Improving meat quality of the broiler chicken: integrated mechanistic frameworks linking pre-slaughter determinants, postmortem transformations, and multi-omics technology.

Broiler meat quality is governed by complex biological interactions spanning genetic, nutritional, environmental, and management factors, yet current literature remains fragmented across disciplinary silos. Most studies focus independently on pre-slaughter conditions or postmortem processes, limiting mechanistic understanding of how upstream determinants collectively shape meat quality outcomes. This review addresses this gap by proposing a unified mechanistic framework that integrates pre-slaughter factors, muscle metabolism at slaughter, and postmortem biochemical transformations as interconnected components governing final meat quality traits, with multi-omics approaches enabling system-level resolution. The framework identifies key mechanistic hubs, including muscle energy metabolism, mitochondrial function, oxidative balance, calcium homeostasis, and proteolytic systems, which act as central regulators linking pre-slaughter influences on postmortem conversion dynamics. These processes collectively determine pH decline kinetics, protein degradation, lipid oxidation, and structural integrity during postmortem transformation, ultimately shaping tenderness, water-holding capacity, color stability, flavor development, and susceptibility to quality defects such as pale, soft, exudative and dark, firm, dry meat. A key feature of the synthesis is resolution of persistent trade-offs in the literature, including growth efficiency versus meat quality, oxidative stability versus nutritional enrichment, and rapid muscle accretion versus myopathy susceptibility. The review further integrates multi-omics technologies, linking genomic variants, proteomic pathways, and metabolomic signatures with physiological and phenotypic outcomes, thereby enabling predictive modeling of meat quality traits across production stages. This system level integration provides a foundation for integrated precision management strategies to highlight the coordinated control of pre-slaughter conditions, muscle metabolism, and postmortem processes in commercial broiler systems to achieve improved quality broiler meat production.