Project Number: 1902-13210-003-00
Project Type: Appropriated

Start Date: Sep 18, 2002
End Date: Sep 17, 2007

Objective:
1) Develop relationships that predict field-scale transformation and losses of phosphorus and nitrogen. 2) Develop a multiple plant species pasture model that describes environmental and seasonal effects on productivity and species composition. 3) Develop nutritional models and feeding strategies to improve animal productivity in pasture-based systems. 4) Develop and use an Integrated Farm System Model to establish recommended practices for profitable and environmentally sound dairy and beef production.

Approach:
Relationships will be derived from scientific theory and available data to better predict nitrogen and phosphorus losses at the field and farm scale. The SPUR (Simulation of Production and Utilization of Rangeland) model will be adapted and validated to pastures with multiple plant species in the temperate climate of the Northeast. A model that predicts feed intake, growth and manure excretion for various ages of beef animals will be developed using the NRC's nutrient requirements of beef cattle and ARS's beef model (DECI). A continuous culture fermenter will be used to assess ruminal fermentation characteristics and bacterial protein production for various pasture forages and feed supplements. In a pasture experiment with lactating dairy cows, forage production, intake, milk production and grazing behavior will be measured for four levels of plant diversity. An Integrated Farm System Model will be created with crop, dairy, and beef production options and used to evaluate systems and solve problems of high priority to the dairy and beef industries and cooperating researchers.