ESR5: The role of neonatal supplementation of glutamine in modulating growth, gut functional development, and antioxidative status in low birthweight piglets

Background

Maintaining high production rates to respond to the consumers’ demand for pork has led to genetic selection for increased litter size resulting in decreased piglet birthweight (BtW) and/or intrauterine growth restriction (IUGR) due to exceeding of uterine capacity. Low BtW (LBW) and IUGR piglets have lower energy reserves and delayed access to colostrum intake immediately after birth, and thus, tailored nutritional solution for those pigs might optimize gut health and development as well as growth performance. Glutamine (Gln) is a major metabolic substrate for dividing cells, such as enterocytes, but has also a role in gene expression regulation and cell signaling pathways. Glutamine has been shown to be beneficial in intestinal maturation, gut oxidative and inflammatory prevention in weaned piglets.

Objectives

  1. In contrast to earlier research where glutamine was supplemented to weaned piglets, a novel paradigm of neonatal oral administration of glutamine is employed to explore if glutamine plays a regulating role in gut development in the pre-weaning period.
  2. Investigate whether early postnatal oral glutamine supplementation affects piglet growth and development, intestinal epithelium characteristics, in LBW and normal BtW piglets differently.
  3. Study whether neonatal oral glutamine supplementation affects the metabolic profile and the glutathione system, especially in LBW compared with normal BtW piglets.
  4. Investigate if neonatal glutamine supplementation influences the intestinal barrier function in vivo, the tight junction proteins and Gln incorporation in intestinal microbial protein.

Methods

  • High Performance Liquid Chromatography (HPLC) and automatic enzymatic analyser will be applied to determine the metabolites and amino acid concentration from plasma, intestine and liver.
  • Cell size (protein:DNA ratio), protein synthetic efficiency (protein:RNA ratio) and protein synthetic capacity (RNA:DNA ratio) will be determined in intestinal tissues.
  • Cellular proliferation and fractional protein synthesis rate will be measured using 5-bromo-2-deoxy-uridine and 2H5-phenylalanine application, respectively.
  • Gas-chromatography/mass spectrometry (GC/MS) and Isotope ratio MS analysis will be used to determine 2H5-phenylalanine abundance in tissue proteins and plasma as well as the oxidation of Gln and glucose and its metabolic conversion in amino acids, respectively.
  • Redox status will be determined using the reduced glutathione to oxidized glutathione ratio (GSH/GSSG), identified by HPLC in red blood cells and intestinal tissue.
  • Transcripts related to intestinal functions will be analysed by qPCR. To evaluate intestinal barrier function, intestinal tissue will be collected for tight junction proteins analysis.
  • Intestinal barrier function will be evaluated with a sugar test, and intestinal tissue will be collected for the analysis of tight junction proteins abundance.

Expected results

  1. Provide proof of concept and validated results that enteral glutamine supplements during the neonatal phase beneficially affect growth and gut health in pre-weaning LBW piglets (D1.3, D1.6, D2.7, D2.8, D2.10, D3.4).
  2. Provide a less expensive way of promoting growth and welfare in neonatal LBW piglets as compared to supplementation of weaner piglets (D1.3, D1.6, D3.4) .

Planned secondments

  • At: WBF-A (1 mo); Learn how to identify IUGR piglets using Machine Learning Model.
  • At: Kaesler Nutrition (2 mo); Training in scientific marketing for livestock nutrition and training in preparing technical documents for customers;
  • At: Chemovator (1 mo); Training on literature search, scientific marketing of feed aditives;

Enrolment in Doctoral degree:

ESR5 will be enrolled at the Faculty of Veterinary Medicine, Free University of Berlin.

Supervisors

Cornelia Metges (FBN), Giuseppe Bee (Agroscope)

X