Ferroptosis induced by preslaughter shackling stress: a mechanism underlying quality deterioration in broiler muscle during postmortem storage

This study systematically examined whether preslaughter shackling stress induces ferroptosis in postmortem broiler muscle. Broilers were allocated into non‑shackled ( C ) and 5‑min shackled ( T ) groups. Untargeted metabolomic analysis of storage exudates from both groups suggested that the observed quality deterioration might be linked to activation of the ferroptosis pathway. Compared with group C, mitochondria in group T exhibited morphological features of ferroptosis, such as shrinkage and outer membrane rupture, along with functional impairment. Additionally, intracellular ferrous ions ( Fe²⁺ ) concentrations increased in group T, leading to iron‑dependent oxidative damage and disruption of intracellular redox homeostasis. Meanwhile, the expression levels of SLC7A11 and glutathione peroxidase 4 ( GPX4 ) were significantly reduced ( P < 0.05), indicating that the balance of the System Xc⁻ transporter was also disrupted. Collectively, these changes demonstrated that preslaughter shackling stress induces ferroptosis in broiler meat during postmortem storage. This finding may aid in developing practical strategies to improve the quality of commercial poultry products.