Animal welfare and meat quality are pivotal for the sustainable development of the agri-food industry, directly impacting economic efficiency, consumer perception, and compliance with EU regulations. Crucially, the stunning method utilized during slaughter dictates both animal welfare and final product quality. This project delivers a multidisciplinary comparison between two commercial poultry stunning techniques: electrical and $CO_2$ controlled atmosphere stunning. By integrating technopathology, physicochemical parameters, and sensory analysis, the study also evaluates the influence of broiler body mass to uncover potential interactions between individual animal traits and the stunning procedure. The innovation of this research lies in its holistic approach, simultaneously assessing carcass defects (petechiae, hemorrhages, fractures) alongside technological quality parameters (pH, color, water holding capacity, texture) and sensory attributes (tenderness, juiciness, aroma, acceptability). Ultimately, this work aims to optimize slaughter processes, minimize economic losses, and provide robust indicators for quality management and animal welfare in poultry production systems.