Agricultural commodity projections for 1985, developed by USDA's Economics, Statistics, and Cooperatives Service, show that the livestock sector acts as a large secondary grain reserve. A mathematical model of the combined world grain-oilseed-livestock (GOLI economy generates consistent projections of world commodity trade and prices, and regional production and consumption. The article presents analysis of the tie between crop and livestock sectors, located mainly in the developed countries. The focus is on the synthesis of feed demand equations containing input-out. put coefficients and price elesticities sensitive to both livestock products and feeds.