Encephalomalacia nutritional

Characteristic lesions of vitamin E deficiency in animals include necrotizing myopathy (inaccurately referred to as nutritional muscular dystrophy), exudative diathesis, nutritional encephalomalacia, irreversible degeneration of testicular tissue, fetal death and resorption, hepatic necrosis, and anemia. Several of these conditions are directly related to peroxidation of unsaturated lipids in the absence of vitamin E, and others can be prevented by synthetic antioxidants or vitamin E. 

In 11)31, Pappenheimer and Goettsch published the first description of a newly discovered disease, which was called nutritional encephaloTnalaeia. Although the diet recommended by Pappenheimer and Goettsch for producing encephalomalacia in chicks contained some 20% lard and about 2 % cod liver oil, it was sometime later that the role of the dietary fats was evaluated. The composition of this diet is shown in Table I. 

Vitamin E has been shown over the past forty years to be important in the nutrition of poultry in health and disease, not only for normal reproduction but also (1) as nature s most effective antioxidant for prevention of encephalomalacia, (2) in a specific role, interrelated with the action of selenium, for prevention of exudative diathesis, and (3) in another role, interrelated with both selenium and cystine, for prevention of nutritional muscular dystrophy. 

Vitamin E deficiency in chicks may lead to a munber of distinct diseases 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 imable to walk or stand and is accompanied by haemorrhages and necrosis of brain cells. Exudative diathesis is a vascular disease of chicks characterised by a generahsed oedema of the subcutaneous fatty tissues, associated with an abnormal permeabUity of the capUlary walls. Both selenium and vitamin E appear to be involved in nutritional myopathy and in exudative diathesis, but the element does not seem to be important in nutritional encephalomacia. It should be stressed that sele-niiun itself is a very toxic element and care is required in its use as a dietary additive. The toxic natine of seleniiun is discussed in Chapter 7. 

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