Intrauterine growth retardation increases lipid deposition in adipose tissue of pigs in response to high-fat/high energy diets

The objective of this study was to investigate the effects of postweaning high-fat (HF)/high energy diets on lipid metabolism response in adipose tissue of normal birth weight (NBW) and intrauterine growth retarded (IUGR) pigs. Twenty NBW and twenty IUGR male piglets were fed either a control diet (without lard) or a HF diet (supplemented with 10% lard) from weaning (d 28) to slaughter at 111.4±2.2 kg of body weight. Feed intake and body weight of pigs were recorded monthly. Blood and backfat samples were collected at the end of the experiment and analyzed for plasma levels of metabolites and hormone, activities and mRNA expressions of enzymes involved in lipid metabolism. The results showed that plasma concentrations of leptin and cholesterol, backfat thickness, index of backfat thickness, and mRNA expressions of leptin and adipocyte differentiation-related protein (ADRP) in backfat were affected by the interaction of birth weight and postweaning diet (P<0.05). Compared with NBW littermates, IUGR pigs had lower average daily feed intake (ADFI) and average daily gain (ADG) but greater slaughter age and plasma levels of triglyceride (P<0.01). Lipid content, adipocyte diameter, activities of fatty acid synthase (FAS) and malic enzyme (ME), mRNA expressions of FAS and peroxisome proliferator-activated receptor gamma (PPARγ) in adipose tissue of IUGR pigs were greater than that of NBW pigs (P<0.01). Moreover, IUGR pigs had lower glucose-6-phosphate dehydrogenase (G-6-PDH) activity and mRNA levels of HSL compared with NBW pigs (P<0.01). Pigs fed HF diets had lower ADFI, slaughter age (P<0.01), mRNA expression abundances of LPL and FAS (P<0.01), and activities of FAS and ME (P<0.05) but greater ADG, plasma levels of triglyceride (P<0.05), and gain to feed ratio than pigs fed control diets. In summary, our results indicated that IUGR pigs had greater capability in adipose tissue lipid deposition than that of NBW offspring in response to postweaning HF/high energy diets.