In China, the processing of prickly ash (PA) produces a large number of by-products, including prickly ash seeds (PASs), which are rich in bioactive components such as flavonoids and phenolic compounds, and which may have an important influence on meat quality and muscle metabolites. Therefore, this study aimed to assess the impact of dietary PAS supplementation on the meat quality, antioxidant activity, and metabolite characteristics of lambs. Eighteen 3-month-old Hu lambs (25.66 ± 3.03 kg body weight) were randomly allotted to three different dietary treatment groups. In the three dietary treatments, 0% (basal diet, CON), 3% (CON with 3% PAS, low-dose PAS, and LPS), and 6% (CON with 6% PAS, high-dose PAS, and HPS) PASs were used. Results indicated significant improvements in the HPS group, including reduced cooking loss and increased fat content. The L* and b* 45 min values were significantly lower in the PAS groups than those in the CON group (p < 0.05). Additionally, dietary PAS supplementation increased in MUFA, PUFA, n-3 PUFA, PUFA/MUFA ratio, NEAA, and FFA compared to the CON group. Furthermore, PAS supplementation significantly improved serum and muscle antioxidant capacity. Metabolomic analyses revealed that increased metabolites, such as tryptophan, leucine, citric acid, adenosine 5′-triphosphate, creatine phosphate, inosine, and α-ketoglutaric acid, were primarily enriched in the biosynthesis of cofactors and nucleotide and purine metabolism pathways. Notably, supplementation with 6% of PASs exhibited the most prominent effect on lamb meat quality in this study. Therefore, the application of PASs as a feed component in lamb production can not only improve meat quality and muscle antioxidant capacity but also save feed costs.

It is known that the addition of feed rich in bioactive components to animal diets will affect rumen fermentation parameters and flora structure. However, research on the regulatory effects of prickly ash seeds (PASs) during rumen development or on the rumen microbiome and its metabolites in sheep is limited. The current study was designed to explore the effects of PASs on sheep rumen development and growth performance using metagenomics and metabolomics. Eighteen 3-month-old Hu lambs were randomly allotted to three different dietary treatment groups: 0% (basal diet, CK), 3% (CK with 3% PAS, low-dose PAS, LPS), and 6% (CK with 6% PAS, high-dose PAS, HPS) PASs. The lambs were slaughtered to evaluate production performance. Our results showed that dietary PAS addition improved the average daily gain and reduced the F/G ratio of the experimental animals. Additionally, the height and width of the rumen papilla in the treatment groups were significantly higher than those in the CK group. The fermentation parameters showed that the levels of acetate and butyrate were significantly higher in the LPS group than in the CK and HPS groups. The propionate levels in the HPS group were significantly higher than those in the CK and LPS groups. Metagenomics analysis revealed that PAS dietary supplementation improved the abundance of Clostridiales and Bacteroidales and reduced the abundance of Prevotella, Butyrivibrio, and Methanococcus. Metabolomic analyses revealed that increased metabolite levels, such as those of serotonin, L-isoleucine, and L-valine, were closely related to growth-related metabolic pathways. The correlations analyzed showed that papilla height and muscular thickness were positively and negatively correlated with serotonin and L-valine, respectively. Average daily gain (ADG) was positively and negatively correlated with L-valine and several Prevotella, respectively. In addition, muscular thickness was positively correlated with Sodaliphilus pleomorphus, four Prevotella strains, Sarcina_sp_DSM_11001, and Methanobrevibacter_thaueri. Overall, PAS addition improved sheep growth performance by regulating beneficial microorganism and metabolite abundances, facilitating bacterial and viral invasion resistance.