This thesis improved a farm-level stochastic model with Monte Carlo simulation to estimate the impact of health performance and market conditions on dairy farm economics. The main objective of this model was to estimate the costs of seven common clinical dairy diseases (mastitis, lameness, metritis, retained placenta, left displaced abomasum, ketosis, and milk fever) in the U.S. An online survey was conducted to estimate veterinary fees, treatment costs, and producer labor data. The total disease costs were higher in multiparous cows than in primiparous cows. Left displaced abomasum had the greatest costs in all parities ($404.74 in primiparous cows and $555.79 in multiparous cows). Milk loss, treatment costs, and culling costs were the largest three cost categories for all diseases. A secondary objective of this model was to evaluate the dairy cow’s value, the optimal culling decision, and the cost of days open with flexible model inputs. Dairy cow value under 2013 market conditions was lower than previous studies due to the high slaughter and feed price and low replacement price. The first optimal replacement moment appeared in the middle of the first parity. Furthermore, the cost of days open was considerably influenced by the market conditions.

Lam Lop Chi. / Thesis submitted in: August 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 114-126). / Abstracts in English and Chinese. / Acknowledgements --- p.I / Abstract in English --- p.II-IV / Abstract in Chinese --- p.V-VI / List of Abbreviations --- p.VII-IX / List of Figures --- p.X / List of Tables --- p.XI-XII / Table of Contents --- p.XIII-XV / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Risk factors --- p.6 / Chapter 1.3 --- Overseas guidelines in CAD management --- p.11 / Chapter 1.4 --- Angioplasty in CAD intervention --- p.15 / Chapter 1.5 --- Prevention or Intervention? --- p.21 / Chapter 1.6 --- Economic impact on PCI --- p.24 / Chapter 1.7 --- Cost of illness --- p.28 / Chapter 1.8 --- Hypothesis --- p.30 / Chapter 1.9 --- Objectives --- p.30 / Chapter Chapter 2 --- Cost of AMI Study / Chapter 2.1 --- Background --- p.31 / Chapter 2.2 --- Objective --- p.32 / Chapter 2.3 --- Method --- p.32 / Chapter 2.4 --- Results --- p.35 / Chapter 2.5 --- Discussion --- p.49 / Chapter 2.6 --- Study limitations --- p.58 / Chapter 2.7 --- Conclusions --- p.58 / Chapter Chapter 3 --- Angina study / Chapter 3.1 --- Background --- p.60 / Chapter 3.2 --- Objective --- p.76 / Chapter 3.3 --- Hypothesis --- p.76 / Chapter 3.4 --- Method --- p.76 / Chapter 3.5 --- Results --- p.79 / Chapter 3.6 --- Discussion --- p.93 / Chapter 3.7 --- Study limitations --- p.101 / Chapter 3.8 --- Conclusions --- p.101 / Chapter Chapter 4 --- Overall Discussion --- p.103 / Chapter Chapter 5 --- Conclusions --- p.112 / References --- p.114 / Appendix --- p.127