Influence of food intake during late gestation on serum lipids of sows and their progeny.

Serum and lipoprotein lipids were quantified in pregnant and nonpregnant sows allowed restricted and ad libitum access to a low-fat cholesterol-free diet, and in the progeny of these sows. Pregnant sows exhibited a mild increase in serum triglycerides in the third trimester, reflecting an increase in very low density lipoprotein (VLDL)-triglyceride concentration. Ad libitum feeding enhanced this increase. Free fatty acids were depressed in mid-pregnancy (60 days gestation), but were normal or elevated in the final trimester. Total cholesterol was similar in all groups. Pregnancy and level of food intake interacted to increase VLDL-cholesterol in pregnant sows fed ad libitum. Pregnancy decreased high density lipoprotein cholesterol. Level of food intake by sows had no influence on serum lipid concentrations of newborn pigs. Distribution of cholesterol and triglyceride between lipoprotein classes was different in newborn pigs when compared to sows. These results imply fetal self-regulation of lipid metabolism during late gestation. Sow serum lipids are not identical to those in humans. However, when fed a modified diet that resembles a human diet, sows may be useful as a model for humans in studies of lipid metabolism during pregnancy.