We investigated the effects of CEC on the fermentation characteristics, epithelial gene expression, and bacterial community in the rumen of lambs fed a high-concentrate diet. Twenty-four 3-month-old female crossbred lambs with an initial body weight of 30.37 ± 0.57 kg were randomly allocated to consume a diet supplemented with 80 mg/kg CEC (CEC) or not (CON). The experiment consisted of a 14 d adaptation period and a 60 d data collection period. Compared with the CON group, the CEC group had higher ADG, epithelial cell thickness, ruminal butyrate proportion, and lower ammonia nitrogen concentration. Increases in the mRNA expression of Occludin and Claudin-4, as well as decreases in the mRNA expression of apoptotic protease activating factor-1 (Apaf-1), cytochrome c (Cyt-C), Caspase-8, Caspase-9, Caspase-3, Caspase-7, and toll-like receptor 4 (TLR4), were observed in the CEC group. Moreover, CEC treatment also decreased the concentration of IL-1β, IL-12, and TNF-α. Supplementation with CEC altered the structure and composition of the rumen bacterial community, which was indicated by the increased relative abundances of Firmicutes, Synergistota, Rikenellaceae_RC9_gut_group, Olsenella, Schwartzia, Erysipelotrichaceae_UCG-002, Lachnospiraceae_NK3A20_group, Acetitomaculum, [Eubacterium]_ruminantium_group, Prevotellaceae_UCG-004, Christensenellaceae_R-7_group, Sphaerochaeta, Pyramidobacter, and [Eubacterium]_eligens_group, and the decreased relative abundances of Acidobacteriota, Chloroflexi, Gemmatimonadota, and MND1. Furthermore, Spearman correlation analysis revealed that the altered rumen bacteria were closely correlated with rumen health-related indices. Dietary CEC supplementation improved growth performance, reduced inflammation and apoptosis, protected barrier function, and modulated the bacterial community of lambs fed a high-concentrate diet.

Complex phytonutrients (CPS) have attracted extensive interest due to their anti-inflammatory effects. This investigation focused on the impact of CPS on rumen health in lambs on high-concentrate diets, emphasizing growth performance, ruminal fermentation, epithelial barrier integrity, ruminal metabolism, and microbial communities. A total of 54 lambs, 3 months old and with a 30.42 ± 0.54 kg body weight, were randomly assigned to three treatment groups, with six replicates per treatment and three lambs per replicate. The lambs received a basal diet (the ratio of concentrate to forage was 75:25) without CPS supplementation (CON) or with the inclusion of 2.5 g/kg (CPS2.5) or 5.0 g/kg CPS (CPS5.0) for a total of 60 days. The CPS groups exhibited increased growth performance and improved rumen fermentation parameters. Mechanistically, CPS enhanced rumen epithelial barrier function, thereby lowering inflammation and inhibiting the overactivation of the JNK/p38 MAPK signaling pathway, and the effect of CPS5.0 was better than that of CPS2.5. Notably, CPS5.0 could optimize the composition of rumen microbiota and increase the levels of Ursolic acid and other metabolites. The strong associations between rumen bacteria and health-related indicators and differential metabolites were further highlighted. Our findings suggest that adding CPS to lambs’ diets has widespread positive impacts, including improved growth performance, reduced inflammation and mRNA relative expression of apoptosis-related genes, enhanced barrier function, and beneficial changes in the rumen microbiome and metabolite profiles.

