In Portugal, sheep and goat meat production constitutes 2.8% of the total meat production, with a self-sufficiency of ~82%. The main autochthonous sheep breeds exploited for meat production are Churra-Galega-Bragançana (CGB) and Bordaleira-de-Entre-Douro-e-Minho (BEDM), whose quality must be optimised in order to ensure adequate income levels for sheep producers. The study aimed to characterise the evolution of spoilage microorganisms in refrigerated vacuum-packed (VP) lamb meat from BEDM and CGB breeds; and elucidate how intrinsic properties of meat can affect its microbial spoilage. Meat from BEDM breed presented higher (p0.05), the growth of spoilage bacteria was found to be exacerbated by higher moisture (p