title: Dietary Amino Acid Deficiency Reduces the Utilization of Amino Acids for Growth in Growing Pigs after a Period of Poor Health.
abstract: BACKGROUND
  During immune system activation, partitioning of amino acids (AAs) changes between protein gain and use by the immune system.
  
  
  OBJECTIVE
  We determined the effects of health status and dietary AA deficiency on nitrogen retention and AA utilization in pigs.
  
  
  METHODS
  Barrows (55 d of age) were obtained from good health (GH, n = 14) or poor health (PH, n = 14) status farms and allocated to a diet either adequate in essential amino acids (Adq) or 25% deficient in Met + Cys, Thr, and Trp (Def). Nitrogen balance was measured and AA irreversible loss rates (ILRs) were measured after an intravenous bolus of U-(13)C-labeled L-AAs.
  
  
  RESULTS
  On arrival at the experimental facilities, the PH pigs had 14% lower serum albumin and 50% greater serum haptoglobin and blood leukocyte counts than the GH pigs (P < 0.01), but the PH pigs showed signs of recovery during the trial. Total tract nitrogen digestibility was 3 percentage points lower in the PH pigs (P < 0.01). The PH-Adq pigs had compensatory body weight gain after arrival, coinciding with 7% greater nitrogen retention (P < 0.01) in the PH pigs than in the GH pigs. The PH pigs had a 24% greater ILR for Lys. Health status × diet interactions for Lys (P = 0.07), Val (P = 0.03), and Leu (P = 0.10) pool sizes and a greater urea pool size in the PH pigs (P = 0.01) support the observation that the increase in the ILR of Lys in the PH pigs was related to oxidation when feeding the Def diet, but to synthesis when feeding the Adq diet. Feeding Def diets increased monocyte counts by 30% (P < 0.01).
  
  
  CONCLUSIONS
  This study illustrates how the competition for AAs between protein synthesis associated with immune system activation and body protein deposition is greater when the dietary supply of Met + Cys, Thr, and Trp is limited in pigs during and after a period of poor health.
authors.affiliation: Wageningen University & Research Centre Livestock Research, Wageningen, Netherlands; Animal Nutrition Group, Wageningen University, Wageningen, Netherlands;
authors.forename: Esther
authors.initials: E
authors.lastname: Kampman-van de Hoek
authors.affiliation: Wageningen University & Research Centre Livestock Research, Wageningen, Netherlands;
authors.forename: Alfons J M
authors.initials: AJ
authors.lastname: Jansman
authors.affiliation: Animal Nutrition Group, Wageningen University, Wageningen, Netherlands;
authors.forename: Joost J G C
authors.initials: JJ
authors.lastname: van den Borne
authors.affiliation: Wageningen University & Research Centre Livestock Research, Wageningen, Netherlands;
authors.forename: Carola M C
authors.initials: CM
authors.lastname: van der Peet-Schwering
authors.affiliation: Netherlands Veterinary Medicines Authority, Utrecht, Netherlands.
authors.forename: Hetty
authors.initials: H
authors.lastname: van Beers-Schreurs
authors.affiliation: Animal Nutrition Group, Wageningen University, Wageningen, Netherlands; walter.gerrits@wur.nl.
authors.forename: Walter J J
authors.initials: WJ
authors.lastname: Gerrits
mesh_terms: D000601:Amino Acids, Essential / Q000008:administration & dosage* / Q000172:deficiency / Q000378:metabolism; D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004032:Diet / Q000662:veterinary; D004044:Dietary Proteins / Q000008:administration & dosage; D009584:Nitrogen / Q000378:metabolism; D013552:Swine; D015430:Weight Gain
chemical_list: D000601:Amino Acids, Essential; D004044:Dietary Proteins; D009584:Nitrogen
keywords: amino acid deficiency; growing pigs; health status; irreversible loss rate; nitrogen retention