EFFECTS OF VITAMIN B12 ON SERUM LIPIDS AND LIPOPROTEINS OF PIGS FED DIETS SUPPLEMENTED WITH PROPIONIC ACID OR CALCIUM PROPIONATE

Abstract

Effects of vitamin B12 supplementation of diets containing propionic acid (PA), or calcium propionate (CP) on feed intake, serum lipids and lipoproteins were studied utilizing 80 crossbred pigs averaging 22.5 kg. Diets, based on barley-soybean meal, containing 0, 3.5 or 7% PA or CP, were fed with and without the addition of 4.95 mg vitamin B12/kg diet. Inclusion of PA or CP with or without the addition of vitamin B12 had no significant effect on feed intake. Addition of PA or CP depressed serum cholesterol, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol and serum triglycerides. Vitamin B12 supplementation had no effect on serum total cholesterol or HDL cholesterol, caused a reduction in LDL cholesterol, and tended to overcome the reduction in serum triglyceride. Supplementation of diets with vitamin B12 reduced liver lipid levels, largely as a result of a decrease in cholesterol and phospholipids. These data suggest that the cholesterol-lowering effect of PA is not simply a result of a depression in feed intake, but arises from a direct action of PA on cholesterol metabolism. Key words: Vitamin B12, lipids, lipo protein, pigs, propionic, propionate