Broiler breast muscle myopathies: association with satellite cells

Heavy weight fast-growing meat-type broiler chickens have largely been selected for growth rate, muscle mass yield especially for the breast muscle, and feed conversion. Substantial improvements have been made, but in recent years breast meat quality issues resulting in product downgrades or condemnation have occurred especially from necrotic and fibrotic myopathies like Wooden Breast. In general, the morphological structure of the broiler breast muscle has changed in the modern commercial broiler with muscle fiber diameters increased, circulatory supply decreased, and connective spacing between individual fibers and fiber bundles decreased. Satellite cells are the primary cell type responsible for all posthatch muscle growth, and the repair and regeneration of muscle fibers. Recent evidence is suggestive of changes in the broiler satellite cell populations which will limit the ability of the satellite cells to regenerate damaged muscle fibers back to their original. These changes in the cellular biology of broiler satellite cells are likely associated with the necrosis and fibrosis observed in myopathies like Wooden Breast.