Updated project metadata. Arouquesa breed is an autochthonous Portuguese breed produced under a traditional mountain system. It is known for its Arouquesa PDO beef, a high-quality product with valued organoleptic characteristics. There is a need to improve production systems without affecting beef quality. The aim of this work is to compare the proteomics profile from the Longissimus thoracis muscle from Arouquesa animals produced under different systems. Sixty weaners were produced under the following systems: traditional (TF) and traditional with starter feed supplementation (TF+S1) with weaning and slaughtering at 8 months, the S1+S2 (weaning at 5 months and grower supplement until slaughter) and two rearing periods with finishing supplementation (TF+S3 and S3). Upon slaughter, samples of L. thoracis were taken and analyzed using a shotgun proteomics workflow. Several putative biomarkers of beef quality for the Arouquesa breed were identified: VIM, FSCN1, SERPINH1, ALDH1A1, NDUFB5, ANXA1, PDK4, CEMIP2, NDUFB9, PDLIM1, OXCT1, MYH4. These proteins were involved in actin binding, skeletal muscle development and in the mitochondrial respiratory chain and they can influence mostly meat tenderness and color. Our results demonstrate the link between production practices and putative meat quality signatures, that have potential to improve traceability of certified products.