Promoting Bone Health in Layer Chickens from the Perspective of Mitochondrial Energy Metabolism in Osteoclasts

Layer chickens have dual physiological demands for rapid growth and continuous egg production. The maintenance of skeletal homeostasis in layer chickens relies on the precise coordination among OCs, osteoblasts (OBs), and osteocytes. The imbalances in the supply of nutrients such as calcium (Ca) and phosphorus (P), as well as dysfunction of the "gut-bone" axis, can disrupt normal bone development in layer chickens, leading to bone diseases such as tibial dyschondroplasia (TD) and osteoporosis (OP), seriously damaging the production performance of layer chickens. This review systematically summarizes the knowledge background of the metabolic reprogramming of OCs in layer chickens, especially mitochondria-mediated biological processes, including oxidative phosphorylation (OXPHOS), glycolysis, reactive oxygen species (ROS) signaling, mitophagy, etc. Notably, the co-culture system of OCs derived from the bone marrow cavity of embryos in vitro has been established in laying chickens. However, there are few reports on the study of mitochondrial metabolism of OCs using this model. Therefore, this review particular focuses on the bone metabolism mediated by OCs in layer chickens and proposes future research priorities, including the application of gene editing and multi-omics methods to ultimately achieve targeted nutritional or pharmacological interventions for optimizing mitochondrial function and promoting bone health.