McConnel, Craig Stephen, authorGarry, Franklyn B., advisorHill, Ashley E., committee memberLombard, Jason E., committee memberGould, Daniel H., committee member2007-01-032007-01-032010http://hdl.handle.net/10217/40471Dairy cow mortality levels in the United States are excessive and increasing over time. This is both a financial concern and an important animal welfare issue. Summary studies of dairy cow removal have been in the literature for decades although information specifically related to dairy cow mortality has been sparse. Even though the increase in dairy cow mortality has generated concern within the industry, the reality is that there is no standard by which to define what might be considered the 'natural' or 'normal' level of mortality in dairy cow production. No evidence suggests that there is any one thing that has led to the rise in mortality and that could be reversed to lower death rates. Rather, numerous agents (influential persons, places, or things) apparently act in concert to influence specific outcomes that may lead to death. The "agents" intimated to be responsible for increasing mortality have been primarily described through the analysis of associations between mortality levels and descriptors such as days postpartum, parity, herd size, and genetics. Such analyses may provide a means for understanding populations at risk but can only illustrate broad principles related to manageable risk factors, potential mitigation procedures, or specific pathologic outcomes. Other studies have attempted to define individual occurrences of death based on the final outcome. Rather than looking at population levels of diseases and associated levels of death, these studies have focused on the pathophysiologic or anatomic descriptions of specific deaths. Such analyses fail to account for the non-biologic unconstrained inputs such as management and environmental factors that ultimately set a pathologic sequence in motion within an at-risk population. Ultimately, with regard to excessive and increasing dairy mortality the difficulty lies in defining the problem (establishing what distinguishes farms with higher death rates from those with more desirable rates) and locating the problem (finding where the trouble really lies within the complex of causal networks on a dairy). This leads to the problem of identifying the actions that might effectively narrow the gap between what-is and what-ought-to-be. Understanding the complexity within such a system demands the recognition of its evolving ecology. Within this evolving industry there is no legitimate means for resetting practices and outcomes back to some undefined acceptable level. Rather than attempting to reverse the irreversible, it would be wise to instead work within the system to improve outcomes through sound scientific principles. The intention of the following work is to characterize and elucidate such principles in an effort to facilitate best intentions becoming better outcomes.born digitaldoctoral dissertationsengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.mortalitydairycowDairy cattle -- Mortality -- United StatesDairy cattle -- Health -- United StatesDairy farms -- United States -- ManagementText