The effect of a combined dietary treatment with cholesterol and cholic acid on the lipid metabolism of geese at low or high choline concentrations

A previous study demonstrated that a dietary treatment of young geese with cholesterol and cholic acid raises lipid concentrations in the liver. The p resent study was carried out to investigate whether such a lipid accumulati on caused by those hyperlipidemic compounds can be intensified by low dieta ry choline concentrations. Therefore, 38 eight-week old geese were divided into four groups of 9 or 10 animals each and received a basal diet poor in choline which consisted predominately of maize and soy protein isolate over a period of 8 weeks. Treatment factors were supplementation of diets with cholesterol and cholic acid (0 vs. 5 g of cholesterol and cholic acid each per kg) and supplementation of choline chloride (0 vs. 1.5 g/kg). Final bod y weights as well as carcass weights were neither influenced significantly by dietary treatment with cholesterol and cholic acid nor by low dietary ch oline concentrations. However, feeding diets supplemented with cholesterol and cholic acid markedly increased liver weights (two-fold), hepatic trigly ceride (3.7-fold) and cholesterol (12-fold) concentrations and percentages of monounsaturated fatty acids at the expense of saturated and polyunsatura ted fatty acids in the liver. In geese fed diets with cholesterol and choli c acid, insufficient choline supply did not intensify, but even slightly re duced hepatic lipid accumulation. Geese fed diets with cholesterol and chol ic acid exhibited markedly increased levels of cholesterol, triglycerides a nd phospholipids in plasma and very low-density lipoproteins, regardless of the choline supply. Muscle tissue of geese fed diets supplemented with cho lesterol and cholic acid exhibited also increased concentrations of triglyc erides and cholesterol whereas the fatty acid composition of muscle lipids remained unchanged. Among geese without hyperlipidemic treatment, concentra tions of triglycerides in plasma and very low-density lipoproteins as well as the concentrations of phosphatidylcholine in liver and muscle tissue wer e not reduced by low dietary choline concentrations. Therefore, it is sugge sted that those animals were able to synthesize endogenous sufficient choli ne.