GLYCEROL AS A FEED COMPONENT AND C-14 GLY CEROL METABOLISM IN RATS

Male Wistar rats (initial weight 58 g) received in four groups (10 ani mals per group) 0.0, 10.6, 21.3, and 31.8% glycerol in the dry matter of the diet (groups 1 to 4). The live weight gain of the animals was, after a feeding time of 3 weeks in the groups 1 to 4, 2.01, 2.49, 2.57 , and 2.52 g, respectively, per animal and day. The higher gain in the glycerol groups resulted from the higher feed intake in these groups. Four rats per group received on the 22nd day of the experiment, 1 h a fter the morning meal, an intraperitoneal injection of carrier-free C- 14-glycerol. The C-14-excretion in the respiration air and in the urin e was measured in the following 10 h. The C-14-excretion in the (CO2)- C-14 of the respiration air was in % of the injected C-14-glycerol dos is in the groups 1 to 4 = 45.4, 44.2, 39.0, and 33.2, respectively. Th e C-14-excretion in the urine was 17.0, 18.1. 25. 1, and 32.3 %, respe ctively. The higher values in groups 3 and 4 resulted from the high ex cretion of free glycerol in the urine. In groups 3 and 4 the glycerol content of the blood plasma was 1.9- and 1.5-fold higher than in group s 1 and 2. It was concluded that up to 40 mg glycerol per hour and ani mal (100 g LW) was metabolized in a physiological way in group 2. As a feeding component glycerol can constitute up to 10 % of the diet-DM i n monogastric animals.