A biochemical explanation for the fatty liver and kidney syndrome of broilers: its alleviation by the short-term use of dietary fat.

1. Fatty livers and kidney syndrome (FLKS) was induced in young broiler chickens by giving them a diet composed principally of wheat and meat meal. 2. FLKS resulted in reduced growth and increased liver weight; fasting for 18 h increased mortality, liver lipid and the specific activity of hepatic ATP-citrate lyase compared with birds fed on a commercial diet. The specific activities of hepatic fructose-1,6-diphosphate-1-phosphohydrolase and pyruvate carboxylase were reduced in birds suffering from FLKS and fasted for 18 h. 3. Feeding of the FLKS-inducing diet supplemented with 150 g animal tallow/kg for 54 h considerably reduced mortality while restoring liver composition and enzyme activities towards those observed in birds fed a commercial diet. Investigations indicated that the glycerol component of the fat was not responsible for the observed responses. 4. The present results suggest that in FLKS insufficiencies of biotin are induced in specific enzyme systems, but the syndrome may be alleviated without the use of supplementary biotin. 5. The evidence indicates that, when stressed, birds affected by FLKS diet from the hypoglycaemia occurring as a result of a reduced capacity for gluconeogenesis.