abstract
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 NBWand 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 111.472.2 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 (Po0.05). 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 (Po0.01). 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 (Po0.01). Moreover, IUGR pigs had lower glucose-6-phosphate
dehydrogenase (G-6-PDH) activity and mRNA levels of HSL compared with NBW pigs
(Po0.01). Pigs fed HF diets had lower ADFI, slaughter age (Po0.01), mRNA expression
abundances of LPL and FAS (Po0.01), and activities of FAS and ME (Po0.05) but greater
ADG, plasma levels of triglyceride (Po0.05), 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.