PSIV-7 Effect of dietary tryptophan supplementation on growth, energy balance and blood metabolites in milk-fed low birth weight pigs

Abstract

Abstract Low birth weight (LBW) is associated with reduced postnatal growth efficiency, glucose intolerance and type II diabetes mellitus in adulthood. Using a piglet model of LBW, the objective of this study was to investigate the effect of supplemental Trp on growth, energy balance and blood metabolites in LBW pigs. LBW (< 1.0 Kg) and normal birth weight (NBW; > 1.0 Kg) pigs were selected from twelve sows (parity=2–4, litter size=14–18; three LBW and one NBW piglets/sow) and randomly assigned to 4 milk-replacer based treatments (n=7–8; 7 days old) including: 1) NBW with 0% L-Trp (NBW-T0), 2) LBW with 0% L-Trp (LBW-T0), 3) LBW with 0.4% L-Trp (LBW-T0.4), and 4) LBW with 0.8% L-Trp (LBW-T0.8) for 3 weeks. Diets were provided 4–5 times/day and the voluntary intake was measured for each feeding throughout the study. Growth parameters, heat production and body weight were recorded biweekly. After an overnight fast at week 3, pigs were allowed to consume their respective diets for 1 hour and blood samples were collected at baseline (0), 60 and 120 min after the meal test. The data were analyzed using univariate GLM with Dunnett’s post-hoc test (SPSS®). No significant differences were observed on growth parameters (i.e. body weight, heart girth, wither height and body length), growth performance (i.e. average daily gain, average daily feed intake, gain:feed, gain:protein) and heat production when LBW-T0 was compared with LBW-T0.4 and LBW-T0.8. The plasma triglycerides for pigs fed LBW T0.4 and T0.8 was lower compared to that offered LBW-T0, but total cholesterol did not differ across groups. Pigs in LBW-T0.8 group had lower blood glucose than those fed LBW-T0 at 60 min after the meal challenge. In conclusion, Trp supplementation did not affect the growth and energy balance, but reduced the blood glucose and triglycerides concentration in LBW pigs.