Costameres are essential for maintaining the integrity of muscle fibers, which affects the meat tenderness. To explore the pattern of alteration in costameres after slaughter, this study investigated the distribution of costamere proteins (desmin, talin-2, vinculin, and integrin β1), their impact on tenderness, and the involved enzymes. Western blot analysis showed that talin-2 significantly degraded in postmortem, while integrin β1 significantly increased at 48 h (