Influence of dietary lipids on serum apoproteins AI and B and on intestinal synthesis of apo AI in the early weaning of piglets: comparison of saturated, unsaturated, and medium-chain triglycerides.

Early weaning of piglets induces a rapid decrease in the concentration of all plasma lipoproteins within 2 d. The decline was more progressive when 20% saturated fatty acid (lard) (SF) was added to the diet; saturated fatty acid was more effective than unsaturated fatty acid (sunflower oil) (UF). Medium-chain triglycerides had no protective effect. Intestinal synthesis of apoprotein AI was twofold higher in preweaning piglets than in adults (12.9% of total synthesis vs 5.9%, p less than 0.01) when measured in intestinal mucosa. On day 4 of weaning, synthesis was still at the preweaning level in all groups but on day 7 was maintained only by the SF diet (11.7%). We conclude that long-chain lipids, particularly saturated fatty acids, prevent a decrease in lipoproteins at weaning, mainly by maintaining intestinal apo AI synthesis at a high level.