Abstract/Details

Potential of antibiotic alternatives to impact nursery pig growth performance, immune status, intestinal morphology, physiology, and microbial populations under both conventional and <i>Salmonella</i> challenge environments


2007 2007

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Abstract (summary)

The purpose of the studies in chapters II, III and IV were to evaluate the efficacy of direct fed microbials (DFMs) and organic acids as potential alternatives to growth promoting antibiotics in weanling pigs, under conventional and Salmonella challenge environments. The study in chapter II was designed to investigate the effects of administration of a bolus of DFMs at weaning with or without in-feed DFMs on weanling pig growth performance and gut health. The study indicated that DFM inclusion in weanling pig diets, in particular, continuous inclusion coupled with oral treatment at weaning, may beneficially enhance the gastrointestinal environment contributing to better overall gut health of the weanling pig. In chapter III, a study was conducted to examine the predominance of each of five probiotic Lactobacillus and Pediococcus strains in the ileum of weaned pigs compared to strain distribution in the feces. In addition, the immunomodulatory potential of this five-strain probiotic combination was investigated. It was concluded that bacteriocin production may offer a competitive advantage over other probiotics in a mixture, allowing for such strains to dominate both in the ileal lumen and to bind more effectively to the ileal wall. The probiotic mixture also demonstrated some potential to modulate host immunity. In chapter IV, a study was conducted to evaluate the potential of a water-delivered Enterococcus and Bacillus combination, or a propionic acid based blend of organic acid as a substitute for antibiotics following a Salmonella challenge in weanling pigs. Following a Salmonella enterica var Typhimurium challenge, both DFM and organic acid administered through drinking water enhanced growth performance and gastrointestinal histology. Salmonella presence in ileal contents was reduced by DFM treatment, and active glucose transport increased, while water acidification reduced induced intestinal chloride ion secretion. Current findings suggest that under a bacterial challenge, DFMs performed similar, or in some cases, superior to in-feed antibiotics, while in healthy pigs, DFMs also demonstrated the potential to enhance intestinal health. Therefore, in a conventional environment, and in particular, during a Salmonella challenge, DFMs should be considered as a viable antibiotic alternative in weanling pig diets.

Indexing (details)


Subject
Livestock
Classification
0475: Livestock
Identifier / keyword
Biological sciences; Antibiotics; Direct-fed microbials; Growth performance; Immune status; Intestinal microbes; Pigs; Salmonella
Title
Potential of antibiotic alternatives to impact nursery pig growth performance, immune status, intestinal morphology, physiology, and microbial populations under both conventional and <i>Salmonella</i> challenge environments
Author
Walsh, Maria C.
Number of pages
277
Publication year
2007
Degree date
2007
School code
0183
Source
DAI-B 68/12, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
9780549357636
Advisor
Richert, Brian T.; Radcliffe, J. Scott
Committee member
Gardiner, Gillian; Rostagno, Marcos; Sutton, Alan
University/institution
Purdue University
Department
Animal Sciences
University location
United States -- Indiana
Degree
Ph.D.
Source type
Dissertations & Theses
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
3291079
ProQuest document ID
304836661
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
http://search.proquest.com/docview/304836661/abstract
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