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.

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.

Fatty acid contributes notably to meat nutrition value. A previous study investigated how complex plant extracts (CPE) can improve the fatty acid composition of ruminants, but the molecular mechanism remains unknown. This study aimed to examine the effect of dietary CPE supplementation on sheep growth performance and fatty acid composition in back fat (BF), combining lipidomics and transcriptomics analyses to explain the underlying mechanisms. Thirty-six female sheep, weighing 29.92 ± 2.52 kg and of a similar age (~4 months old), were randomly assigned into two groups: one received a basal diet (CTRL group), and the other received the same diet supplemented with 80 mg/kg of CPE (CPE group) for 75 days. The results revealed that the values of carcass fat content (GR) in the CPE group were significantly increased (p = 0.008), and the composition of fatty acid was changed. Lipidomic analysis indicated that CPE modulated lipid metabolism by regulating the contents of lipid molecules such as phosphatidylcholine (PC), fatty acyls (FAs), cardiolipin (CL), and triglyceride (TAG). After the addition of CPE, the lipid metabolism of BF was regulated mainly by regulating the glycerophospholipid metabolism, TNF signaling pathway, and cytokine–cytokine receptor interaction signaling pathway. These results revealed that changes in fatty acids were affected by the added CPE and corresponding molecular changes, which may provide new insights on the molecular level for applying CPE in sheep to improve fatty acid composition.

This study aimed to investigate the regulatory effects of dietary dandelion supplementation on the ruminal physiological status of lambs fed a high-concentrate diet. Twenty-two 6-month-old female crossbred lambs with an initial body weight of 32.05 ± 0.43 kg were randomly assigned to two groups (n = 11 per group): the HC group (fed a high-concentrate basal diet) and the DD group (basal diet supplemented with 2 g/kg dandelion powder), with a 14-day adaptation and 60-day experimental period. The results showed that compared with the HC group, dandelion supplementation significantly improved lamb growth performance and modulated ruminal fermentation parameters and tissue morphology. For inflammatory indices, the concentration of interleukin-10 (IL-10) was significantly increased, while the concentrations of interleukin-1β (IL-1β), lipopolysaccharide (LPS) and histamine (HIS) were significantly decreased (p < 0.05). Meanwhile, dandelion supplementation upregulated the mRNA expression of ruminal epithelial tight junction proteins and hexokinase II (HK-II), while downregulating the mRNA expression of myeloid differentiation factor 88 (MyD88), voltage-dependent anion channel 1 (VDAC1), inositol 1,4,5-trisphosphate receptor (IP3R), NLR family pyrin domain containing 3 (NLRP3), and caspase-1. Metagenomic analysis revealed that dandelion supplementation did not alter ruminal microbial α-diversity, but slightly modulated community composition and functional profiles. The abundances of dominant phyla Bacteroidota and Bacillota showed only slight fluctuations, while fiber-degrading genera (Xylanibacter, Quinella, Selenomonas) showed a trend toward enrichment, and proteolytic taxa were decreased. CAZyme analysis revealed an upward trend in families CE4, CE8, GH32, and GH13_46 (pectin/starch degradation) and a downward trend in GH73, GH27, and GT14 (oligosaccharide/peptidoglycan/polysaccharide metabolism) in the DD group. KEGG orthology annotation suggested that nominal KO differences were mainly associated with carbohydrate metabolism pathways, including starch and sucrose metabolism and peptidoglycan biosynthesis. None of these features, however, remained significant after FDR correction (raw p < 0.05; all q > 0.05). Collectively, dietary dandelion supplementation was associated with alterations in ruminal physiological status and microbial community in lambs fed a high-concentrate diet, providing foundational data for dandelion application in lamb diets under short-term feeding conditions.