Impact of Tylosin Phosphate, Flaxseed, and Flaxseed Fractions on Small Intestinal Microbial Profiles in Pigs
Year: 2006
Type: dissertation
Abstract: Understanding how antimicrobial growth promoters (AGPs) affect small intestinal microbiota may help to discover effective alternatives.The impact of dietary supplementation with tylosin phosphate on small intestinal microbial profiles was investigated in growing pigs, and compared with the microbial profile of pigs fed flaxseed or its fractions.Eighteen ilealcannulated barrows (33.1 ± 2.4 kg) received either the control diet (C, wheat, peas and soybean meal), or C plus 22 mg/kg tylosin phosphate (T), 20% whole flaxseed (WF), 18% hot-water extracted flaxseed (HWE), 4% flaxseed hulls (H), or 8% flaxseed oil (O) during three 21-d periods in a change over design.Ileal digesta (100 mL) was collected on d 16 and 17 of each period.Two chaperonin-60 universal target (cpn60 UT) libraries were constructed from pooled ileal digesta DNA extracted from the C and T diets.A total of 1634 nucleotide sequences were determined, and 117 different cpn60 UT sequences identified.Microbial diversity was greatest in the C library compared to T. Taxonomic composition between libraries differed, and included Lactobacillales (94% of C and 86% of T sequences), Enterobacteriaceae (3% of C and 13% of T), Clostridiales, Bacillales and Bifidobacterium taxa.T had a reduced ratio of Lactobacillales: Enterobacteriaceae sequences (6:1) compared to C (35:1).Lactobacilli: enterobacteria plate count ratios were highest in WF compared to C or T diets.Lactobacillus johnsonii genomes detected by qPCR were increased by 17.2 and 12%, in T and WF diets, respectively, compared to C. Numbers of L. amylovorus genomes were 25% lower in the H diet compared to C. Numbers of Escherichia coli and Streptococcus alactolyticus genomes were unaffected by dietary treatment, despite differences in library clone frequency for these species.Increased L. johnsonii colonization with tylosin suggests possible probiotic properties of this bacterium.Only inclusion of whole flaxseed resulted in a similar increase in L. johnsonii.Overall, ileal microbial profiles of iii growing pigs were similar and remained mostly unaffected by dietary tylosin or flaxseed inclusion.I would like to thank my supervisor, Andrew Van Kessel, for creating and supporting a research environment in our laboratory that encourages critical, independent thinking, dedication, teamwork, and friendship among students, technicians and faculty alike.It is because of this environment that I have succeeded and enjoyed my experience as a graduate student.Thank-you to my committee members-to Janet Hill for willingly sharing her knowledge, humour, and encouraging attitude; to Ruurd Zijlstra and Fiona Buchanan for their support and dedication to this project.Special thanks to Tim Dumonceaux and Jason Marshall for always answering questions, providing assistance, advice, encouragement and friendship.
Author: Laura Faye Smith
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2128959397