This study interfaces a U.S. livestock econometric model with a crop market econometric model and analyzes the impacts upon the livestock sector of various grain and livestock policy alternatives. The livestock model, which was developed at the Center for Agricultural and Rural Development (CARD) by Roberts and Heady, consists of five livestock and poultry commodities: beef, pork, lamb, chicken, and turkey. The crop market model is an updated and revised version of the market sector of the CARD National Agricultural Simulation Model. The crop market model is composed of feed grain, wheat, soybean, and cotton submodels.