A histopathological study on the carp fed .ALPHA.-tocopherol deficient diets including oxidized methyl linolate.

Abstract

Five month feeding experiments were conducted on the carp, Cyprinus carpio, with diets which included oxidized methyl linolate of unsaturated fatty acid. The experimental diets included 10% of 30, 40, 90 and 200hrs-oxidized methyl linolate and 0 or 50mgα-tocopherol acetate per 100g diet. The diets for control included 10% purified soy bean oil and 0 or 25mg α-tocopherol acetate per 100g diet. Carps fed the tocopherol free diets including oxidized methyl linolate showed less growth and visibly thinner across the back. The histopathological signs were characterized by atrophy and necrosis of white muscle fibers and visceral ceroidosis. Carps fed a diet containing 40hrs oxidized methyl linolate with 50mg α-tocopherol acetate and a tocopherol free diet including soy bean oil showed lesser growth, visceral ceroidosis and no sign of myopathy. No pathological change was found in carps fed the diet including soy bean oil supplemented with 25mg α-tocopherol acetate. These results indicated nutritional myopathy of the carp was caused by oxidized fatty acid and tocopherol deficiency.