Contribution of colostral fat to thermogenesis and glucose homeostasis in the newborn pig.

This study was designed to determine the effects of colostral fat on energy metabolism, fat oxidation and glucose homeostasis in newborn pigs maintained during the first 29h of life at thermal neutrality (34 degrees C) or in the cold (21 degrees C). Piglets were intragastric fed normal colostrum (NFC, 6% fat) or colostrum deprived of fat (LFC, less than 1% fat). A total of 21 meals of 15 to 18g colostrum/kg birthweight was given at 65- to 70-min intervals. Feeding NFC resulted in a higher amount of retained fat with the highest value being obtained in the 34 degrees C group (P less than 0.01). Fat oxidation represented 47% of the absorbed fat in NFC-fed piglets at 34 degrees C; it was 4.5 fold higher in piglets fed NFC than in those fed LFC (P less than 0.01), and 1.8 fold higher at 21 degrees C than at 34 degrees C (P less than 0.01). At both temperatures, feeding LFC resulted in a lower energy balance (P less than 0.01), whereas nitrogen balance was not affected by temperature and colostrum treatments. At 29 hours of age, rectal temperature was the lowest in piglets fed LFC at 21 degrees C (P less than 0.05). Postnatal enhancement of fat metabolism in relation to environmental and nutritional conditions was evidenced at the tissue level through an adaptation of lipoprotein lipase and cytochrome oxidase activities, especially in the red rhomboideus muscle and the liver.(ABSTRACT TRUNCATED AT 250 WORDS)