Sentence:  The poultry industry is characterized by a vertical integration in which an <WSD>agribusiness</WSD> firm, either through direct ownership or contract, controls the entire production process. Such firms own processing plants, feed mills, and hatcheries, and contract with farmers to raise the chickens. 
Meaning of the word marked with <WSD> tags:  A business or group of businesses engaged in agriculture, particularly if using modern farming techniques in the process.