Requirement of Essential Fatty Acids and Avian Atherosclerosis

Abstract

ALTHOUGH Reiser in 1950¹ claimed that chickens needed a source of essential fatty acids during growth, the same author later concluded² that mature hens, maintained for a full year on a fat-free diet, did not require essential fatty acids for egg production or hatchability. More recently Bieri et al.^3,4 showed that chicks could be grown to maturity on an essentially fat-free ration without marked deficiency symptoms and suggested that Reiser's purified chick ration may have been deficient in thiamine and vitamin A. In contrast with the chicken, exclusion of essential fatty acids from the diet of several mammals leads to a clear deficiency disease which, among more apparent external symptoms, is also characterized by an increase in liver and epidermal cholesterol and a decrease in serum cholesterol in the rat⁵, and by aortic lesions in the pig⁶. Such observations lend support to the view of a possible connexion between deficiency of essential fatty acid and atherosclerosis⁷. Since atherosclerosis develops in the chicken on low-fat as well as on normal rations⁸, it seemed of interest to determine if rigid exclusion of essential fatty acid from the diet would aggravate aortic lesions. At the same time more information regarding the requirement of essential fatty acids and deficiency symptoms would be obtained from a group of birds maintained continuously on a diet deficient in essential fatty acids from the day of hatching until 19 months of age.