Feed fermentation formulate gut microbiota of weanling pigs - Effects of exopolysaccharides and reutericyclin

  • Author / Creator
  • Enteric bacterial infections, especially post-weaning diarrhea, are among the most common diseases affecting pigs and economically significant in swine production. Antibiotics were a cost-effective method to treat and prevent these bacterial diseases. However, with concerns of the prevalence of antimicrobial resistance bacteria from extensive usage, antibiotics are limited or prohibited to be used for animal growth promoter in many countries. Great interest of research in alternatives was thus raised. Lactic acid bacteria (LAB) and their metabolites were found to be effective in protecting against E. coli infection both in vitro and in vivo. This thesis aims to evaluate the potential application of exopolysaccharides synthesized by LAB to prevent and treat post-weaning diarrhea and its effects on pigs’ fecal microbiota in a pig feeding trial. Pigs (36) were divided into 6 treatment groups and fed wheat, acidified wheat, or wheat fermented with Lactobacillus reuteri. Fecal samples were obtained at weaning and 1, 2, or 3 weeks after weaning and gut digesta samples were collected from week 3 of weaning when the pigs were euthanized. Quantitative PCR results indicated the decreasing gene counts of E. coli and its virulence factors in pigs fed with fermented wheat. Reuteran containing diets had a better performance than other diets and have the potential in preventing and controlling E. coli infections in pigs. Diets supplemented with L. reuteri fermented feed have a promising future in the swine industry. Microbiota analysis was based on sequencing of 16S rRNA gene amplicons; sequences were evaluated with the QIIME pipeline. Sequencing provided more than 7939 sequences per sample. The composition of microbiota changed over time (p < 0.0001) and the diversity of microbiota increased at week 3 (p < 0.001). At week 3, microbiota were composed of Bacteroidetes and Firmicutes, accounting for up to 90% of sequences, followed by Tenericutes, Spirochaetes, Proteobacteria, Planctomycetes, and unassigned organisms. Tenericutes increased over time; Proteobacteria peaked at week 1 but decreased thereafter. Changes within the Bacteriodetes and Firmicutes were at the family level; the overall increase of microbial diversity was mainly attributable to an increase of unassigned organisms and several genera in the phylum Firmicutes. When compared to the effect of time, only few significant changes of intestinal microbiota were attributable to the diet. In conclusion, this is the first in depth analysis of the development of piglet microbiota after weaning. Results will support future efforts to manage the transition period in commercial pig production.

  • Subjects / Keywords
  • Graduation date
    Spring 2015
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.