MOLDAVI : A model to predict nutrient and energy fluxes from meat-poultry production systems

MOLDAVI is a dynamic model developed to predict nutrient (water, C, N, P, K, Cu, and Zn) and energy fluxes from meat-poultry production systems at an hourly time-step. It can simulate a wide range of poultry production systems with or without an outdoor run. MOLDAVI predictions are based first on animal growth, simulated by a Gompertz function. Heat, water and carbon dioxide produced by animals and nutrient excretion are then calculated. Animal feeding is included in the model, with the ability to simulate different feed compositions. Feed intake, body retention and excretion are also predicted by the model. The indoor climatic conditions are calculated, and ventilation and heating rates are regulated in order to meet indoor condition targets. The amount and chemical composition of manure also are predicted. Emissions of NH3, CH4 and N2O from manure are calculated with emission factors from literature and modulated according to manure management practices. This paper presents the model and simulations that illustrate the effect of different farming practices on manure characteristics and gaseous emissions