The use of modern metabolomics and proteomics to address the health challenges facing the Canadian cattle industry

  • Author / Creator
  • Naturally cattle only consumed grass, hay and other forage crops but modern cattle industry has started shifting them from a natural grazing diet to a more balanced grain-rich diet. However, feeding dairy cows grain rich diet is associated with a rapid release of large amounts of SCFA that have been linked to acute and sub-acute rumen acidosis and related metabolic diseases. However, one disease in particular had more profound impact than all of other disaeses-- bovine spongiform encephalopathy (BSE). When BSE was discovered in Alberta in 2003 it nearly wiped out Canada’s beef export industry.
    The central objective of my thesis is to address: 1) Ruminal acidosis and acidosis-related metabolic disorders, 2) BSE, commonly known as mad mcow disease. More specifically, I tested the hypothesis that modern cattle feeding practices (i.e. grain rich diets) significantly changed the rumen environment, its chemical composition and is responsible for all of these conditions. Metabolomics is such a powerful approach for studying the chemical changes in biological systems. To test these hypotheses, I chose to use modern metabolomics techniques including NMR, GC-MS and DFI-MS to characterize the ruminal fluid of dairy cattle fed with different diets. From these experiments I determined that grain-rich diets led to ruminal acidosis along with unusually high levels of ruminal LPS. Based on the association of high-grain diets with various metabolic diseases, this suggests that feeding practices lower the ruminal pH and alter the chemical content of the ruminal fluid, thereby leading to elevated levels of LPS which, in turn, lead to greater risk for developing these diseases. LPS induces the conversion of helical native prion proteins into protease-resistant, beta-sheet rich proteins similar to that of infectious prions. This suggests that elevated levels of LPS in the rumen from grain-rich diets may also play a role in the induction of BSE.

  • Subjects / Keywords
  • Graduation date
    Fall 2013
  • Type of Item
  • Degree
    Doctor of Philosophy
  • 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.