Orsel, KarinSchuster, Jessica Claire2020-01-202020-01-202020-01-15Schuster, J. C. (2020). Longevity in Canadian Dairy Cows (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.http://hdl.handle.net/1880/111519A thorough review of longevity in dairy cows was conducted to evaluate current understanding of longevity. Current terminology referring to longevity is inconsistent; therefore, standardized definitions are needed. Longevity is affected by genetics, environment and management impacts, along with culling decisions for genetic improvement. Therefore, this thesis proposes that producers aim to optimize longevity by ensuring a favourable environment via optimal management, providing each cow an opportunity to reach her full genetic potential. An evaluation of animal-level variables was conducted to identify intrinsic factors affecting longevity. Additionally, an economic evaluation that assessed individual impact of each of these variables on lifetime profitability was estimated. Reproductive performance had the greatest impact on estimated culling time and profitability in young-stock and cows, suggesting performance indicators (e.g. milk production, reproduction, health and young-stock performance) should be incorporated into farm level evaluations of longevity to enable producers to make evidence-based decisions for optimizing longevity.University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.EconomicsEconomics--AgriculturalAgricultureBiostatisticsEpidemiologymaster thesis10.11575/PRISM/37471