title: Alterations in ileal mucosa bacteria related to diet complexity and growth performance in young pigs.
abstract: BACKGROUND
  Evaluation of the prolonged impact of weaning diet on ileal mucosa bacteria and during periods of reduced and improved growth was conducted using 454 pyrosequencing.
  
  
  RESULTS
  Weaned pigs were fed HIGH or LOW complexity diets, with or without antibiotics, for 6 weeks, followed by a common grower diet. Pigs were killed at 2 (n = 4 or 5) and 8 (n = 6) weeks post-weaning (periods of reduced and improved growth, respectively). Mucosal bacteria were removed; DNA was extracted and amplified using the V1-V3 region of the 16S rRNA gene. Mucosal bacteria clustered more closely by week post-weaning than diet but 44% of bacterial species did not change from week 2 to 8. There was no effect of diet complexity or antibiotic inclusion on indices of bacterial diversity. Firmicutes made up 91 and 96% of total reads at week 2 and 8, respectively. The proportion of Clostridium paraputrificum increased (P = 0.003) from week 2 to 8 in pigs fed LOW but didn't change in pigs fed HIGH; whereas Clostridium leptum decreased (P = 0.02) from week 2 to 8 in pigs fed LOW but didn't change in pigs fed HIGH. The proportion of Sarcina genus was 3-fold higher in pigs fed A+ compared to A- at week 2 and 5-fold higher at week 8 despite the lack of in-feed antibiotics at that time.
  
  
  CONCLUSIONS
  Shifts in mucosal bacteria populations may be related to dietary induced changes in growth performance during reduced and improved growth but further studies are required to confirm causative relationship. Weaning diet results in species specific prolonged alterations in mucosal bacteria, particularly where high levels of in-feed antibiotics are used. A considerable portion of ileal mucosal bacteria colonize early and remain stable over time despite changes in diet.
authors.affiliation: Department of Animal Science, South Dakota State University, Brookings, South Dakota, United States of America.
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Levesque
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada; Department of Animal Sciences, University of Illinois-Urbana Champaign, Urbana, Illinois, United States of America.
authors.forename: Seema
authors.initials: S
authors.lastname: Hooda
authors.affiliation: Department of Animal Sciences, University of Illinois-Urbana Champaign, Urbana, Illinois, United States of America.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Swanson
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Kees
authors.initials: K
authors.lastname: de Lange
mesh_terms: D000821:Animal Feed; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D002751:Chlortetracycline / Q000008:administration & dosage; D003013:Clostridium / Q000302:isolation & purification; D004032:Diet / Q000662:veterinary*; D004044:Dietary Proteins; D000069196:Gastrointestinal Microbiome; D007082:Ileum / Q000382:microbiology*; D007413:Intestinal Mucosa / Q000382:microbiology*; D013025:Glycine max; D034421:Sus scrofa / Q000254:growth & development / Q000382:microbiology*; D013552:Swine; D015430:Weight Gain; D000067796:Whey; D003313:Zea mays
chemical_list: D000900:Anti-Bacterial Agents; D004044:Dietary Proteins; D002751:Chlortetracycline