Fatty liver and kidney syndrome (FLKS) was induced in a proportion of a group of 4-week-old chickens by giving a diet of meat meal and wheat; inclusion in the diet of animal tallow for 54 h substantially reduced the occurrence of FLKS. 2. Measurements of dynamic aspects of glucose metabolism were made with single injections of [2-3H]glucose which indicated that birds given the 'FLKS-inducing' diet and showing physical symptoms of FLKS had significantly lower rates of synthesis of glucose than birds given either the same diet supplemented with tallow or a commercial diet. 3. In a second series of experiments glucose metabolism was studied in birds (1) with or without physical symptoms that were given the 'FLKS-inducing' diet and (2) birds given the same diet supplemented with tallow or biotin. Affected birds fed the 'FLKS-inducing' diet had significantly lower plasma glucose concentrations, pool sizes and synthesis rates than birds fed the same diet and not showing symptoms, or birds fed the supplemented diets. 4. It is suggested that the cause of death in birds with FLKS is a low rate of gluconeogenesis during periods without feed which results in a lack of glucose to meet essential functions.
