Electron microscopic findings in the skeletal musculature of broilers with nutritional encephalomalacia]

Sings of myopathy were recorded by means of electron microscopy from the skeletal muscles of 20 broiler chickens, aged five and six weeks and suffering from spontaneous nutritional encephalomalacia. Focal deposits of osmiophilic, granular or amorphous matter, intermixed also with membrane fragments and condensed to homogenous osmiophilic bodies, were found quite often in the sarcoplasm. Those deposits were interpreted as lipoproteid complexes (pigmentation due to vitamin E deficit). Also observed were degenerative disorders of compensatory reactions of membraneous fibre organelles (sarcoplasmic reticulum, mitochondria) as well as decomposition of myofibrils and fibre hyalinization. Fibre regeneration and vascular damage occurred less often. Pathogenetically, the changes are interpreted particularly with regard to a membrane-stabilising anti-oxidant action of vitamin E and compared to the selenium-dependent myopathies of ruminants from which primary myofibrillar damage was recordable but no pigment accumulation.