An Integrated Model for Swine Production

This thesis begins with the observation that significant structural changes in livestock production practices have occurred since the traditional or piece-wise approach to the analysis of livestock production was established in the 1950's (e.g., Heady, 1954). The purpose of this work is to analyze the effects of two sources of these changes, shifts in consumer's tastes and preferences and changes in the regulatory environment in which production takes place, on overall swine farm profitability. The traditional approach to livestock production analysis regards the effects of these changes on values generated by production components in a piece-wise way. The integrated swine production model, developed here, is based on a more comprehensive or integrated approach (Zering, 2001). The integrated model simultaneously accounts for the effects of ration, growth and manure handling decisions on overall farm profitability and jointly optimizes pork and manure nutrient outputs. Accounting for value interactions between production components expands the farmer's choice set of activities for either mitigating or exploiting nutrient related parameter changes. This is the main benefit of the integrated approach (Zering, 2001). Overall farm profitability generated under the integrated approach will at worst be identical to overall profitability generated under the piece-wise approach to modeling the nutrient related aspects of livestock production. Considering how the structural changes listed have magnified the importance of accounting for value interactions between production components leads to the formulation of specific of hypotheses regarding how parameters and generated values associated with individual production components interact to shape overall farm profitability. The specified relationships include the following: the effect of regulatory and agronomic restrictions on optimized values for pork output, ingredient demands and production cycle length (Chapter 1), ration decision effects on manure value (Chapter 2), and ration decision effects on pork output, and growth rate effects on manure nutrient generation (Chapter 3). The specified value interactions, and the market, physiological, regulatory, agronomic and biological information embedded them, are incorporated into a working simulation model of swine production (Chapter 4).