Metabolism in two breeds of geese with moderate or large overfeeding induced liver-steatosis

Biochemical mechanisms which may control fat deposition in liver and/or per ipheral tissues have been studied in Poland and Landes geese. Post-prandial plasma substrates and post-heparin lipoprotein-lipase (LPL) activity were measured in 10-week-old animals. At 23 weeks of age, geese were overfed for 14 days then slaughtered. Hepatic steatosis was more important in Landes g eese, while muscle and subcutaneous adipose tissue were less developed. In this breed, fatty liver weight negatively scaled to LPL activity, suggestin g that a low LPL activity is a limiting factor of peripheral fat deposition . Consequently, non-catabolized VLDL may return to liver and increase hepat ic steatosis. In Poland geese, such a mechanism does not exist. On the othe r hand, fatty liver weight was positively correlated to very low density li poproteins (VLDL) and triacylglycerols measured in overfed Poland geese, su ggesting that lipids synthetized by liver are better transfered from liver to extrahepatic tissues. Kinetics of post-prandial plasma glucose? triacylg lycerols, phospholipids and uric acid were similar in the two breeds. Howev er, the marked decrease in post-prandial plasma glycerol in Poland geese su ggests that an extrahepatic tissue lipolysis inhibition could contribute to the higher peripheral fattening in overfed Poland geese and could be a lim iting factor of hepatic steatosis in this breed. (C) 2000 Elsevier Science Inc. All rights reserved.