8:30 am - 9:30 am
A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES PhD Final Exam Seminar by Seyed Ali Goldansaz. This seminar is open to the general public to attend.
Meeting ID: 953 8748 4883
Thesis Topic: Investigating Blood Biomarkers of Economic Traits in Sheep Using Metabolomics
PhD with Drs. Graham Plastow and David Wishart.
The ability to indirectly measure important production traits in livestock using metabolomics technologies is attracting a lot of interest in recent years. The ability to rapidly detect and quantify hundreds of metabolites within a single sample is helping livestock scientists paint a far more complete picture of animal metabolism and physiology. It is also helping livestock researchers identify robust biomarkers of health and disease. In my PhD thesis, I applied livestock metabolomics techniques to study domestic sheep with the overarching objective of identifying blood biomarkers for important economic traits in sheep farming. In particular, I focused on several key traits including feed efficiency (the major pillar of cost of production), carcass merit and pregnancy (traits with substantial contribution to farm income). To lay the groundwork for these studies, I first conducted a systematic review of livestock metabolomics to assess the status of the field in general, and to identify important gaps and trends relative to other fields of metabolomics research. As part of this review, I compiled all the known livestock metabolome data published until 2017 and made it publicly available in the Livestock Metabolome Database (LMDB; available at www.lmdb.ca). Using the knowledge gained from this review, I then conducted a study that looked at sheep residual feed intake (RFI; a measure of feed efficiency) and carcass merit from using metabolomics. Direct measurement of these traits is labor-intensive and expensive. Therefore, finding easily measured metabolite markers for indirect measurement of these traits is expected to reduce cost of production and encourage the widespread measurement of these traits. Using a combination of quantitative metabolomic methods, I assessed the serum metabolome and identified 161 unique metabolites. I also identified a panel of biomarkers consisting of three metabolites for sheep RFI (with an area-under-the-receiver-operating-characteristic-curve [AU-ROC]=0.80), and two panels of biomarkers for sheep carcass merit, including seven metabolites for carcass yield grade (AU-ROC=0.77) and one metabolite for carcass muscle-to-bone ratio (AU-ROC=0.74). I also used these techniques to identify and validate blood biomarkers of sheep pregnancy and litter size (PLS). Early detection of pregnant ewes and the number of expected lambs allows producers to adjust their management practices and the feed rations based on ewe pregnancy requirement. I employed a longitudinal experimental design with separate discovery and validation phases aimed at identifying blood biomarkers of sheep PLS. In doing so, I identified and quantified 107 metabolites associated with ewe pregnancy, and validated three panels of biomarkers (AU-ROC of 0.81-0.93) that can identify ewe PLS as early as 50 days post-breeding. These biomarkers are currently being translated into a handheld device that could be used as a low-cost, pen-side test for ewe PLS. It is hoped that the methods presented will encourage more widespread application of metabolomics in livestock research, and the results will provide added value for sheep production.