Figure 2.

Microscopic findings. White striping myopathy, Pectoralis major muscle, chicken. Hematoxylin and eosin (HE). (A) Grade 0: some myodegenerative fibers (arrows) (<10% affected myofibrils) are present between the unaffected muscle fibers, Grade 1: moderate degeneration in muscle fibrils (10 to 50% of myofibrils affected), Grade 2: extensive degeneration in muscle fibrils (more than 50% of myofibrils affected). Interstitial areas seem expanded with loose fibrous tissue. Lymphohistiocytic inflammatory cell infiltrates can be seen around venules. Bars, 200 µm (for low magnifications) and 100 µm (for high magnifications). (B) Mean scores of histological lesions. Asterisk indicates statistical difference between macroscopic lesion scores (*: P < 0.05; **: P < 0.01; ***: P < 0.001).