Recent theoretical and empirical studies of beef cattle producers by Barros, Jarvis, Nores, Reutlinger, and Yver have focused on producers' supply response assuming cattle represent consumption goods and capital goods. To differentiate producer price response for cattle sold as consumption goods and cattle retained as capital goods requires data on herd and slaughter age‐sex structure. This has limited the range of econometric work which could be carried out in many developing countries. This study utilizes a time series of the Colombian cattle herd which was recently constructed by Rivas and Valdes and which has the necessary age‐sex and slaughter data to develop a complete system of structural equations representing the simultaneous determination of demand and supply for Colombian cattle over the 1950–1970 p