Intramuscular Collagen Synthesis, Muscle Fiber Growth and Histomorphology of of a Fast-Growing Broiler Strain .

Collagen protein has been considered as major culprit to myopathy condition affecting , called woody breast (WB) in (broiler). The WB myopathy is characterized by macroscopic stiffness of and the affected tissue have reduced protein quality. This study measured the soluble (S-) and insoluble (I-) collagen fractional synthesis and degradation rates (FSR and FDR) in over typical grow-out cycle of broiler using stable isotope of 1-C proline as metabolic tracer. Collagen content and muscle fiber histomorphology of were also assessed simultaneously. The FSR and FDR for S- and I-collagen decreased over age, however FSR remained higher than FDR suggesting collagen was accreting during the grow-out period. This was reflected by increment in total collagen content in in maturing broiler. Histomicrographs showed myodegeneration occurring as early as 21 days followed by greater accumulation of collagenous tissue in perimysial and endomysial connective tissue spaces of muscle fibers as bird aged. The findings suggest that reduced turnover of collagen in at the later age of bird could have evolved due to adaptive physiological feedback mechanism against further synthesis and deposition of collagen in the extracellular matrix.