251 - Dietary Tryptophan Supplementation Improves Fat and Glucose Metabolism in Low Birthweight Piglets

Low birthweight (LBW) is associated with complications such as insulin resistance, obesity and metabolic disturbances of glucose and fat metabolism in early life. Dietary tryptophan (Trp) has been shown to reduce liver fat and suppress hyperglycemia in different species. The objective of this study was to assess the effect of dietary Trp on growth and glucose and fat metabolism in LBW pigs. Piglets (7-days old) weighing < 2 kg were considered as LBW while those weighting > 2 kg were considered as normal birthweight (NBW) and randomly allocated to 4 milk-replacer based treatments (n = 7-8): 1) NBW-0% Trp (NBW-T0), 2) LBW-0% Trp (LBW-T0), 3) LBW-0.4% Trp (LBW-T0.4), and 4) LBW-0.8% Trp (LBW-T0.8) for 3 weeks. Growth parameters and body weight were measured biweekly. At week 3, blood and tissue samples were collected in overnight-fasted pigs after a meal test. The mRNA and protein abundance of key glucose and lipid metabolism markers were determined using qPCR and western blot, respectively. Univariate GLM with Dunnett's post-hoc test (SPSS^®) was used to analyze the data. Growth parameters did not change among groups. Plasma triglycerides concentration was lower in LBW-T0.4 and LBW-T0.8 compared to LBW-T0. Blood glucose was lower in LBW-T0.8 than LBW-T0 at 60 min following the meal test. LBW-T0.8 had a lower transcript and protein abundance of liver glucose transporter-2 relative to LBW-T0. Compared to LBW-T0, LBW-T0.8 had a higher mRNA abundance of glucokinase and tended to have a lower transcript of phosphoenolpyruvate carboxykinase in liver. Relative to LBW-T0, LBW-T0.4 tended to have a lower protein abundance of sodium-glucose co-transporter 1 in jejunum. Compared to LBW-T0, LBW-T0.4 and LBW-T0.8 had a lower transcript of liver acetyl-CoA carboxylase and LBW-T0.4 had a higher transcript of liver 3-hydroxyacyl-CoA dehydrogenase. In conclusion, Trp supplementation reduced the lipogenesis and gluconeogenesis, but increased the glycolysis in LBW piglets.