Histomorphometric study of the anterior latissimus dorsi muscle and evaluation of enzymatic markers of broilers affected with dorsal cranial myopathy

Abstract Dorsal cranial myopathy (DCM), which affects the anterior latissimus dorsi (ALD) muscles of commercial broilers, is of unknown etiology, and it represents up to 6% of the partial condemnations in Brazilian slaughterhouses. This study was performed to achieve histomorphometric characterizations of the ALD muscles from male Cobb 500 broilers slaughtered at either 35 d or 42 d and to evaluate the effects of DCM on the enzymatic markers aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK), and lactate dehydrogenase (LDH) and on uric acid and creatinine metabolites. Blood samples (1.5 to 3 mL) and ALD muscle fragments were collected from each carcass, all of which were processed in a commercial inline processing system. For each age, twelve macroscopically normal animals and twelve animals found to exhibit DCM were randomly selected for histomorphometric evaluation and analysis of serologic profiles. Microscopic evaluations demonstrated that the muscle fibers of those with DCM exhibited a strong presence of multifocal regenerative myodegeneration as well as a substitution of muscle tissue with connective tissue (P