Description: Deficiency of vitamin E or selenium causes nutritional muscular dystrophy, also known as white muscle disease. Other signs of vitamin E deficiency in chickens involve derangement of cell permeability causing encephalomalacia and/or exudative diathesis. The white streaks in the breast muscle of the chicken are due to degeneration of muscle fibers (myopathy), in the course of which calcium salts may be deposited among the muscle fibers. Selenium supplementation can prevent exudative diathesis but not encephalomalacia. Other symptoms include pancreatic fibrosis, steatitis (inflammation of the adipose tissue), and myopathies of the gizzard and heart in turkeys. Egg production and hatchability are reduced and deformaties are common including lack of eyes, and deformed wings and feet. Some recently formed volcanic soils and the glaciated soils of the northeastern USA contain very little selenium. As a result, plants grown on them are seriously selenium deficient. It is recommended that poultry at all stages of growth or production be supplemented with .2 to .3 ppm added selenium as sodium selenite or selenate. The toxic level of selenium, 2 ppm, is lower than for other farm animals (8.5 ppm).