Effect of gestation diet intake on plasma lipids and progeny birth and weaning weights of genetically lean, obese and contemporary swine.

Genetically obese (O), and lean (L) and contemporary (C) primiparous swine were assigned from day 30 to 40 of pregnancy to parturition to one of two dietary treatments: 1) 1.8 kg daily (6000 kcal DE) digestible energy, and 2) 0.6 kg daily (2000 kcal DE) of a standard corn-soybean meal-based diet. O gilts weighed less and were fatter at week 16 than L or C gilts. L and C gilts fed the low diet intake maintained constant body weight throughout pregnancy while O gilts gained approximately 10 kg. All gilts fed adequate energy gained weight. Plasma free fatty acids were higher and triglycerides were lower in pregnant gilts fed restricted energy. Plasma cholesterol and blood glucose appeared to be unaffected by genetic background, suggesting that genetic propensity to obesity is not necessarily associated with hypercholesterolemia or hyperglycemia. Pig birth weight was reduced by maternal feed restriction only in O and C pigs; survival was higher in progeny of O dams than in those of L and C dams. Maternal energy restriction had no effect on survival in L, C, or O pigs. Preweaning growth of C but not of L or O progeny was adversely affected by maternal feed restriction. The data illustrate the significance of genetic X gestation energy interactions in dam and progeny traits and suggest that a consideration of genetic background is essential in evaluating response criteria related to feed restriction during pregnancy.