Degenerative myopathy in turkey breeder hens: a comparative study of normal and affected muscle

The pH of affected tissue within the green lesion characteristic of degenerative myopathy in the supracoracoideus muscle of turkey breeder hens was 7.4 to 7.8 and there was a high concentration of albumin. Histological examination showed that the striations of affected muscle fibres were more pronounced and curved than those of normal fibres. Examination of the affected fibres using the electron microscope showed that the curvature resulted from displacement of groups of myofibrils. The ultrastructure of these myofibrils differed markedly from that of normal muscle. The A‐band was granular and ill‐defined, while extensive degradation of the I‐band and Z‐line was observed. In addition, the sarcoplasmic reticulum was extensively disrupted and mitochondria had degenerated.