Lipopolysaccharide (LPS) triggers oxidative damage in sheep hepatocytes, linked to ferroptosis. Ferulic acid (FA) is known for its antioxidative properties, but its protective role against LPS via ferroptosis regulation was unclear. The objective of this research is to explore the protective role of FA in mitigating LPS-induced oxidative stress in sheep hepatocytes. The experimental setup consisted of three groups: a control group, an LPS group treated with 10 µg/mL of LPS, and FA group that received both 10 µg/mL of LPS and 750 µg/mL of FA. We found that FA treatment decreased in contents of MDA and LDH. Metabolomics revealed that LPS affected glycerophospholipid metabolism, unsaturated fatty acids biosynthesis, ferroptosis, and arachidonic acid metabolism mainly by reducing the level of PUFAs and LPC in the hepatocyte supernatant, while FA affected glutathione metabolism by increasing L-cysteine, L-ornithine, L-glutamic acid, and L-glutamine. Moreover, transcriptomics demonstrated that the comparison of LPS and control groups were mainly enriched in arachidonic acid metabolism, glycerophospholipid metabolism, and ferroptosis, the comparison of FA and LPS groups was mainly enriched in glutathione metabolism. The results further confirmed the findings in the metabolomics and transcriptomics analyses, showing that LPS treatment upregulated the mRNA expression of ACSL4, LPCAT3, ALOX15, STEAP3, GPX4, GCLC, and GCL in hepatocytes, while reducing GSH and GR levels. In contrast, FA intervention attenuated LPS-induced iron overload by decreasing Fe²⁺ accumulation and suppressing the mRNA expression of ACSL4, LPCAT3, STEAP3, and ALOX15. Furthermore, FA enhanced the expression of GPX4, GCLC, GCLM, and restored GSH content in LPS-exposed hepatocytes. The above results demonstrated that the protective effect of FA on LPS-induced oxidative damage in the sheep hepatocytes was achieved by activating the GSH-GPX4 pathway and inhibiting lipid metabolism-mediated ferroptosis.

Dietary regulation of intramuscular fat (IMF) deposition and fatty acid composition offers an effective strategy to enhance meat nutritional value. As phytogenic supplements rich in bioactive compounds, complex plant extracts (CPE) have demonstrated potential in improving meat quality through lipid metabolism modulation while ensuring food safety. In this study, we used 36 female sheep, approximately 4 months old and with a similar weight (29.92 ± 2.52 kg), to investigate the effects of CPE supplementation (80 mg/kg) on lipid metabolism. After the 75-day standardized feeding trial, the sheep were subjected to humane slaughter procedures and collected the Longissimus dorsi muscle (LDM) for further experimental process. The findings indicate that CPE significantly increased (p < 0.05) the IMF content (36%) and total fatty acids concentration (10,045.79 to 26,451.99 ug/g). Lipid metabolism in LDM was mainly affected by regulating phospholipids (six lipid subclasses were affected). The qRT-PCR analysis showed that differential expressed genes, PLA2G2D and PLA2G4E, associated with lipid metabolism were significantly reduced. CPE appears to modulate the fatty acids through sphingolipid, linolenic acid metabolism, and glycosphingolipid biosynthesis pathways. Thus, this study uncoded the mechanisms of CPE on fatty acid, providing critical evidence that CPE can regulate the meat quality of ruminants.

This study aimed to determine the optimal supplementation level of sodium humate (SH) for improving rumen fermentation efficiency in vitro. Using rumen fluid from four donor ewes with three experimental replicates per treatment, we evaluated a basal diet supplemented with SH at 0 (control), 0.5 (SH0.5), 1 (SH1), and 2 (SH2) g/kg dry matter. The results of this study revealed that after 12 h of incubation, compared to the control group, the SH0.5 group significantly decreased gas production (GP) by −11.66% (p < 0.01). There were no significant differences in pH values, bacterial crude protein (BCP) content, and ammonia nitrogen (NH₃-N) concentration among the groups (p > 0.05). After 24 h of incubation, no significant differences in pH values were observed among the groups (p > 0.05). The SH1 group exhibited significantly higher BCP content compared to other treatments (p < 0.05), concomitant with a marked reduction in NH₃-N concentration (p < 0.01). Compared to the control group, GP in the SH1 group increased significantly by 7.16%, and a significant increase of 5.43% (p < 0.05), while it decreased significantly by −9.96% in the SH0.5 group (p < 0.01). However, no significant differences in volatile fatty acids were observed among the groups after either 12 or 24 h of fermentation. The addition of 1 g/kg SH altered the composition of the rumen bacterial community, which was indicated by the increased relative abundances of Prevotella, Anaerovibrio, and Saccharofermentans and the decreased relative abundances of Actinobacteriota, Lachnospiraceae_NK3A20_group, and [Ruminococcus]_gauvreauii_group (p < 0.05). Furthermore, Anaerovibrio was negatively correlated with NH₃-N and positively correlated with gas production, while [Ruminococcus]_gauvreauii_group was negatively correlated with gas production. The study indicates that the addition of 1 g/kg SH optimizes rumen fermentation efficiency and improves nutrient utilization by modulating the structure and composition of the bacterial community, thus serving as an effective additive for enhancing rumen fermentation and feed utilization in ruminants.