Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
The poultry industry is a big business. In the last year, poultry producers enjoyed a 1,500,000,000 dollar income. The size of this figure is emphasized when it is realized that this income exceeded that of cattle raisers by 200 million dollars, topped the value of the national corn crop by 300 million dollars, and in five of the last six years was only second in value to dairy products.
Iowa State University Veterinarian: Vol. 4
, Article 4.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol4/iss2/4