Association between commensal bacterial establishment and mucosal innate immune genes expression throughout the gastro-intestinal tract of dairy calves

  • Author / Creator
    Malmuthuge, Nilusha
  • Communication between commensal microbes and host in gastro-intestinal tract (GIT) has been proven to be vital for host immune responses and health maintenance. This study investigated the relationship between bacterial community and mucosal innate immune gene expression throughout the GIT of dairy calves, as well as their potential age related changes. Mucosal tissue and ingesta samples were collected from rumen, jejunum, ileum, cecum and colon of 3 week old (newborn, n = 8) and 6 month old (weaned, n = 8) dairy calves. Analysis of bacterial profiles revealed that predominant mucosa-associated bacteria in calves were distinct from those inhabiting the ingesta, and that bacterial diversity varied significantly among GIT regions. The estimated bacterial populations displayed significant regional differences for bovine mucosa and for ingesta only at 6 months of age, signifying an established segregation of enteric bacterial population through the GIT in weaned calves. Analysis of expression of bovine toll-like receptors (TLR1-10), β-defensin, and peptidoglycan recognition protein1 revealed significant age dependent changes in mucosal innate immune system of dairy calves. TLR10 expression in ileum was significantly higher than that in other gut regions irrespective of calf age; suggesting TLR10 plays a vital role in the recognition of commensal microbes in bovine ileum. Our study provides a fundamental understanding with respect to commensal bacteria establishment and mucosal innate immune gene expression along with their association, in dairy calves. This understanding would be a cutting edge in developing multidisciplinary techniques to improve cattle health.

  • Subjects / Keywords
  • Graduation date
    Fall 2011
  • 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.