The influence of dietary fatty acids and vitamin E on plasma prostanoids and liver microsomal alkane production in broiler chickens with regard to nutritional encephalomalacia.

Nutritional encephalomalacia (NE) in broiler chicken is considered as a peroxidative dysfunction caused by vitamin E-deficient diets. A feeding experiment was performed to investigate the consequences of feeding different fats in combination with increasing amounts of vitamin E on liver lipid peroxidation and plasma prostanoid pattern. Newly hatched chicks from hens on a vitamin E-poor diet were fed with either mainly linolenic, linoleic or oleic acid-rich oils in a vitamin E-deficient (5 ppm) basic diet. The animals were supplemented with vitamin E on three levels (0, 20 or 120 ppm). On appearance of the first symptoms of NE after 8 days post-hatching, the animals were examined. Typical symptoms with a high incidence only occurred in the group fed linoleic acid and 5 ppm vitamin E. Plasma prostanoids and microsomal alkane production in liver as a measure of endogenous lipid peroxidation were determined. The dietary conditions affected plasma prostaglandin E2 and thromboxane A2, but not prostacyclin. However, it seems unlikely that the prostanoids are involved in the pathogenesis of NE. Liver lipid peroxidation increased in vitamin E deficiency. The level of alkanes depended on the type of fat supplied. The consequences of the different dietary fats in combination with vitamin E deficiency on peroxidative metabolism of broiler chickens are evident, indicating that a high level of oxidative stress is imposed by the linoleic acid-rich fat.