Experimentally induced "fatty liver syndrome" condition in laying hens

Two experiments were conducted with aged laying hens to determine the influence of feeding 5,000 p.p.m. of iodine as potassium iodine (KI) and/or injecting 12 mg. of estradiol upon fat accumulation in the liver and serum cholesterol levels. The KI was fed for 8 days before making liver and blood determinations, and the estradiol was injected 3 days prior to making the determinations. The feeding of KI or injection of estradiol resulted in significantly increased liver weight. When the two treatments were combined a further significant increase in liver weights was obtained. The percent of fat in the liver was significantly increased by the injection of estradiol. However, the feeding of KI in the presence or absence of estradiol did not affect the percentage of fat in the liver. Neither of the treatments significantly affected the fatty acid composition of the liver fat. Feeding of KI or injection of estradiol significantly increased total serum cholesterol levels. When the two treatments were combined a further increase in serum cholesterol level was observed. Histological changes of the livers of hens treated with KI and estradiol were similar to those previously described for the "fatty liver syndrome."