decreased high-density lipoprotein and low-density lipoprotein (LDL) content in plasma (P = 0.002). Hepatic index, VLDL, LDL, triglyceride and total cholesterol content in liver, nonalcoholic fatty liver activity score of liver and alanine aminotransferase activity in plasma were decreased with supplementation of 25(OH)D₃ (linear or quadratic; P < 0.05). The decreased hepatic apolipoprotein B 100 and lipoprotein lipase expression, and increased hepatic peroxisome proliferator-activated receptor-α and sterol regulatory element binding protein-1 expression resulted from 25(OH)D₃ supplementation (linear, quadratic; P < 0.05). Moreover, 25(OH)D₃ supplementation increased the villus/crypt ratio (linear, quadratic; P < 0.05) and expression of zonula occludens protein 1 and nuclear factor-κ-gene binding in duodenum (P < 0.05). The supplementation of 25(OH)D₃ reduced the abundance of Wittenberg polluted soil-2 bacteria, Synergistota, Bacteroidales, Colidextribacter, Eggerthellaceae, Oscillospira, Oscillibacter, UCG-009, Barnesiellaceae and Lachnospiraceae_UCG-010 in cecal contents (P < 0.05). Dietary requirements for 25(OH)D₃ for ducks (60 to 76 wk), were estimated to be 3377 IU/kg for egg production, 3434 IU/kg for egg mass, and 3256 IU/kg for FCR. In summary, dietary 25(OH)D₃ supplementation improved productive performance and influenced liver and plasma lipid homeostasis in aged laying ducks, which may be associated with the reduction of bacteria involved in carbohydrate metabolism in the cecum. Supplementing the basal diet with 3250 to 3450 IU/kg 25(OH)D₃ is recommended for aged laying ducks (60 to 76 wk).

High energy diets are a risk factor for intestinal barrier damage. Butyrate, a major energy source for intestinal epithelial cells, has been shown to improve barrier dysfunction and modulate the gut microbiota. In this trial, we examined the preventative effect of coated sodium butyrate (CSB) on high-energy and low-protein (HELP)-induced intestinal barrier injury in laying hens, and also worked to determine the underlying mechanisms by an integrative analysis of gut microbiota and the metabolome. A total of 216 healthy 28-week-old Huafeng laying hens were randomly assigned to 3 groups with 6 replicates each: the CON group (normal diet), HELP group (HELP diet) and CH500 group (500 mg/kg CSB added to HELP diet). The duration of the trial encompassed a period of 10 weeks. The results revealed that CSB treatment improved the laying rate and mitigated the detrimental effects on intestinal barrier function and the inflammatory response induced by the HELP diet in laying hens (P < 0.05). Microbial profiling analysis revealed that the CSB treatment reshaped the HELP-perturbed gut microbiota and promoted the growth of beneficial bacteria (P < 0.05). Untargeted metabolomics analysis revealed that CSB reduced the metabolites associated with intestinal inflammation (P < 0.05). In conclusion, CSB did not merely modulate alterations in the gut microbiota composition and microbial metabolites but also yielded increased egg production, while mitigating intestinal barrier dysfunction and inflammatory responses induced by HELP in laying hens.