Equine osteoarthritis (OA) is a major cause of lameness and economic loss in horses. While platelet-rich plasma (PRP) has clinical potential, the biological effects of fresh PRP (F-PRP) and freeze-dried PRP (FD-PRP) remain insufficiently defined. This pilot study compared 25% and 50% F-PRP and FD-PRP in an interleukin-1β-induced equine cartilage-synovium explant co-culture model. PRP treatments reduced inflammatory responses, with significant downregulation of COX-2 and PGE2 expression, and 25% F-PRP showed the most consistent inhibition of nitric oxide production. PRP also significantly reduced glycosaminoglycan release and altered matrix-related gene expression; however, FD-PRP significantly upregulated MMP13, indicating a potential pro-catabolic response. Untargeted LC/MS metabolomics showed that F-PRP and FD-PRP were associated with changes in glucose, purine, amino acid, lipid, and nucleotide metabolism. Growth factor analysis further showed lower PDGF and TGF-β1 concentrations in FD-PRP than in F-PRP. Overall, F-PRP showed more consistent anti-inflammatory and matrix-protective effects, whereas FD-PRP requires further optimization and safety validation before clinical application.

This study characterized the rumen microbiota of Duolang sheep, a Xinjiang local breed, to identify potential probiotics for Hu sheep. 16S rRNA sequencing revealed that Duolang sheep possessed a distinct rumen microbial structure (beta-diversity, p < 0.05), lower diversity (higher Simpson index, p < 0.01), and a higher Firmicutes-to-Bacteroidetes ratio compared to Hu sheep. Subsequently, a Duolang-derived strain, Ligilactobacillus salivarius (L. salivarius) KS1018, was evaluated in a 56-day feeding trial with Hu sheep. Supplementation enhanced systemic immunity (serum IgG and IgM) and antioxidant status (SOD) (p < 0.05). Metabolic profiles were also modified, with serum β-hydroxybutyrate (BHB) level increasing significantly in both medium-dose (p < 0.001) and high-dose (p < 0.05) groups, whereas BUN and lipid markers (TG, CHOL) elevated significantly in the medium-dose (p < 0.05) and high-dose group (p < 0.05), respectively. The strain with medium- and high-dose also reduced fecal crude fat (p < 0.01) and influenced mucosal secretory immunoglobulin A (sIgA) by increasing levels in the duodenum while decreasing them in the rumen (p < 0.05). Ruminal histology was also altered (p < 0.01). Spearman’s correlation analysis showed that Prevotellaceae_UCG-003 was positively correlated with serum BUN (p < 0.001), IgM (p < 0.05), BHB (p < 0.01), and SOD (p < 0.01). Overall, L. salivarius KS1018 improved antioxidant capacity, systemic and mucosal immunity, and ruminal structure in Hu sheep, demonstrating its potential to influence host–microbe interactions in livestock.

Rumen-derived probiotics may help regulate fermentation and microbial activity in lambs, but the dose-related effects remain unclear. This study evaluated the effects of rumen-derived Ligilactobacillus salivarius KS1018 on rumen function in Hu lambs using integrated assessments of growth performance, serum hormones, rumen fermentation, rumen microbiota and metabolomics profiling. Thirty-two male Hu lambs were allocated to four groups (n = 8/group): control (C) or KS1018 at 0.5 × 10⁹ (L), 1.0 × 10⁹ (M), or 1.5 × 10⁹ CFU/lamb/day (H) for 56 days. Growth performance, including final BW and ADG, did not differ significantly among groups (p > 0.05). Serum T3 and T4 were significantly higher in M and H than in C (p < 0.01). Group H exhibited significantly lower NH₃-N and higher total VFA concentration of rumen fluid compared with group C (p < 0.05). Significant increases in isobutyric acid concentration were observed in groups M and H (p < 0.05). Genus-level shifts and dose-related metabolite changes were detected; oxidative phosphorylation was enriched in group H and amino acid biosynthesis in group M. Procrustes analysis indicated significant concordance between the rumen microbiome and metabolome datasets (M² = 0.56, p < 0.001). These results indicate that KS1018 supplementation was associated with dose-related changes in rumen fermentation and selected microbiome–metabolome associations in Hu lambs, although the optimal dose requires further validation.