Updated project metadata. Cultivated meat production requires stable, scalable muscle cell lines, yet the molecular consequences of immortalization in livestock species remain poorly characterized. In this study we establish CDK4/hTERT‑immortalized ovine satellite cells via flow‑cytometry‑based purification and dual lentiviral transduction, and perform integrated transcriptomic–proteomic profiling to define species‑specific adaptations relevant for cultivated meat applications. Label‑free quantitative proteomics was used to compare primary lamb satellite cells (PLM, passage 5) and late‑passage immortalized cells (LPILM, passage 30), revealing 960 differentially expressed proteins that collectively indicate coordinated extracellular matrix remodeling, inflammatory S100‑family activation, and erosion of canonical myogenic regulators without emergence of oncogenic signatures. Pathway and enrichment analyses (GO, KEGG) were performed to identify affected biological processes and metabolic pathways, and the proteomic dataset was further interrogated for allergenicity using AllergenOnline to support preliminary safety assessment for food use. The deposited dataset provides the full raw and processed LC‑MS/MS data, protein identifications, and quantitative values underlying all proteomics results in the manuscript, enabling reuse for comparative analyses of immortalized livestock cell lines and multi‑omics integration in cultivated meat research.