dc.contributor.advisor | Porter, Richard | en |
dc.contributor.author | MCKENNA, CLARE | en |
dc.date.accessioned | 2018-08-14T10:38:58Z | |
dc.date.available | 2018-08-14T10:38:58Z | |
dc.date.issued | 2018 | en |
dc.date.submitted | 2018 | en |
dc.identifier.citation | MCKENNA, CLARE, An examination of the molecular control of feed efficiency in beef cattle, Trinity College Dublin.School of Biochemistry & Immunology.BIOCHEMISTRY, 2018 | en |
dc.identifier.other | Y | en |
dc.identifier.uri | http://hdl.handle.net/2262/83761 | |
dc.description | APPROVED | en |
dc.description.abstract | Global agriculture is faced with the enormous challenge of feeding a rapidly
growing population while being cognizant of the environmental footprint of
such endeavours. A consequence of increased meat consumption worldwide is
an increase in demand for animal feed. As feed provision is the single largest
cost incurred by beef farmers, cattle with improved feed efficiency are central
to profitable, sustainable and efficient beef production. A major constraint to
genetic progress in feed efficiency is the difficulty and enormous expense of
measuring it directly. Therefore, robust cost-effective molecular-based
biomarkers for feed efficiency are necessary. This multidisciplinary thesis
aimed to: (i) establish and physiologically characterise two populations of
cattle, genetically and phenotypically divergent for feed efficiency as measured
by residual feed intake (RFI); (ii) examine the premise that efficiency of energy
transduction in cattle is a function of mitochondrial abundance and
mitochondrial functional efficiency; (iii) examine the expression of genes
involved in fatty acid metabolism in adipose tissue from animals divergent for
RFI; and (iv) to examine the effect of RFI status, gender and diet as well as
their interactions on targeted and global transcriptomic expression across three
metabolically important tissues. The observations from this work suggest that
firstly variation in mitochondrial number and/or enzymatic capacity may not be
major contributors to variation in RFI. Secondly, the expression of GLUT4 in
adipose tissue is related to RFI and has potential to be investigated as a
biomarker for RFI in cattle. Thirdly, transcriptomic analysis in liver tissue
from bulls divergent for RFI, revealed evidence that efficient heifers had an
enhanced capacity for mitochondrial function in muscle tissue, while oxidative
response, protein mediation and cell signaling are likely to be processes that
are influencing variation in feed efficiency in bull liver tissue. Finally, effects
of RFI on gene expression in muscle of beef cattle are not consistent across
breed type or dietary phase. In conclusion, while the results of this thesis
provide a greater insight into the biological mechanisms governing RFI in
cattle, they challenge the practicality of developing a robust set of biomarkers
for RFI that would be of ubiquitous utility to the beef cattle industry. | en |
dc.publisher | Trinity College Dublin. School of Biochemistry & Immunology. Discipline of Biochemistry | en |
dc.rights | Y | en |
dc.subject | feed efficiency | en |
dc.subject | cattle | en |
dc.subject | transcriptomics | en |
dc.subject | mitochondria | en |
dc.title | An examination of the molecular control of feed efficiency in beef cattle | en |
dc.type | Thesis | en |
dc.contributor.sponsor | Teagasc | en |
dc.type.supercollection | thesis_dissertations | en |
dc.type.supercollection | refereed_publications | en |
dc.type.qualificationlevel | Postgraduate Doctor | en |
dc.identifier.peoplefinderurl | http://people.tcd.ie/mckenncl | en |
dc.identifier.rssinternalid | 190932 | en |
dc.rights.ecaccessrights | openAccess | |