Diet-induced residual formation in pigs

Area of Science:

• Veterinary Pathology
• Nutritional Biochemistry
• Cellular Biology

Background:

• Antioxidants like vitamin E and selenium are crucial for preventing cellular damage.
• Oxidized lipids can induce oxidative stress and tissue degeneration.
• Understanding the cellular mechanisms of lipid-induced pathology is important for animal health.

Purpose of the Study:

• To investigate the effects of a diet lacking antioxidants and containing oxidized cod liver oil on piglet health.
• To examine the resulting myodegeneration and hepatic alterations.
• To explore the role of lysosomes and superoxide dismutase in the observed pathology.

Main Methods:

• Feeding weaned piglets a diet deficient in vitamin E and selenium, enriched with oxidized cod liver oil.
• Necropsy and histopathological examination of skeletal muscle, heart, and liver tissues.
• Light and electron microscopy, including immunocytochemistry for copper-zinc superoxide dismutase (CuZnSOD).
• Measurement of erythrocyte superoxide dismutase (E-SOD) activity.

Main Results:

• Experimental piglets developed myodegeneration of skeletal muscles and pale, mottled livers.
• Histopathology revealed degenerative alterations in cardiac and skeletal muscles, with lipid infiltrations.
• Ultrastructural analysis showed lipid droplets resembling ceroid and lipofuscin, and frequent peroxisomes in hepatocytes.
• Increased erythrocyte superoxide dismutase (E-SOD) activity was observed, suggesting zinc recruitment for antioxidant defense.

Conclusions:

• A diet lacking antioxidants and rich in oxidized lipids induces significant muscle and liver damage in piglets.
• Lysosomal involvement in residual body formation is suggested by ultrastructural findings.
• Increased E-SOD activity indicates a potential compensatory antioxidant response involving zinc.