INTRODUCTIONTHE fatty liver syndrome of laying hens is a disease of considerable economic importance to the poultry industry (Couch, 1956). The disease is characterized by a pale, friable liver with a lipid content about double that of normal birds and by a marked reduction of egg production. While this disease is thought to be related to the diet (Leveille and Bray, 1970), the inability to produce the syndrome experimentally has resulted in its specific cause remaining obscure and poorly defined (Bossard and Combs, 1970; and Leveille and Bray, 1970).Because young chickens with aflatoxicosis frequently have a pale, enlarged, and friable liver (Carnaghan et al., 1966; and Smith and Hamilton, 1970) with an increased lipid content the possibility that dietary aflatoxin can induce the fatty liver syndrome in laying hens was investigated. An experiment was designed to determine the effect of graded doses of dietary aflatoxin on egg production,…