ANN 111: Principles of Animal Nutrition and Feed Technology (2+1)

DEFICIENCY

Deficiency – Nutritional myopathy / white muscle disease / stiff lamb disease / mulberry heart disease / exudative diathesis / crazy chick disease

• The most frequent and the most important manifestation of Selenium deficiency in farm animals is muscle degeneration (myopathy).
• Nutritional myopathy , also known as muscular dystrophy, frequently occurs in cattle, particularly calves.
• The myopathy primarily affects the skeletal muscles and the affected animals have weak leg muscles, a condition manifested by difficulty in standing and, after standing, a trembling and staggering gait.
• Eventually, the animals are unable to rise and weakness of the neck muscles prevents them from raising their heads.
• A popular descriptive name for this condition is white muscle disease.
• The heart muscle may also be affected and death may result.
• Nutritional myopathy also occurs in lambs, with similar symptoms to those of calves. The condition is frequently referred to as stiff lamb disease.
• In pigs, the two main diseases associated with vitamin E and selenium deficiency are myopathy and cardiac disease.
• The pigs demonstrate an uncoordinated staggering gait, or are unable to rise.
• The pigs heart muscle is more commonly affected.
• Sudden cardiac failure occurs and on post-mortem examination the lesions of the cardiac muscles are seen as pale patches or white streaks. This condition is commonly known as mulberry heart disease.
• Vitamin E deficiency in chicks may lead to a number of distinct diseases: nutritional myopathy, encephalomalacia and exudative diathesis. In nutritional myopathy the main muscles affected are the pectorals although the leg muscles also may be involved.
• Nutritional encephalomalacia or crazy chick disease is a condition in which the chick is unable to walk or stand, and is accompanied by hemorrhages and necrosis of brain cells.
• Exudative diathesis is a vascular disease of chicks characterized by a generalized oedema of the subcutaneous fatty tissues, associated with an abnormal permeability of the capillary walls.
• Both selenium and vitamin E appear to be involved in nutrition myopathy and in exudative diathesis but selenium does not seem to be important in nutritional encephalomacia.